Influence of laser texturing sequence on interfacial adhesion and tribological behavior of TiAlN-coated cemented carbide cutting tool

Investigating femtosecond laser surface textured tungsten carbide-cobalt cutting tools to improve coating-substrate adhesion and substrate integrity. Two texturing sequences were evaluated Prior to Coating Texturing and After Coating Texturing. Prior to Coating Texturing offers a more even coating across the entire surface providing substantial conformality, and overly distorted structural features created by laser-induced hardening within the carbide. These characteristics were verified using X-ray photoelectron spectroscopy showing excellent adherence of the Ti-N/Al-N bonds following the laser process. After Coating Texturing resulted in damaged surfaces, such as micro cracks. Scratch testing conducted on both the macaroni tree and the laser tree confirmed that the macaroni tree produced significantly superior interfacial adhesion and formed greater cohesive failure at higher loads based upon representative scratch curve and profilometry images. Scratching of both styles of textured cutting tools clearly identified that the macaroni tree experienced a dramatically delayed cohesive failure compared to the laser-textured tree, supporting interfacial stability. Tribological testing illustrated reduced coefficient of friction and decreased wear rates because of the improved mechanical interlock between the coatings and substrates. Lastly, Simulation results support the outcomes of this study, showing uniformity of stress distribution across both styles of textured coated tools. Quantitatively, texturing before coating resulted in higher surface roughness (232.12 nm vs. 92.35 nm), reduced friction (−20.13 N), and lower cutting temperatures (≈110 °C reduction). This approach effectively enhances adhesion, wear resistance, and cutting stability for high-performance industrial tools.