Controllable preparation of micro-textures on WC/Co substrate surface by an integrated laser-dry etching process for improving PVD coatings adhesion

Abstract

The micro-texture fabricated on the substrate surface of coatings is an established method for enhancing the Physical Vapor Deposition (PVD) coatings adhesion. Currently, laser micromachining is widely used to prepare the micro/nano-texture. Nevertheless, it has a problem of low processing accuracy, such as irregular texture edges and irregular protrusions inside the textures. Here, we propose an ion beam etching (IBE)-assisted laser machining approach to fabricate micro-texture, and the effect of IBE/laser textures on the PVD coatings adhesion is revealed for the first time. The profile evolution mechanism of the micro-textures on the cemented carbide during etching process was investigated. By IBE-assisted laser machining, a ring-shaped microholes array with high precision and controllability was fabricated on the cemented carbide substrate surface. Then, the textured substrates were coated with TiAlN materials using cathode arc-evaporation technique. The scratch tests and dry wear tests on the coatings with the textured substrates were carried out, demonstrating that the IBE/laser textured coatings exhibited higher adhesive strength compared to that of the untextured and laser textured ones. Thus, the IBE-assisted laser machining shows a great potential in the preparation of high precision micro-textures for enhancing PVD coatings adhesion.