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Modeling of deformation energy at elevated temperatures and its application in Mg-Li-Al-Y alloy 被引量:3
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作者 Fu-rong CAO Bi-jin ZHOU +3 位作者 Bin YIN Guo-qiang XUE Xiao-tong ZHU Guang-ming XU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第11期2434-2442,共9页
To control the superplastic flow and fracture and examine the variation in deformation energy,the stress and grain size of Mg-7.28Li-2.19Al-0.091Y alloy were obtained using tensile testing and microstructure quantific... To control the superplastic flow and fracture and examine the variation in deformation energy,the stress and grain size of Mg-7.28Li-2.19Al-0.091Y alloy were obtained using tensile testing and microstructure quantification,and new high temperature deformation energy models were established.Results show that the grain interior deformation energy increases with increasing the strain rate and decreases with increasing the temperature.The variation in the grain boundary deformation energy is opposite to that in the grain interior deformation energy.At a given temperature,critical cavity nucleation energy decreases with increasing strain rate and cavity nucleation becomes easy,whereas at a given strain rate,critical cavity nucleation energy increases with increasing temperature and cavity nucleation becomes difficult.The newly established models of the critical cavity nucleation radius and energy provide a way for predicting the initiation of microcrack and improving the service life of the forming parts. 展开更多
关键词 high temperature deformation SUPERPLASTICITY CREEP deformation energy Mg-Li-Al-Y alloy
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Influence of niobium and yttrium on plastic deformation energy and plasticity of Ti-based amorphous alloys 被引量:1
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作者 Sheng-feng Shan Hao Wang +2 位作者 Bing Zhang Yuan-zhi Jia Ming-zhen Ma 《China Foundry》 SCIE CAS 2021年第1期60-67,共8页
Many amorphous alloys have been developed to date,but the low plasticity has limited their application.To achieve an amorphous alloy with high plasticity,a series of(Ti_(40)Zr_(25)Cu_(9)Ni_(8) Be_(18))_(100-x)TM_(x)(x... Many amorphous alloys have been developed to date,but the low plasticity has limited their application.To achieve an amorphous alloy with high plasticity,a series of(Ti_(40)Zr_(25)Cu_(9)Ni_(8) Be_(18))_(100-x)TM_(x)(x=0,1,2,3,4 at.%,TM=Nb,Y)alloys were designed to study the influence of Nb and Y addition on the plasticity.The amorphous samples were prepared using the vacuum melting and copper mold casting process.The microstructures,glass forming ability and mechanical properties of the alloys were investigated by X-ray diffractometry(XRD),scanning electron microscopy(SEM),high-resolution transmission electron microscopy(HRTEM),depth-sensitive nanoindentation,and uniaxial compressive test.The plasticity of different bulk amorphous alloys was investigated by measuring the plastic deformation energy(PDE)during loading.The relationship between the PDE value and plasticity in bulk amorphous alloys was explored.Results show that Nb addition decreases the PDE value and promotes the generation of multiple shear bands,which significantly increases the fracture strength and plasticity,while the addition of Y element reduces the fracture strength and plastic strain of the alloy. 展开更多
关键词 copper mold casting bulk amorphous alloy plastic deformation energy PLASTICITY
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Measurement of the Energy Absorbed during Nanoscale Deformation of Human Peritubular and Intertubular Dentin
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作者 Jiahau Yan Burak Taskonak John J. Mecholsky Jr. 《Materials Sciences and Applications》 2022年第4期144-157,共14页
Mineralized tissues are usually constructed of nanosized materials with ordered hierarchical structures. The main reason for their high load-bearing ability is the multi-scale hierarchy. It is important to have a meth... Mineralized tissues are usually constructed of nanosized materials with ordered hierarchical structures. The main reason for their high load-bearing ability is the multi-scale hierarchy. It is important to have a method for measuring the energy absorbed during the nanoscale deformation of mineralized tissues. The objective of this study was to use a combination of nanoindentation and elastic-plastic mechanics techniques to measure the damage resistance of peritubular and intertubular dentin, based on the energy consumed