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Yang C, Xu T, Zhao H, Hu C, Dong H. Regulation Law of Tempering Cooling Rate on Toughness of Medium-Carbon Medium-Alloy Steel. MATERIALS (BASEL, SWITZERLAND) 2023; 17:205. [PMID: 38204058 PMCID: PMC10779875 DOI: 10.3390/ma17010205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/25/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024]
Abstract
Temper embrittlement is a major challenge encountered during the heat treatment of high-performance steels for large forgings. This study investigates the microstructural evolution and mechanical properties of Cr-Ni-Mo-V thick-walled steel, designed for large forgings with a tensile strength of 1500 MPa, under different tempering cooling rates. Optical microscopy (OM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD) were employed to analyze the microstructural features. The results demonstrate that the embrittlement occurring during air cooling after tempering is attributed to the concentration of impurities near Fe3C at the grain boundaries. The low-temperature impact toughness at -40 °C after water quenching reaches 29 J due to the accelerated cooling rate during tempering, which slows down the diffusion of impurity elements towards the grain boundaries, resulting in a reduced concentration and dislocation density and an increased stability of the grain boundaries, thereby enhancing toughness. The bainite content decreases and the interface between martensite and bainite undergoes changes after water quenching during tempering. These alterations influence the crack propagation direction within the two-phase microstructure, further modifying the toughness. These findings contribute to the understanding of temper embrittlement and provide valuable guidance for optimizing heat treatment processes to enhance the performance of high-performance steels in large forgings.
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Affiliation(s)
- Chao Yang
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China; (C.Y.); (H.Z.); (H.D.)
| | - Tingting Xu
- Zhongyuan Special Steel Co., Ltd., Jiyuan 459000, China;
| | - Hongshan Zhao
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China; (C.Y.); (H.Z.); (H.D.)
- Zhejiang Institute of Advanced Materials, Shanghai University, Jiaxing 314100, China
| | - Chundong Hu
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China; (C.Y.); (H.Z.); (H.D.)
- Zhejiang Institute of Advanced Materials, Shanghai University, Jiaxing 314100, China
| | - Han Dong
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China; (C.Y.); (H.Z.); (H.D.)
- Zhejiang Institute of Advanced Materials, Shanghai University, Jiaxing 314100, China
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2
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Effect of Intercritical Annealing Time on Microstructure Evolution and Mechanical Properties of Low Carbon Medium Manganese Steel Subjected to Multi-Step Heat Treatment Process. MATERIALS 2022; 15:ma15072425. [PMID: 35407766 PMCID: PMC8999702 DOI: 10.3390/ma15072425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 03/16/2022] [Accepted: 03/18/2022] [Indexed: 11/17/2022]
Abstract
A novel multi-step heat treatment process was performed for 0.2C–5Mn steel, and the effect of intercritical annealing (IA) durations on the microstructure evolution and mechanical properties was studied. The results showed that the content of primary reversed austenite (PRA) hardly changed as the IA time increased from 6 h to 50 h, but only less than 10% of PRA remained after being tempered at 200 °C due to the appearance of secondary martensite (SM). The final microstructure contained SM, the primary martensite (PM), and RA, which was protected by the SM so that the transformation-induced plasticity (TRIP) effect was unlikely to occur. Meanwhile, the (Ti, V, Mo)C particle sizes were 14.27, 14.68 and 15.65 nm for the intermediate processes of IA-6 h, IA-12 h, and IA-50 h, respectively. As the IA time increased from 6 h to 50 h, both the dislocation and precipitation strengthening increment decreased. As a result, the best mechanical properties were obtained from the intermediate process of IA-12 h, with a yield strength of 1115.5 MPa, tensile strength of 1573.5 MPa, and −20 °C impact energy of 30.4 J.
