Effect of Deformation-Induced ω Phase on the Mechanical Properties of Metastable β-Type Ti–V Alloys

Abstract

A series of metastable ¢-type binary Ti­(18­22)V alloys were prepared to investigate the effect of deformation-induced products (deformation-induced ½ phase transformation and mechanical twinning) on the mechanical properties of metastable ¢-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 ¢ phase and a small amount of athermal ½ phase, while Ti­22V alloy subjected to solution treatment consists of a single ¢ 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 ½ phase transformation and {332}¢h113i¢ mechanical twinning occur in all of the alloys during cold rolling. The occurrences of {332}¢h113i¢ mechanical twinning and deformationinduced ½ phase transformation are dependent on the ¢ stability of the alloys. After cold rolling, all of the alloys comprise a ¢ phase and an ½ phase. The Young’s moduli of Ti­(18­22)Valloys increase because of the formation of a deformation-induced ½ phase during cold rolling. The significant increase in tensile strength is attributed to the combined effect of the deformation-induced ½ phase transformation and workhardening during cold rolling. [doi:10.2320/matertrans.M2012116]