High-temperature compression behaviour and phase analysis of additively manufactured Ti45V45Al5Cr5 medium-entropy alloy

This manuscript describes study of solidification behaviour, high-temperature compression behaviour, phase evolution, and microstructure of novel lightweight Ti45V45Al5Cr5 medium-entropy alloy (MEA) developed by micro-plasma powder additive manufacturing (µ-PPAM) process. Solidification behaviour of Ti45V45Al5Cr5 MEA predicted by Thermo-Calc simulation indicated complete solidification of BCC and HCP phases at temperatures up to 2000 K and 900 K, respectively. Previously identified optimum parameters of µ-PPAM process were used for multi-layer deposition of the MEA. The developed MEA showed 590 MPa compressive strength at 900 °C which is enabled by solid solution strengthening, formation of the precipitates, reduced grain growth, and phase decomposition at the elevated temperatures. Its microstructural analysis revealed the presence of two distinct phases with overall BCC crystal structure of Ti–rich and V-rich phases. Its elemental colour mapping indicated that V-rich phase is enriched with Cr and Ti–rich phase is enriched with Al. The developed MEA will be useful in aerospace applications requiring high-temperature strength.