TC17钛合金片状组织球化演变及Burgers关系的缺失

The microstructure evolution and the loss of Burgers orientation relationship during dynamic globularization for TC17 titanium alloy

摘要:

采用EBSD技术研究了TC17钛合金片状组织在热变形过程中的球化演变规律，并对比分析了变形前后α相与β相间Burgers关系的变化。结果表明，热变形导致β相发生明显的动态再结晶。变形初期片状组织内部首先形成位错亚结构，随后在动态回复作用下形成小角度晶界；随着变形的增大，亚晶界转化为大角度晶界导致片状α的破裂；破碎α相的相界再通过扩散作用继续迁移，最终实现α相的球化。热变形在改变片状组织形貌和稳定性的同时，也破坏了片状组织中α相和β相间严格的Burgers关系，热变形过程中柱滑移和其他滑移系或孪晶系的启动，是造成α相与β相间严格Burgers关系破坏的根本原因。

Abstract:

The microstructure evolution and the change of Burgers orientation relationship between α and β phase of TC17 titanium alloy with initial lamellar microstructure were analyzed and researched by EBSD. The results shown that dynamic recrystallization of β phase was occured during hot deformation process. Meanwhile, the dynamic globularization of α phase contained the formation of subboundary and the fragmentation of α phase. The fragmentized α phase was eventually transformed to globularized particle. Meanwhile, the strict Burgers orientation relationship between α and β phase was destroyed, which was due to the activation of prismatic slip system and othe slip or twin system.