in the plastic deformation regime and the volume created by the indents. The control materials were soda-lime glass, gold, and poly-methyl methacrylate (PMMA). Plastic deformation energy was calculated from the plastic part of load-displacement curves. The mean values of peritubular dentin and intertubular dentin were 3.8 × 10<sup>9</sup>, and 5.2 × 10<sup>9</sup> J/m<sup>3</sup>, respectively, compared to glass, PMMA, and gold which were 3.3 × 10<sup>7</sup>, 1.3 × 10<sup>9</sup>, and 3.1 × 10<sup>9</sup> J/m<sup>3</sup>, respectively. This method can be applied to study the resistance of mineralized tissues or organic/inorganic hybrid materials to deformation at the nanoscale. 展开更多
关键词 DENTIN Nano-Indentation Plastic deformation energy Elastic-Plastic Mechanics
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VARIATIONAL PRINCIPLES OF ASYMMETRIC ELASTICITY THEORY OF FINITE DEFORMATION 被引量:1
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作者 宋彦琦 陈至达 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1999年第11期1200-1206,共7页
In this paper, based on the finite deformation S-R decomposition theorem, the definition of the body moment is renewed as the stem of its internal and external. The expression of the increment rate of the deformation ... In this paper, based on the finite deformation S-R decomposition theorem, the definition of the body moment is renewed as the stem of its internal and external. The expression of the increment rate of the deformation energy is derived and the physical meaning is clarified. The power variational principle and the complementary power variational principle for finite deformation mechanics are supplemented and perfected. 展开更多
关键词 body moment deformation energy finite deformation variation principle
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Hot compression deformation behavior of the Mg-Al-Y-Zn magnesium alloy 被引量:10
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作者 FANG Xiya YI Danqing WANG Bin WU Chunping ZHANG Hong 《Rare Metals》 SCIE EI CAS CSCD 2008年第2期121-126,共6页
The hot deformation behavior of a Mg-Al-Y-Zn magnesium alloy was investigated by hot compressive testing on a Gleeble-1500 thermal simulator at the temperature ranging from 523 to 673 K with the strain rate varying fr... The hot deformation behavior of a Mg-Al-Y-Zn magnesium alloy was investigated by hot compressive testing on a Gleeble-1500 thermal simulator at the temperature ranging from 523 to 673 K with the strain rate varying from 0.001 to 1 s^-1. The relationships among flow stress, strain rate, and deformation temperature were analyzed, and the deformation activation energy and stress exponent were calculated. Microstructure evolution of the alloy under different conditions was examined. The results indicated that the maximum value of the flow stress increased with the decrease of deformation temperature or the increase of strain rate. Under the present deformation conditions, dynamic recrystallization (DRX) occurred in the alloy, which was the main softening mechanism during deformation at elevated temperature. The deformation temperature and strain had significant effects on the microstructure of the alloy. 展开更多
关键词 Mg-Al-Y-Zn magnesium alloy thermal deformation simulation deformation activation energy dynamic recrystallization
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THE HOT DEFORMATION BEHAVIOR AND DYNAMIC RECRYSTALLIZATION MODEL OF 35CrMo STEEL 被引量:5
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作者 B.Zhang H.B.Zhang +1 位作者 X.Y.Ruan Y.Zhang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2003年第3期183-191,共9页
The isothermal single-stage compression of 35CrMo structural steel has been carried out by using Gleeble 1500 simulator at the temperature range of 950℃ to 1150℃ and strain rate range of 0.01s-1 to 10s-1. The effect... The isothermal single-stage compression of 35CrMo structural steel has been carried out by using Gleeble 1500 simulator at the temperature range of 950℃ to 1150℃ and strain rate range of 0.01s-1 to 10s-1. The effect of hot deformation parameters, such as strain rate, deformed temperature and initial grain size on the flow stress behavior was investigated. The activation energy of tested alloy was calculated, which is 378.16kJ/mol; The relationships between the peak stress (σp), the peak stain (εp), the critical strain (εc) and Z parameter were established. The micro structure evolution shows the pre-existing austenite grain boundaries constitute the principal nucleation sites for dynamic recrystallization (DRX), and the initial austenite grain size affects the grain size of DRX slightly. The kinetic mathematical model of DRX of 35CrMo is: XDRX=1-exp(-3.23-2.28) and Ddyn = 2.252× 10Z-0.22. 展开更多
