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Cao J, Xia J, Shen X, Song K, Zhou Y, Cui C. Research Progress on Rolling Forming of Tungsten Alloy. MATERIALS (BASEL, SWITZERLAND) 2024; 17:4531. [PMID: 39336272 PMCID: PMC11433000 DOI: 10.3390/ma17184531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2024] [Revised: 08/05/2024] [Accepted: 09/11/2024] [Indexed: 09/30/2024]
Abstract
Tungsten is a metal with many unique characteristics, such as a high melting point, high hardness, high chemical stability, etc. It is widely used in high-end manufacturing, new energy, the defense industry, and other fields. However, tungsten also has room-temperature brittleness, recrystallization brittleness, and other shortcomings due to the adjustment of the composition and organizational structure, such as the addition of alloying elements, adjusting the phase ratio, the use of heat treatment and deformation strengthening, etc. Its performance can be improved to meet the requirements for use in different fields. At present, the main production method of tungsten alloy is powder metallurgy. The use of a rolling open billet rotary forging-stretching process can improve production efficiency and product quality, but in actual production, due to the combined effects of various factors, such as elastic deformation of rolling elements, plastic deformation of the rolled material, etc., the mechanical properties of tungsten plates and bars are often difficult to control effectively, seriously affecting rolling stability and production efficiency. For this reason, researchers have conducted extensive and deep research and optimization on the rolling process of tungsten alloys, including establishing mathematical models, performing numerical simulations, optimizing process parameters, etc., providing important references for the rolling and forming of tungsten alloys. Meanwhile, the material properties are greatly influenced by the microstructure, and the evolution of the microstructure can be well quantified by some advanced characterization techniques, such as SEM, TEM, EBSD, etc., so that certain properties of tungsten can be obtained by controlling the texture evolution. In conclusion, this paper comprehensively summarizes the research progress of tungsten alloy roll forming and provides an important reference for further improving the processing performance and production efficiency of tungsten alloy.
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Affiliation(s)
- Jun Cao
- School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo 454000, China
| | - Jie Xia
- School of Mechanical and Power Engineering, Henan Polytechnic University, Jiaozuo 454000, China
| | - Xiaoyu Shen
- Zhejiang Tony Electronic Co., Ltd., Huzhou 313000, China
| | - Kexing Song
- Henan Academy of Sciences, Zhengzhou 450046, China
| | - Yanjun Zhou
- School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471000, China
| | - Chengqiang Cui
- State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment, Guangdong University of Technology, Guangzhou 510006, China
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2
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Wang Y, Yi C, Tian W, Liu F, Cheng GJ. Free-space direct nanoscale 3D printing of metals and alloys enabled by two-photon decomposition and ultrafast optical trapping. NATURE MATERIALS 2024:10.1038/s41563-024-01984-z. [PMID: 39169240 DOI: 10.1038/s41563-024-01984-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 07/30/2024] [Indexed: 08/23/2024]
Abstract
Nanoscale three-dimensional (3D) printing of metals and alloys has faced challenges in speed, miniaturization and deficiency in material properties. Traditional nanomanufacturing relies on lithographic methods with material constraints, limited resolution and slow layer-by-layer processing. This work introduces polymer-free techniques using two-photon decomposition and optical force trapping for free-space direct 3D printing of metals, metal oxides and multimetallic alloys with resolutions beyond optical limits. This method involves the two-photon decomposition of metal atoms from precursors, rapid assembly into nanoclusters via optical forces and ultrafast laser sintering, yielding dense, smooth nanostructures. Enhanced near-field optical forces from laser-induced localized surface plasmon resonance facilitate nanocluster aggregation. Our approach eliminates the need for organic materials, layer-by-layer printing and complex post-processing. Printed Mo nanowires show an excellent mechanical performance, closely resembling the behaviour of single crystals, while Mo-Co-W alloy nanowires outperform Mo nanowires. This innovation promises the customizable 3D nanoprinting of high-quality metals and metal oxides, impacting nanoelectronics, nanorobotics and advanced chip manufacturing.
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Affiliation(s)
- Yaoyu Wang
- Institute of Technological Sciences, Wuhan University, Wuhan, China
| | - Chenqi Yi
- Institute of Technological Sciences, Wuhan University, Wuhan, China
| | - Wenxiang Tian
- State Key Laboratory of Water Resources Engineering and Management, Wuhan University & Changjiang Institute of Survey, Planning, Design and Research Corporation, Wuhan, P.R. China
- Institute of Water Engineering Sciences, Wuhan University, Wuhan, China
| | - Feng Liu
- Institute of Technological Sciences, Wuhan University, Wuhan, China
- School of Power and Mechanical Engineering, Wuhan University, Wuhan, China
| | - Gary J Cheng
- Institute of Technological Sciences, Wuhan University, Wuhan, China.
- School of Industrial Engineering, Purdue University, West Lafayette, IN, USA.
- School of Materials Engineering, Purdue University, West Lafayette, IN, USA.
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3
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Han Y, Wang L, Cao K, Zhou J, Zhu Y, Hou Y, Lu Y. In Situ TEM Characterization and Modulation for Phase Engineering of Nanomaterials. Chem Rev 2023; 123:14119-14184. [PMID: 38055201 DOI: 10.1021/acs.chemrev.3c00510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Solid-state phase transformation is an intriguing phenomenon in crystalline or noncrystalline solids due to the distinct physical and chemical properties that can be obtained and modified by phase engineering. Compared to bulk solids, nanomaterials exhibit enhanced capability for phase engineering due to their small sizes and high surface-to-volume ratios, facilitating various emerging applications. To establish a comprehensive atomistic understanding of phase engineering, in situ transmission electron microscopy (TEM) techniques have emerged as powerful tools, providing unprecedented atomic-resolution imaging, multiple characterization and stimulation mechanisms, and real-time integrations with various external fields. In this Review, we present a comprehensive overview of recent advances in in situ TEM studies to characterize and modulate nanomaterials for phase transformations under different stimuli, including mechanical, thermal, electrical, environmental, optical, and magnetic factors. We briefly introduce crystalline structures and polymorphism and then summarize phase stability and phase transformation models. The advanced experimental setups of in situ techniques are outlined and the advantages of in situ TEM phase engineering are highlighted, as demonstrated via several representative examples. Besides, the distinctive properties that can be obtained from in situ phase engineering are presented. Finally, current challenges and future research opportunities, along with their potential applications, are suggested.
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Affiliation(s)
- Ying Han
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR 999077, China
| | - Liqiang Wang
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR 999077, China
| | - Ke Cao
- School of Advanced Materials and Nanotechnology, Xidian University, Xi'an, Shaanxi 710026, China
| | - Jingzhuo Zhou
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR 999077, China
| | - Yingxin Zhu
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR 999077, China
| | - Yuan Hou
- Department of Mechanical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR 999077, China
| | - Yang Lu
- Department of Mechanical Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR 999077, China
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4
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Fujimoto A, Hamada A, Kojio K. Deformation Behavior of Body-Centered Cubic Lattice in Polymers. J Phys Chem Lett 2023; 14:10019-10024. [PMID: 37906638 DOI: 10.1021/acs.jpclett.3c02376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
A body-centered cubic (BCC) lattice is a crystal unit cell structure observed in metals, inorganics, and polymers. The deformation behavior of the BCC lattice in metals has been well elucidated, whereas that of polymers remains unclear. We used a microphase-separated copolymer with randomly oriented grains wherein spherical phases are packed in the BCC lattice. The copolymer showed affine deformation under a strain of 1.8, which is much larger than that observed for metals, followed by spectacular rearrangement and "push-and-shove" deformation. To the best of our knowledge, these structural changes have not yet been observed in metals. These differences in the behavior of metals and polymers arise depending on the contact state of the spherical phases.
