The Effect of α Phase on the Deformation Mechanisms of β Titanium Alloys

The effects of alpha and beta phase interactions on the tensile and creep deformation behavior of beta titanium alloys was studied using Ti-6.0wt.%Mn and Ti-8.1wt.%V as the model two-phase alloys, and Ti-13.0wt.%Mn and Ti-14.8wt.%V as the single-phase beta alloys. The beta phase of alpha-betaTi-8.1V deforms by stress-induced hexagonal martensite (alpha'), while slip and twinning occurs in the single-phase beta alloy with the same chemistry as the beta phase. No stress-induced martensite was observed in the beta or alpha-betaTi-Mn alloys. This behavior is modeled in terms of a number of factors, including elastic interaction stresses between the a and beta phases, coherency between the alpha phase and hexagonal martensite, and beta phase stability.