关键词 dynamic recrystallization deformation activation energy stress/strain curve grain size
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Hot Deformation Behavior of Squeeze Casting SiC_p/2 A50 Matrix Composites 被引量:4
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作者 徐宏 张新 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第3期443-449,共7页
The flow stress behaviors of squeeze casting SiCp/2A50 matrix composites were investigated by means of compression tests on a Gleeble 1500 therma1 mechanical simulator at isothermal constant strain rates ranging from ... The flow stress behaviors of squeeze casting SiCp/2A50 matrix composites were investigated by means of compression tests on a Gleeble 1500 therma1 mechanical simulator at isothermal constant strain rates ranging from of 0.001 to 1.0 with the testing temperature ranging from 350 to 500 ℃. The experiments showed that the relationship between stress and strain was obviously influenced by the strain rate and temperature. Dynamic recrystallization generally occurred at a higher temperature and a 1ower strain rate. A linear equation could be fitted between the Zener-Hollomon parameter Z and stress in the experiments. The mean value reciprocal of temperature at every true strain had a linear relation with natural logarithm of Z parameter, and the correlation coefficient, R=0.99, which was very significant by examination. The hot deformation activation energy of SiCp/2A50 matrix composites was 163.47 KJ/mol by calculation. 展开更多
关键词 SiCp/2A50 matrix composites deformation activation energy stress and strain dynamic recrystallization
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Hot deformation behavior of FGH96 superalloys 被引量:4
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作者 Jiantao Liu Guoquan Liu +3 位作者 Benfu Hu Yuepeng Song Ziran Qin Yiwen Zhang 《Journal of University of Science and Technology Beijing》 CSCD 2006年第4期319-323,共5页
The hot deformation behavior of FGH96 superalloys at 1070-1170℃ and 5×10^-4-2×10^-1 s^-1 were investigated by means of the isothermal compression tests at a Gleeble-1500 thermal mechanical simulator. The re... The hot deformation behavior of FGH96 superalloys at 1070-1170℃ and 5×10^-4-2×10^-1 s^-1 were investigated by means of the isothermal compression tests at a Gleeble-1500 thermal mechanical simulator. The results show that dynamic recovery acts as the main softening mechanism below 2×10^-3 s^-1, whereas dynamic recrystallization acts as the main softening mechanism above 2× 10^-3 s^-1 during deformation; the temperature increase caused by the deformation and the corresponding softening stress is negligible; the thermal-mechanical constitutive model to describe the hot deformation behavior is given, and the value of the apparent deformation activation energy (Qdef) is determined to be 354.93 kJ/mol. 展开更多
关键词 FGH96 superalloys hot deformation hot deformation activation energy dynamic recovery dynamic recrystallization
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Effect of processing parameters on flow behaviors and microstructure during high temperature deformation of GH4586 superalloy 被引量:3
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作者 LUO Jiao LI Xiang-yang +1 位作者 LI Cong LI Miao-quan 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第2期338-350,共13页
The apparent activation energy for deformation(Q)and strain rate sensitivity(m)of GH4586 superalloy are calculated and the variation trend is reasonably explained by the microstructure observations.Constitutive modell... The apparent activation energy for deformation(Q)and strain rate sensitivity(m)of GH4586 superalloy are calculated and the variation trend is reasonably explained by the microstructure observations.Constitutive modelling of this superalloy is established and the processing maps at different strains are constructed.The results show that the Q value is in the range of 751.22−878.29 kJ/mol.At a temperature of 1060°C,strain rate of 0.001 s^(−1),and strain of 0.65,the m value of GH4586 superalloy reaches a maximum of 0.42.The optimal processing parameter of GH4586 superalloy is at a deformation temperature of 1050°C and a strain rate of 0.001 s^(−1).The domains of flow instability notably expand with increasing strain during high temperature deformation of GH4586 superalloy. 展开更多
关键词 GH4586 superalloy apparent activation energy for deformation strain rate sensitivity constitutive model processing maps