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Kardani A, Montazeri A, Urbassek HM. Strain-rate-dependent plasticity of Ta-Cu nanocomposites for therapeutic implants. Sci Rep 2023; 13:15788. [PMID: 37737499 PMCID: PMC10516883 DOI: 10.1038/s41598-023-43126-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 09/20/2023] [Indexed: 09/23/2023] Open
Abstract
Recently, Ta/Cu nanocomposites have been widely used in therapeutic medical devices due to their excellent bioactivity and biocompatibility, antimicrobial property, and outstanding corrosion and wear resistance. Since mechanical yielding and any other deformation in the patient's body during treatment are unacceptable in medicine, the characterization of the mechanical behavior of these nanomaterials is of great importance. We focus on the microstructural evolution of Ta/Cu nanocomposite samples under uniaxial tensile loading conditions at different strain rates using a series of molecular dynamics simulations and compare to the reference case of pure Ta. The results show that the increase in dislocation density at lower strain rates leads to the significant weakening of the mechanical properties. The strain rate-dependent plastic deformation mechanism of the samples can be divided into three main categories: phase transitions at the extreme strain rates, dislocation slip/twinning at lower strain rates for coarse-grained samples, and grain-boundary based activities for the finer-grained samples. Finally, we demonstrate that the load transfer from the Ta matrix to the Cu nanoparticles via the interfacial region can significantly affect the plastic deformation of the matrix in all nanocomposite samples. These results will prove useful for the design of therapeutic implants based on Ta/Cu nanocomposites.
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Affiliation(s)
- Arash Kardani
- Computational Nanomaterials Lab (CNL), Faculty of Materials Science and Engineering, K. N. Toosi University of Technology, Tehran, Iran
| | - Abbas Montazeri
- Computational Nanomaterials Lab (CNL), Faculty of Materials Science and Engineering, K. N. Toosi University of Technology, Tehran, Iran
| | - Herbert M Urbassek
- Physics Department and Research Center OPTIMAS, University Kaiserslautern-Landau, Erwin-Schrödinger-Straße, 67663, Kaiserslautern, Germany.
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Zhu D, Wang C, Zou P, Zhang R, Wang S, Song B, Yang X, Low KB, Xin HL. Deep-Learning Aided Atomic-Scale Phase Segmentation toward Diagnosing Complex Oxide Cathodes for Lithium-Ion Batteries. NANO LETTERS 2023; 23:8272-8279. [PMID: 37643420 DOI: 10.1021/acs.nanolett.3c02441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Phase transformation─a universal phenomenon in materials─plays a key role in determining their properties. Resolving complex phase domains in materials is critical to fostering a new fundamental understanding that facilitates new material development. So far, although conventional classification strategies such as order-parameter methods have been developed to distinguish remarkably disparate phases, highly accurate and efficient phase segmentation for material systems composed of multiphases remains unavailable. Here, by coupling hard-attention-enhanced U-Net network and geometry simulation with atomic-resolution transmission electron microscopy, we successfully developed a deep-learning tool enabling automated atom-by-atom phase segmentation of intertwined phase domains in technologically important cathode materials for lithium-ion batteries. The new strategy outperforms traditional methods and quantitatively elucidates the correlation between the multiple phases formed during battery operation. Our work demonstrates how deep learning can be employed to foster an in-depth understanding of phase transformation-related key issues in complex materials.
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Affiliation(s)
- Dong Zhu
- Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697, United States
- Computer Network Information Centre, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Chunyang Wang
- Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697, United States
| | - Peichao Zou
- Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697, United States
| | - Rui Zhang
- Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697, United States
| | - Shefang Wang
- BASF Corporation, Iselin, New Jersey 08830, United States
| | - Bohang Song
- BASF Corporation, Beachwood, Ohio 44122, United States
| | - Xiaoyu Yang
- Computer Network Information Centre, Chinese Academy of Sciences, Beijing, 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Ke-Bin Low
- BASF Corporation, Iselin, New Jersey 08830, United States
| | - Huolin L Xin
- Department of Physics and Astronomy, University of California Irvine, Irvine, California 92697, United States
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7
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Dang B, Liu K, Wu X, Yang Z, Xu L, Yang Y, Huang R. One-Phototransistor-One-Memristor Array with High-Linearity Light-Tunable Weight for Optic Neuromorphic Computing. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2204844. [PMID: 35917248 DOI: 10.1002/adma.202204844] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 07/21/2022] [Indexed: 06/15/2023]
Abstract
The recent advances in optic neuromorphic devices have led to a subsequent rise in use for construction of energy-efficient artificial-vision systems. The widespread use can be attributed to their ability to capture, store, and process visual information from the environment. The primary limitations of existing optic neuromorphic devices include nonlinear weight updates, cross-talk issues, and silicon process incompatibility. In this study, a highly linear, light-tunable, cross-talk-free, and silicon-compatible one-phototransistor-one-memristor (1PT1R) optic memristor is experimentally demonstrated for the implementation of an optic artificial neural network (OANN). For optic image recognition in the experiment, an OANN is constructed using a 16 × 3 1PT1R memristor array, and it is trained on an online platform. The model yields an accuracy of 99.3% after only ten training epochs. The 1PT1R memristor, which shows good performance, demonstrates its ability as an excellent hardware solution for highly efficient optic neuromorphic and edge computing.
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Affiliation(s)
- Bingjie Dang
- Beijing Advanced Innovation Center for Integrated Circuits, School of Integrated Circuits, Peking University, Beijing, 100871, China
| | - Keqin Liu
- Beijing Advanced Innovation Center for Integrated Circuits, School of Integrated Circuits, Peking University, Beijing, 100871, China
| | - Xulei Wu
- Beijing Advanced Innovation Center for Integrated Circuits, School of Integrated Circuits, Peking University, Beijing, 100871, China
| | - Zhen Yang
- Beijing Advanced Innovation Center for Integrated Circuits, School of Integrated Circuits, Peking University, Beijing, 100871, China
| | - Liying Xu
- Beijing Advanced Innovation Center for Integrated Circuits, School of Integrated Circuits, Peking University, Beijing, 100871, China
| | - Yuchao Yang
- Beijing Advanced Innovation Center for Integrated Circuits, School of Integrated Circuits, Peking University, Beijing, 100871, China
- Center for Brain Inspired Chips, Institute for Artificial Intelligence, Peking University, Beijing, 100871, China
- Center for Brain Inspired Intelligence, Chinese Institute for Brain Research (CIBR), Beijing, Beijing, 102206, China
- Beijing Academy of Artificial Intelligence, Beijing, 100084, China
| | - Ru Huang
- Beijing Advanced Innovation Center for Integrated Circuits, School of Integrated Circuits, Peking University, Beijing, 100871, China
- Center for Brain Inspired Chips, Institute for Artificial Intelligence, Peking University, Beijing, 100871, China
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8
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Wang J, Ma Q, Cheng H, Yu H, Zhang S, Shang H, Zhang G, Wang W. Investigation of the Micromechanical Behavior of a Ti 68Nb 7Ta 3Zr 4Mo 18 (at.%) High-Entropy Alloy. MATERIALS (BASEL, SWITZERLAND) 2023; 16:5126. [PMID: 37512400 PMCID: PMC10383748 DOI: 10.3390/ma16145126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/11/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023]
Abstract
Intense research efforts are focused on the development of advanced high-entropy alloys intended for premium aerospace components and other applications, where high strength and good formability are crucial. The mechanical properties of these alloys are closely related to the phase transformation, dislocation evolution, and grain size, and these factors are affected by the deformation temperature. The response of the retained austenite to strain-induced martensitic transformation at various temperatures was studied in an advanced Ti68Nb7Ta3Zr4Mo18 (at.%) high-entropy alloy via molecular dynamics simulation. It was found that the Ti68Nb7Ta3Zr4Mo18 alloy changes from a single crystal to a polycrystal during the tensile process, and the transition of the Ti68Nb7Ta3Zr4Mo18 (at.%) high-entropy alloy from the BCC phase to the FCC phase occurs. At high temperatures and low strain rates, grain boundary slip is the main deformation mechanism, and at low temperatures and high strain rates, dislocation slip replaces grain boundary slip as the dominant deformation mechanism, which improves the strength of the alloy. Moreover, when the grain size is too small, the strength of the alloy decreases, which does not satisfy the fine grain strengthening theory and shows an inverse Hall-Petch relationship. This study offers a new compositional window for the additive manufactured lightweight high-strength material categories for various applications including the aerospace industry.
