Effect of Si addition on the microstructure and tribological properties of FeCrNi medium entropy alloy

FeCrNi medium-entropy alloys (MEAs) have attracted widespread attention due to the excellent toughness and corrosion resistance, but its relatively low hardness results in poor tribological properties. Herein, a series of FeCrNiSix MEAs (x = 0, 0.1, 0.15, and 0.2) were prepared by arc melting and their tribological behavior was systematically investigated. The results showed that Si doping promoted the precipitation of fine σ particles in the FCC matrix, which not only enhanced the hardness, but also reduced the scratching of the wear surface by the counterpart ball. The friction coefficient and specific wear rate of the Si0.2 MEA decreased significantly (0.53 and 5.53 × 10−4 mm3/(Nm)), which were reduced by 24% and 28%, respectively, compared with the base alloy. This study provides effective guidance for improving the wear resistance of high-performance structural materials.