A feasibility study of preparing MCrAlX/BN composite coatings by electrospark deposition process

MCrAlX/BN composite coatings have been attempted to prepare by electrospark deposition (ESD). The effects of different contents of BN addition (0 wt.%, 1 wt.%, 3 wt.% and 5 wt.%) on the microstructure and hardness of the coatings were presented. The results showed that, with increasing BN contents, the phase composition of the coatings changed from single γ-Ni(Co,Cr) to complex γ-Ni(Co,Cr), (Ni,Co)3B, CrB, TaB2 multi-phases. The microstructure morphology changed from cellular columnar to equiaxed dendrite. The average microhardness of the coatings increased from 450 HV to 850 HV.