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Affiliation(s)
- Jin Wang
- School of Mechatronics Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China
- School of Mechanical and Transportation Engineering, Hunan University, Changsha 410082, China
| | - Qianli Ma
- School of Mechatronics Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China
| | - Hepeng Cheng
- School of Mechatronics Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China
| | - Hechun Yu
- School of Mechatronics Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China
| | - Suxiang Zhang
- School of Mechatronics Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China
| | - Huichao Shang
- School of Mechatronics Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China
| | - Guoqing Zhang
- School of Mechatronics Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China
| | - Wenbo Wang
- School of Mechatronics Engineering, Zhongyuan University of Technology, Zhengzhou 450007, China
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9
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Ou X, Shen Y, Yang Y, You Z, Wang P, Yang Y, Tian X. Mechanical Properties and Deformation Mechanisms of Nanocrystalline U-10Mo Alloys by Molecular Dynamics Simulation. MATERIALS (BASEL, SWITZERLAND) 2023; 16:4618. [PMID: 37444932 DOI: 10.3390/ma16134618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 06/18/2023] [Accepted: 06/25/2023] [Indexed: 07/15/2023]
Abstract
U-Mo alloys were considered to be the most promising candidates for high-density nuclear fuel. The uniaxial tensile behavior of nanocrystalline U-10Mo alloys with average grain sizes of 8-23 nm was systematically studied by molecular dynamics (MD) simulation, mainly focusing on the influence of average grain size on the mechanical properties and deformation mechanisms. The results show that Young's modulus, yield strength and ultimate tensile strength follow as average grain size increases. During the deformation process, localized phase transitions were observed in samples. Grain boundary sliding and grain rotation, as well as twinning, dominated the deformation in the smaller and larger grain sizes samples, respectively. Increased grain size led to greater localized shear deformation, resulting in greater stress drop. Additionally, we elucidated the effects of temperature and strain rate on tensile behavior and found that lower temperatures and higher strain rates not only facilitated the twinning tendency but also favored the occurrence of phase transitions in samples. Results from this research could provide guidance for the design and optimization of U-10Mo alloys materials.
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Affiliation(s)
- Xuelian Ou
- The College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China
| | - Yanxin Shen
- The College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China
| | - Yue Yang
- The College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China
| | - Zhenjiang You
- Center for Sustainable Energy and Resources, Edith Cowan University, Joondalup, WA 6027, Australia
| | - Peng Wang
- The College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China
| | - Yexin Yang
- The College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China
| | - Xiaofeng Tian
- The College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu 610059, China
- Applied Nuclear Technology in Geosciences Key Laboratory of Sichuan Province, Chengdu University of Technology, Chengdu 610059, China
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10
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Wang C, Wang X, Zhang R, Lei T, Kisslinger K, Xin HL. Resolving complex intralayer transition motifs in high-Ni-content layered cathode materials for lithium-ion batteries. NATURE MATERIALS 2023; 22:235-241. [PMID: 36702885 DOI: 10.1038/s41563-022-01461-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 12/09/2022] [Indexed: 06/18/2023]
Abstract
High-Ni-content layered materials are promising cathodes for next-generation lithium-ion batteries. However, investigating the atomic configurations of the delithiation-induced complex phase boundaries and their transitions remains challenging. Here, by using deep-learning-aided super-resolution electron microscopy, we resolve the intralayer transition motifs at complex phase boundaries in high-Ni cathodes. We reveal that an O3 → O1 transformation driven by delithiation leads to the formation of two types of O1-O3 interface, the continuous- and abrupt-transition interfaces. The interfacial misfit is accommodated by a continuous shear-transition zone and an abrupt structural unit, respectively. Atomic-scale simulations show that uneven in-plane Li+ distribution contributes to the formation of both types of interface, and the abrupt transition is energetically more favourable in a delithiated state where O1 is dominant, or when there is an uneven in-plane Li+ distribution in a delithiated O3 lattice. Moreover, a twin-like motif that introduces structural units analogous to the abrupt-type O1-O3 interface is also uncovered. The structural transition motifs resolved in this study provide further understanding of shear-induced phase transformations and phase boundaries in high-Ni layered cathodes.
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Affiliation(s)
- Chunyang Wang
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA, USA
| | - Xuelong Wang
- Chemistry Division, Brookhaven National Laboratory, Upton, NY, USA
| | - Rui Zhang
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA, USA
| | - Tianjiao Lei
- Department of Materials Science and Engineering, University of California, Irvine, Irvine, CA, USA
| | - Kim Kisslinger
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, USA
| | - Huolin L Xin
- Department of Physics and Astronomy, University of California, Irvine, Irvine, CA, USA.
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11
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Yang Y, Qian Y, Luo Z, Li H, Chen L, Cao X, Wei S, Zhou B, Zhang Z, Chen S, Yan W, Dong J, Song L, Zhang W, Feng R, Zhou J, Du K, Li X, Zhang XM, Fan X. Water induced ultrathin Mo 2C nanosheets with high-density grain boundaries for enhanced hydrogen evolution. Nat Commun 2022; 13:7225. [PMID: 36433983 PMCID: PMC9700844 DOI: 10.1038/s41467-022-34976-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 11/14/2022] [Indexed: 11/26/2022] Open
Abstract
Grain boundary controlling is an effective approach for manipulating the electronic structure of electrocatalysts to improve their hydrogen evolution reaction performance. However, probing the direct effect of grain boundaries as highly active catalytic hot spots is very challenging. Herein, we demonstrate a general water-assisted carbothermal reaction strategy for the construction of ultrathin Mo2C nanosheets with high-density grain boundaries supported on N-doped graphene. The polycrystalline Mo2C nanosheets are connected with N-doped graphene through Mo-C bonds, which affords an ultra-high density of active sites, giving excellent hydrogen evolution activity and superior electrocatalytic stability. Theoretical calculations reveal that the dz2 orbital energy level of Mo atoms is controlled by the MoC3 pyramid configuration, which plays a vital role in governing the hydrogen evolution activity. The dz2 orbital energy level of metal atoms exhibits an intrinsic relationship with the catalyst activity and is regarded as a descriptor for predicting the hydrogen evolution activity.
