The Effect of TiC and Zr Additions on the Microstructure and Mechanical Properties of Ti-30Mo Alloy

In this study, Ti-30Mo-nTiC (0, 0.5 wt.%) and Ti-30Mo-0.5TiC-xZr (0, 4, 8, 12 wt.%) alloys were prepared using the powder metallurgy process with the addition of Zr at different rates. The effect of TiC and Zr additions on the microstructure and mechanical properties of the Ti-30Mo alloys were investigated, respectively. The results demonstrated that the addition of 0.5 wt.% TiC significantly improved the density, tensile strength and elastic modulus. The ultimate tensile strength, elongation and elastic modulus of the Ti-30Mo-0.5TiC alloy were determined to be 825 MPa, 7.3% and 112 GPa, respectively. For Ti-30Mo-0.5TiC-xZr alloys, the addition of Zr (8 wt.% or less) results in alloys having a high relative density (>98%), with the density of the alloy decreasing significantly when the Zr content is 12 wt.%. As the Zr content increases, the β phase lattice constant also increases along with the amount of carbide aggregation. This leads to a decrease in the alloy strength, with an increase in the alloy hardness. During high temperature tensile testing at 600 °C, the Ti-30Mo-0.5TiC alloy still had suitable mechanical properties, with its ultimate tensile strength and elongation being 472 MPa and 12.8%, respectively.