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Strengthening Effect of Nb on Ferrite Grain Boundary in X70 Pipeline Steel. MATERIALS 2020; 14:ma14010061. [PMID: 33375580 PMCID: PMC7796326 DOI: 10.3390/ma14010061] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 12/17/2020] [Accepted: 12/22/2020] [Indexed: 11/25/2022]
Abstract
Understanding the strengthening effect of niobium on ferrite grain boundaries from the perspective of valence electron structures will help to use niobium and other microalloying elements more effectively to improve the performance of steel materials. In this paper, the effect of niobium element on ferrite grain boundary strengthening is studied based on microstructure analysis at the nanometer scale. The enrichment of niobium in pipeline steel at ferrite boundary was observed by a three-dimensional atomic probe test. Segregation of Nb is observed in the ferrite grain boundaries of X70 steel, and its maximum concentration is 0.294–0.466 at.%. The charges in the occupancy of the Fe 3d state in grain and grain boundary were 7.23 and 7.37, respectively, based on quantitative analysis of electron energy loss spectra (EELS). The first-principle calculation suggests that the charges in the occupancy of 3d state for grain boundary iron are 6.57 and 6.68, respectively, before and after the Nb doping (with an increase of 1.67%), which reveals a similar trend to that of the EELS results. Through Nb alloying, the 3d valence electronic density of the state of Fe in grain boundary moves to a lower energy, which can reduce the total energy of the system and make the grain boundary more stable. Meanwhile, the charges in the occupancy of the 3d state for Fe in the grain boundary increases, providing more electrons for grain boundary bonding. These improve the strength and toughness of the material. This work provides a fundamental understanding for pipeline steel strengthening by element alloying.
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Darvishi Kamachali R. A model for grain boundary thermodynamics. RSC Adv 2020; 10:26728-26741. [PMID: 35515770 PMCID: PMC9055388 DOI: 10.1039/d0ra04682e] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 06/29/2020] [Indexed: 11/21/2022] Open
Abstract
Systematic microstructure design requires reliable thermodynamic descriptions of each and all microstructure elements. While such descriptions are well established for most bulk phases, thermodynamic assessment of microstructure defects is challenging because of their individualistic nature. In this paper, a model is devised for assessing grain boundary thermodynamics based on available bulk thermodynamic data. We propose a continuous relative atomic density field and its spatial gradients to describe the grain boundary region with reference to the homogeneous bulk and derive the grain boundary Gibbs free energy functional. The grain boundary segregation isotherm and phase diagram are computed for a regular binary solid solution, and qualitatively benchmarked for the Pt-Au system. The relationships between the grain boundary's atomic density, excess free volume, and misorientation angle are discussed. Combining the current density-based model with available bulk thermodynamic databases enables constructing databases, phase diagrams, and segregation isotherms for grain boundaries, opening possibilities for studying and designing heterogeneous microstructures.
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Affiliation(s)
- Reza Darvishi Kamachali
- Federal Institute for Materials Research and Testing (BAM) Unter den Eichen 87 12205 Berlin Germany .,Max-Planck-Institut für Eisenforschung Max-Planck-Str. 1 40237 Düsseldorf Germany
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Heckman NM, Foiles SM, O'Brien CJ, Chandross M, Barr CM, Argibay N, Hattar K, Lu P, Adams DP, Boyce BL. New nanoscale toughening mechanisms mitigate embrittlement in binary nanocrystalline alloys. NANOSCALE 2018; 10:21231-21243. [PMID: 30417913 DOI: 10.1039/c8nr06419a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Nanocrystalline metals offer significant improvements in structural performance over conventional alloys. However, their performance is limited by grain boundary instability and limited ductility. Solute segregation has been proposed as a stabilization mechanism, however the solute atoms can embrittle grain boundaries and further degrade the toughness. In the present study, we confirm the embrittling effect of solute segregation in Pt-Au alloys. However, more importantly, we show that inhomogeneous chemical segregation to the grain boundary can lead to a new toughening mechanism termed compositional crack arrest. Energy dissipation is facilitated by the formation of nanocrack networks formed when cracks arrested at regions of the grain boundaries that were starved in the embrittling element. This mechanism, in concert with triple junction crack arrest, provides pathways to optimize both thermal stability and energy dissipation. A combination of in situ tensile deformation experiments and molecular dynamics simulations elucidate both the embrittling and toughening processes that can occur as a function of solute content.
