Achieving outstanding room and high-temperature mechanical properties matching in a near α high-temperature titanium alloy with fine lamellar microstructure and nanosilicides

Abstract

Achieving an optimal balance between room temperature and high-temperature mechanical properties in near-α titanium alloys is a significant challenge. This task requires careful material design and processing strategies, where high-strength ductility synergies can be achieved through severe plastic deformation (SPD) to obtain lamellar structures and well-dispersed nanosilicides. In this study, the alloys exhibited a room temperature tensile strength of 1118.4 MPa and ductility of 15.2%. At 650°C and 700°C, the tensile strengths were 772.5 MPa and 618.7 MPa, with ductility of 20.5% and 48.1%, respectively. Refined primary α lamellae and silicides activate a pyramidal <c + a> slip system during deformation, enhancing room temperature ductilities. At high temperatures, grain boundaries and silicides resist α_p deformation, improving high-temperature strength. These findings provide a crucial theoretical and practical foundation for developing titanium alloys with outstanding mechanical properties at both room and elevated temperatures.