Influence mechanism of AlCoCrFeNi content on the wide temperature domain tribological properties of WC-based cemented carbides

Abstract

High-entropy alloys (HEAs) are a new class of materials with excellent properties, and the preparation of WC/HEA-cemented carbides has significant application prospects. Therefore, WC/HEA-cemented carbides with different HEA weight ratios (x = 10, 20, and 30 wt%) were prepared by hot-pressing sintering, which included WC1H, WC2H, and WC3H cemented carbides, respectively. It was found that the distribution of the bonding phase in the cemented carbide block changed from a sporadic distribution to a large aggregated distribution and then to a mixed distribution of large aggregates and small dispersions as the proportion of HEA increased in WC/HEA-cemented carbide. The HEA in WC1H and WC3H had a face-centered cubic (FCC) structure, whereas the HEA in WC2H had a body-centered cubic (BCC) structure. The hardness and density of the WC/HEA cemented carbide both decreased with increasing HEA content. With an increase in temperature, the wear mechanism mainly changes from abrasive wear to fatigue wear, and then to oxidation wear. The BCC structure formed by WC2H contributed to the better friction stability of WC2H over a wide temperature domain. When the mass proportion of the HEA is below 30%, a continuous frictional oxide layer cannot be formed at high temperatures to reduce wear and abrasion.