Molybdenum disulfide (MoS 2 ) is one of the most widely used solid lubricants applied in different ways on the surfaces under friction. In this work, AISI 316 austenitic stainless steel was coated with MoS 2 , using thermo-diffusion method at different temperatures and times. Coatings properties were investigated using SEM, EDX, XRD and FTIR, Hardness Tester and Roughness tester. The results illustrated the formation of a uniform layer on the surface, containing MoS 2 and MoO 3-X phases. The thickness, grain size and the hardness of the coatings were 20-50 μm, 400-1000 nm and 350-550 HV respectively. Friction tests carried out using ball-on-disc method under normal loads of 10 N under ambient conditions showed values of the friction coefficient 0.30-0.40. In addition, the kinetics of diffusion layers between the substrate and the coating were also investigated. It was found that there at steady temperature there is a parabolic relationship between the thickness of the diffusion layer and the treatment time. The activation energy for the process was estimated to be 143 kJ mol . Depending on the treatment time and temperature, the thicknesses of diffusion layer varied between 0.5 and 2.5 microns.

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In this investigation, physical vapor deposited Ti-Cr-N coatings were coated on tool steel substrates using reactive arc evaporation. Microstructure and mechanical properties of coatings such as roughness, thickness, phase composition, hardness, Young’s modulus and coefficient of friction were studied. Phase compositions were investigated by X-ray diffraction method. Surface microstructure and morphology were studied using scanning electron microscope (SEM) and coating compositions were determined by energy dispersive spectroscopy (EDS). Mechanical properties were measured by nano indentation. The friction behavior of the coatings were investigated using ball-on-disc tests under normal loads of 7 N.The results showed that (Ti, Cr)N and TiN coatings consisted of only one cubic phase solid solution, while CrN coatings consisted of hexagonal Cr2N and cubic CrN phases. Average grain 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. doi: 10.5829/idosi.ije.2014.27.07a.1

Molybdenum disulfide (MoS2) is one of the most widely used solid lubricants. In this study, MoS2-Cr composite coatings were deposited onto AISI 1045 steel substrates by direct-current magnetron sputtering. The MoS2/Cr ratio in the coatings was controlled by sputtering the composite targets. The coatings were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and nano-indentation and nano-scratch techniques. The tribological behavior of the coatings was investigated using the pin-on-disc test at room temperature. The results showed that the thickness and the hardness of the coating were 6 µmand 850-1300 HV, respectively. The degree of the crystallization of the composite coatings was enhanced with increasing the Cr contents. The incorporation of Cr into MoSx coatings resulted in the considerable improvement of coating adhesion and hardness. The optimum doping level for MoS2-Cr coatings to show the best tribological propertie was 13 atomic percent. The main wear mechanisms of the coating were delamination, tribochemical and abrasive micro cracking