Ta-7.5%W在退火过程中的组织和织构演变

Microstructures and textures evolution of Ta-7.5%W during annealing process

通过金相组织观察、透射电子显微镜(TEM)及显微硬度测试,研究冷轧变形量为95%的Ta-7.5%W合金箔材在1050,1200和1360℃退火时的组织和性能变化,并采用取向密度函数(ODF)分析在此过程中其织构演变规律。对其实验结果进行研究发现:冷轧态Ta-7.5%W合金硬度为HV300,经1360℃退火后硬度迅速减小,说明此时合金已发生回复再结晶。轧制后的Ta-7.5%W合金箔材具有各向异性,在轧面//{111}取向上形成位错胞亚结构,在轧面//{100}取向上形成了形变带,冷轧态的主要织构为{001}110,{112}110和{110}110织构;在1200℃退火时,在轧面//{111}取向上,再结晶通过亚晶界迁移、亚晶长大形核,而在轧面//{100}取向上,主要是通过亚晶转动、聚合形核;{001}110织构增强,{112}110织构减弱;在1360℃退火时,{001}110织构急剧减弱,{111}112织构增强。

The organization and performance evolution of Ta-7.5%W at 1 050, 1 200 and 1 360℃ were investigated by microstructure observation, transmission electron microscope （TEM） and hardness tests, and the texture evolution was investigated by orientation density function （ODF）. It was found that after 1 360 ℃ annealing the hardness decreases rapidly from HV 300 to HV 240, and the recovery recrystallization occurs. Ta-7.5%W is anisotropic; the dislocation substructure appears in {111} orientation and the deformation zone appears in {100} orientation. The main textures of cold-rolled Ta-W alloy are {001} （110）, {112} （110） and {110} （110）. As the annealing temperature is 1 200℃, the recrystallization nucleation is mainly through the migration of the subgrain boundary and the growth of the subgrain in { 111 } orientation, while the recrystallization nucleation is mainly through the rotation and polymerization of the subgrain in { 100} orientation; the texture of {001 } （110） increases and the texture of { 112} （110） decreases. While annealing at 1 360℃, the texture of {001 } （110） decreases rapidly, and the texture of { 111 } （112） increases.