Effect of Heat Treatment on the Evolution of Microstructure and Mechanical Properties Of A Novel Ti5114 Alloy

Abstract

In this work, the microstructural evolution and mechanical properties of a novel titanium alloy (Ti5114 alloy) during different heat treatment processes were systematically studied. The results showed that the alloy had a multi-scaled structure, which was composed of primary α (αp), acicular secondary α (αs), and nano-sized β particles. The content and size of the αp phase were greatly influenced by solution temperature, but not sensitive to aging temperature. The increase in solution temperature would reduce the content of αp and enlarge the width of αs, which will influence the mechanical properties of Ti5114 alloy. As the aging temperature increased, αs began to precipitate and gradually coarsen, the strength of the alloy increased first and then decreased. Tensile test results of Ti5114 alloy under different heat-treatment regimes indicated that the Ti5114 alloy after the solution treatment at 900 ℃ for 1h and the aging treatment at 550 ℃ for 4 h can achieve a good match between strength (1293 MPa) and plasticity (9.9%).

Keywords: Ti5114 alloy, Multi-scaled microstructure, Mechanical properties, Heat treatment, Strengthening and toughening mechanism