Structure, phase composition and mechanical properties of hard alloy treated by intense pulsed electron beams

Phase and structural changes in surface layers of WC–TiC–Co hard alloy treated by intense pulsed electron beams (IPEB) with electron energy of 20 kV are studied. IPEB energy density absorbed by surface layer was 10–80 J/cm2, pulse duration was 100–200 μs. IPEB action with energy density of 30–80 J/cm2 results in the formation of tungsten-supersaturated solid solution (Ti,W)C and transformation WC → W2C caused by melting of surface layers and their subsequent rapid quenching from liquid. Electron beam treatment leads to the formation of layered structure. Changes of structure and phase composition result in the increase of surface microhardness in 1.5–3 times and in the reduction of friction coefficient in 2–3.5 times.