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Hot Deformation Behavior and Microstructure Evolution of 6063 Aluminum Alloy Modified by Rare Earth Y and Al-Ti-B Master Alloy. MATERIALS 2020; 13:ma13194244. [PMID: 32977667 PMCID: PMC7579208 DOI: 10.3390/ma13194244] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/20/2020] [Accepted: 09/21/2020] [Indexed: 11/24/2022]
Abstract
The hot deformation behaviors of the new 6063 aluminum alloy modified by rare earth Y and Al-Ti-B master alloy were studied through isothermal hot compression experiments on the Gleeble-3800 thermal simulator. By characterizing the flow curves, constitutive models, hot processing maps, and microstructures, we can see from the true stress–true strain curves that the flow stress decreases with the increase of deformation temperature and the decrease of strain rate. Through the calculation of the constitutive equation, we derived that the activation energy of the new composite modified 6063 aluminum alloy is 224.570 KJ/mol. we roughly obtained its excellent hot processing range of temperatures between 470–540 °C and the strain rates of 0.01–0.1 s−1. The verification of the deformed microstructure shows that with the decrease of lnZ, the grain boundary changes from a low-angle one to a high-angle one and the dynamic recrystallization is dominated by geometric dynamic recrystallization and continuous dynamic recrystallization. Analysis of typical samples at 480 °C/0.01 s−1 shows that the addition of rare earth Y mainly helps form Al3Y5 and AlFeSiY phases, thus making the alloy have the performance of high-temperature recrystallization, which is beneficial to the hot workability of the alloy.
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Manuel N, Galvão I, Leal RM, Costa JD, Loureiro A. Nugget Formation and Mechanical Behaviour of Friction Stir Welds of Three Dissimilar Aluminum Alloys. MATERIALS 2020; 13:ma13112664. [PMID: 32545259 PMCID: PMC7321648 DOI: 10.3390/ma13112664] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/06/2020] [Accepted: 06/09/2020] [Indexed: 11/16/2022]
Abstract
The aim of this research was to investigate the influence of the properties of the base materials and welding speed on the morphology and mechanical behavior of the friction stir welds of three dissimilar aluminum alloys in a T-joint configuration. The base materials were the AA2017-T4, AA5083-H111, and AA6082-T6 alloys in 3 mm-thick sheets. The AA6082-T6 alloy was the stringer, and the other alloys were located either on the advancing or retreating sides of the skin. All the T-joint welds were produced with a constant tool rotation speed but with different welding speeds. The microstructures of the welds were analyzed using optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, and the electron backscatter diffraction technique. The mechanical properties were assessed according to micro-hardness, tensile, and fatigue testing. Good quality welds of the three dissimilar aluminum alloys could be achieved with friction stir welding, but a high ratio between the tool's rotational and traverse speeds was required. The welding speed influenced the weld morphology and fatigue strength. The positioning of the skin materials influenced the nugget morphology and the mechanical behavior of the joints. The joints in which the AA2017 alloy was positioned on the advancing side presented the best tensile properties and fatigue strength.
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Affiliation(s)
- Neves Manuel
- CEMMPRE, Departamento de Engenharia Mecânica, Universidade de Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra, Portugal; (I.G.); (R.M.L.); (J.D.C.); (A.L.)
- Escola Superior Politécnica do Namibe, Rua Amílcar Cabral, Moçâmedes 201, Angola
- Correspondence: ; Tel.: +351-239-790-700
| | - Ivan Galvão
- CEMMPRE, Departamento de Engenharia Mecânica, Universidade de Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra, Portugal; (I.G.); (R.M.L.); (J.D.C.); (A.L.)
- ISEL, Departamento de Engenharia Mecânica, Instituto Politécnico de Lisboa, Rua Conselheiro Emídio Navarro 1, 1959-007 Lisboa, Portugal
| | - Rui M. Leal
- CEMMPRE, Departamento de Engenharia Mecânica, Universidade de Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra, Portugal; (I.G.); (R.M.L.); (J.D.C.); (A.L.)
