Microstructure and Mechanical Properties of the Ti62Nb12Mo12Ta12W2 Refractory High Entropy Alloy Prepared through Spark Plasma Sintering

Abstract

A refractory high entropy alloy Ti₆₂Nb₁₂Mo₁₂Ta₁₂W₂ was prepared by mechanical alloying and spark plasma sintering. The microstructure and mechanical properties of the Ti₆₂Nb₁₂Mo₁₂Ta₁₂W₂ alloy were analyzed. The experimental results show that the microstructure of the alloy is composed of two BCC phases, an FCC precipitated phase, and the precipitated phase which is a mixture of TiC, TiN and TiO. The alloy exhibits good room temperature compressive properties. The plasticity of the sample sintered at 1550 °C can reach 10.8%, and for the sample sintered at 1600 °C, the yield strength can be up to 2032 MPa, in the meantime the plasticity is 9.4%. The alloy also shows high strength at elevated temperature. The yield strength of the alloy exceeds 420 MPa at 900 °C, and value of which is still above 200 MPa when the test temperature reaches 1000 °C. Finally, the compressive yield strength model at room temperature is constructed. The prediction error of the model ranges from − 7.9% to − 12.4%, expressing fair performance.