Trigger stress for stress-induced martensitic transformation during tensile deformation in Ti-Al-Nb alloys: Effect of grain size

Abstract

The effect of beta grain size on trigger stress for stress-induced martensitic transformation during tensile deformation in Ti-Al-Nb alloys was investigated. The trigger stress for stress-induced martensitic transformation (SIMT) in Ti-Al-Nb alloys exhibited a U-shaped behavior with variation in grain size. The variation of trigger stress with grain size was explained qualitatively, in terms of the contrasting change in the internal elastic energy stored in matrix due to formation of martensite (Delta E (el) ) and the irreversible work done in overcoming the internal frictional resistance to phase boundary movement (partial derivative E-irr) with beta grain size.