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 (/) and a difference in atomic radii of alloying element/s and the base element (Δ), is proposed to predict the twin formation in titanium alloys. The revised / versus Δ 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 / versus Δ diagram. The conventional maximum limit reported for the twinning in titanium alloys is / = 4.20; however, it has been found that twinning in titanium alloys is possible up to the / of 4.30.