On beta forging of Ti-17 alloy

This paper presents the suitable hotworking parameters for Ti-17 alloy forging. The test results for three different methods of forging-β, near β, and normal-show that β and near β are better and that β is a little superior to near β. In the tests, forging temperature ranges from 820-950°C, deformation degree ranges from 10% to 70%, and either air or water cooling is used. It is found that the suitable hotworking parameters for β forging are: (1) heating temperature 40-60°C above β transus point (870°C), (2) above 30% deformation, (3) water cooling after forging. Such parameters are conducive to a good combination of strength and ductility. Water cooling after forging can reduce or even eliminate beta brittleness. Beta brittleness is related to coarsening of prior β grain, to grain boundary α, and to morphology and distribution of core α.