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Affiliation(s)
- Yang Yang
- Institute of Crystalline Materials, Shanxi University, Taiyuan, Shanxi, 030006, China
- Key Laboratory of Interface Science and Engineering in Advanced Materials, College of Chemistry, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, China
| | - Yumin Qian
- Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Haidian, Beijing, 100081, China
| | - Zhaoping Luo
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Haijing Li
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Lanlan Chen
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Xumeng Cao
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Shiqiang Wei
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Bo Zhou
- Institute of Microstructure and Properties of Advanced Materials, Beijing University of Technology, Chaoyang District, Beijing, 100124, China
| | - Zhenhua Zhang
- Innovative Center for Advanced Materials, Hangzhou Dianzi University, Hangzhou, Zhejiang, 310018, China
| | - Shuai Chen
- Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, China
| | - Wenjun Yan
- Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, 030001, China
| | - Juncai Dong
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China
| | - Li Song
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Wenhua Zhang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Renfei Feng
- Canadian Light Source, Saskatoon, SK, S7N2V3, Canada
| | - Jigang Zhou
- Canadian Light Source, Saskatoon, SK, S7N2V3, Canada
| | - Kui Du
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Xiuyan Li
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China
| | - Xian-Ming Zhang
- Institute of Crystalline Materials, Shanxi University, Taiyuan, Shanxi, 030006, China.
- Key Laboratory of Interface Science and Engineering in Advanced Materials, College of Chemistry, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, China.
| | - Xiujun Fan
- Institute of Crystalline Materials, Shanxi University, Taiyuan, Shanxi, 030006, China.
- Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, School of Chemistry, Xi'an Jiaotong University, Xi'an, 710049, China.
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12
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Kou Z, Feng T, Lan S, Tang S, Yang L, Yang Y, Wilde G. Observing Dislocations Transported by Twin Boundaries in Al Thin Film: Unusual Pathways for Dislocation-Twin Boundary Interactions. NANO LETTERS 2022; 22:6229-6234. [PMID: 35876496 DOI: 10.1021/acs.nanolett.2c01763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Twins are generally regarded as obstacles to dislocations in face-centered cubic metals and can modify individual dislocations by locking them in twin boundaries or obliging them to dissociate. Through in situ tensile experiments on Al thin film in a transmission electron microscope, we report a dynamic process of dislocations being transported by twin lamella via periodic twinning and detwinning at the atomic scale. Following this process, a 60° dislocation first transforms into a sessile step of the twin boundary, then migrates under stress as a step and finally reverts back into a 60° dislocation. Our results reveal a novel evolution route of dislocations by a dislocation-twin interaction where the twins act as transport vehicles rather than as obstacles. The potential implications of this mechanism on toughening are also discussed.
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Affiliation(s)
- Zongde Kou
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China
| | - Tao Feng
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China
| | - Si Lan
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China
| | - Song Tang
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China
| | - Lixia Yang
- College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, PR China
| | - Yanqing Yang
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, PR China
| | - Gerhard Wilde
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China
- Institute of Materials Physics, University of Muenster, Wilhelm-Klemm Str. 10, Muenster 48149, Germany
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13
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Zhang H, Wang W, Sun J, Zhong L, He L, Sun L. Surface-Condition-Dependent Deformation Mechanisms in Lead Nanocrystals. Research (Wash D C) 2022; 2022:9834636. [PMID: 36016690 PMCID: PMC9362692 DOI: 10.34133/2022/9834636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 07/02/2022] [Indexed: 11/23/2022] Open
Abstract
Serving as nanoelectrodes or frame units, small-volume metals may critically affect the performance and reliability of nanodevices, especially with feature sizes down to the nanometer scale. Small-volume metals usually behave extraordinarily in comparison with their bulk counterparts, but the knowledge of how their sizes and surfaces give rise to their extraordinary properties is currently insufficient. In this study, we investigate the influence of surface conditions on mechanical behaviors in nanometer-sized Pb crystals by performing in situ mechanical deformation tests inside an aberration-corrected transmission electron microscope (TEM). Pseudoelastic deformation and plastic deformation processes were observed at atomic precision during deformation of pristine and surface-oxidized Pb particles, respectively. It is found that in most of the pristine Pb particles, surface atom diffusion dominates and leads to a pseudoelastic deformation behavior. In stark contrast, in surface-passivated Pb particles where surface atom diffusion is largely inhibited, deformation proceeds via displacive plasticity including dislocations, stacking faults, and twinning, leading to dominant plastic deformation without any pseudoelasticity. This research directly reveals the dramatic impact of surface conditions on the deformation mechanisms and mechanical behaviors of metallic nanocrystals, which provides significant implications for property tuning of the critical components in advanced nanodevices.
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Affiliation(s)
- Hongtao Zhang
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing 210096, China
| | - Wen Wang
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing 210096, China
| | - Jun Sun
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing 210096, China
| | - Li Zhong
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing 210096, China
| | - Longbing He
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing 210096, China
| | - Litao Sun
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing 210096, China
- Center for Advanced Materials and Manufacture, Southeast University-Monash University Joint Research Institute, Suzhou 215123, China
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14
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Zhang H, Peng R, Wen H, Xie H, Liu Z. A hybrid method for lattice image reconstruction and deformation analysis. NANOTECHNOLOGY 2022; 33:385706. [PMID: 35696988 DOI: 10.1088/1361-6528/ac780f] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 06/12/2022] [Indexed: 06/15/2023]
Abstract
Geometric phase analysis (GPA) is a powerful tool to investigate the deformation in nanoscale measurement, especially in dealing with high-resolution transmission electron microscopy images. The traditional GPA method using the fast Fourier transform is built on the relationship between the displacement and the phase difference. In this paper, a nano-grid method based on real-space lattice image processing was firstly proposed to enable the measurement of nanoscale interface flatness, and the thickness of different components. Then, a hybrid method for lattice image reconstruction and deformation analysis was developed. The hybrid method enables simultaneous real-space and frequency-domain processing, thus, compensating for the shortcomings of the GPA method when measuring samples with large deformations or containing cracks while retaining its measurement accuracy.
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Affiliation(s)
- Hongye Zhang
- School of Technology, Beijing Forestry University, Beijing 100083, People's Republic of China
- School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | - Runlai Peng
- School of Technology, Beijing Forestry University, Beijing 100083, People's Republic of China
| | - Huihui Wen
- School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
- School of Electrical Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, People's Republic of China
| | - Huimin Xie
- AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, People's Republic of China
| | - Zhanwei Liu
- School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, People's Republic of China
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15
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Ionic Polymer Nanocomposites Subjected to Uniaxial Extension: A Nonequilibrium Molecular Dynamics Study. Polymers (Basel) 2021; 13:polym13224001. [PMID: 34833305 PMCID: PMC8621629 DOI: 10.3390/polym13224001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/12/2021] [Accepted: 11/13/2021] [Indexed: 11/17/2022] Open
Abstract
We explore the behavior of coarse-grained ionic polymer nanocomposites (IPNCs) under uniaxial extension up to 800% strain by means of nonequilibrium molecular dynamics simulations. We observe a simultaneous increase of stiffness and toughness of the IPNCs upon increasing the engineering strain rate, in agreement with experimental observations. We reveal that the excellent toughness of the IPNCs originates from the electrostatic interaction between polymers and nanoparticles, and that it is not due to the mobility of the nanoparticles or the presence of polymer-polymer entanglements. During the extension, and depending on the nanoparticle volume fraction, polymer-nanoparticle ionic crosslinks are suppressed with the increase of strain rate and electrostatic strength, while the mean pore radius increases with strain rate and is altered by the nanoparticle volume fraction and electrostatic strength. At relatively low strain rates, IPNCs containing an entangled matrix exhibit self-strengthening behavior. We provide microscopic insight into the structural, conformational properties and crosslinks of IPNCs, also referred to as polymer nanocomposite electrolytes, accompanying their unusual mechanical behavior.
