Texture evolution, silicide precipitation and strength-ductility synergy in a novel α + β titanium alloy during radial forging

This study explored the microstructure evolution and strength-ductility synergy in a novel silicon-containing α + β titanium alloy Ti-5Al-7.5V-0.5Mo-0.5Zr-0.5Si (TC5751S) during radial forging. The results demonstrate that with the increase of radial forging deformation, the strength and plasticity of the alloy are simultaneously enhanced. At a deformation of 0.38, the alloy exhibited a tensile strength of 1120 MPa and an elongation of 21.5%. Strength enhancement was primarily attributed to grain refinement of the equiaxed α_p phase and increased Orowan strengthening from silicide precipitation. The improvement in ductility is mainly attributed to the increased globularization degree of the α_p grains and the weakened texture, which reduce the anisotropy of intragranular deformation, and the incompatibility of deformation between soft and hard-oriented grains, respectively, thereby enhancing the overall plastic deformation capability. Besides, the negligible effect of silicides on ductility was due to their consistently small size, resulting in minimal strain mismatch with the matrix. These results indicate that variations in deformation during radial forging can regulate the microstructure evolution of the alloy, thereby enhancing its strength and ductility.