- LIDA-ESAD.CR, Instituto Politécnico de Leiria, Rua Isidoro Inácio Alves de Carvalho, 2500-321 Caldas da Rainha, Portugal
| | - José D. Costa
- CEMMPRE, Departamento de Engenharia Mecânica, Universidade de Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra, Portugal; (I.G.); (R.M.L.); (J.D.C.); (A.L.)
| | - Altino Loureiro
- CEMMPRE, Departamento de Engenharia Mecânica, Universidade de Coimbra, Rua Luís Reis Santos, 3030-788 Coimbra, Portugal; (I.G.); (R.M.L.); (J.D.C.); (A.L.)
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Luo L, Liu Z, Bai S, Zhao J, Zeng D, Wang J, Cao J, Hu Y. Hot Deformation Behavior Considering Strain Effects and Recrystallization Mechanism of an Al-Zn-Mg-Cu Alloy. MATERIALS 2020; 13:ma13071743. [PMID: 32283587 PMCID: PMC7178691 DOI: 10.3390/ma13071743] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 03/29/2020] [Accepted: 04/03/2020] [Indexed: 11/25/2022]
Abstract
The hot deformation behavior of an Al-Zn-Mg-Cu alloy was investigated by hot compression test at deformation temperatures varying from 320 to 440 °C with strain rates ranging from 0.01 to 10 s−1. The results show that the Mg(Zn, Cu)2 particles as a result of the sufficient static precipitation prior to hot compression have an influence on flow softening. A constitutive model compensated with strain was developed from the experimental results, and it proved to be accurate for predicting the hot deformation behavior. Processing maps at various strains were established. The microstructural evolution demonstrates that the dominant dynamic softening mechanism stems from dynamic recovery (DRV) and partial dynamic recrystallization (DRX). The recrystallization mechanism is continuous dynamic recrystallization (CDRX). The microstructure observations are in good agreement with the results of processing maps. On account of the processing map and microstructural observation, the optimal hot processing parameters at a strain of 0.6 are at deformation temperature range of 390–440 °C and strain rate range of 0.010–0.316 s−1 with a peak efficiency of 0.390.
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Affiliation(s)
- Lei Luo
- Light Alloy Research Institute, Central South University, Changsha 410083, China;
- Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083, China; (J.Z.); (D.Z.); (J.W.); (J.C.); (Y.H.)
| | - Zhiyi Liu
- Light Alloy Research Institute, Central South University, Changsha 410083, China;
- Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083, China; (J.Z.); (D.Z.); (J.W.); (J.C.); (Y.H.)
- School of Material Science and Engineering, Central South University, Changsha 410083, China
- National Key Laboratory of Science and Technology for National Defense on High-Strength Structural Materials, Central South University, Changsha 410083, China
- Correspondence: (Z.L.); (S.B.); Tel.: +86-731-88836927 (Z.L. & S.B.)
| | - Song Bai
- Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083, China; (J.Z.); (D.Z.); (J.W.); (J.C.); (Y.H.)
- School of Material Science and Engineering, Central South University, Changsha 410083, China
- Correspondence: (Z.L.); (S.B.); Tel.: +86-731-88836927 (Z.L. & S.B.)
| | - Juangang Zhao
- Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083, China; (J.Z.); (D.Z.); (J.W.); (J.C.); (Y.H.)
- School of Material Science and Engineering, Central South University, Changsha 410083, China
| | - Diping Zeng
- Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083, China; (J.Z.); (D.Z.); (J.W.); (J.C.); (Y.H.)
- School of Material Science and Engineering, Central South University, Changsha 410083, China
| | - Jian Wang
- Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083, China; (J.Z.); (D.Z.); (J.W.); (J.C.); (Y.H.)
- School of Material Science and Engineering, Central South University, Changsha 410083, China
| | - Jing Cao
- Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083, China; (J.Z.); (D.Z.); (J.W.); (J.C.); (Y.H.)
- School of Material Science and Engineering, Central South University, Changsha 410083, China
| | - Yangcheng Hu
- Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083, China; (J.Z.); (D.Z.); (J.W.); (J.C.); (Y.H.)
