The high temperature deformation behaviors of α＋β type titanium alloy TC11 （Ti-6.5Al-3.5Mo-1.5Zr-0.3Si） with coarse lamellar starting microstructure were investigated based on the hot compression tests in the tem...The high temperature deformation behaviors of α＋β type titanium alloy TC11 （Ti-6.5Al-3.5Mo-1.5Zr-0.3Si） with coarse lamellar starting microstructure were investigated based on the hot compression tests in the temperature range of 950-1100 ℃ and the strain rate range of 0.001-10 s-1. The processing maps at different strains were then constructed based on the dynamic materials model, and the hot compression process parameters and deformation mechanism were optimized and analyzed, respectively. The results show that the processing maps exhibit two domains with a high efficiency of power dissipation and a flow instability domain with a less efficiency of power dissipation. The types of domains were characterized by convergence and divergence of the efficiency of power dissipation, respectively. The convergent domain in a＋fl phase field is at the temperature of 950-990 ℃ and the strain rate of 0.001-0.01 s^-1, which correspond to a better hot compression process window of α＋β phase field. The peak of efficiency of power dissipation in α＋β phase field is at 950 ℃ and 0.001 s 1, which correspond to the best hot compression process parameters of α＋β phase field. The convergent domain in β phase field is at the temperature of 1020-1080 ℃ and the strain rate of 0.001-0.1 s^-l, which correspond to a better hot compression process window of β phase field. The peak of efficiency of power dissipation in ℃ phase field occurs at 1050 ℃ over the strain rates from 0.001 s^-1 to 0.01 s^-1, which correspond to the best hot compression process parameters of ,8 phase field. The divergence domain occurs at the strain rates above 0.5 s^-1 and in all the tested temperature range, which correspond to flow instability that is manifested as flow localization and indicated by the flow softening phenomenon in stress-- strain curves. The deformation mechanisms of the optimized hot compression process windows in a＋β and β phase fields are identified to be spheroidizing and dynamic recrystallizing controlled by self-diffusion mechanism, respectively. The microstructure observation of the deformed specimens in different domains matches very well with the optimized results.展开更多
以采集于紫茎泽兰(E up a torium ad enophorum Spreng.)危害较为严重的云南、广西、贵州、四川以及澳大利亚共17个种群的紫茎泽兰为实验材料,采用人工模拟气候法、模糊数学中隶属函数法(测定了净光合速率、M DA、叶绿素荧光)比较了不...以采集于紫茎泽兰(E up a torium ad enophorum Spreng.)危害较为严重的云南、广西、贵州、四川以及澳大利亚共17个种群的紫茎泽兰为实验材料,采用人工模拟气候法、模糊数学中隶属函数法(测定了净光合速率、M DA、叶绿素荧光)比较了不同种群紫茎泽兰耐热性.结果表明,高温处理后云南元江与其它种群相比热害指数最低、隶属函数值较高,最为耐热,其次为元谋种群;而云南大理种群热害指数较高,隶属函数均值也较低,其次为广西隆林.说明元江、元谋种群较为耐热,而隆林、大理种群则较为敏感.结合其生境来看,恶性杂草紫茎泽兰种群之间的这种差异性反映了其对入侵地环境的适应性.展开更多
基金Project (51005112) supported by the National Natural Science Foundation of ChinaProject (2010ZF56019) supported by the Aviation Science Foundation of China+1 种基金Project (GJJ11156) supported by the Education Commission of Jiangxi Province, ChinaProject(GF200901008) supported by the Open Fund of National Defense Key Disciplines Laboratory of Light Alloy Processing Science and Technology, China
文摘The high temperature deformation behaviors of α＋β type titanium alloy TC11 （Ti-6.5Al-3.5Mo-1.5Zr-0.3Si） with coarse lamellar starting microstructure were investigated based on the hot compression tests in the temperature range of 950-1100 ℃ and the strain rate range of 0.001-10 s-1. The processing maps at different strains were then constructed based on the dynamic materials model, and the hot compression process parameters and deformation mechanism were optimized and analyzed, respectively. The results show that the processing maps exhibit two domains with a high efficiency of power dissipation and a flow instability domain with a less efficiency of power dissipation. The types of domains were characterized by convergence and divergence of the efficiency of power dissipation, respectively. The convergent domain in a＋fl phase field is at the temperature of 950-990 ℃ and the strain rate of 0.001-0.01 s^-1, which correspond to a better hot compression process window of α＋β phase field. The peak of efficiency of power dissipation in α＋β phase field is at 950 ℃ and 0.001 s 1, which correspond to the best hot compression process parameters of α＋β phase field. The convergent domain in β phase field is at the temperature of 1020-1080 ℃ and the strain rate of 0.001-0.1 s^-l, which correspond to a better hot compression process window of β phase field. The peak of efficiency of power dissipation in ℃ phase field occurs at 1050 ℃ over the strain rates from 0.001 s^-1 to 0.01 s^-1, which correspond to the best hot compression process parameters of ,8 phase field. The divergence domain occurs at the strain rates above 0.5 s^-1 and in all the tested temperature range, which correspond to flow instability that is manifested as flow localization and indicated by the flow softening phenomenon in stress-- strain curves. The deformation mechanisms of the optimized hot compression process windows in a＋β and β phase fields are identified to be spheroidizing and dynamic recrystallizing controlled by self-diffusion mechanism, respectively. The microstructure observation of the deformed specimens in different domains matches very well with the optimized results.
文摘以采集于紫茎泽兰(E up a torium ad enophorum Spreng.)危害较为严重的云南、广西、贵州、四川以及澳大利亚共17个种群的紫茎泽兰为实验材料,采用人工模拟气候法、模糊数学中隶属函数法(测定了净光合速率、M DA、叶绿素荧光)比较了不同种群紫茎泽兰耐热性.结果表明,高温处理后云南元江与其它种群相比热害指数最低、隶属函数值较高,最为耐热,其次为元谋种群;而云南大理种群热害指数较高,隶属函数均值也较低,其次为广西隆林.说明元江、元谋种群较为耐热,而隆林、大理种群则较为敏感.结合其生境来看,恶性杂草紫茎泽兰种群之间的这种差异性反映了其对入侵地环境的适应性.