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Affiliation(s)
- Nathan M Heckman
- Materials Science and Engineering Center, Sandia National Laboratories, Albuquerque, NM 87185, USA.
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Friák M, Zelený M, Všianská M, Holec D, Šob M. An Ab Initio Study of Connections between Tensorial Elastic Properties and Chemical Bonds in Σ5(210) Grain Boundaries in Ni₃Si. MATERIALS 2018; 11:ma11112263. [PMID: 30428570 PMCID: PMC6265990 DOI: 10.3390/ma11112263] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 11/03/2018] [Accepted: 11/05/2018] [Indexed: 11/16/2022]
Abstract
Using quantum-mechanical methods we calculate and analyze (tensorial) anisotropic elastic properties of the ground-state configurations of interface states associated with Σ 5(210) grain boundaries (GBs) in cubic L1 2 -structure Ni 3 Si. We assess the mechanical stability of interface states with two different chemical compositions at the studied GB by checking rigorous elasticity-based Born stability criteria. In particular, we show that a GB variant containing both Ni and Si atoms at the interface is unstable with respect to shear deformation (one of the elastic constants, C 55 , is negative). This instability is found for a rectangular-parallelepiped supercell obtained when applying standard coincidence-lattice construction. Our elastic-constant analysis allowed us to identify a shear-deformation mode reducing the energy and, eventually, to obtain mechanically stable ground-state characterized by a shear-deformed parallelepiped supercell. Alternatively, we tested a stabilization of this GB interface state by Al substituents replacing Si atoms at the GB. We further discuss an atomistic origin of this instability in terms of the crystal orbital Hamilton population (COHP) and phonon dispersion calculations. We find that the unstable GB variant shows a very strong interaction between the Si atoms in the GB plane and Ni atoms in the 3rd plane off the GB interface. However, such bond reinforcement results in weakening of interaction between the Ni atoms in the 3rd plane and the Si atoms in the 5th plane making this GB variant mechanically unstable.
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Affiliation(s)
- Martin Friák
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
| | - Martin Zelený
- Institute of Materials Science and Engineering, NETME Centre, Faculty of Mechanical Engineering, Brno University of Technology, Technická 2896/2, CZ-616 69 Brno, Czech Republic.
- Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, CZ-121 16 Prague, Czech Republic.
| | - Monika Všianská
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
- Central European Institute of Technology, CEITEC MU, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
- Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic.
| | - David Holec
- Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Franz-Josef-Strasse 18, A-8700 Leoben, Austria.
| | - Mojmír Šob
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
- Central European Institute of Technology, CEITEC MU, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
- Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic.
