Optimized mechanical properties of titanium-oxygen alloys by powder metallurgy

Abstract

Oxygen solid solution-strengthened titanium-oxygen (Ti–O) alloys with ultrahigh yield strength and large ductility were designed and synthesized via high-energy ball milling (BM) combined with spark plasma sintering (SPS) in compression. The morphology, dispersion state, and solid solution microstructure of the Ti–O alloys were optimized by regulating the mixing method, sintering temperature, and added oxygen content. Outstanding properties that include a compressive yield strength of 1220 MPa and large ductility of 36.3% were achieved after 1 h high-energy BM and 1000 °C SPS with the addition of about 1.8 at% oxygen. The grain refinement and oxygen solid solution strengthening indicate that the dense morphology, refined grain size, and oxygen solid solute atoms are responsible for the balance between the superior strength and ductility of the titanium alloys.