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Deformation behavior of Fe-Mn-C TWIP steel within the temperature range of hot rolling
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作者 Ma Fengcang Feng Weijun +1 位作者 Wang Li Zhang Di 《Baosteel Technical Research》 CAS 2008年第4期8-11,共4页
The hot-deformation behavior of Fe-Mn-C twinning induced plasticity (TWIP) steel was investigated by conducting hot compression tests within a recommended hot rolling temperature range at various strain rates. Flow ... The hot-deformation behavior of Fe-Mn-C twinning induced plasticity (TWIP) steel was investigated by conducting hot compression tests within a recommended hot rolling temperature range at various strain rates. Flow resistance curves during hot-deformation were obtained, and strain rate sensitivities and activation energies for plastic deformation were calculated using the power law. It is found that the addition of Al and Si clearly increases the peak stresses for the present alloys, especially at 950℃. But Mn has a minor effect on the stress-strain curves and activation energy when its content varies from 15 mass% to 22 mass% for the present alloys. 展开更多
关键词 TWIP steel hot deformation behavior peak stress activation energy for plastic deformation
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Design and energy absorption enhancement of vehicle hull under high dynamic loads
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作者 Mohammad-Ali Saeimi-Sadigh Amin Paykani +1 位作者 Amir Afkar Dehghan Aminollah 《Journal of Central South University》 SCIE EI CAS 2014年第4期1307-1312,共6页
V-shape hulls are widely used in peacekeeping efforts such as demining vehicles in order to deflect the blast energy and reduce the effects of mine blast. Blast resistant design and energy absorption enhancement of V-... V-shape hulls are widely used in peacekeeping efforts such as demining vehicles in order to deflect the blast energy and reduce the effects of mine blast. Blast resistant design and energy absorption enhancement of V-shape plates were carried out using finite element analysis package ABAQUS. Various geometries of V-shape plates with and without interlayer of materials like Al-foams and honeycomb were employed to analyze their effects on the deformation of the plate and applied stresses and strains. The results obtained show that application of metallic foams leads to better response of the plate and consequently results in more energy dissipation, less dame to vehicle and enhances crew survivability. 展开更多
关键词 V-shape plate blast Al-foam energy absorption deformation
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Energy dissipation and contour integral characterizing fracture behavior of incremental plasticity
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作者 Qi-Lin He Lin-Zhi Wu Ming Li Hong-Bo Chen 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第2期251-258,共8页
J ep -integral is derived for characterizing the frac- ture behavior of elastic-plastic materials. The J ep -integral differs from Rice’s J-integral in that the free energy density rather than the stress working dens... J ep -integral is derived for characterizing the frac- ture behavior of elastic-plastic materials. The J ep -integral differs from Rice’s J-integral in that the free energy density rather than the stress working density is employed to define energy-momentum tensor. The J ep -integral is proved to be path-dependent regardless of incremental plasticity and deformation plasticity. The J epintegral possesses clearly clear physical meaning: (1) the value J ep tip evaluated on the infinitely small contour surrounding the crack tip represents the crack tip energy dissipation; (2) when the global steadystate crack growth condition is approached, the value of J ep farss calculated along the boundary contour equals to the sum of crack tip dissipation and bulk dissipation of plastic zone. The theoretical results are verified by simulating mode I crack problems. 展开更多
关键词 J-integral · energy dissipation · Proportional loading · deformation plasticity · Incremental plasticity
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Simulation of strain induced abnormal grain growth in aluminum alloy by coupling crystal plasticity and phase field methods 被引量:2
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作者 Ru-xue LIU Kai LI +4 位作者 Guo-wei ZHOU Wei-qin TANG Yao SHEN Ding TANG Da-yong LI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第12期3873-3886,共14页
