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云南宾川盆地及周边地震波走时的季节性变化和可能的物理机制
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作者 寇华东 王伟君 +4 位作者 闫坤 彭菲 叶志鹏 吕恒茹 常利军 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2024年第4期1412-1425,共14页
基于背景噪声自相关方法,本文计算了云南宾川盆地及周边区域地震波在四个频段的相对走时变化(dt/t),发现存在比较显著的年变和半年变特征,最大变化幅度从0.1~0.2 Hz(7 km左右深度最敏感)的±0.8%逐渐降低至1.0~2.0 Hz(对应1 km以浅... 基于背景噪声自相关方法,本文计算了云南宾川盆地及周边区域地震波在四个频段的相对走时变化(dt/t),发现存在比较显著的年变和半年变特征,最大变化幅度从0.1~0.2 Hz(7 km左右深度最敏感)的±0.8%逐渐降低至1.0~2.0 Hz(对应1 km以浅介质)的±0.05%.噪声源季节性变化可能是dt/t周期性起伏的一个潜在因素,但雨水和温度与其有更直接的关联性.其中雨水渗透产生的介质孔隙压变化是年变和半年变的重要贡献因素;而温度起伏产生的介质热力学形变,主要对一定深度范围(3 km左右最敏感)的介质有明显的年变影响.不同频段走时变化存在幅度差异和不同步,可能和各频段敏感核的深度范围以及水与热力学形变从地表向深部渗透/传播过程有关.研究表明,环境因素对地下介质的地震波走时有较为显著的影响,区分出它们的贡献,才能更可靠地评估地震构造应力或人文生态环境的变化. 展开更多
关键词 单台背景噪声干涉 走时周期性变化 环境因素 孔隙压变化 热力学形变
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Rate controlling mechanisms in hot deformation of 7A55 aluminum alloy 被引量:4
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作者 冯迪 张新明 +2 位作者 刘胜胆 吴泽政 谈琦 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第1期28-35,共8页
The hot deformation behavior of 7A55 aluminum alloy was investigated at the temperature ranging from 300 ℃ to 450 ℃ and strain rate ranging from 0.01 s-1 to 1 s-1 on a Gleeble-3500 simulator. Processing maps were es... The hot deformation behavior of 7A55 aluminum alloy was investigated at the temperature ranging from 300 ℃ to 450 ℃ and strain rate ranging from 0.01 s-1 to 1 s-1 on a Gleeble-3500 simulator. Processing maps were established in order to apprehend the kinetics of hot deformation and the rate controlling mechanism was interpreted by the kinetic rate analysis obeying power-law relation. The results indicated that one significant domain representing dynamic recrystallization (DRX) existed on the processing maps and lying in 410-450 &#176;C and 0.05-1 s-1. The conclusions of kinetic analysis correlated well with those obtained from processing maps. The apparent activation energy values calculated in the dynamic recrystallization (DRX) domain and the stability regions except dynamic recrystallization (DRX) domain were 91.2 kJ/mol and 128.8 kJ/mol, respectively, which suggested that grain boundary self-diffusion and cross-slip were the rate controlling mechanisms. 展开更多
关键词 7A55 aluminum alloy processing maps hot deformation kinetic analysis dynamic recrystallization
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Effects of T9I6 thermo-mechanical process on microstructure, mechanical properties and ballistic resistance of 2519A aluminum alloy 被引量:6
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作者 顾刚 叶凌英 +3 位作者 蒋海春 孙大翔 张盼 张新明 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第7期2295-2300,共6页
The effects of T916 thermo-mechanical process on microstructures, mechanical properties and ballistic resistance of 2519A aluminum alloy were investigated by optical microscopy (OM), transmission electron microscopy... The effects of T916 thermo-mechanical process on microstructures, mechanical properties and ballistic resistance of 2519A aluminum alloy were investigated by optical microscopy (OM), transmission electron microscopy (TEM), tensile tests and ballistic resistance test. After T916 treatment, the yield strength, tensile strength and elongation rate of 2519A aluminum alloy reach 501 MPa, 540 MPa and 14%, respectively. And the ballistic limit velocity of 2519A-T916 alloy (30 mm in thickness) is 715 rn/s. The microstructure varies near the sidewalls of crater. The interrupted ageing contributes to these excellent properties of the alloy. During T916 process, the precipitation of Guinier Preston (GP) zone is finer and denser during the interrupted ageing, thus resulting in well precipitated strengthening phase. 展开更多
关键词 2519A aluminum alloy T916 thermo-mechanical treatment mechanical properties MICROSTRUCTURE ballistic resistance
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Quantitative contributions of solution atoms, precipitates and deformation to microstructures and properties of Al-Sc-Zr alloys 被引量:8
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作者 Ren-guo GUAN Hong-mei JIN +5 位作者 Wensen JIANG Xiang WANG Yu-xiang WANG Zheng LI Jian ZHANG Huinan LIU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第5期907-918,共12页
