Wear Resistance of the Multilayer TiN/Ti(B,N) Coating Deposited on Cold Work Tool Steels

Abstract

Abstract This paper investigates the abrasion and erosion wear resistance of the multilayer coating within the system Ti-B-N applied to samples made of two hardened and tempered tool steels: Böhler grades K390 MC and X155CrVMo12-1. The multilayer coating consists from the thin interlayer TiN deposited directly on steel substrate and the Ti(B,N) coating, with continuous variation of stoichiometric ratio of boron and nitrogen through the thickness of the coating. Near the TiN interlayer Ti(B,N) coating has only a small content of boron while at the surface the layer TiB2 has been obtained. The multilayer TiN/Ti(B,N) coating was produced by the direct current plasma-assisted chemical vapor deposition (dc PACVD) in an industrial furnace with a hot wall. Tests of abrasive wear resistance were performed using an abrasive wear testing machine constructed according to ASTM G65-15, Standard Test Method for Measuring Abrasion Using the Dry Sand/Rubber Wheel Apparatus. The weight loss of samples was measured after a total wear path of 358 m. The test of erosion resistance was carried out by exposing the samples to impact erosion of fine sand particles and by determining the weight loss after 60 min of wear. Worn surfaces were analyzed by scanning electron microscopy (SEM). The results show a significant improvement in the abrasion and the erosion wear resistance of the TiN/Ti(B,N) coating applied to both tool steel samples with compared with the noncoated samples.