变形近 α 钛合金局部组织不均匀性与局部织构的关联性

Connection Between Local Microstructure Heterogeneity and Local Texture in Deformed Near-α Titanium Alloy

摘要:

一种具有双态组织的近α钛合金经压缩变形后微观组织呈现出不均匀性。利用电子背散射衍射技术分析了局部织构对组织形貌的影响，通过取向数据处理研究了初生α相（α_p）和β相微织构。结果表明，局部组织不均匀性和局部织构之间具有紧密联系。引入角θ定量分析α_p相与相邻β相偏离Burgers取向关系程度，发现在具有粗大β晶粒的区域内具有较小θ角的α_p/β界面体积分数高于完全再结晶的β晶粒区域。α_p相和β相之间的取向关系不仅影响原始β晶粒变形过程中再结晶，还通过影响变体选择对转变α相形貌产生影响。

Abstract:

A heterogeneous microstructure was found in a compressed near-α titanium alloy with a bimodal microstructure. The effect of the local texture on microstructural morphology was analyzed by electron backscattering diffraction techniques. Advanced orientation data processing was performed to study the micro-texture of primary α (α_p) and β. The results show that there is a close relationship between local microstructure heterogeneity and local texture. The deviation angle θ can be used to quantitatively evaluate the orientation relationship (OR) between α_p and the surrounding β grains from Burgers OR. The fractions of the α_p/β boundary with small θ are always higher in the regions where coarse β grains exist than in the regions where the β grain is completely recrystallized. The orientation relationship between α_p and β affects the recrystallization of prior β during deformation; it also exerts effects on the morphology of the transformed α phase by variant selection.