Influence of Surface Finish on the Tribological Performance of AlTiBN Coatings Deposited on Forming Tools

Coatings based on aluminum and titanium nitrides are widely used in industrial applications due to their versatility and properties (wear resistance, hardness, and oxidation resistance). The addition of elements such as boron can improve the tribological properties. However, the influence of surface finish can strongly influence the performance of the coating. In this study, flat samples with different surface finish and real forming tool components are coated with AlTiBN via PVD. The structure and chemical composition of the coatings are studied using scanning electron microscopy (SEM) and GD‐OES. Rockwell tests are used to evaluate the adhesion to the substrate, and nanoindentation is used to characterize the mechanical properties of the coatings. Pin‐on‐disc tests are carried out to study wear resistance of coated samples. Coated forming tools are used in‐service applications to test the performance of the coating and corroborate the results. The lifetime of components for forming applications increases. The influence of underlaying substrate's roughness is mitigated by the AlTiBN upper coating, thus obtaining similar results to middle polished and high‐quality polished substrates in terms of wear resistance. However, poor polishing and too rough surfaces show direct influence on the wear behavior of the components, presenting higher wear rate values.