Characterization of surface properties of TiC ceramic coating developed on AISI 1020 steel

Abstract

The aim of this research was to develop the TiC ceramic coating on the AISI 1020 steel substrate by a tungsten inert gas cladding (TIG) process and to comprehensively assess the surface properties of deposited TiC coatings. Various TIG currents were employed to deposit the TiC coating. The study included a detailed investigation of the two pivotal aspects: wear rate and microhardness. Additionally, a comprehensive examination of the microstructure and the presence of different phases in the coating layers was done. TiC ceramics were found to be dispersed remarkably and uniformly over the whole coating region, as revealed by scanning electron microscopy (SEM) examinations. Additionally, it was noted that neither the coating area nor the interfacial areas included any harmful flaws like voids or cracks. The results of this experiment clearly showed that the processing current and the subsequent wear resistance and microhardness were directly correlated. In particular, it was shown that wear resistance and microhardness both showed a noticeable increase when the processing current decreased. The coating developed at lower proceeding current 80 A found the most remarkable results, achieving a peak microhardness of 2846 HV0.1 and an impressively low wear rate of only 10.96 × 10−8 g/Nm. These extraordinary results can be directly attributable to the hard TiC phase's significant presence inside the coatings layer. Due to its improved wear behaviour and microhardness as compared to untreated mild steel, pure TiC-coated AISI 1020 steel finds a suitable material for application in wear-resistance components where hardness is considered as a crucial factor. The TiC coating has achieved an exceptionally high friction coefficient, making it particularly valuable for applications within the automobile industry.