The tribological behaviour of detonation sprayed TiMo(CN) based cermet coatings

The objective of the present study was to evaluate the tribological performance of 200 μm thick TiMo(CN)-28Co and TiMo(CN)-36NiCo coatings obtained using the detonation spray coating system. Towards the above purpose, the detonation spray coating conditions were optimized to obtain the best coating properties (low porosity, high wear resistance) by varying two of the important coating process variables, i.e., oxygen to fuel ratio and gas volume. In both the coatings it was observed that the best tribological performance and also the lowest porosity were obtained at intermediate OF ratios. However, the coatings with the highest hardness did not exhibit the best tribological performance. A comparison of the tribological performance of the optimized TiMo(CN) type coatings with that of optimized WC-Co coatings revealed that the abrasion resistance of TiMo(CN) type coatings is comparable to that of WC-Co coatings. However, the erosion and sliding wear resistance of TiMo(CN) type coatings were considerably lower than that of WC-Co coatings.