Microstructure and Wear Properties of WMoNbTaV-Al2O3 High Entropy Alloy Prepared by Spark Plasma Sintering

Abstract:

A new refractory high entropy alloy WMoNbTaV containing Al₂O₃ was prepared by spark plasma sintering. The effects of sintering temperature on densification behavior, phase structure, microstructure and wear resistance of the alloy were studied. The results show that when sintered at 1800?1900 °C, the matrix of WMoNbTaV-Al₂O₃ has a single bcc phase structure, and the average grain size of Al₂O₃ is 1.15 μm. With the increase in sintering temperature, the grain size of the alloy increases, the density and microhardness also increase, and the hardness reaches 7967.4 MPa when the sintering temperature is 1900 °C. The alloy sintered at 1900 °C has excellent wear resistance, and the wear amount is only half of that of the alloy sintered at 1800 °C. The wear resistance of WMoNbTaV-Al₂O₃ high entropy alloy is much higher than that of pure W material. When the abrasive particle size is 37.5 μm, the wear mass loss of alloy sintered at 1900 °C is 0.9 mg, and the wear resistance of alloy is 83 times higher than that of pure W material.

Key words:spark plasma sintering;refractory high entropy alloy;microstructure;wear