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Morvan T, Ganster P, Barnier V, Wolski K. Surface and grain boundary segregation in 16MND5 steel. SURF INTERFACE ANAL 2017. [DOI: 10.1002/sia.6206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Tanguy Morvan
- Mines Saint-Etienne Centre SMS; Laboratoire Georges Friedel, CNRS UMR5307; 158 cours Fauriel Saint-Etienne 42023 France
| | - Patrick Ganster
- Mines Saint-Etienne Centre SMS; Laboratoire Georges Friedel, CNRS UMR5307; 158 cours Fauriel Saint-Etienne 42023 France
| | - Vincent Barnier
- Mines Saint-Etienne Centre SMS; Laboratoire Georges Friedel, CNRS UMR5307; 158 cours Fauriel Saint-Etienne 42023 France
| | - Krzysztof Wolski
- Mines Saint-Etienne Centre SMS; Laboratoire Georges Friedel, CNRS UMR5307; 158 cours Fauriel Saint-Etienne 42023 France
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Bhattacharya SK, Kohyama M, Tanaka S, Shiihara Y. Si segregation at Fe grain boundaries analyzed by ab initio local energy and local stress. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:355005. [PMID: 25077891 DOI: 10.1088/0953-8984/26/35/355005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Using density-functional theory calculations combined with recent local-energy and local-stress schemes, we studied the effects of Si segregation on the structural, mechanical and magnetic properties of the Σ3(1 1 1) and Σ11(3 3 2) Fe GBs formed by rotation around the [1 1 0] axis. The segregation mechanism was analyzed by the local-energy decomposition of the segregation energy, where the segregation energy is expressed as a sum of the following four terms: the local-energy change of Si atoms from the isolated state in bulk Fe to the GB segregated state, the stabilization of replaced Fe atoms from the GB to the bulk, the local-energy change of neighboring Fe atoms from the pure GB to the segregated GB and the local-energy change of neighboring Fe atoms from the system of an isolated Si atom in the bulk Fe to the pure bulk Fe. The segregation energy and value of each term greatly depends on the segregation site and Si concentration. The segregation at interface Fe sites with higher local energies in the original GB configurations naturally leads to higher segregation-energy gains, while interface sites with lower local energies can lead to larger energy gains if stronger Si-Fe interactions occur locally in the final segregated configurations. The high Si concentration reduces the segregation-energy gain per Si atom due to the local-energy increases of Si atoms neighboring to each other or through the reduction in the number of stabilized Fe atoms per Si atom as observed in a Si dimer in bulk Fe. In the Si-segregated GBs, Si-Fe bonds enhance local Young's moduli and tend to suppress the interface weakening, while the GB adhesion is slightly reduced. And Fe atoms contacting Si atoms have reduced magnetic moments, due to Si-Fe sp-d hybridization interactions.
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Affiliation(s)
- Somesh Kr Bhattacharya
- Research Institute for Ubiquitous Energy Devices, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 536-8577, Japan
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Hatcher N, Madsen GKH, Drautz R. Parameterized electronic description of carbon cohesion in iron grain boundaries. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:145502. [PMID: 24651649 DOI: 10.1088/0953-8984/26/14/145502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We employ a recently developed iron-carbon orthogonal tight-binding model in calculations of carbon in iron grain boundaries. We use the model to evaluate the properties of carbon near and on the Σ5 (3 1 0)[0 0 1] symmetric tilt grain boundary (GB) in iron, and calculations show that a carbon atom lowers the GB energy by 0.29 eV/atom in accordance with DFT. Carbon segregation to the GB is analyzed, and we find an energy barrier of 0.92 eV for carbon to segregate to the carbon-free interface while segregation to a fully filled interface is disfavored. Local volume (via Voronoi tessellation), magnetic, and electronic effects are correlated with atomic energy changes, and we isolate two different mechanisms governing carbon's behavior in iron: a volumetric strain which increases the energy of carbon in interstitial α iron and a non-strained local bonding which stabilizes carbon at the GB.
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Hemesath ER, Schreiber DK, Gulsoy EB, Kisielowski CF, Petford-Long AK, Voorhees PW, Lauhon LJ. Catalyst incorporation at defects during nanowire growth. NANO LETTERS 2012; 12:167-71. [PMID: 22111988 DOI: 10.1021/nl203259f] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Scanning and transmission electron microscopy was used to correlate the structure of planar defects with the prevalence of Au catalyst atom incorporation in Si nanowires. Site-specific high-resolution imaging along orthogonal zone axes, enabled by advances in focused ion beam cross sectioning, reveals substantial incorporation of catalyst atoms at grain boundaries in <110> oriented nanowires. In contrast, (111) stacking faults that generate new polytypes in <112> oriented nanowires do not show preferential catalyst incorporation. Tomographic reconstruction of the catalyst-nanowire interface is used to suggest criteria for the stability of planar defects that trap impurity atoms in catalyst-mediated nanowires.
