Structurally different interfaces between electrospark-deposited titanium carbonitride and tungsten carbide films on steel

Protective hard coatings on steel that are produced by electrospark deposition (ESD) methods that do not require vacuum conditions are compared, and the interfaces formed are interrogated by a combination of analytical methods. A titanium carbonitride (TiCN) coating is produced and compared to a tungsten carbide (WC) ESD coating. Following deposition onto a 4140 grade steel substrate, the coatings were compared by X-ray photoelectron spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, atomic force microscopy, X-ray diffraction, and nanoindentation test to determine Young's modulus as an indicator of mechanical strength. It was found that the coatings produced void- and impurity-free interfaces but that the interfaces are drastically different for the two coatings investigated and some of the differences can be explained based on the different melting points of the two materials that affect the process of ESD.