In order to investigate the effects of solid solution atoms, precipitated particles and cold deformation on the microstructures and properties of Al-Sc-Zr alloys, the Al-Sc-Zr alloys prepared by continuous rheo-extrus... In order to investigate the effects of solid solution atoms, precipitated particles and cold deformation on the microstructures and properties of Al-Sc-Zr alloys, the Al-Sc-Zr alloys prepared by continuous rheo-extrusion were treated by thermomechanical treatment, analyzed for conductivity and mechanical properties by tensile and microhardness testing, and characterized using optical microscope, TEM and STEM. A mathematical model was established to quantitatively characterize the contribution of solid solution atoms, precipitates and cold deformation to the conductivity of the alloy. The results show that the strength of Al alloy can be significantly improved by solid solution, aging and cold deformation, and the quantitative impacts of solution atoms, precipitates and cold deformation on the conductivity of Al alloy are 10.5%(IACS), 2.3%(IACS) and 0.5%(IACS), respectively. Aging and cold deformation treatments are the keys to obtain high-strength and high-conductivity aluminum alloy wires. 展开更多
关键词 Al.Sc.Zr alloy thermal treatment cold deformation mechanical properties CONDUCTIVITY
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Physical and mechanical properties of Beishan granite after different high temperature treatments 被引量:2
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作者 WANG Zi-hui ZHOU Hong-wei +2 位作者 HEINZ Konietzky LI Shu-min WANG Ting-zheng 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第6期1957-1972,共16页
In China,Beishan granite is chosen as a potential host surrounding rock of a high-level radioactive waste(HLW)repository.For this research,Beishan granite specimens were heated up to 300℃,400℃ and 500℃,respectively... In China,Beishan granite is chosen as a potential host surrounding rock of a high-level radioactive waste(HLW)repository.For this research,Beishan granite specimens were heated up to 300℃,400℃ and 500℃,respectively.And conventional triaxial compression tests were conducted after cooling down the samples.The results show that after 300℃,400℃ and 500℃ heating treatment,the diameter of samples increases by 0.066%,0.143%and 0.409%,respectively,which is a little larger than the axial length changes.Mechanical tests show that peak strength increases slightly with increasing temperature.However,the dilatancy threshold is lower than that observed for samples which have not experienced heating treatment.Peak strain and dilatancy threshold strain show a strong temperature dependence.The higher the temperature,the greater the strain.Furthermore,increasing temperature has negative influence on threshold elastic modulus E_(c) and tangent elastic modulus E_(t).Poisson ratio decreases when temperature increases from 300℃ to 500℃,but it is still larger than that observed for samples which have not experienced heating treatment.In addition,AE monitoring shows a quiet period in the initial loading stage,which proves that the micro cracks are closed during heating and contribute to the increase of peak strength. 展开更多
关键词 Beishan granite heating treatment DEFORMATION thermo-mechanical properties acoustic emission
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A new mathematical model for predicting flow stress of X70HD under hot deformation 被引量:2
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作者 王健 王小巩 +2 位作者 杨海涛 余超 肖宏 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第6期2052-2059,共8页
To realize numerical simulation of rolling and obtain the hot forming process parameters for X70 HD steel, the flow stress behaviors of X70 HD steel were investigated under different temperatures(820-1100 ℃ and stra... To realize numerical simulation of rolling and obtain the hot forming process parameters for X70 HD steel, the flow stress behaviors of X70 HD steel were investigated under different temperatures(820-1100 ℃ and strain rates(0.01-10 s-1) on a Gleeble-3500 thermo-simulation machine. A new flow stress model was established. The linear and exponential relationship methods were applied to the parameters with respect to temperature and deformation rates. The rise of curve ends under certain conditions was analyzed. The flow stress of X70 HD steel predicted by the proposed model agrees well with the experimental results. So, it greatly improves the precision of the metal thermoplastic processing through finite element method and practical application of engineering. 展开更多
关键词 flow stress dynamic recovery dynamic reerystallization Z parameter
