Department of Materials Engineering, Isfahan University of Technology
In this investigation PVD Ti-Cr)N coatings were deposited on hardened and tempered tool steel substrates using reactive arc evaporation. Physical and mechanical properties of coatings such as roughness, thickness, phase composition, hardness and modulus young and coefficient friction were evaluated. Phase compositions were studies by X-ray diffraction method. The surface microstructure and morphology were studied using scanning electron microscope (SEM) and coating compositions were determined by energy dispersive spectroscopy (EDS). Mechanical Properties were determined by Nano indentation. The friction behavior of the coatings were investigated using ball-on-disc test under normal loads of 7 .The results showed that(Ti, Cr)N and TiN coating had only one solid solution cubic phase While CrN coatings had Hexagonal Cr2N and Cubic CrN phases. Average grain size of the coatings was found in the range of 14 to 20 nm. Physical-Mechanical Properties of CrN and (Ti, Cr)N and TiN coatings, respectively, increases. Mechanical behavior of the (Ti, Cr)N coatings is related to Ti content and hardness decreases with decreasing Ti content.