Investigation of mountainous laser texturing for improving the adhesion and tribological properties of AlCrN coatings

The effect of mountainous laser texturing on improving the interfacial adhesion and tribological properties of WC-TiC-Co-based AlCrN coatings was studied, which is crucial for the durability of AlCrN coatings. The substrate surface was modified by nanosecond lasers with different powers to prepare mountainous laser texturing with different dimensions. The AlCrN coatings was deposited on the textured substrate surfaces by PVD. The micromorphology, elastic modulus, hardness and surface roughness of textured surface and coatings were obtained. Scratch tests and friction tests were carried out to evaluate the adhesive strength and friction properties of AlCrN coatings on the textured substrates. The results showed that the dimensions of mountainous laser texturing increased with the increase of laser power. The adhesion and tribological properties of the coatings deposited on textured substrates were effectively improved compared to that on polished substrate. Compared with the coatings on polished substrate, the adhesion of the coatings on the laser textured specimen with the power of 6 W increased by up to 37.7%, while the wear depth was reduced by up to 90%. The main mechanism was that the mountainous laser texturing increased the interface contact area and caused mechanical anchorage between the coatings and the substrate. In addition, the laser texturing improved the wettability and surface energy of the substrate surface.