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Affiliation(s)
- Eric R Hemesath
- Department of Materials Science and Engineering, Northwestern University, 1881 Sheridan Road, Evanston, Illinois 60208, USA
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Abstract
The GB embrittlement mechanism of Fe enhanced by P segregation has been investigated by first-principles tensile tests because a P atom is a famous GB embrittler in Fe. The first-principles tensile tests have been performed on Fe with two P-segregated GBs, where P atoms are located at the different sites, and with a nonsegregated GB. The tensile strength and the strain to failure in the P-segregated GBs were lower than those in the nonsegegated GB. The first bond breaking occurred at the Fe-P bond owing to the covalent-like characteristics, although the charge densities were high at the Fe-P bonds even just before the bond breaking. This premature bond breaking of Fe-P was independent of the location of the P atom.
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Abstract
ABSTRACTThis paper provides a comprehensive review of current efforts on design of ductile polycrystalline Ni3 AI alloys. Microalloying has proven to be very effective in alleviating the grain-boundary emibrittlement problem. The ductility and fabricability of Ni3 Al (24 at. % Al) are dramatically improved by adding a few hundred parts per million of boron. The beneficial effect of boron is related to its unusual segregation behavior as predicted from the theory of grain-boundary cohesion developed by Rice, based on thermodynamic analyses. Alloy stoichiometry strongly influences grain-boundary chemistry, which, in turn, affects the boundary cohesion and overall ductility of Ni3 Al.The solid-solution hardening of Ni3 AI depends on the substitutional behavior of alloying elements, atomic size misfit, and the degree of nonstoichiometry of the alloy. Hafnium additions are very effective in improving high-temperature properties of ternary Ni3Al (Al + Hf = 24 at. %) doped with boron. Alloying with <2% Hf substantially increases the yield stress and raises the peak-strength temperature. In addition, hafnium substantially improves creep properties and oxidation resistance. The Ni3 Al aluminides truly represent a new series of heat resistant materials which do not depend on chromium for oxidation resistance.
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Abstract
ABSTRACTA review of rapid solidification studies of high temperature ordered intermetallic compounds is presented. Emphasis is on the nickel - and iron - aluminides which are of potential interest as structural materials. The nickel-base aluminides which have been rapidly solidified exhibit changes in grain size, compositional segregation, and degree of long range order (as reflected in APB size and distribution) which markedly affect mechanical properties. Some experiments indicate the formation of a metastable L12 phase in rapidly solidified Fe-(Ni, Mn)-Al-C alloys, while other work observes only a metastable fcc phase in the same composition range. The metastable phases and/or microstructures in both nickel and iron aluminides are destroyed by annealing at temperatures >750K, with subsequent degradation of mechanical properties. Rapid solidification studies of several other intermetallic compounds are briefly noted.
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Abstract
ABSTRACTThis paper will provide an overview of the current status of the development of ordered alloys for high temperature structural applications. The physical and mechanical properties of ordered alloys will be reviewed with particular emphasis on aluminides and (FeNiCo)3V alloys. Alloy theory, slip systems, yielding, strain hardening, fatigue, wear resistance and processing are among the subjects to be covered. Current research programs in the U.S. and abroad will be outlined, and the kinds of scientific and application-oriented research needed in the future will be discussed.
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Yuasa M, Mabuchi M. Effects of segregated Cu on an Fe grain boundary by first-principles tensile tests. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:505705. [PMID: 21406808 DOI: 10.1088/0953-8984/22/50/505705] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Cu is known as one of the harmful tramp elements in recycled Fe. In the present work, the effects of Cu on Fe grain boundary (GB) embrittlement have been investigated by first-principles tensile tests. Because the Fe-Cu bonds are rather isotropic and the effects due to their difference in atomic size are negligibly small, the GB atomic structure prior to straining is little changed by Cu segregation. However, the Fe-Fe bond around the Cu atom is weakened due to charge transfer from the Fe atom to the Cu atom, and premature bond breaking occurs at the weakened Fe-Fe bond, resulting in an enhancement of GB embrittlement by Cu segregation. The s and p electrons play a vital role in the charge transfer.
