Dependence of mechanical properties on the microstructure characteristics of a near β titanium alloy Ti-7333

In this work, the microstructure and the corresponding tensile properties of the rolled Ti-7Mo-3Nb-3Cr-3Al (Ti-7333) alloy before and after the thermal treatments were investigated. The results show that a strong alpha-fiber texture is developed in the rolled Ti-7333 alloy. The deformed matrix and the texture significantly induce the variant selection of alpha phase. The high strength of the rolled Ti-7333 alloy is attributed to the < 110 > texture parallel to the tensile direction and the dispersed alpha phase within the matrix. After the solution treatment followed by the aging treatment, the texture decreases and the microstructure consists of the equiaxed beta grains, the spheroidal alpha(p) phase and various needle-like alpha variants. Eventually, the alloy could achieve an optimal combination with the strength of about 1450 MPa, the ductility of about 10.5% and a considerable shear strength of about 775 MPa. This balance can be ascribed to the performance of the spheroidal u p phase and various needle-like alpha(s) variants. The results indicate that the Ti-7333 alloy could be a promising candidate material for the high-strength fastener. (C) 2018 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.