Sliding wear of borided sintered AISI M2 steel coated with AlTiN/CrN multilayer

In this work, the effect of the combination of solid boriding treatment on High Speed Steel AISI M2 produced by conventional powder metallurgy (P/M) and AlTiN/CrN film deposition by cathodic arc PVD process is evaluated in terms of the ability to withstand load during sliding wear tests and in terms of adhesion of the multilayer film. The wear resistance of the compound was evaluated by pin-on-disc sliding tests using variable speeds (0.1 m/s and 0.3 m/s) and alumina counter-body diameters (3 mm and 6 mm). The boriding treatment in AISI M2 steel promoted the formation of FeB and Fe2B layers. The average hardness of the borided layer (2162 HV0.025) was approximately 2 times greater than the hardness of quenched and tempered AISI M2 steel (945 HV0.025). The average hardness of the multilayer film was 3912 ± 504.76 HV0.025. The Borided + Film (BF) samples presented higher dry sliding wear resistance in all test conditions. For BF samples, wear on the counter-body was greater and the material removed from the counter-body formed a transfer layer onto the track, resulting in negative wear volume for some test conditions. The boriding treatment improved resistance to plastic deformation in both Borided (B) and Borided + Film (BF) conditions.