热加工过程中两相钛合金的α相与β相的协调演变

Evolution of coordination between α and β phases for two-phase titanium alloy during hot working

为了研究两相钛合金中α和β相的协调演变行为,在不同条件下对合金进行热压缩和热处理。研究结果表明,α和β相之间的协调变形能力能影响显微组织演变的均匀性。当变形协调能力较好时,α相保持原来的片状结构,β相的再结晶程度较低。此时,尽管变形较大,但α相与两侧的β相仍保持Burgers取向关系,α和β相之间的原始相界面没有被破坏。随着变形协调能力的下降,片状α相的变形程度及β相的再结晶程度增加。此时,α相仅与一侧的β相保持Burgers取向关系,而与另一侧的β相取向产生偏移,偏移角度在10°以内。当变形协调能力较差时,α相和β相发生较为严重的偏移,界面位错程度增大,α相与周围的β相偏离Burgers取向关系。

The evolution of coordination betweenαandβphases for a two-phase titanium alloy was investigated.For this purpose,hot compression and heat treatment under different conditions were carried out.The results show that the ability of coordinated deformation betweenαandβphases can influence uniformity of microstructure evolution.Specifically,αphase maintains the lamellar structure andβphase has a low degree of recrystallization when the ability of coordinated deformation is good.In this case,αandβphases still maintain the BOR(Burgers orientation relationship),and their interface relationship is not destroyed even at large deformation.Both of the deformation extent ofαlamellae and recrystallization degree ofβphase increase with the decline of ability of coordinated deformation.Theαphase only maintains the BOR withβphase on one side,while the uncoordinated rotation with theβphase on the other side occurs within 10°.Theαandβphases rotate asynchronously when ability of coordinated deformation is poor.The degree of interface dislocation increases,andαandβphases deviate from the BOR.