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16
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He S, Jiang B, Wang C, Chen C, Duan H, Jin S, Ye H, Lu L, Du K. High Reversible Strain in Nanotwinned Metals. ACS APPLIED MATERIALS & INTERFACES 2021; 13:46088-46096. [PMID: 34541843 DOI: 10.1021/acsami.1c10949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Development of bulk metals exhibiting large reversible strain is of great interest, owing to their potential applications in flexible electronic devices. Bulk metals with nanometer-scale twins have demonstrated high strength, good ductility, and promising electrical conductivity. Here, ultrahigh reversible strain as high as ∼7.8% was observed in bent twin lamellae with 1-2 nm thickness in nanotwinned metals, where the maximum reversible strain increases with the reduction in twin lamella thickness. This high reversible strain is attributed to the suppression of dislocation nucleation, including both hard mode dislocations in the bent twin lamellae, while soft mode dislocations along twin boundaries have insignificant contribution. In situ transmission electron microscopy experiments show that higher recoverability was achieved in twinned Au nanorods compared with twin-free ones with similar aspect ratios and diameters during bending deformation, which demonstrates that the introduction of thin twin lamellae also significantly improves the shape recoverability of Au nanorods. This result introduces a novel pathway for developing bulk metals with the capability for large reversible strain.
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Affiliation(s)
- Suyun He
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
| | - Binbin Jiang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
| | - Chunyang Wang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
| | - Chunjin Chen
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
- School of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Huichao Duan
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
- School of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Shuai Jin
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
| | - Hengqiang Ye
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
- Jihua Laboratory, Foshan 528251, China
| | - Lei Lu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
| | - Kui Du
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People's Republic of China
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17
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Timely and atomic-resolved high-temperature mechanical investigation of ductile fracture and atomistic mechanisms of tungsten. Nat Commun 2021; 12:2218. [PMID: 33850117 PMCID: PMC8044182 DOI: 10.1038/s41467-021-22447-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 03/12/2021] [Indexed: 11/08/2022] Open
Abstract
Revealing the atomistic mechanisms for the high-temperature mechanical behavior of materials is important for optimizing their properties for service at high-temperatures and their thermomechanical processing. However, due to materials microstructure’s dynamic recovery and the absence of available in situ techniques, the high-temperature deformation behavior and atomistic mechanisms of materials are difficult to evaluate. Here, we report the development of a microelectromechanical systems-based thermomechanical testing apparatus that enables mechanical testing at temperatures reaching 1556 K inside a transmission electron microscope for in situ investigation with atomic-resolution. With this unique technique, we first uncovered that tungsten fractures at 973 K in a ductile manner via a strain-induced multi-step body-centered cubic (BCC)-to-face-centered cubic (FCC) transformation and dislocation activities within the strain-induced FCC phase. Both events reduce the stress concentration at the crack tip and retard crack propagation. Our research provides an approach for timely and atomic-resolved high-temperature mechanical investigation of materials at high-temperatures. High-temperature deformation of materials is challenging to evaluate. Here the authors develop a novel device that allows atomic resolved in situ high temperature mechanical tests inside a transmission electron microscope and reveal ductile fracture of a single crystal tungsten deformed at 973 K.
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18
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Boulbitch A, Korzhenevskii AL. Transformation toughness induced by surface tension of the crack-tip process zone interface: A field-theoretical approach. Phys Rev E 2021; 103:023001. [PMID: 33736011 DOI: 10.1103/physreve.103.023001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/11/2021] [Indexed: 11/07/2022]
Abstract
We study a crystal with a motionless crack exhibiting the transformational process zone at its tip within the field-theoretical approach. The latter enables us to describe the transformation toughness phenomenon and relate it to the solid's location on its phase diagram. We demonstrate that the zone extends backward beyond the crack tip due to the zone boundary surface tension. This setback engenders the crack-tip shielding, thus forming the transformation toughness. We obtain a quadrature expression for the effective fracture toughness using two independent approaches-(i) with the help of the elastic Green function and, alternatively, (ii) using the weight functions-and calculate it numerically applying the results of our simulations. Based on these findings, we derive an accurate analytical approximation that describes the transformation toughness. We further express it in terms of the experimentally accessible parameters of the phase diagram: the hysteresis width, the phase transition line slope, and the transformation strain.
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Affiliation(s)
| | - Alexander L Korzhenevskii
- Institute for Problems of Mechanical Engineering, Russian Academy of Sciences, Bol'shoi Prospect V.O. 61, 199178 Saint Petersburg, Russia
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19
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Tsianikas S, Chen Y, Jeong J, Zhang S, Xie Z. Self-toughened high entropy alloy with a body-centred cubic structure. NANOSCALE 2021; 13:3602-3612. [PMID: 33537685 DOI: 10.1039/d0nr06798a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Multiple interstitial elements (B, C and O), were incorporated into a body-centred cubic (BCC) FeMnCoCr-based interstitial high entropy alloy (iHEA). While achieving an impressive yield strength of 2.55 GPa, the new alloy also possesses appreciable ductility under mechanical loading. The unusual combination of hardening effects brought about by interstitial atoms, compositional fluctuations, and fine grain size greatly strengthened the alloy by inhibiting dislocation motion. Moreover, interstitial elements helped reinforce the grain boundaries through segregation and also assisted in tuning the phase stability. The new alloy transformed from the BCC to hexagonal closed-packed (HCP) phase initially. With increasing load the HCP phase was gradually converted into face-centred cubic (FCC); the resultant HCP/FCC nanolaminates enhanced plasticity via strain partitioning. Under higher loads, the FCC phase became dominant, giving rise to deformation twinning. Taken together, the newly developed BCC structured iHEA affords not only high strength, but also confers remarkable ductility through multiple deformation pathways.
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Affiliation(s)
- Simon Tsianikas
- School of Mechanical Engineering, The University of Adelaide, SA 5005, Australia.
| | - Yujie Chen
- School of Mechanical Engineering, The University of Adelaide, SA 5005, Australia. and Centre for Advanced Thin Film Materials and Devices, Faculty of Materials and Energy, Southwest University, Chongqing 400715, China
| | - Jiwon Jeong
- Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Siyuan Zhang
- Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237 Düsseldorf, Germany
| | - Zonghan Xie
- School of Mechanical Engineering, The University of Adelaide, SA 5005, Australia.
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20
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Ion irradiation induced phase transformation in gold nanocrystalline films. Sci Rep 2020; 10:17864. [PMID: 33082480 PMCID: PMC7576776 DOI: 10.1038/s41598-020-74779-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 10/07/2020] [Indexed: 11/19/2022] Open
Abstract
Gold is a noble metal typically stable as a solid in a face-centered cubic (FCC) structure under ambient conditions; however, under particular circumstances aberrant allotropes have been synthesized. In this work, we document the phase transformation of 25 nm thick nanocrystalline (NC) free-standing gold thin-film via in situ ion irradiation studied using atomic-resolution transmission electron microscopy (TEM). Utilizing precession electron diffraction (PED) techniques, crystallographic orientation and the radiation-induced relative strains were measured and furthermore used to determine that a combination of surface and radiation-induced strains lead to an FCC to hexagonal close packed (HCP) crystallographic phase transformation upon a 10 dpa radiation dose of Au4+ ions. Contrary to previous studies, HCP phase in nanostructures of gold was stabilized and did not transform back to FCC due to a combination of size effects and defects imparted by damage cascades.
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21
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Boulbitch A, Korzhenevskii AL. Morphological transformation of the process zone at the tip of a propagating crack. I. Simulation. Phys Rev E 2020; 101:033003. [PMID: 32289996 DOI: 10.1103/physreve.101.033003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 02/11/2020] [Indexed: 11/07/2022]
Abstract
Stress concentration at a crack tip engenders a process zone, a small domain containing a phase, different from that in the bulk of the solid. We demonstrate that this zone at the tip of a propagating crack exhibits a morphological transformation with an increase of the crack velocity. The concave zone shape with an invagination in its back that is characteristic of a slow crack transforms into a droplet-shaped convex zone upon exceeding a critical velocity value, v_{G}. In this latter case, a metastable wake follows the propagating zone. We obtained this result by computer simulation of a crack propagating in a solid exhibiting a first-order phase transformation.