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Relationship among microstructure,mechanical properties and texture of TA32 titanium alloy sheets during hot tensile deformation 被引量:13
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作者 Rong-lei FAN Yong WU +1 位作者 Ming-he CHEN Lan-sheng XIE 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第4期928-943,共16页
The relationship among microstructure,mechanical properties and texture of TA32 titanium alloy sheets during hot tensile deformation at 800℃was investigated.In the test,the original sheet exhibited relatively low flo... The relationship among microstructure,mechanical properties and texture of TA32 titanium alloy sheets during hot tensile deformation at 800℃was investigated.In the test,the original sheet exhibited relatively low flow stress and sound plasticity,and increasing the heat treatment temperature resulted in an increased ultimate tensile strength(UTS)and a decreased elongation(EL).The deformation mechanism of TA32 alloy was dominated by high angle grain boundaries sliding and coordinated by dislocation motion.The coarsening of grains and the annihilation of dislocations in heat-treated specimens weakened the deformation ability of material,which led to the increase in flow stress.Based on the high-temperature creep equation,the quantitative relationship between microstructure and flow stress was established.The grain size exponent andαphase strength constant of TA32 alloy were calculated to be 1.57 and 549.58 MPa,respectively.The flow stress was accurately predicted by combining with the corresponding phase volume fraction and grain size.Besides,the deformation behavior of TA32 alloy was also dependent on the orientation of predominantαphase,and the main slip mode was the activation of prismaticslip system.The decrease of near prism-oriented texture in heat-treated specimens resulted in the enhancement of strength of the material. 展开更多
关键词 TA32 titanium alloy sheets hot tensile deformation microstructure evolution mechanical properties TEXTURE
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Influence of Cu content on microstructure and mechanical properties of thixoformed Al-Si-Cu-Mg alloys 被引量:5
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作者 M.S.SALLEH M.Z.OMAR 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第11期3523-3538,共16页
The effects of Cu content on the microstructure and mechanical properties of thixoformed Al-6Si-xCu-0.3Mg(x= 3,4,5and 6,mass fraction,%) alloys were studied.The samples were thixoformed at 50%liquid content and severa... The effects of Cu content on the microstructure and mechanical properties of thixoformed Al-6Si-xCu-0.3Mg(x= 3,4,5and 6,mass fraction,%) alloys were studied.The samples were thixoformed at 50%liquid content and several of the samples were treated with the T6 heat treatment.The samples were then examined by optical microscopy(OM),scanning electron microscopy(SEM),energy dispersive X-ray(EDX) spectroscopy and X-ray diffraction(XRD) analysis,as well as hardness and tensile tests.The results show that the cooling slope casting and thixoforming process promote the formation of very fine and well distributed intermetallic compounds in the aluminium matrix and the mechanical properties of the alloys increase considerably compared with the permanent mould casting.The results also reveal that as the Cu content in the alloy increases,the hardness and tensile strength of the thixoformed alloys also increase.The ultimate tensile strength,yield strength and elongation to fracture of the thixoformed heat-treated Al-6Si-3Cu-0.3Mg alloy are 298 MPa,201 MPa and 4.5%,respectively,whereas the values of the thixoformed heat-treated alloy with high Cu content(6%) are 361 MPa,274 MPa and 1.1%,respectively.The fracture of the thixoformed Al-6Si-3Cu-0.3Mg alloy shows a dimple rupture,whereas in the alloy that contains the highest Cu content(6%),a cleavage fracture is observed. 展开更多
关键词 Al-Si-Cu-Mg alloy Cu content THIXOFORMING T6 heat treatment mechanical properties
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Microstructure evolution,mechanical properties and tailoring of coefficient of thermal expansion for Cu/Mo/Cu clad sheets fabricated by hot rolling 被引量:2
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作者 Jiang-jiang LIU Ze-jun CHEN +3 位作者 Zhan-song ZHOU Tai-qian MO Peng-ju WANG Wei-jun HE 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第7期2290-2308,共19页
