预变形TA2剪切带中微观组织的演变  

Microstructural Evolution in the Adiabatic Shear Bands of Predeformation TA2

作　　者：李淑华[1] 王富耻[2] 谭成文[2] 陈志永[2] 孙智[2] 

机构地区：[1]解放军军械工程学院,河北石家庄050003 [2]北京理工大学,北京100081

出　　处：《稀有金属材料与工程》2007年第9期1527-1529,共3页Rare Metal Materials and Engineering

基　　金：国家"973"资金资助项目(510003)

摘　　要：采用HOPKINSON压杆装置和帽形试样对工业纯钛TA2进行高速冲击,利用扫描电镜(SEM)、透射电镜(TEM)、和高分辨透射电镜(HREM)研究剪切带内部微观组织的演化过程。结果表明:剪切带内没发生相变,剪切带组织由细小的等轴晶组成,剪切带内的动态再结晶过程是通过晶粒机械碎化及晶界迁移、亚晶粗化的混合机制和渐进式亚晶位向差的再结晶机制共同作用完成。Microstructural evolution of the adiabatic shear bands originated by the deformation of high strain for TA2 has been examined. Tests were performed using a specially designed stepped specimens in a Hopkinson bar. Upon completion of deformation, the region is cooled below half the temperature achieved during adiabatic heating for less than one millisecond. Microsturctural characterizations of shear bands were analysed using SEM, TEM and the TEM of high resolving power. No evidence of transition from a-Ti to another phases within the adiabatic shear bands could be found. However, the kinetics of boundary refinement processes were not taken into account in these studies with the distinctive characteristic of recrystallized microstructure. It is shown that there is no phase transformation in the TA2 adiabatic shear bands, which are composed of fine equiaxed grains. The dynamic recrystallization in the TA2 adiabatic shear bands was performed by the mixed mechanism of grain mechanical fragmentation, grain boundary transfer and subgrain roughen, and the recrystallization mechanism of progressive subgrain misorientation.

关 键 词：TI 热剪切带 回复 动态再结晶 

分 类 号：TG115[金属学及工艺—物理冶金]