The effect of dynamic annealing on dynamic strain aging phenomena in commercial purity titanium

Abstract

A study has been made of the effect of dynamic annealing, associated with climb, on the dynamic strain aging phenomena in commercial purity titanium. In speciemens deformed at a strain-rate of 10⁻⁴ s⁻¹ with an average grain diam of about 17 μm, dynamic annealing starts to become important at the temperature of the major work hardening peak maximum. Metallographic evidence supports a conclusion that the shape of the high temperature side of the peak is determined largely by climb controlled processes. Reducing the grain size to 6 μm lowers the temperature, at which dynamic annealing becomes significant, enough so that the work hardening peak, the “blue-brittle” ductility minimum and the yield stress plateau are either nearly eliminated or greatly reduced in importance.