abstract
- © 2020 Elsevier B.V.In this work, a gas nitriding pretreatment (iron nitrides layer) formed on the surface of 4140 steel is proposed to improve the adhesion and wear resistance of the AlCrN coatings deposited by arc cathodic PVD. AlCrN, FexN and AlCrN/FexN (duplex) systems were formed with total thicknesses of 3, 10 and 13 µm, respectively. Using spherical instrumented indentation, hardness more than 22 GPa were determined for the AlCrN-based coatings, meanwhile 10 GPa for the iron nitrides. The adhesion of the coatings were evaluated by progressive load scratch tests (PLST) where the duplex coating reduced the CoF and changed the failure mode from adhesive to cohesive for the AlCrN coating. The AlCrN/FexN coating exhibited the lowest specific wear rate and the severity of damage was reduced in multipass scratch wear tests (MPST). The duplex system presented the best adhesion and wear resistance.