Testing the influence of coating thickness PACVD TiN adhesion to the surface of the tool steel for hot work

U radu je opisano ispitivanje utjecaja debljine prevlake na prionjivost na površinu alatnog čelika za topli rad X38CrMoV5–3. Prevlaka TiN je dobivena plazmatski potpomognutim prevlačenjem iz parne faze (PACVD). Debljina prevlake određena je kalotestom i skenirajućom elektronskom mikroskopijom. Prionjivost prevlake ispitana je prema normi VDI 3198 i metodom brazdanja. Ispitivanje nanotvrdoće na karakterističnim mjestima prevlake provedeno je metodom Vickers. Iz provedenih ispitivanja utvrđeno je da položaj obratka u odnosu na smjer nastrujavanja plinova ne utječe na debljinu prevlake niti na kvalitetu prionjivosti prevlake. Značajan utjecaj na debljinu prevlake pokazuje udaljenost dijela prevlačene površine od katode PACVD uređaja. Područje s najvećom debljinom prevlake nalazi se na udaljenosti od 10 do 50 mm od podloge (katode).In this paper, the effect of the coating thickness on the surface adhesion of the hot work tool steel X38CrMoV5–3, is described. TiN coating was produced by plasma assisted chemical vapour deposition (PACVD). Coating thickness is determined by ball rotation test (Calotester) and scanning electron microscope (SEM). Coating adhesion is determined according to the VDI 3198 norm and scratch test. Nanohardness tests were carried out on the characteristic places of the coating and were conducted by the Vickers method. From tests carried out it has been found that the position of the workpiece in relation to the gas upstream flow direction does not affect the thickness of the coating nor the quality of coating adhesion. Distance of the part’s coated surface from the PACVD machine cathode, shows significant influence on the coating thickness. The area with the greatest thickness of the coating is located at a distance of 10 to 50 mm from the base (cathode)