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Affiliation(s)
| | - Alexander L Korzhenevskii
- Institute for Problems of Mechanical Engineering, RAS, Bol'shoi prosp. V. O. 61, 199178 St. Petersburg, Russia
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22
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Zheng H, Cao F, Zhao L, Jiang R, Zhao P, Zhang Y, Wei Y, Meng S, Li K, Jia S, Li L, Wang J. Atomistic and dynamic structural characterizations in low-dimensional materials: recent applications of in situ transmission electron microscopy. Microscopy (Oxf) 2019; 68:423-433. [PMID: 31746339 DOI: 10.1093/jmicro/dfz038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 09/14/2019] [Accepted: 09/16/2019] [Indexed: 11/14/2022] Open
Abstract
In situ transmission electron microscopy has achieved remarkable advances for atomic-scale dynamic analysis in low-dimensional materials and become an indispensable tool in view of linking a material's microstructure to its properties and performance. Here, accompanied with some cutting-edge researches worldwide, we briefly review our recent progress in dynamic atomistic characterization of low-dimensional materials under external mechanical stress, thermal excitations and electrical field. The electron beam irradiation effects in metals and metal oxides are also discussed. We conclude by discussing the likely future developments in this area.
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Affiliation(s)
- He Zheng
- School of Physics and Technology, Center for Electron Microscopy, MOE Key Laboratory of Artificial Micro- and Nano-structures, and Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Fan Cao
- School of Physics and Technology, Center for Electron Microscopy, MOE Key Laboratory of Artificial Micro- and Nano-structures, and Institute for Advanced Studies, Wuhan University, Wuhan 430072, China.,Hubei Key Lab of Ferro- and Piezo-electric Materials and Devices, Faculty of Physics & Electronic Sciences, Hubei University, Wuhan 430062, China
| | - Ligong Zhao
- School of Physics and Technology, Center for Electron Microscopy, MOE Key Laboratory of Artificial Micro- and Nano-structures, and Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Renhui Jiang
- School of Physics and Technology, Center for Electron Microscopy, MOE Key Laboratory of Artificial Micro- and Nano-structures, and Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Peili Zhao
- School of Physics and Technology, Center for Electron Microscopy, MOE Key Laboratory of Artificial Micro- and Nano-structures, and Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Ying Zhang
- School of Physics and Technology, Center for Electron Microscopy, MOE Key Laboratory of Artificial Micro- and Nano-structures, and Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Yanjie Wei
- School of Physics and Technology, Center for Electron Microscopy, MOE Key Laboratory of Artificial Micro- and Nano-structures, and Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Shuang Meng
- School of Physics and Technology, Center for Electron Microscopy, MOE Key Laboratory of Artificial Micro- and Nano-structures, and Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Kaixuan Li
- School of Physics and Technology, Center for Electron Microscopy, MOE Key Laboratory of Artificial Micro- and Nano-structures, and Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Shuangfeng Jia
- School of Physics and Technology, Center for Electron Microscopy, MOE Key Laboratory of Artificial Micro- and Nano-structures, and Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
| | - Luying Li
- Center for Nanoscale Characterization and Devices, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jianbo Wang
- School of Physics and Technology, Center for Electron Microscopy, MOE Key Laboratory of Artificial Micro- and Nano-structures, and Institute for Advanced Studies, Wuhan University, Wuhan 430072, China
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23
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Wang Q, Wang J, Li J, Zhang Z, Mao SX. Consecutive crystallographic reorientations and superplasticity in body-centered cubic niobium nanowires. SCIENCE ADVANCES 2018; 4:eaas8850. [PMID: 29984304 PMCID: PMC6035040 DOI: 10.1126/sciadv.aas8850] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Accepted: 05/22/2018] [Indexed: 05/16/2023]
Abstract
Plasticity of metallic nanowires is often controlled by the activities of single deformation mode. It remains largely unclear whether multiple deformation modes can be activated in an individual metallic nanowire and how much plasticity they can contribute. In situ nanomechanical testing reveals a superior plastic deformation ability of body-centered cubic (BCC) niobium nanowires, in which a remarkable elongation of more than 269% is achieved before fracture. This superplastic deformation originates from a synergy of consecutively nucleated multiple reorientation processes that occur for more than five times via three distinct mechanisms, that is, stress-activated phase transformation, deformation twinning, and slip-induced crystal rotation. These three coupled mechanisms work concurrently, resulting in sequential reorientations and therefore superplastic deformation of Nb nanowires. Our findings reveal a superior mechanical property of BCC Nb nanowires through the close coordination of multiple deformation modes, which may have some implications in other metallic nanowire systems.
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Affiliation(s)
- Qiannan Wang
- Center of Electron Microscopy and State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Jiangwei Wang
- Center of Electron Microscopy and State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
- Corresponding author. (J.W.); (S.X.M.)
| | - Jixue Li
- Center of Electron Microscopy and State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Ze Zhang
- Center of Electron Microscopy and State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Scott X. Mao
- Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA 15261, USA
- Corresponding author. (J.W.); (S.X.M.)
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24
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Zhu H, Gao G, Du M, Zhou J, Wang K, Wu W, Chen X, Li Y, Ma P, Dong W, Duan F, Chen M, Wu G, Wu J, Yang H, Guo S. Atomic-Scale Core/Shell Structure Engineering Induces Precise Tensile Strain to Boost Hydrogen Evolution Catalysis. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1707301. [PMID: 29737007 DOI: 10.1002/adma.201707301] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 02/25/2018] [Indexed: 06/08/2023]
Abstract
Tuning surface strain is a new strategy for boosting catalytic activity to achieve sustainable energy supplies; however, correlating the surface strain with catalytic performance is scarce because such mechanistic studies strongly require the capability of tailoring surface strain on catalysts as precisely as possible. Herein, a conceptual strategy of precisely tuning tensile surface strain on Co9 S8 /MoS2 core/shell nanocrystals for boosting the hydrogen evolution reaction (HER) activity by controlling the MoS2 shell numbers is demonstrated. It is found that the tensile surface strain of Co9 S8 /MoS2 core/shell nanocrystals can be precisely tuned from 3.5% to 0% by changing the MoS2 shell layer from 5L to 1L, in which the strained Co9 S8 /1L MoS2 (3.5%) exhibits the best HER performance with an overpotential of only 97 mV (10 mA cm-2 ) and a Tafel slope of 71 mV dec-1 . The density functional theory calculation reveals that the Co9 S8 /1L MoS2 core/shell nanostructure yields the lowest hydrogen adsorption energy (∆EH ) of -1.03 eV and transition state energy barrier (∆E2H* ) of 0.29 eV (MoS2 , ∆EH = -0.86 eV and ∆E2H* = 0.49 eV), which are the key in boosting HER activity by stabilizing the HER intermediate, seizing H ions, and releasing H2 gas.
