Microstructure and mechanical properties of Ta-Ti alloy by plasma-activated sintering

Tantalum-based alloys have developed rapidly in the fields of aerospace, nuclear industry, weapons, and national defense heavy industries due to their high melting point, low ductility-brittle transition temperature, and well ductility. However, pure tantalum exhibits low room-temperature strength and intergranular fracture, which is attributable to its strong adsorption to interstitial oxygen during sintering. In this work, high-strength Ta-Ti alloy is achieved by introducing Ti to consume oxygen by forming TiO2 and inhabiting the solution of oxygen in Ta alloys. The Ta-Ti alloys mainly consist of dense Ta matrix and dispersed TiO2 second phase. With the addition of 2 wt% Ti, the Ta-Ti alloy with high densification of 99.2% not only exhibits high ultimate bending strength of 1345 MPa from dispersion strengthening by TiO2 oxides, but also has good plasticity of 6% with a transgranular fracture and numerous dimple. The present work may facilitate the development and industrial application of Tabased alloys.