Predicting the formation characteristics of titanium alloy self-locking nuts

Abstract

Titanium alloy is important for the aerospace industry because of its high specific strength as well as excellent anti-corrosion and anti-oxidative properties. In this paper, a three-dimensional thermo-mechanical coupled simulation was carried out to predict the formation characteristics of a TC4 titanium alloy self-locking nut during the upset forging process. The stability of the upset-forged material was analyzed, and the influences of initial temperature and deformation velocity on the quality of the formed material were investigated. The results show that if the length:diameter ratio of the sample is less than 3.27, the upset-forged material tends to be stable, so we selected a length:diameter ratio of 2.89. Additionally, the properties of the TC4 self-locking nut improved when the initial temperature was increase, and decreased when the velocity of the upper die was increased. Our results provide a theoretical guidance for the formation of TC4 titanium alloy nuts using upset forging.