Laser texturing of substrate of coated tools - Performance during machining and in adhesion tests

In machining, a laser beam with a high density of energy can be used to promote nano- or microstructural surface changes of the substrate of the tools with the goal of improving the adhesion of the coatings. The detachment and fragmentation of coatings during machining will compromise tool performance by the premature exposition of the substrate and may cause wear by fragments of hard and abrasive particles. The goal of this study is to test this new technology of laser texturing of cemented carbide inserts of ISO K grade before coating them with TiAlN and AlCrN. The performance of these laser-textured tools was compared with that of microblasted tools (the commercial technique normally used). Tool life tests in face milling of compacted graphite cast iron (CGI, grade 450) were carried out and the adhesion of the coated layers to the substrates of the tools was characterized by Rockwell indentation tests and scratch tests with a progressive load. The tool life results showed that the laser-textured tools outperformed the microblasted commercial cutting tools under the conditions tested. The adhesion results measured by scratch and Rockwell indentation tests showed greater delamination of the microblasted tools than of the laser-textured tools.