Effect of heat treatment on the microstructure and mechanical properties of TC4 titanium alloy

Abstract

The effects of solution treatment (920∼1080°C) and aging treatment (600∼820°C) on the microstructure and tensile properties of a hot-rolled TC4 titanium alloy were investigated. Increasing solution temperature transforms the microstructure from bimodal to Widmanstädter structure, with equiaxed α area fraction decreasing sharply. Higher aging temperatures coarsen and merge equiaxed α grains, evolving the microstructure from nano-disperse precipitates to coarse lamellae. Aging at 600°C increases yield strength but severely reduces ductility; aging at 820°C lowers strength while slightly recovering ductility due to coarse equiaxed grains. The results provide guidance for heat treatment optimization of TC4 alloy.