A mesoscale modeling methodology is proposed to predict the strain induced abnormal grain growth in the annealing process of deformed aluminum alloys. Firstly, crystal plasticity finite element(CPFE) analysis is perfo... A mesoscale modeling methodology is proposed to predict the strain induced abnormal grain growth in the annealing process of deformed aluminum alloys. Firstly, crystal plasticity finite element(CPFE) analysis is performed to calculate dislocation density and stored deformation energy distribution during the plastic deformation. A modified phase field(PF) model is then established by extending the continuum field method to consider both stored energy and local interface curvature as driving forces of grain boundary migration. An interpolation mapping approach is adopted to transfer the stored energy distribution from CPFE to PF efficiently. This modified PF model is implemented to a hypothetical bicrystal firstly for verification and then the coupled CPFE-PF framework is further applied to simulating the 2D synthetic polycrystalline microstructure evolution in annealing process of deformed AA3102 aluminum alloy.Results show that the nuclei with low stored energy embedded within deformed matrix tend to grow up, and abnormal large grains occur when the deformation is close to the critical plastic strain, attributing to the limited number of recrystallized nuclei and inhomogeneity of the stored energy. 展开更多
关键词 abnormal grain growth stored deformation energy RECRYSTALLIZATION crystal plasticity phase field
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Three dimensional finite element study on torsion extrusion processing of 1050 aluminum alloy 被引量:1
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作者 Ali KHOSRAVIFARD Mohammad JAHEDI Amir Hossein YAGHTIN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第11期2771-2776,共6页
The capability of the torsion extrusion (TE) process as a severe plastic deformation (SPD) method was compared with the conventional forward extrusion (FE) process. The TE and FE processes were successfully perf... The capability of the torsion extrusion (TE) process as a severe plastic deformation (SPD) method was compared with the conventional forward extrusion (FE) process. The TE and FE processes were successfully performed on AA1050 alloy samples at room temperature. To simulate the above mentioned processes, finite element analysis was carried out using the commercial elasto-plastic finite element analysis ABAQUS/Explicit Simulation. It is shown that load requirement for the TE process is lower than that for the FE process. The equivalent plastic strain calculated by the FEA proved that higher values of strain are imposed to the sample in the TE process. The strain distribution for the TE sample at the final stage of extrusion shows smoother strain gradient in comparison with the one produced by the FE process. 展开更多
关键词 AA-1050 alloy severe plastic deformation (SPD) torsion extrusion (TE) equivalent plastic strain strain distribution deformation energy
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BEHAVIOR OF FLOW STRESS OF ALUMINUM SHEETS USED FOR PRESSURE CAN DURING COMPRESSION AT ELEVATED TEMPERATURE 被引量:9
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作者 G.S. Fu W.Z. Chen K. W. Qian 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2005年第6期756-762,共7页
The behavior of flow stress of Al sheets used for pressure can prepared by different melt-treatment during plastic deformation at elevated temperature was studied by isothermal compression test using Gleeble1500 dynam... The behavior of flow stress of Al sheets used for pressure can prepared by different melt-treatment during plastic deformation at elevated temperature was studied by isothermal compression test using Gleeble1500 dynamic hot-simulation testing machine. The results show that the AI sheets possess the remarkable characteristic of steady state flow stress when they are deformed in the temperature range of 350-500℃ at strain rates within the range of 0.01-10.0s^-1. A hyperbolic sine relationship is found to correlate well the flow stress with the strain rate, and an Arrhenius relationship with the temperature, which implies that the process of plastic deformation at elevated temperature for this material is thermally activated. Compared with the AI pieces prepared by no or conventional melt-treatment, hot deformation activation energy of AI sheets prepared by high-efficient melt-treatment is the smallest ( Q= 168.0kJ/mol), which reveals that the hot working formability of this material is very better, and has directly to do with the effective improvement of its metallurgical quality. 展开更多
