Wear resistance and hardness properties of TiB2– Fe coating developed on AISI 1020 steel by tungsten inert gas (TIG) cladding

Abstract

The present work is attempted to improve the microhardness and wear properties of AISI 1020 steel by depositing TiB2–Fe composite coating using tungsten inert gas (TIG) cladding. In this study, different compositions of TiB2–Fe paste form were preplaced on the substrate plates and then TIG heat input was applied to deposit hard composite coating layer. The main objective of the present work was to explore the influence of TIG input current as well as iron content on the microstructure and surface properties of deposited coatings. Microhardness, microstructural and phase characterization of the coating have been done by the Vickers microhardness tester, scanning electron microscope (SEM), Energy dispersive spectroscopy (EDS) and X-ray diffractrometer (XRD). The results showed that the microhardness of the TiB2–Fe coating was strongly influenced by the composition of the coating materials as well as the TIG processing current. The microhardness increases with decreasing Fe contents in the coating materials with constant processing current (90 A) as well as it also increases with decreasing processing current with the fixed composition of coating materials (80TiB2–20Fe). The maximum average microhardness found was 3082 HV0.1 for the coating of 100TiB2–0Fe composition ratio and 90 A processing current which was about 18 times higher than that of the substrate average microhardness value (163 HV0.1). Average wear rate evaluated by considering weight loss of the TIG cladded samples using pin on disc tribometer by the sliding distance of 864 m and 20 N normal loads. The wear results also showed that the coating contains 100 wt% of TiB2 (0 wt% of Fe) exhibited lower rate of wear 6.74 × 10−8 g/Nm which is about 24 times lower as compared to AISI 1020 mild steel wear rate (166.31 × 10−8 g/Nm).