Influence of cold-rolling and short-time aging on mechanical properties of Ti-20V-4Al-1Sn alloy

This study was conducted to examine the effect of aging treatment for a short time between 6 s and 1.8 ks after cold-rolling on the mechanical proper-ties of the beta titanium alloy Ti-20V-4Al-1Sn. Cold-rolling at between 30% and 70% reduction accelerated hardening with aging at 673 K. It was thought that the dislocations introduced during cold-rolling provided suitable places for alpha fine-phase precipitation. When the alloy was cold-rolled at 70% reduction and then aged at between 673 K and 823 K by induction heating, the a phase precipitation occurred from 6 s and its volume fraction increased with time. As the aging temperature was lower and the aging time was longer, the average distance between the particles of the precipitated alpha phase became small, so that hardness and tensile strength increase was remarkable. In particular, the tensile strength of the alloy was significantly improved to 1510 MPa by aging for 1.8 ks at 723 K after cold-rolling at 70% reduction although ductility was greatly decreased.