硫系玻璃是一种良好的消热差用红外用光学元件材料,广泛应用于红外热成像系统。通过口径f10.4 mm Ge-SeTe硫系玻璃非球面精密模压工艺试验研究,制备出面型精度满足设计要求(PV≤0.5 mm)的模压镜片。测试模压产品折射率和比重发现:模压...硫系玻璃是一种良好的消热差用红外用光学元件材料,广泛应用于红外热成像系统。通过口径f10.4 mm Ge-SeTe硫系玻璃非球面精密模压工艺试验研究,制备出面型精度满足设计要求(PV≤0.5 mm)的模压镜片。测试模压产品折射率和比重发现:模压后镜片折射率和比重都降低,且模压降温速率越快,模压镜片折射率和比重降幅越大,通过松弛理论以及外场方程分析了原因。展开更多
In order to present the microstructures of dynamic recrystallization(DRX) in different deformation zones of hot extruded NiTi shape memory alloy(SMA) pipe coupling,a simulation approach combining finite element method...In order to present the microstructures of dynamic recrystallization(DRX) in different deformation zones of hot extruded NiTi shape memory alloy(SMA) pipe coupling,a simulation approach combining finite element method(FEM) with cellular automaton(CA) was developed and the relationship between the macroscopic field variables and the microscopic internal variables was established.The results show that there exists a great distinction among the microstructures in different zones of pipe coupling because deformation histories of these regions are diverse.Large plastic deformation may result in fine recrystallized grains,whereas the recrystallized grains may grow very substantially if there is a rigid translation during the deformation,even if the final plastic strain is very large.As a consequence,the deformation history has a significant influence on the evolution path of the DRX as well as the final microstructures of the DRX,including the morphology,the mean grain size and the recrystallization fraction.展开更多
文摘硫系玻璃是一种良好的消热差用红外用光学元件材料,广泛应用于红外热成像系统。通过口径f10.4 mm Ge-SeTe硫系玻璃非球面精密模压工艺试验研究,制备出面型精度满足设计要求(PV≤0.5 mm)的模压镜片。测试模压产品折射率和比重发现:模压后镜片折射率和比重都降低,且模压降温速率越快,模压镜片折射率和比重降幅越大,通过松弛理论以及外场方程分析了原因。
基金Projects(51305091,51475101)supported by the National Natural Science Foundation of ChinaProject(20132304120025)supported by Specialized Research Fund for the Doctoral Program of Higher Education,China
文摘In order to present the microstructures of dynamic recrystallization(DRX) in different deformation zones of hot extruded NiTi shape memory alloy(SMA) pipe coupling,a simulation approach combining finite element method(FEM) with cellular automaton(CA) was developed and the relationship between the macroscopic field variables and the microscopic internal variables was established.The results show that there exists a great distinction among the microstructures in different zones of pipe coupling because deformation histories of these regions are diverse.Large plastic deformation may result in fine recrystallized grains,whereas the recrystallized grains may grow very substantially if there is a rigid translation during the deformation,even if the final plastic strain is very large.As a consequence,the deformation history has a significant influence on the evolution path of the DRX as well as the final microstructures of the DRX,including the morphology,the mean grain size and the recrystallization fraction.
