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 to 1.6 • 10^–9 g/km for the samples and from 5.5 • 10^–8 to 1.1 • 10^–8 g/km for the counterface. It is established that, during sliding 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 an increase in hardness for 20–30% of both high-entropy alloys and the counterface material. It is established that high temperatures at the contact points during sliding friction promote the formation of an ordered β-phase with BCC lattice on the friction surface of the Fe₂₅Cr₂₀Ni₂₀ Mn₁₅Co₁₀Al₁₀ high entropy alloy.