The law of microstructure evolution and mechanical properties of hot roll bonded Cu/Mo/Cu clad sheets were systematically investigated and the theoretical prediction model of the coefficient of thermal expansion(CTE)o... The law of microstructure evolution and mechanical properties of hot roll bonded Cu/Mo/Cu clad sheets were systematically investigated and the theoretical prediction model of the coefficient of thermal expansion(CTE)of Cu/Mo/Cu clad sheets was established successfully.The results show that the deformation of Cu and Mo layers was gradually coherent with an increase in rolling reduction and temperature and excellent interface bonding was achieved under the condition of a large rolling reduction.The development of the microstructure and texture through the thickness of Cu and Mo layers was inhomogeneous.This phenomenon can be attributed to the friction between the roller and sheet surface and the uncoordinated deformation between Cu and Mo.The tensile strength of the clad sheets increased with increasing rolling reduction and the elongation was gradually decreased.The CTE of Cu/Mo/Cu clad sheets was related to the volume fraction of Mo.The finite element method can simulate the deformation and stress distribution during the thermal expansion process.The simulation result indicates that the terminal face of the clad sheets was sunken inward. 展开更多
关键词 Cu/Mo/Cu clad sheets roll bonding collaborative deformation mechanical properties coefficient of thermal expansion prediction model
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Microstructural evolution and mechanical properties of thixoformed A319 alloys containing variable amounts of magnesium
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作者 M.S.SALLEH M.Z.OMAR +3 位作者 K.S.ALHAWARI M.N.MOHAMMED M.A.MAD ALI E.MOHAMAD 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第8期2029-2042,共14页
The effects of Mg content on the microstructure and tensile properties of thixoformed A319 alloys were studied. The samples were thixoformed at 50% liquid content and some of the thixoformed samples were subjected to ... The effects of Mg content on the microstructure and tensile properties of thixoformed A319 alloys were studied. The samples were thixoformed at 50% liquid content and some of the thixoformed samples were subjected to the T6 heat treatment. The samples were then examined by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy and X-ray diffraction (XRD) analysis as well as tensile tests. The results showed that magnesium was able to refine the eutectic silicon in the samples. It was also observed that a compact Al9FeMg3Si5 phase was formed when the magnesium content was 1.0% and 1.5%. The results also revealed that as the magnesium content in the alloy increases, the tensile strengths of the thixoformed alloys also increase. The ultimate tensile strength, yield strength and elongation to fracture of the thixoformed A319 heat treated alloy were 298 MPa, 201 MPa and 4.5%, respectively, whereas the values of the thixoformed heat treated alloy with 1.5% Mg content were 325 MPa, 251 MPa and 1.4%, respectively. Thixoformed A319 alloy showed a dimple fracture behaviour, while thixoformed A319 alloys with 1.5% Mg showed a mixed mode fracture behaviour, where dimple and cleavage ruptures were seen on the fracture surface of the samples. 展开更多
关键词 aluminium alloy THIXOFORMING T6 heat treatment mechanical properties
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Modeling of metadynamic recrystallization kinetics after hot deformation of low-alloy steel Q345B 被引量:3
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作者 马博 彭艳 +1 位作者 刘云飞 贾斌 《Journal of Central South University》 SCIE EI CAS 2010年第5期911-917,共7页
Based on the steady-state strain measured by single-pass hot compression tests,the method by a double-pass hot compression testing was developed to measure the metadynamic-recrystallization kinetics.The metadynamic re... Based on the steady-state strain measured by single-pass hot compression tests,the method by a double-pass hot compression testing was developed to measure the metadynamic-recrystallization kinetics.The metadynamic recrystallization behavior of low-alloy steel Q345B during hot compression deformation was investigated in the temperature range of 1 000-1 100℃,the strain rate range of 0.01-0.10 s -1 and the interpass time range of 0.5-50 s on a Gleeble-3500 thermo-simulation machine.The results show that metadynamic recrystallization during the interpass time can be observed.As the deformation temperature and strain rate increase,softening caused by metadynamic recrystallization is obvious.According to the data of thermo-simulation,the metadynamic recrystallization activation energy is obtained to be Qmd=100.674 kJ/mol and metadynamic recrystallization kinetics model is set up.Finally,the error analysis of metadynamic recrystallization kinetics model proves that the model has high accuracy(correlation coefficient R=0.988 6). 展开更多