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Affiliation(s)
- Han Zhu
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China
| | - Guohua Gao
- Shanghai Key Laboratory of Special Artificial Microstructure, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Mingliang Du
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China
| | - Jinhui Zhou
- Department of Materials Science & Engineering and BIC-ESAT, College of Engineering, Peking University, Beijing, 100871, China
| | - Kai Wang
- Department of Materials Science & Engineering and BIC-ESAT, College of Engineering, Peking University, Beijing, 100871, China
| | - Wenbo Wu
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, China
| | - Xu Chen
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Yong Li
- Institute of Applied and Physical Chemistry and Center for Environmental Research and Sustainable Technology, Universität Bremen, 28359, Bremen, Germany
| | - Piming Ma
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China
| | - Weifu Dong
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China
| | - Fang Duan
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China
| | - Mingqing Chen
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, 214122, China
| | - Guangming Wu
- Shanghai Key Laboratory of Special Artificial Microstructure, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Jiandong Wu
- School of Material Science and Engineering, North Minzu University, Yinchuan, 750021, China
| | - Haitao Yang
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, China
| | - Shaojun Guo
- Department of Materials Science & Engineering and BIC-ESAT, College of Engineering, Peking University, Beijing, 100871, China
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Wang C, Du K, Song K, Ye X, Qi L, He S, Tang D, Lu N, Jin H, Li F, Ye H. Size-Dependent Grain-Boundary Structure with Improved Conductive and Mechanical Stabilities in Sub-10-nm Gold Crystals. PHYSICAL REVIEW LETTERS 2018; 120:186102. [PMID: 29775360 DOI: 10.1103/physrevlett.120.186102] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 12/16/2017] [Indexed: 06/08/2023]
Abstract
Low-angle grain boundaries generally exist in the form of dislocation arrays, while high-angle grain boundaries (misorientation angle >15°) exist in the form of structural units in bulk metals. Here, through in situ atomic resolution aberration corrected electron microscopy observations, we report size-dependent grain-boundary structures improving both stabilities of electrical conductivity and mechanical properties in sub-10-nm-sized gold crystals. With the diameter of a nanocrystal decreasing below 10 nm, the high-angle grain boundary in the crystal exists as an array of dislocations. This size effect may be of importance to a new generation of interconnects applications.
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Affiliation(s)
- Chunyang Wang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kui Du
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Kepeng Song
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Xinglong Ye
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Lu Qi
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Suyun He
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Daiming Tang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Ning Lu
- Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA
| | - Haijun Jin
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Feng Li
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Hengqiang Ye
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
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26
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Guo J, Haberfehlner G, Rosalie J, Li L, Duarte MJ, Kothleitner G, Dehm G, He Y, Pippan R, Zhang Z. In situ atomic-scale observation of oxidation and decomposition processes in nanocrystalline alloys. Nat Commun 2018; 9:946. [PMID: 29507370 PMCID: PMC5838172 DOI: 10.1038/s41467-018-03288-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 02/01/2018] [Indexed: 11/09/2022] Open
Abstract
Oxygen contamination is a problem which inevitably occurs during severe plastic deformation of metallic powders by exposure to air. Although this contamination can change the morphology and properties of the consolidated materials, there is a lack of detailed information about the behavior of oxygen in nanocrystalline alloys. In this study, aberration-corrected high-resolution transmission electron microscopy and associated techniques are used to investigate the behavior of oxygen during in situ heating of highly strained Cu-Fe alloys. Contrary to expectations, oxide formation occurs prior to the decomposition of the metastable Cu-Fe solid solution. This oxide formation commences at relatively low temperatures, generating nanosized clusters of firstly CuO and later Fe2O3. The orientation relationship between these clusters and the matrix differs from that observed in conventional steels. These findings provide a direct observation of oxide formation in single-phase Cu-Fe composites and offer a pathway for the design of nanocrystalline materials strengthened by oxide dispersions.
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Affiliation(s)
- Jinming Guo
- Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben, 8700, Austria
| | - Georg Haberfehlner
- Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, Graz, 8010, Austria
| | - Julian Rosalie
- Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben, 8700, Austria
| | - Lei Li
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory of Green Preparation and Application for Functional Materials, Hubei Key Lab of Ferro & Piezoelectric Materials and Devices, School of Materials Science and Engineering, Hubei University, Wuhan, 430062, China
| | - María Jazmin Duarte
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf, 40237, Germany
| | - Gerald Kothleitner
- Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, Graz, 8010, Austria
| | - Gerhard Dehm
- Max-Planck Institut für Eisenforschung GmbH, Max-Planck-Straße 1, Düsseldorf, 40237, Germany
| | - Yunbin He
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory of Green Preparation and Application for Functional Materials, Hubei Key Lab of Ferro & Piezoelectric Materials and Devices, School of Materials Science and Engineering, Hubei University, Wuhan, 430062, China.
| | - Reinhard Pippan
- Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben, 8700, Austria
| | - Zaoli Zhang
- Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben, 8700, Austria.
- Department of Materials Physics, Montanuniversität Leoben, 8700, Leoben, Austria.
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27
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Feng Y, Liao WB, Zheng J, Wang LW, Zhang Y, Sun J, Pan F. Nanocrystals generated under tensile stress in metallic glasses with phase selectivity. NANOSCALE 2017; 9:15542-15549. [PMID: 28984322 DOI: 10.1039/c7nr04466f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Revealing the mechanism of phase selectivity can provide guidance for controlling crystals with certain phases for special properties. In the present work, nanocrystals of about 2-4 nm diameters with a B2 structure (thermodynamic metastable phase) are generated from CuZr glassy fiber by applying tensile stress at ambient temperature. By combining the ab initio calculations with the molecular dynamics simulations, the stabilities of B2 austenite and B19' martensitic phases under applied tensile stress are compared, and the phase transformation mechanism is revealed. The results show that the B2 structure has a bigger attractive basin, and the phase transition could occur with a larger applied stress during the deformation. Therefore, insights into the higher symmetric B2 nanocrystal with selective nucleation driven under directional stress are provided.
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Affiliation(s)
- Yancong Feng
- School of Advanced Materials, Peking University, Shenzhen Graduate School, Shenzhen 518055, China.
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28
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Boulbitch A, Gufan YM, Korzhenevskii AL. Crack-tip process zone as a bifurcation problem. Phys Rev E 2017; 96:013005. [PMID: 29347102 DOI: 10.1103/physreve.96.013005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Indexed: 06/07/2023]
Abstract
Stress concentration at a crack tip generates a solid structural transformation in its vicinity, the process zone. We argue that its formation represents a local phase transition described by a multicomponent order parameter. We derive a system of equations describing the dynamics of the order parameter driven by an inhomogeneous, time-dependent stress field in the solid and show that it exhibits a bifurcation. The latter corresponds to the emergence of a process zone characterized by the distribution of the order parameter localized in the vicinity of the crack tip. The emergence temperature T_{*} considerably differs from the temperature of the bulk phase transformation T_{c}. We demonstrate that T_{*} exhibits a universal behavior T_{*}-T_{c}∼K_{I}^{4/3}, in terms of the stress intensity factor K_{I}, and that the zone universally vanishes upon achieving a critical velocity. These facts together give rise to a universal dynamic phase diagram.
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Affiliation(s)
- Alexei Boulbitch
- IEE S.A. ZAE Weiergewan, 11, rue Edmond Reuter, L-5326 Contern, Luxembourg
| | - Yury M Gufan
- Institute for Physics, Stachki 194,344090 Rostov-on-Don, Russia
| | - Alexander L Korzhenevskii
- Institute for Problems of Mechanical Engineering, RAS, Bol'shoi prosp. V. O. 61, 199178 St. Petersburg, Russia
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29
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Boulbitch A, Korzhenevskii AL. Crack velocity jumps engendered by a transformational process zone. Phys Rev E 2016; 93:063001. [PMID: 27415348 DOI: 10.1103/physreve.93.063001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Indexed: 11/07/2022]
Abstract
We study a concerted propagation of a fast crack with the process zone where a rearrangement of the solid structure takes place. The latter is treated as a second-order local phase transformation. We demonstrate that the propagation of such a zone gives rise to a nonlinear frictionlike force exerted on the crack tip, resisting its propagation. Depending on the temperature, it produces three regimes of crack motion, which differ in the behavior of the crack tip process zone: (i) always existing, (ii) only emerging at a high crack speed, and (iii) flickering. We show that the latter regime exhibits crack velocity jumps.