关键词 Al sheets used for can melt-treatment plastic deformation at elevatedtemperature flow stress hot deformation activation energy
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Determination of dynamic recrystallization parameter domains of Ni80A superalloy by enhanced processing maps 被引量:9
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作者 Guo-zheng QUAN Qiao LIU +2 位作者 Jiang ZHAO Wei XIONG Rui-ju SHI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第7期1449-1464,共16页
The determination of intrinsic deformation parameters inducing grain refinement mechanism of dynamic recrystallization (DRX) contributes to the relative forming process design. For Ni80A superalloy, the processing map... The determination of intrinsic deformation parameters inducing grain refinement mechanism of dynamic recrystallization (DRX) contributes to the relative forming process design. For Ni80A superalloy, the processing maps were constructed by the derivation of the stress-strain data coming from a series of isothermal compression tests at temperatures of 1273^-1473 K and strain rates of 0.01-10 s^-1. According to the processing maps and microstructural validation, the deformation parameter windows with DRX mechanism were separated in an innovative deformation mechanism map. In addition, the deformation activation energy representing deformation energy barrier was introduced to further optimize such windows. Finally, the enhanced processing maps were constructed and the parameter domains corresponding to DRX mechanism and lower deformation barrier were determined as follows: at ε=0.3, domains: 1296-1350 K, 0.056-0.32 s^-1 and 1350-1375 K, 0.035-0.11 s^-1;at ε=0.5, domains: 1290-1348 K, 0.2-0.5 s^-1 and 1305-1370 K, 0.035-0.2 s^-1;at ε=0.7, domains: 1290-1355 K, 0.042-0.26 s^-1;at ε=0.9, domains: 1298-1348 K, 0.037-0.224 s^-1. 展开更多
关键词 nickel-based superalloy deformation activation energy processing map dynamic recrystallization
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Dynamic Recrystallization Behaviour of Nb-Ti Microalloyed Steels 被引量:3
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作者 MA Liqiang LIU Zhenyu +2 位作者 JIAO Sihai YUAN Xiangqian WU Di 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2008年第4期551-557,共7页
The dynamic recrystallization (DRX) behavior of Nb-Ti microalloyed steels was investigated by isothermal single compression tests in the temperature range of 900-1 150 ℃ at constant strain rates of 0.1-5 s^-1. DRX ... The dynamic recrystallization (DRX) behavior of Nb-Ti microalloyed steels was investigated by isothermal single compression tests in the temperature range of 900-1 150 ℃ at constant strain rates of 0.1-5 s^-1. DRX was retarded effectively at low temperature due to the onset of dynamic precipitation of Nb and Ti carbonitrides, resulting in higher values of the peak strain. An expression was developed for the activation energy of deformation as a function of the contents of Nb and Ti in solution as well as other alloying elements. A new value of corrective factor was determined and applied to quantify the retardation produced by increase in the amount of Nb and Ti dissolved at the reheating temperature. The ratio of critical strain to peak strain decreases with increasing equivalent Nb content. In addition, the effects of Ti content and deformation conditions on DRX kinetics and steady state grain size were determined. Finally, the kinetics of dynamic precipitation was determined and effect of dynamic precipitation on the onset of DRX was clarified based on the comparison between precipitate pinning force and recrystallization driving force. 展开更多
关键词 Nb-Ti microalloyed steels dynamic recrystallization activation energy of deformation dynamic precipitation
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Constitutive model and deformation microstructure of fine-grain Mg-Zn-Y alloy solidified under high pressure 被引量:5
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作者 樊志斌 林小娉 +3 位作者 董允 徐瑞 李婵 刘宁宁 《Journal of Rare Earths》 SCIE EI CAS CSCD 2016年第9期945-951,共7页