- School of Material Science and Engineering, Central South University, Changsha 410083, China
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Liao B, Cao L, Wu X, Zou Y, Huang G, Rometsch PA, Couper MJ, Liu Q. Effect of Heat Treatment Condition on the Flow Behavior and Recrystallization Mechanisms of Aluminum Alloy 7055. MATERIALS 2019; 12:ma12020311. [PMID: 30669505 PMCID: PMC6356346 DOI: 10.3390/ma12020311] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 01/11/2019] [Accepted: 01/14/2019] [Indexed: 11/16/2022]
Abstract
The flow behavior and the microstructural evolution of aluminum alloy 7055 in two heat treatment conditions (homogenized vs. pre-rolled, solution treated, stretched and naturally aged (T3)) were investigated for a height reduction of 60% with deformation temperatures ranging from 370 °C to 450 °C and strain rates ranging from 0.01 s−1 to 10 s−1. Flow stress decline ratio maps as a function of deformation temperature and strain rate were produced along with processing maps at a strain of 0.8 to reveal optimum hot-working conditions for deformation at strain rates of 0.01 s−1 to 0.1 s−1. The results showed that the stress drop ratio during deformation is higher for the homogenized condition than for the pre-rolled, T3 condition. A higher degree of recrystallization after deformation was observed in the pre-rolled, T3 condition due to finer second phase particles, smaller grain size, and more numerous sub-grains. The mechanism for deformation softening is discussed in the context of grain boundary characteristics.
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Affiliation(s)
- Bin Liao
- International Joint Laboratory for Light Alloys (Ministry of Education), College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
| | - Lingfei Cao
- International Joint Laboratory for Light Alloys (Ministry of Education), College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
- Electron Microscopy Center of Chongqing University, Chongqing University, Chongqing 400044, China.
| | - Xiaodong Wu
- International Joint Laboratory for Light Alloys (Ministry of Education), College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
| | - Yan Zou
- International Joint Laboratory for Light Alloys (Ministry of Education), College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
| | - Guangjie Huang
- International Joint Laboratory for Light Alloys (Ministry of Education), College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
| | - Paul A Rometsch
- Department of Materials Science and Engineering, Monash University, Clayton, VIC 3800, Australia.
| | - Malcolm J Couper
- Department of Materials Science and Engineering, Monash University, Clayton, VIC 3800, Australia.
| | - Qing Liu
- International Joint Laboratory for Light Alloys (Ministry of Education), College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
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Tomczyk A, Seweryn A, Grądzka-Dahlke M. The Effect of Dynamic Recrystallization on Monotonic and Cyclic Behaviour of Al-Cu-Mg Alloy. MATERIALS 2018; 11:ma11060874. [PMID: 29882887 PMCID: PMC6025297 DOI: 10.3390/ma11060874] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 05/20/2018] [Accepted: 05/21/2018] [Indexed: 11/16/2022]
Abstract
The paper presents an investigation that was conducted to determine the possibility of the occurrence of the process of dynamic recrystallization in 2024 alloy during monotonic tensile and creep tests at the elevated temperatures of 100 °C, 200 °C, and 300 °C. As-extruded material was subjected to creep process with constant force at elevated temperatures, until two varying degrees of deformation were reached. After cooling at ambient temperature, the pre-deformed material was subjected to monotonic and fatigue tests as well as metallographic analysis. The process of dynamic recrystallization was determined in monotonic tests to occur at low strain rate (0.0015/s) only at the temperature of 300 °C. However, in the creep tests, this process occurred with varying efficiency, both during creep at 200 °C and 300 °C. Dynamic recrystallization was indicated to have a significant influence on the monotonic and cyclic properties of the material.
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Affiliation(s)
- Adam Tomczyk
- Faculty of Mechanical Engineering, Białystok University of Technology, Wiejska 45C Str., 15-351 Białystok, Poland.
| | - Andrzej Seweryn
- Faculty of Mechanical Engineering, Białystok University of Technology, Wiejska 45C Str., 15-351 Białystok, Poland.
| | - Małgorzata Grądzka-Dahlke
- Faculty of Mechanical Engineering, Białystok University of Technology, Wiejska 45C Str., 15-351 Białystok, Poland.