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Affiliation(s)
- A Boulbitch
- IEE S.A. ZAE Weiergewan, 11, rue Edmond Reuter, L-5326 Contern, Luxembourg
| | - A L Korzhenevskii
- Institute for Problems of Mechanical Engineering, RAS, Bol'shoi prosp. V. O. 61, 199178 St. Petersburg, Russia
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30
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Rolling-induced Face Centered Cubic Titanium in Hexagonal Close Packed Titanium at Room Temperature. Sci Rep 2016; 6:24370. [PMID: 27067515 PMCID: PMC4828854 DOI: 10.1038/srep24370] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 03/23/2016] [Indexed: 12/03/2022] Open
Abstract
Combining transmission electron microscopes and density functional theory calculations, we report the nucleation and growth mechanisms of room temperature rolling induced face-centered cubic titanium (fcc-Ti) in polycrystalline hexagonal close packed titanium (hcp-Ti). Fcc-Ti and hcp-Ti take the orientation relation: 〈0001〉hcp||〈001〉fcc and , different from the conventional one. The nucleation of fcc-Ti is accomplished via pure-shuffle mechanism with a minimum stable thickness of three atomic layers, and the growth via shear-shuffle mechanisms through gliding two-layer disconnections or pure-shuffle mechanisms through gliding four-layer disconnections. Such phase transformation offers an additional plastic deformation mode comparable to twinning.
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31
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Lu N, Du K, Lu L, Ye HQ. Transition of dislocation nucleation induced by local stress concentration in nanotwinned copper. Nat Commun 2015; 6:7648. [PMID: 26179409 PMCID: PMC4518316 DOI: 10.1038/ncomms8648] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 05/27/2015] [Indexed: 11/10/2022] Open
Abstract
Metals with a high density of nanometre-scale twins have demonstrated simultaneous high strength and good ductility, attributed to the interaction between lattice dislocations and twin boundaries. Maximum strength was observed at a critical twin lamella spacing (∼15 nm) by mechanical testing; hence, an explanation of how twin lamella spacing influences dislocation behaviours is desired. Here, we report a transition of dislocation nucleation from steps on the twin boundaries to twin boundary/grain boundary junctions at a critical twin lamella spacing (12–37 nm), observed with in situ transmission electron microscopy. The local stress concentrations vary significantly with twin lamella spacing, thus resulting in a critical twin lamella spacing (∼18 nm) for the transition of dislocation nucleation. This agrees quantitatively with the mechanical test. These results demonstrate that by quantitatively analysing local stress concentrations, a direct relationship can be resolved between the microscopic dislocation activities and macroscopic mechanical properties of nanotwinned metals. Metallic materials with a nanometre-scaled lamella structure can have properties that are very different from their coarser-grained counterparts. Here, the authors demonstrate how dislocations in such a material—nanotwinned copper—can nucleate in two distinctly different mechanisms depending on local stress
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Affiliation(s)
- N Lu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - K Du
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - L Lu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - H Q Ye
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
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32
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Ke X, Bittencourt C, Van Tendeloo G. Possibilities and limitations of advanced transmission electron microscopy for carbon-based nanomaterials. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2015; 6:1541-57. [PMID: 26425406 PMCID: PMC4578338 DOI: 10.3762/bjnano.6.158] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 06/25/2015] [Indexed: 05/28/2023]
Abstract
A major revolution for electron microscopy in the past decade is the introduction of aberration correction, which enables one to increase both the spatial resolution and the energy resolution to the optical limit. Aberration correction has contributed significantly to the imaging at low operating voltages. This is crucial for carbon-based nanomaterials which are sensitive to electron irradiation. The research of carbon nanomaterials and nanohybrids, in particular the fundamental understanding of defects and interfaces, can now be carried out in unprecedented detail by aberration-corrected transmission electron microscopy (AC-TEM). This review discusses new possibilities and limits of AC-TEM at low voltage, including the structural imaging at atomic resolution, in three dimensions and spectroscopic investigation of chemistry and bonding. In situ TEM of carbon-based nanomaterials is discussed and illustrated through recent reports with particular emphasis on the underlying physics of interactions between electrons and carbon atoms.
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Affiliation(s)
- Xiaoxing Ke
- EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
- Institute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124, China
| | - Carla Bittencourt
- Chemistry of Interaction Plasma Surface (ChiPS), University of Mons, Place du Parc 20, 7000 Mons, Belgium
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33
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Li N, Misra A, Shao S, Wang J. Experimental Quantification of Resolved Shear Stresses for Dislocation Motion in TiN. NANO LETTERS 2015; 15:4434-4439. [PMID: 26065576 DOI: 10.1021/acs.nanolett.5b00791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Experimental quantification of the critical resolved shear stress (CRSS) at the level of unit dislocation glide is still a challenge. By using in situ nanoindentation in a high-resolution transmission electron microscope and strain analysis of the acquired structural images, the CRSS for the motion of individual dislocations on {110}⟨011⟩ slip system and glide dislocation re-emission from a tilt grain boundary in TiN are quantified. This work offers an approach to measure the local stresses associated with dislocation motion in high-strength materials.
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Affiliation(s)
| | - A Misra
- §Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
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34
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Lin KH, Liao BY, Ju SP, Lin JS, Hsieh JY. Mechanical properties and thermal stability of ultrathin molybdenum nanowires. RSC Adv 2015. [DOI: 10.1039/c5ra01359c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The most stable structures of three ultrathin molybdenum (Mo) nanowires were predicted by the simulated annealing basin-hopping method (SABH) with the penalty algorithm.
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Affiliation(s)
- Ken-Huang Lin
- Department of Mechanical and Electro-Mechanical Engineering
- Center for Nanoscience and Nanotechnology
- National Sun Yat-sen University
- Kaohsiung 80424
- Taiwan
| | - Bo-Yuan Liao
- Department of Mechanical and Electro-Mechanical Engineering
- Center for Nanoscience and Nanotechnology
- National Sun Yat-sen University
- Kaohsiung 80424
- Taiwan
| | - Shin-Pon Ju
- Department of Mechanical and Electro-Mechanical Engineering
- Center for Nanoscience and Nanotechnology
- National Sun Yat-sen University
- Kaohsiung 80424
- Taiwan
| | - Jenn-Sen Lin
- Department of Mechanical Engineering
- National United University
- Miaoli 36003
- Taiwan
| | - Jin-Yuan Hsieh
- Department of Mechanical Engineering
- Minghsin University of Science and Technology
- Hsinchu 30401
- Taiwan
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35
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Abstract
Cu-deficient CZTS (copper zinc tin sulfide) thin films were grown on soda lime as well as molybdenum coated soda lime glass by reactive cosputtering. Polycrystalline CZTS film with kesterite structure was produced by annealing it at 500°C in Ar atmosphere. These films were characterized for compositional, structural, surface morphological, optical, and transport properties using energy dispersive X-ray analysis, glancing incidence X-ray diffraction, Raman spectroscopy, scanning electron microscopy, atomic force microscopy, UV-Vis spectroscopy, and Hall effect measurement. A CZTS solar cell device having conversion efficiency of ~0.11% has been made by depositing CdS, ZnO, ITO, and Al layers over the CZTS thin film deposited on Mo coated soda lime glass. The series resistance of the device was very high. The interfacial properties of device were characterized by cross-sectional SEM and cross-sectional HRTEM.
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