Wear Resistance of High-Entropy Alloys

Abstract

The tribotechnical properties of high-entropy alloys in pair with 65G steel in air under dry sliding friction conditions are investigated in comparison with wear-resistant steel and powder materials. The sliding friction rate was 6, 8, and 12 m/sec and the pressure was 0.5 and 1.0 MPa. It is determined that the wear intensity of high-entropy alloys at the sliding friction rate 5–10 m/sec under 0.5 and 1.0 MPa loads ranges from 6.1 · 10–10 g/km to 1.6 · 10–9 g/km for the samples and from 5.5 · 10–8 g/km to 1.1 · 10–8 g/km for the counterface. It is established that, when friction, the shear deformations promote the formation of thermally stable nanostructures with grains 30–70 nm in size in the surface layer of the secondary structures. It is shown that the formation of nanostructures is accompanied with 20–30% increase in hardness for both high-entropy alloys and counterface material. It is established that, when friction, high temperatures at the contact points promote the formation of ordered β-phase with BCC lattice on the friction surface of the Fe25Cr20Ni20 Mn15Co10Al10 high-entropy alloy.