Fine-grain Mg95.50Zn3.71Y0.79 alloy was prepared by high pressure solidification. By comparison with the conventional cast-ing alloy, the true stress-strain curve characteristic and deformation microstructure of Mg95.... Fine-grain Mg95.50Zn3.71Y0.79 alloy was prepared by high pressure solidification. By comparison with the conventional cast-ing alloy, the true stress-strain curve characteristic and deformation microstructure of Mg95.50Zn3.71Y0.79 alloy solidified under high pressure were studied via unilateralism compress tests under the strain rate of 0.001–1 s–1 and deformation temperature of 523–623 K. Constitutive equations were constructed. According to the experimental results, compared to the conventional casting alloy, the true stress-strain curve of the fine-grain alloy solidified under high pressure not only had the high strain hardening characteristic but the dynamic recrystallization softening after the peak stress was more than the working hardening and would soon reach a stable flow stress - strain state. The deformation activation energy of the alloy solidified under high pressure was 151 kJ/mol, around 49 kJ/mol lower than that of the conventional casting alloy. The fine-grain Mg-Zn-Y alloy solidified under high pressure could obtain 95 percent of dynamic recrystallization grain at 573 K during hot deformation process. 展开更多
关键词 high pressure solidification Mg95.50Zn3.71Y0.79 alloy deformation activation energy rare earths
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Deformation behavior and processing maps during isothermal compression of TC21 alloy 被引量:6
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作者 Jun Gao Miao-Quan Li +1 位作者 Ge-Jun Liu Shao-Fei Liu 《Rare Metals》 SCIE EI CAS CSCD 2017年第2期86-94,共9页
In this study,isothermal compression tests were conducted at a Gleeble-1500 simulator at deformation temperatures ranging from 1073 to 1283 K,strain rates ranging from 0.01 to 5.00 s^(-1),and height reductions rangi... In this study,isothermal compression tests were conducted at a Gleeble-1500 simulator at deformation temperatures ranging from 1073 to 1283 K,strain rates ranging from 0.01 to 5.00 s^(-1),and height reductions ranging from 20%to 60%.The flow stress and apparent activation energy for deformation and constitutive equation were used to characterize the deformation behavior of TC21 alloy during the isothermal compression.The processing maps combined microstructure observations were established based on dynamic material model(DMM) over a range of strain rates and temperatures.The results show that an initial yield drop is observed above 1203 K or at higher strain rates ranging from 1.00 to 5.00 s^-1,and oscillatory flow curves are presented particularly at a strain rate of 5.00 s^-1.Strain has some influence on the apparent activation energy for deformation during the isothermal compression of TC21 alloy.The Q-values and microstructure observation confirm that dynamic recrystallization(DRX) occurs in the β single-phase region.The constitutive equation during the isothermal compression of TC21 alloy is developed using the Zener-Hollomon parameter in the exponent-type equation.The maximum and minimum relative errors between the calculated and the experimental flow stress are 14.1%and 0.3%,respectively.The peak efficiency of power dissipation at a strain of 0.7 is about 0.51 occurring at a deformation temperature of 1073 K and strain rate of 0.01 s^-1,corresponding to an optimal deformation condition of TC21 alloy. 展开更多
关键词 TC21 alloy Flow stress Apparent activation energy for deformation Constitutive equation PROCESSING MAPS
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Microstructure Characteristics of an Fe-Mn-C TWIP Steel After Deformation 被引量:3
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作者 DAI Yong-juan TANG Di +1 位作者 MI Zhen-li LU Jian-chong 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2010年第9期53-59,共7页
The microstructure characteristics of an Fe-Mn-C TWIP steel after deformation are investigated. The results show that the hot-rolled, cold-rolled and then annealed sample of the Fe-Mn-C TWIP steel has excellent mechan... The microstructure characteristics of an Fe-Mn-C TWIP steel after deformation are investigated. The results show that the hot-rolled, cold-rolled and then annealed sample of the Fe-Mn-C TWIP steel has excellent mechanical properties, and the true stress-true strain curve from tension tests exhibits repeated serrations. The deformed microstructure exhibits the typical planar glide characteristics such as no cell formation, dislocation pile-ups on a single slip plane, mechanical twins and stacking faults. There are equiaxial and deep dimple structures in the fractograph, indicative of a ductile fracture. Microcracks initiate from inclusions and twin-twin intersections. Deformation and fracture processes are the formation, growth and coalescence of microvoids. 展开更多
关键词 planar glide deformed twinning stack fault energy ductile fracture
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