Evolution of coordination between α and β phases for two-phase titanium alloy during hot working
(1. Shaanxi Key Laboratory of High-Performance Precision Forming Technology and Equipment, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China;
2. Defense Technologies Innovation Center of Precision Forging and Ring Rolling, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China;
3. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China)
2. Defense Technologies Innovation Center of Precision Forging and Ring Rolling, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China;
3. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China)
Abstract: The evolution of coordination between α and β phases 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 between α and β phases can influence uniformity of microstructure evolution. Specifically, α phase maintains the lamellar structure and β phase has a low degree of recrystallization when the ability of coordinated deformation is good. In this case, α and β phases still maintain the BOR (Burgers orientation relationship), and their interface relationship is not destroyed even at large deformation. Both of the deformation extent of α lamellae and recrystallization degree of β phase increase with the decline of ability of coordinated deformation. The α phase only maintains the BOR with β phase on one side, while the uncoordinated rotation with the β phase on the other side occurs within 10°. The α and β phases rotate asynchronously when ability of coordinated deformation is poor. The degree of interface dislocation increases, and α and β phases deviate from the BOR.
Key words: coordination ability; titanium alloy; orientation relationship; globularization; recrystallization