A multi-deformation mechanisms assisted metastable β-ZrTiAlV alloy exhibits high yield strength and high work hardening rate

Abstract

A metastable β-51.1Zr-40.2Ti-4.5Al-4.2V (wt.%) alloy with both TRIP and TWIP effects, exhibiting high yield strength of 800 MPa, high work hardening rate and good total elongation close to 17.5% was reported. The solid solution strengthening of high content of Ti and the special initial deformation mechanisms result in the outstanding yield strength. Microstructural analyses show that the dominant deformation mechanisms transformed from deformation-induced β→α′ martensitic transformation and kinking band at low strain to deformation-induced β→α′ martensitic transformation, widening and merging of α′ martensite, and {101‾1}α′ twinning at high strain. Changes in the dominant deformation mechanisms at different deformation stages lead to changes in special boundaries, resulting in a substantial high work hardening rate (2000–5440 MPa) until 10% strain. In addition, the reason for the TWIP effect in present alloy is internal {101‾1}α′ twin, which is different from that of the previously reported twins.