Characterization of TiN, CrN and (Ti, Cr) N Coatings Deposited by Cathodic ARCEvaporation

In this investigation, physical vapor deposited Ti-Cr-N coatings were coated on tool steel substratesusing reactive arc evaporation. Microstructure and mechanical properties of coatings such asroughness, thickness, phase composition, hardness, Young’s modulus and coefficient of friction werestudied. Phase compositions were investigated by X-ray diffraction method. Surface microstructureand morphology were studied using scanning electron microscope (SEM) and coating compositionswere determined by energy dispersive spectroscopy (EDS). Mechanical properties were measured bynano indentation. The friction behavior of the coatings were investigated using ball-on-disc tests undernormal loads of 7 N .The results showed that (Ti, Cr)N and TiN coatings consisted of only one cubicphase solid solution, while CrN coatings consisted of hexagonal Cr2N and cubic CrN phases. Averagegrain size of the coatings was found to be in the range of 14 to 20 nm. Mechanical behavior of the (Ti,Cr)N coatings was related to the Ti content, i.e. hardness decreased with decreasing Ti content.