Enhancing fine-scale α phase precipitation and mechanical behavior by addition of Cu to metastable β Ti-5553 alloy

Abstract

Metastable β Ti alloys in the β quenched condition exhibit relatively low mechanical strength. Aging heat treatment can improve mechanical strength because of controlled α phase precipitation into the β matrix. This study aimed to examine the aging response of a β quenched Cu-modified Ti-5553 alloy, α phase precipitation therein, and the resulting mechanical behavior. It was found that Cu addition resulted in the precipitation of a nanometric Ti2Cu intermetallic compound, which upon aging, affected α phase precipitation and therefore increased the ultimate tensile strength from 1147 to 1222 MPa at the expense of ductility.