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Zhang T, Li L, Lu SH, Gong H, Wu YX. Comparisons of Different Models on Dynamic Recrystallization of Plate during Asymmetrical Shear Rolling. MATERIALS 2018; 11:ma11010151. [PMID: 29342080 PMCID: PMC5793649 DOI: 10.3390/ma11010151] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/04/2018] [Accepted: 01/08/2018] [Indexed: 11/16/2022]
Abstract
Asymmetrical shear rolling with velocity asymmetry and geometry asymmetry is beneficial to enlarge deformation and refine grain size at the center of the thick plate compared to conventional symmetrical rolling. Dynamic recrystallization (DRX) plays a vital role in grain refinement during hot deformation. Finite element models (FEM) coupled with microstructure evolution models and cellular automata models (CA) are established to study the microstructure evolution of plate during asymmetrical shear rolling. The results show that a larger DRX fraction and a smaller average grain size can be obtained at the lower layer of the plate. The DRX fraction at the lower part increases with the ascending speed ratio, while that at upper part decreases. With the increase of the offset distance, the DRX fraction slightly decreases for the whole thickness of the plate. The differences in the DRX fraction and average grain size between the upper and lower surfaces increase with the ascending speed ratio; however, it varies little with the change of the speed ratio. Experiments are conducted and the CA models have a higher accuracy than FEM models as the grain morphology, DRX nuclei, and grain growth are taken into consideration in CA models, which are more similar to the actual DRX process during hot deformation.
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Affiliation(s)
- Tao Zhang
- College of Mechanic and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
| | - Lei Li
- College of Mechanic and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
| | - Shi-Hong Lu
- College of Mechanic and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
| | - Hai Gong
- State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, China.
| | - Yun-Xin Wu
- State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, China.
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Precipitation Behavior and Quenching Sensitivity of a Spray Deposited Al-Zn-Mg-Cu-Zr Alloy. MATERIALS 2017; 10:ma10091100. [PMID: 28925964 PMCID: PMC5615754 DOI: 10.3390/ma10091100] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 09/17/2017] [Accepted: 09/17/2017] [Indexed: 11/17/2022]
Abstract
Precipitation behavior and the quenching sensitivity of a spray deposited Al-Zn-Mg-Cu-Zr alloy during isothermal heat treatment have been studied systematically. Results demonstrate that both the hardness and the ultimate tensile strength of the studied alloy decreased with the isothermal treatment time at certain temperatures. More notably, the hardness decreases rapidly after the isothermal heat treatment. During isothermal heat treatment processing, precipitates readily nucleated in the medium-temperature zone (250–400 °C), while the precipitation nucleation was scarce in the low-temperature zone (<250 °C) and in the high-temperature zone (>400 °C). Precipitates with sizes of less than ten nanometers would contribute a significant increase in yield strength, while the ones with a larger size than 300 nm would contribute little strengthening effect. Quenching sensitivity is high in the medium-temperature zone (250–400 °C), and corresponding time-temperature-property (TTP) curves of the studied alloy have been established.
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An Investigation on the Softening Mechanism of 5754 Aluminum Alloy during Multistage Hot Deformation. METALS 2017. [DOI: 10.3390/met7040107] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Hot Deformation and Processing Window Optimization of a 70MnSiCrMo Carbide-Free Bainitic Steel. MATERIALS 2017; 10:ma10030318. [PMID: 28772678 PMCID: PMC5503376 DOI: 10.3390/ma10030318] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 03/08/2017] [Accepted: 03/15/2017] [Indexed: 11/16/2022]
Abstract
The hot deformation behavior of a high carbon carbide-free bainitic steel was studied through isothermal compression tests that were performed on a Gleeble-1500D thermal mechanical simulator at temperatures of 1223-1423 K and strain rates of 0.01-5 s-1. The flow behavior, constitutive equations, dynamic recrystallization (DRX) characteristics, and processing map were respectively analyzed in detail. It is found that the flow stress increases with increasing the strain rate and decreases with increasing the temperature, and the single-peak DRX can be easily observed at high temperatures and/or low strain rates. The internal relationship between the flow stress and processing parameters was built by the constitutive equations embracing a parameter of Z/A, where the activation energy for hot deformation is 351.539 kJ/mol and the stress exponent is 4.233. In addition, the DRX evolution and the critical conditions for starting DRX were discussed. Then the model of the DRX volume fraction was developed with satisfied predictability. Finally, the processing maps at different strains were constructed according to the dynamic material model. The safety domains and flow instability regions were identified. The best processing parameters of this steel are within the temperature range of 1323-1423 K and strain rate range of 0.06-1 s-1.
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