Adhesion of AlCrN coating deposited on TiB₂/Ti composites sintered by SPS dedicated for high temperature tribological applications

The aim of the work was to investigate the adhesion of AlCrN coating deposited by PVD method on TiB₂/Ti composites manufactured by Spark Plasma Sintering (SPS). The composites were produced from three kinds of mixtures of powders: (1) Ti and TiB₂, (2) Ti6Al4V and TiB₂ and (3) Ti and B. Each of the mixtures was prepared at 50/50 wt. % ratio of components. Before the coating deposition the specimens were polished to obtain the surface roughness typically required for machine parts. For each set of specimens an individual surface preparation procedure was developed. The coating adhesion was measured using a scratch tester. The process of scratching was carried out to observe the characteristic moments of adhesive and cohesive failures. The highest critical loads were obtained for the coating deposited on composites produced from the mixture of two powders containing pure Ti and TiB₂. (paper)