Formation of hardened layer in WC–TiC–Co alloy by treatment of high intensity pulse ion beam and compression plasma flows

The effect of treatment by high intensity pulse ion beam (HPIB) and compression plasma flow (CPF) with energy density greater than 10 J/cm2 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 (W1−xTix)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/cm2 provides convective mixing of meltʹs components and forms fused layer, the thickness of which reaches 8–10 µm (40 J/cm2). The hardness of the surface layer containing oversaturated (W1−xTix)C solid solution with the thickness of several microns exceeds the hardness of untreated hard alloy in 2 times.