Influence of heat treatment on the microstructure and mechanical properties of TC17 Titanium Alloy

Abstract

The influence of heat treatment on the microstructure and mechanical properties of TC17 titanium alloy was investigated by changing holding time before forging and aging temperature after β-forging. A better heat treatment mechanism was chosen according to its working requirements. The results showed that the holding time and aging temperature had a significant influence on microstructures and mechanical properties of TC17 alloy. With the increase of holding time before forging in the single β phase region, the original β grain size enlarge, the strength and fracture toughness decrease, and the plasticity increases. The size of lamellar α-phase bundles enlarge with the rise of aging temperature after β-forging, the orientated relationship becomes simple, and the content of β-transformation increases. And the plasticity and fracture toughness of the alloy increase, the strength and hardness decreases. The fracture toughness is better under the heat treatment mechanism at 873°C/2h +918°C/64min before forging, 800°C/4h,WC+660°C /8h AC after forging, with the high and low cycle fatigue properties meet the technical requirements.