The effect of 0.3 wt% oxygen on mechanical properties of a TiZrAl alloy prepared by vacuum arc melting

Firstly, the phase and microstructure of vacuum arc melted hexagonal close-packed (HCP) medium-entropy Ti-40Zr-6Al alloy with 0.2-0.4 wt% oxygen (O) addition are studied, the results show that the addition of 0.2 wt% O has no obvious effect on the microstructure, and the addition of 0.4 wt% O results in compounds, only 0.3 wt% O can refine the microstructure on the basis of no compounds. Therefore, the effect of 0.3 wt% O addition on room temperature tensile properties and high temperature creep properties of Ti-40Zr-6Al alloy are studied in depth. The tensile strength, the work hardening rate and the elongation are all improved by 0.3 wt% O addition, the high strength of 1300 MPa and the elongation of 12.7% are obtained. In addition, creep resistance is increased by 0.3 wt% O addition, and {1011} creep twinning along with the dislocation movement became the main creep mechanism as 0.3 wt% O addition in Ti-40Zr-6Al alloy. The present study shows a new perspective to enhance comprehensive mechanical properties and creep resistance by addition appropriate O in Ti-based alloys and thus should be of interest.