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MoCN coatings have been formed by cathodic arc evaporation using the mixture of acetylene and nitrogen and pure molybdenum target. The surface structure, in conjunction with x-ray data, was analyzed by atomic force microscopy (AFM). The AFM results show differently shaped grain forms on the surface of coatings investigated. The increase in carbon in chemical coatings composition results in the reduction in surface grain size and the increase in roughness of the coatings.

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Here, the e ect of adhesion of CrN hard coatings on modi ed 42CrMo4 steel substrate is presented. Modi cations of the substrate are shot peening, nitriding, shot peening, and nitriding joined process. In the shot peening process, two variable process parameters were used: exposure time (t) and air pressure (p). e nitriding process was conducted in the following parameters: nitriding potential N p � 4.86, nitriding time t n � 3 h, and temperature process T � 530°C. Modi ed substrates were characterized by surface hardness HV5 and hardness pro les on the cross section of samples and by surface roughness parameters. On such prepared substrates, the CrN coating was deposited. e adhesion of CrN coating on modi ed substrates was de ned by the scratch test. Chemical and phase composition of the lms was determined using EDS method and X-ray di raction, respectively. e surface hardness of deposited lms was also de ned. e substrate of 42CrMo4 steel without mechanical and heat treatment coated by hard CrN lm was used as a reference.

Cr-O-N coatings with different oxygen concentration were deposited using vacuum arc plasma fluxes on steel substrates. The coatings were investigated using atomic force microscopy under ambient temperature and humidity controlled conditions. The surface structure, friction and wear were investigated. The results indicate that coefficient of friction and friction force of Cr-O(50)-N coating consisted of Cr2O3 phase tested in a sliding regime are the lowest compared to other Cr-O-N coatings characterized by cubic CrN phase. In the ploughing regime the Cr-O(20)-N coating is characterized by the lowest coefficient of friction of and the wear rate.