Effect of deformation-induced ω phase on the mechanical properties of metastable β-type Ti-V alloys

Abstract

A series of metastable β-type binary Ti( 1822) V alloys were prepared to investigate the effect of deformation-induced products (deformation-induced ω phase transformation and mechanical twinning) on the mechanical properties of metastable β-type titanium alloys. The microstructures, Young's moduli, and tensile properties of the alloys were systemically examined. Ti( 1820) V alloys subjected to solution treatment comprise a β phase and a small amount of athermal ω phase, while Ti22V alloy subjected to solution treatment consists of a single β phase. Ti( 1820) V alloys subjected to solution treatment exhibit relatively low Young's moduli and low tensile strengths as compared to cold-rolled specimens. Both deformation-induced ω phase transformation and {332} βh113i β mechanical twinning occur in all of the alloys during cold rolling. The occurrences of {332} βh113i β mechanical twinning and deformationinduced ω phase transformation are dependent on the β stability of the alloys. After cold rolling, all of the alloys comprise a β phase and an ω phase. The Young's moduli of Ti( 1822) V alloys increase because of the formation of a deformation-induced ω phase during cold rolling. The significant increase in tensile strength is attributed to the combined effect of the deformation-induced ω phase transformation and workhardening during cold rolling. © 2012 The Japan Institute of Metals.