Deformation mechanisms in a β-quenched Ti-5321 alloy: In-situ investigation related to slip activity, orientation evolution and stress induced martensite

The deformation behavior of beta-quenched near beta Ti-5321 (Ti-5Al-3Mo-3V-2Cr-2Zr-1Nb-1Fe) alloy was systematically studied using in-situ tensile test monitored by the scanning electron microscopy (SEM). Besides, the electron backscatter diffraction (EBSD) was performed to thoroughly discuss the deformation mechanisms. The results indicated that slip activities, crystal rotation and stress induced martensite transformation were the major deformation mechanisms in the beta-quenched Ti-5321 alloy during in-situ tensile testing. The slip activities were investigated by using the EBSD-trace analysis, which demonstrated that {110}< 111 >, {112}< 111 > and {123}< 111 > slip systems were activated and the {110}< 111 > slip system dominated. Besides, beta grains rotated about 7.8 degrees to accommodate the increased macrostrain. Notably, the stress induced martensite alpha '' which was related to the double yielding behavior during tensile process exhibited multiple characteristics. The different alpha '' variants divided the beta matrix into smaller beta blocks with a typical zigzag morphology, in which one alpha '' variant passed through another one by deflecting its initial growth direction. Moreover, the deformation twinning in martensite alpha '' and slip bands cutting through martensite alpha '' effectively accommodated the local strain. These systematically analysis can provide insightful information about the deformation mechanisms in near beta titanium alloys. (c) 2021 Published by Elsevier Ltd on behalf

Automated summary

The deformation behavior and mechanisms of beta-quenched near beta Ti-5321 alloy were studied using in-situ tensile testing and microscopy analysis. Slip activities, crystal rotation, and stress-induced martensite transformation were identified as the major deformation mechanisms. The dominant slip system was {110}<111>, and the rotation of beta grains accommodated the increased macrostrain. Stress-induced martensite alpha '' exhibited multiple characteristics, and deformation twinning and slip bands effectively accommodated local strain.