Pseudo-spinodal mechanism approach to designing a near-β high-strength titanium alloy through high-throughput technique

Abstract

The main reason for the high strength in near-β titanium alloys is the ultrafine precipitation of the acicular secondary α phase in the β matrix. The purpose of this study is to use the pseudo-spinodal mechanism to obtain the ultrafine α phase for the design of a new high-strength near-β titanium alloy. Thermodynamic calculations and TC21-(TC21 + 15Mo) diffusion couple composition gradient experiments were used to demonstrate that TC21 + 3Mo alloy can undergo a pseudo-spinodal decomposition to obtain the ultrafine α phase, resulting in a high-strength alloy. By adjusting the heat treatment process to obtain a bimodal microstructure, the alloy exhibits a good balance between ultimate tensile strength (1351 MPa) and plasticity (8.5% strain). Thus, it was demonstrated that the pseudo-spinodal mechanism combined with a high-throughput diffusion couple technique is an effective method for designing high-strength titanium alloys. Pseudo-spinodal mechanism combined with high-throughput diffusion couple technique is an effective method for designing high-strength titanium alloys. TC21 + 3Mo alloy can undergo a pseudo-spinodal decomposition to obtain the ultrafine α phase, resulting in a high-strength alloy. Compared with other alloys, there is considerable potential for application of TC21 + 3Mo alloy.