Tribological Characteristics, Phase Composition and Microhardness of Subsurface Regions of WC–(Fe–Mn–C) Composites after High-Speed Sliding on Steel

The authors investigated tribological characteristics, phase composition of worn surfaces and microhardness subsurface regions WC–(Fe–Mn–C) composites with a two-phase (γ + α′) matrix containing 4 wt % Mn (WC–80G4), single-phase γ-iron 20 (WC–80G20) after sliding against disk high-speed steel at contact pressure 5 MPa speeds in the range from 10 to 37 m/s. wear intensity WC–80G4 WC–80G20 increased increasing speed, while rate fixed was approximately three times higher than that WC–80G4. values friction coefficient decrease speed such way were lower those WC–80G20. amount mixed oxide FeWO4 formed during tribo-oxidation composites’ surface directly proportional inversely values. At tribooxidation leads formation larger on compared composite. Indentation Vickers pyramid showed nature indentation resistance tribolayers high (30 m/s m/s) differs for obtained relatively low (10 m/s), namely, characterized by more tough behavior. Measurement below tha recorded fact hardening near-surface and, contrary, softening case Thus, under conditions intensive heating severe plastic deformation surface, structural-phase state substrate composites, which this viscous protective tribolayer is formed, turns out be very important factor. It that, frictional heating, provides effective heterophase composite layer reduces has fracture upon indentation.