关键词 low-alloy steel kinetics model hot deformation metadynamic recrystallization activation energy
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New method for analyzing recrystallization kinetics of deformed metal by differential scanning calorimeter
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作者 陈建 马晓光 +3 位作者 李军 要玉宏 严文 范新会 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第3期849-854,共6页
The drawn copper wires have been analyzed by differential scanning calorimeter(DSC) and a new method, which uses DSC measurements to determine the Johnson-Mehl-Avrami-Kolmogorov(JMAK) exponent via introducing Arrheniu... The drawn copper wires have been analyzed by differential scanning calorimeter(DSC) and a new method, which uses DSC measurements to determine the Johnson-Mehl-Avrami-Kolmogorov(JMAK) exponent via introducing Arrhenius behavior and modifying the baseline of DSC curves, has been proposed. The results show that JMAK exponent and recrystallization activation energy of the drawn copper wires with a strain of 2.77 are about 2.39 and 125 k J/mol, respectively. The line linking the tangency points of DSC curve hypotenuse can be used as the baseline when calculating recrystallization fraction. The JMAK exponent obtained by the DSC method is in a good agreement with that obtained by microhardness measurements. Compared to traditional methods to measure the exponent, the proposed method is faster and less labor intensive. 展开更多
关键词 crystallization kinetics differential scanning calorimeter Johnson-Mehl-Avrami-Kolmogorov(JMAK) exponent deformed metal
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Morphological Evolution of a Void under Thermal and Mechanical Loads 被引量:3
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作者 李二丽 陈曦 +2 位作者 王华 王熙 李中华 《Journal of Shanghai Jiaotong university(Science)》 EI 2009年第1期69-72,共4页
A model for the morphological evolution of a void under thermal and mechanical loads is established, and the thermodynamics potential of the model is given based on energy principle. Thus, the path and the bifurcation... A model for the morphological evolution of a void under thermal and mechanical loads is established, and the thermodynamics potential of the model is given based on energy principle. Thus, the path and the bifurcation condition of the morphological evolution of the void are described, which gives some insight into the reliability of the interconnect under combined thermal and mechanical loads. 展开更多
关键词 thermal and mechanical loads morphological evolution of void thermodynamics potential
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A new interpretation of internal-variable theory in finite thermo-viscoelasticity 被引量:3
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作者 HUANG ZhuPing DUI GuanSuo YANG ShengYou 《Science China Chemistry》 SCIE EI CAS 2013年第3期610-616,共7页
Based on the non-equilibrium thermodynamics,an internal-variable theory in thermo-viscoelasticity at finite deformation was proposed by Huang in 1999.In this theory,a modified stretch of the molecular chain was introd... Based on the non-equilibrium thermodynamics,an internal-variable theory in thermo-viscoelasticity at finite deformation was proposed by Huang in 1999.In this theory,a modified stretch of the molecular chain was introduced,and hence the molecular network model in rubber elasticity was extended to take into account the viscous and thermal effects of the material.The viscous dissipation of the material can then be described by means of these internal variables,which appear in the expression of the modified stretch.In order to give a clearer explanation on the physical implication of the internal variables,a connection between the internal-variable theory and theoretical formulation based on the multiplicative decomposition of the deformation gradient in existing literature is presented in this paper,which allows the above internal-variable theory to be more systematic. 展开更多
关键词 thermo-viscoelasticity internal variables finite deformation multiplicative decomposition of the deformation gradient
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