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Affiliation(s)
- Motohiro Yuasa
- Department of Energy Science and Technology, Graduate School of Energy Science, Kyoto University, Sakyo-ku, Kyoto, Japan.
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Abstract
Many ordered intermetallic alloys have attractive high-temperature properties; however, low ductility and brittle fracture limit their use for structural applications. The embrittlement in these alloys is mainly caused by an insufficient number of slip systems (bulk brittleness) and poor grain-boundary cohesion. Recent studies have shown that the ductility and fabricability of ordered intermetallics can be substantially improved by alloying processes and control of microstructural features through rapid solidification and thermomechanical treatments. These results demonstrate that the brittleness problem associated with ordered intermetallics can be overcome by using physical metallurgical principles. Application of these principles will be illustrated by results on Ni(3)Al and Ni(3)V-Co(3)V-Fe(3)V. The potential for developing these alloys as a new class of high-temperature structural materials is discussed.
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Chen HP, Kalia RK, Kaxiras E, Lu G, Nakano A, Nomura KI, van Duin ACT, Vashishta P, Yuan Z. Embrittlement of metal by solute segregation-induced amorphization. PHYSICAL REVIEW LETTERS 2010; 104:155502. [PMID: 20481998 DOI: 10.1103/physrevlett.104.155502] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Indexed: 05/29/2023]
Abstract
Impurities segregated to grain boundaries of a material essentially alter its fracture behavior. A prime example is sulfur segregation-induced embrittlement of nickel, where an observed relation between sulfur-induced amorphization of grain boundaries and embrittlement remains unexplained. Here, 48x10(6)-atom reactive-force-field molecular dynamics simulations provide the missing link. Namely, an order-of-magnitude reduction of grain-boundary shear strength due to amorphization, combined with tensile-strength reduction, allows the crack tip to always find an easy propagation path.
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Affiliation(s)
- Hsiu-Pin Chen
- Collaboratory for Advanced Computing and Simulations, Department of Physics & Astronomy, University of Southern California, Los Angeles, California 90089-0242, USA
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Lemarchand D, Cadel E, Chambreland S, Blavette D. Investigation of grain-boundary structure-segregation relationship in an N18 nickel-based superalloy. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/01418610208235682] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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20
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The Segregation of Bi and S from a Cu(Bi,S) Ternary System. E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY 2009. [DOI: 10.1380/ejssnt.2009.480] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Yamaguchi M, Shiga M, Kaburaki H. Grain Boundary Decohesion by Impurity Segregation in a Nickel-Sulfur System. Science 2005; 307:393-7. [PMID: 15637235 DOI: 10.1126/science.1104624] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The sulfur-induced embrittlement of nickel has long been wrapped in mystery as to why and how sulfur weakens the grain boundaries of nickel and why a critical intergranular sulfur concentration is required. From first-principles calculations, we found that a large grain-boundary expansion is caused by a short-range overlap repulsion among densely segregated and neighboring sulfur atoms. This expansion results in a drastic grain-boundary decohesion that reduces the grain-boundary tensile strength by one order of magnitude. This decohesion may directly cause the embrittlement, because the critical sulfur concentration of this decohesion agrees well with experimental data on the embrittlement.
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Affiliation(s)
- Masatake Yamaguchi
- Center for Promotion of Computational Science and Engineering, Japan Atomic Energy Research Institute, Tokai-mura, Ibaraki 319-1195, Japan.
