Abstract The effect of treatment by high intensity pulse ion beam (HPIB) and compression plasma flow (CPF) with energy density greater than 10 J/cm 2 on the phase and element composition, microstructure, hardness and depth of modified layer of WC–TiC–Co hard alloy was investigated. It was found that the increase of short-pulse (9 ⁎ 10 − 2 µs) HPIB energy density (due to the increase of pulses number from 3 to 300) led to the fusion of tungsten and titanium carbides particles following to formation of (W 1− x Ti x )C solid solution oversaturated by tungsten. The formation of great number of cracks inside of fused layer and inside of carbide particles allocated below fused layer takes place as a result of impact of power shock waves generated by HPIB at great number of pulses (100, 300). The higher duration (~ 100 µs) of CPF pulse with the energy density of 13–40 J/cm 2 provides convective mixing of melt's components and forms fused layer, the thickness of which reaches 8–10 µm (40 J/cm 2). The hardness of the surface layer containing oversaturated (W 1− x Ti x )C solid solution with the thickness of several microns exceeds the hardness of untreated hard alloy in 2 times.