Revised Semiempirical Approach to Predict the Occurrence of Twinning in Titanium Alloys

A revised semiempirical approach, considering the average values of the valence electron to atom ratio (e/ā) and a difference in atomic radii of alloying element/s and the base element (Δr¯), is proposed to predict the twin formation in titanium alloys. The revised e/ā versus Δr¯ diagram is plotted, considering the reported results of 90 titanium alloys fabricated using various processing methods. A new twin/slip boundary has been plotted and recommended based on the revised e/ā versus Δr¯ diagram. The conventional maximum limit reported for the twinning in titanium alloys is e/ā = 4.20; however, it has been found that twinning in titanium alloys is possible up to the e/ā of 4.30.