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Possible role of oxygen impurities in degradation of nc-TiN∕a-Si[sub 3]N[sub 4] nanocomposites. ACTA ACUST UNITED AC 2005. [DOI: 10.1116/1.2131086] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Schweinfest R, Paxton AT, Finnis MW. Bismuth embrittlement of copper is an atomic size effect. Nature 2004; 432:1008-11. [PMID: 15616557 DOI: 10.1038/nature03198] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2004] [Accepted: 11/05/2004] [Indexed: 11/09/2022]
Abstract
Embrittlement by the segregation of impurity elements to grain boundaries is one of a small number of phenomena that can lead to metallurgical failure by fast fracture. Here we settle a question that has been debated for over a hundred years: how can minute traces of bismuth in copper cause this ductile metal to fail in a brittle manner? Three hypotheses for Bi embrittlement of Cu exist: two assign an electronic effect to either a strengthening or weakening of bonds, the third postulates a simple atomic size effect. Here we report first principles quantum mechanical calculations that allow us to reject the electronic hypotheses, while supporting a size effect. We show that upon segregation to the grain boundary, the large Bi atoms weaken the interatomic bonding by pushing apart the Cu atoms at the interface. The resolution of the mechanism underlying grain boundary weakening should be relevant for all cases of embrittlement by oversize impurities.
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Affiliation(s)
- Rainer Schweinfest
- Atomistic Simulation Centre, Department of Physics and Astronomy, Queen's University Belfast, Belfast BT7 1NN, UK
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Duscher G, Chisholm MF, Alber U, Rühle M. Bismuth-induced embrittlement of copper grain boundaries. NATURE MATERIALS 2004; 3:621-626. [PMID: 15322533 DOI: 10.1038/nmat1191] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2004] [Accepted: 06/08/2004] [Indexed: 05/24/2023]
Abstract
Catastrophic brittle fracture of crystalline materials is one of the best documented but most poorly understood fundamental phenomena in materials science. Embrittlement of copper by bismuth is a classic example of this phenomenon. Because brittle fracture in any structural material can involve human tragedy, a better understanding of the mechanisms behind it is of the highest interest. In this study, we use a combination of two state-of-the-art atomic characterization techniques and ab initio theoretical materials simulations to investigate the geometric and electronic structure of a copper grain boundary with and without bismuth. Only with this unique combination of methods are we able to observe the actual distribution of bismuth in the boundary and detect changes in the electronic structure caused by the bismuth impurity. We find that the copper atoms that surround the segregated bismuth in the grain boundary become embrittled by taking on a more zinc-like electronic structure.
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Affiliation(s)
- Gerd Duscher
- Oak Ridge National Laboratory, Condensed Matter Sciences Division, Oak Ridge, Tennessee 37831-6030, USA
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Kioussis N, Herbranson M, Collins E, Eberhart ME. Topology of electronic charge density and energetics of planar faults in fcc metals. PHYSICAL REVIEW LETTERS 2002; 88:125501. [PMID: 11909471 DOI: 10.1103/physrevlett.88.125501] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2001] [Indexed: 05/23/2023]
Abstract
Using ab initio calculations we have studied the energetics and the evolution of the electronic charge density with shear in three fcc metals exhibiting different deformation properties, aluminum, silver, and iridium. The charge redistribution described by the change in character of specific charge density critical points (cps), is ascertained from the values of the charge density, rho(0), and its three principal curvatures, rho( parallel parallel), rho(hh), and rho(vv), respectively. The change in character of cps correlates with the energetics. For all three metals, rho(hh) vanishes near the unstable stacking configuration. The symmetry or asymmetry of the charge redistribution, measured by rho(hh)/rho(vv), may be an important factor determining stacking fault energies.
