Comparison of the PVD coatings

Purpose: of the paper was comparison of the structure, adhesion and wear resistance of the monolayers CrN and TiN PVD coatings deposited onto plasma nitrited X37CrMoV5-1 type hot work tool steel. Design/methodology/approach: Diffraction and thin film structue were tested with the use of the transmision electron microscopy. The surfaces’ thopography and the structure of the PVD coatings were observed on the scanning electron microscopy.The evaluation of the adhesion of coatings to the substrate was made using the scratch test. The wear and friction tests were performed on a pin-on-disc device at the room temperature and at the temperature of 500°C. Findings: The best wear resistance in both conditions (20°C, 500°C temperature) demonstrate the TiN coating. These test results correspond with the very good adhesion of the coating to the substrate material and its high hardness. The critical load Lc5 (coating total delamination) lies within the range 86-92 N, depending on the coating type. It was revealed that the coating damage mechanism in the scrtch test commences in all cases with the widespread coating at the edge of the scratch being made and next develops depending on the coating type and location of the originated defects. Practical implications: The good properties of the plasma nitriding and the PVD coatings make them suitable in various engineering and industrial applications. Originality/value: The duplex surfaces treatment of the hot work tool steel for tools made for work at the elevated temperature improves their abrasion wear resistance significantly, compared to coatings developed with the PVD process.