Microstructure and wear performance of spark plasma-sintered AlCrFeMnNiW0.5 high-entropy alloy

Abstract

In this study, we prepared the AlCrFeMnNiW_0.5 high-entropy alloy (HEA) by mechanical alloying (MA) and subsequent spark plasma sintering (SPS). The investigation focused on the alloy's phase composition and microstructural characteristics. The milled powders revealed a single-phase BCC solid solution. After SPS, the sample exhibited a sigma phase (σ), ordered B2, BCC, and minor FCC phases with high hardness of 839 ± 10 HV. To assess the wear behavior of HEA, dry sliding tests were performed at room temperature by varying the normal load from 2 to 15 N at a constant sliding velocity (6 cm/s) and sliding time (10 min). The results found that the coefficient of friction (COF) decreased from 0.16 to 0.12, while the specific wear rate reduced from 2.49 to 1.65 × 10⁻⁵ mm³/Nm with increasing normal load. These findings indicate exceptional wear resistance in this HEA compared to other HEAs, attributed to its superior hardness. Consequently, the tungsten-containing high-entropy alloy demonstrates significant importance for outstanding hardness and wear resistance, as discussed comprehensively in this work. Moreover, tungsten-containing HEAs broaden their potential applications across diverse industries such as cutting tools and the aerospace industry, offering enhanced performance, extended service life, and improved efficiency in various critical components and tools.