Experimental Investigation on Tribological Performance of TiB2-CoTi Composite Coating Fabricated on AISI 304 Stainless Steel by Argon Arc Cladding Technique

Abstract

In this study, TiB₂-CoTi composite coatings were fabricated on AISI 304 stainless steel (SS) substrate through argon arc cladding (AAC) technique. The effects of AAC processing currents and weight percentage of titanium (Ti) content on mechanical and wear rate of the coatings have been examined. Microstructural and element distribution maps, as well as phase analysis of the produced coating, were determined using field emission scanning electron microscopy, energy-dispersive spectroscopy, and x-ray diffraction. Results revealed that the coating exhibited good metallurgical bond to the substrate with columnar and network-shaped dendrite structure. The top surface of composite coatings was mainly comprised of TiB₂, NiTi, TiB, Co₃Ti, Co₂B, CoTi, and α-Ti phases. Components of the composite phases were beneficial for improved microhardness and reduced the wear rates. The maximum average microhardness of TiB₂-CoTi composite coating was achieved as 1582 HV_0.1. This is significantly seven times higher than that of AISI 304SS substrate hardness (223 HV_0.1). The wear rate of TiB₂-CoTi coating was determined to be 2.53 × 10⁻⁸ g/N m, whereas average wear rate of AISI 304SS substrate was 24.39 × 10⁻⁸ g/N m. The wear resistance of the TiB₂-CoTi coating was 9 times higher than that of AISI 304 SS substrate. Its durability and performance under challenging conditions suggest that it is suitable for applications that demand superior durability and performance.