高温变形过程中钛合金微观组织的晶体取向演变特征研究OA

The globularization of α phase has an important effect on the properties of titanium alloys.The globularization process is influenced by the crystallographic orientation and the second phase.The characteristics of orientation evolution of lamellar structure of titanium alloy during globularization were studied by thermal simulation compression tests.The results show that the stress-strain variation trend of different deformation amounts is similar in the process of hot compression,which can be divided into work hardening stage and stress softening stage,and the hardening peak value is similar.However,there are some differences in the microstructure characteristics,50％deformation causes some lamellar dynamic globularization,while 70％deformation causes a large number of lamellar dynamic globularization.This is because with the progress of deformation,the energy and dislocation in the α phase of the lamella gradually accumulate,and some parts of the lamella sag.Finally the β phase is embedded in the sag,causing the lamella to fracture globularization.In the whole dynamic globularization process,α phase and β phase always maintain a nearly Burgers orientation relationship.Based on the morphological evolution of the α phase in the globularization process,the crystal orientation and α/β phase coordination relationship were further studied.The globularization mechanism and α/β phase coordination evolution law were revealed from the perspective of crystallography,and theoretical reference was provided for the study of the relationship between the crystal orientation of α phase and β phase in the globularization process.