Influence of Interfacial Oxides Formed During Dry Sliding Wear of NiCrBSiCFe Plasma Coating on AISI 316 Steel Substrates

Recent thermal spray processes such as plasma spraying are usually employed to deposit Nickel–Chromium coatings onto the AISI 316 steel substrates to improve the wear resistance. Ni-base alloys, which are widely used to obtain wear resistant coatings, are usually heat treated after thermal spraying to improve their tribological properties. The dry sling wear experiments were carried out in pin on disc tribometer at room temperature 35 °C (308 K), 150 °C (423 K), 250 °C (523 K) and 350 °C (623 K) against medium carbon steel (EN8). The worn surfaces were examined by X-ray diffraction and SEM (Scanning Electron Microscopy) with EDS (Energy dispersive spectroscopy). The applied load was 40 N and sliding speed was 2 m/s. In 350 °C, the wear rate was marginally lesser than the rest of the temperatures due to the initiation of oxide layer formation, which was also substantiated by SEM and EDS. Fe peaks and O peaks were found scarcely. Few Fe peaks were also predominantly noticed by EDS analysis. The presence of Fe3O4 in the tribolayers formed during sliding wear acted as a protective film to retard the wear rate in terms of mass loss.