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Affiliation(s)
- Nicholas Kioussis
- Department of Physics, California State University Northridge, Northridge, California 91330-8268, USA
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Kameda J, Nishiyama Y, Bloomer TE. Non-equilibrium intergranular segregation and embrittlement in neutron-irradiated ferritic alloys. SURF INTERFACE ANAL 2001. [DOI: 10.1002/sia.1080] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Smialek JL. Advances in the oxidation resistance of high-temperature turbine materials. SURF INTERFACE ANAL 2001. [DOI: 10.1002/sia.1085] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Alber U, Müllejans H, Rühle M. Improved quantification of grain boundary segregation by EDS in a dedicated STEM. Ultramicroscopy 1997. [DOI: 10.1016/s0304-3991(97)00036-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Sun SN, Kioussis N, Ciftan M. First-principles determination of the effects of boron and sulfur on the ideal cleavage fracture in Ni3Al. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:3074-3078. [PMID: 9986204 DOI: 10.1103/physrevb.54.3074] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Wu R, Freeman AJ, Olson GB. Effects of carbon on Fe-grain-boundary cohesion: First-principles determination. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:7504-7509. [PMID: 9982202 DOI: 10.1103/physrevb.53.7504] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Ito O, Tamaki H. Molecular orbital approach to the chemical bonding at grain boundary in γ′-Ni3Al. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0956-7151(94)00472-t] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Huang YM, Spence JCH, Sankey OF. The effect of impurities on the ideal tensile strength of silicon. ACTA ACUST UNITED AC 1994. [DOI: 10.1080/01418619408242537] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Tang S, Freeman AJ, Olson GB. Local-density studies of the structure and electronic properties of B and S in an Fe grain boundary. PHYSICAL REVIEW. B, CONDENSED MATTER 1994; 50:1-4. [PMID: 9974507 DOI: 10.1103/physrevb.50.1] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Hong T, Smith JR, Srolovitz DJ. Impurity effects on adhesion: Nb, C, O, B, and S at a Mo/MoSi2 interface. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 47:13615-13625. [PMID: 10005675 DOI: 10.1103/physrevb.47.13615] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Lappalainen R, Pannikkat A, Raj R. Superplastic flow in a non-stoichiometric ceramic: Magnesium aluminate spinel. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/0956-7151(93)90172-o] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Wu R, Freeman AJ, Olson GB. Effects of P and B adsorbates on the Fe(111) surface. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 47:6855-6858. [PMID: 10004678 DOI: 10.1103/physrevb.47.6855] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Lin H, Pope D. The influence of grain boundary geometry on intergranular crack propagation in Ni3Al. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/0956-7151(93)90085-7] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Hong T, Smith JR, Srolovitz DJ. Impurity effects on adhesion. PHYSICAL REVIEW LETTERS 1993; 70:615-618. [PMID: 10054159 DOI: 10.1103/physrevlett.70.615] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Tang S, Freeman AJ, Olson GB. Phosphorus-induced relaxation in an iron grain boundary: A cluster-model study. PHYSICAL REVIEW. B, CONDENSED MATTER 1993; 47:2441-2445. [PMID: 10006292 DOI: 10.1103/physrevb.47.2441] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Chongyu W, Bing W, Peng F, Keng L, Zhe G. Localized electronic structure of boron-impurity-vacancy complexes in Ni. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 46:2693-2698. [PMID: 10003955 DOI: 10.1103/physrevb.46.2693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Kung H, Rasmussen D, Sass S. Grain boundaries in Ni3Al—I. The local compositional order. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/0956-7151(92)90201-o] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Vitek V, Chen S. Modeling of grain boundary structures and properties in intermetallic compounds. ACTA ACUST UNITED AC 1991. [DOI: 10.1016/0956-716x(91)90393-f] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Takasugi T, Izumi O. Electronic effect on grain boundary properties of ordered intermetallics. ACTA ACUST UNITED AC 1991. [DOI: 10.1016/0956-716x(91)90394-g] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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50
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Kung H, Rasmussen D, Sass S. The local compositional order at grain boundaries in Ni3Al. ACTA ACUST UNITED AC 1991. [DOI: 10.1016/0956-716x(91)90400-u] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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