Research Status and Prospects of High-Strength Titanium Alloys Fabricated by Selective Laser Melting

Abstract:

High-strength titanium alloys, represented by near/metastable β titanium alloys, have high specific strength, good plastic processing properties, and excellent hardenability, and they can be strengthened through heat treatment to get a better match of strength-plasticity-toughness. They have been widely used in load-bearing components of major equipment in aerospace and other fields. Selective laser melting (SLM), as an important technique in the field of titanium alloy additive manufacturing, has significant advantages such as near-net shaping and integrated forming of complex structures. So it has become a key development technique and cutting-edge direction in the aerospace manufacturing field. This review focuses on the principle and characteristics of SLM, starting from the extremely high heating/cooling rate and unique thermal cycle history of SLMed high-strength titanium alloy, and primarily discusses the microstructural features, phase composition, and mechanical properties of high-strength titanium alloys. The types of heat treatment processes of SLMed high-strength titanium alloy and their main influencing rules are summarized, aiming to provide a reference for obtaining excellent mechanical property match. Finally, drawing upon an analysis of existing research outcomes, the challenges of SLMed high-strength titanium alloys are summarized. It also offers a forward-looking perspective on potential research directions in this field.