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The Diamond like carbon (DLC) and diamond coatings were deposited on a steel substrate using plasma assisted chemical vapor deposition (PA CVD) method. The parameters of deposition were analyzed in relation to the effectiveness of the process and the quality of coatings. It was found that the DLC coatings formed only at specific conditions of temperature and pressure of precursor gases. The characterization of coatings were performed by Raman spectromicroscopy, X-ray diffraction and infrared spectromicroscopy which allowed us to recognize the dominant phases and the distribution of bonds inside the coatings. The chemical bonds such as sp2 C-C, sp3 CH3/CH2 and sp3 CH were found in microstructure coatings. The maps of distribution of bonds in the coatings were also prepared. Additionally, their microstructure was investigated by scanning electron microscopes which have revealed a spherical grains morphology of the coatings.

The effect of plasma gases (argon, helium) on the structure and properties of the WC-CrC-Ni coatings deposited at the graphite substrate has been investigated. The coatings were deposited by plasma spraying method in equipment Cham Pro –Thermal Spray Systems produced by Sulzer company. The microstructure of coatings were investigated by light microscopy (MO) and scanning electron microscopy (SEM). The performed investigations have been shown that with the increasing of amounts of argon and reducing volumes of helium and nitrogen, the microhardnees increased. The plasma gases also influenced on the porosity of coatings. Keywords: WC-CrC-Ni coatings, plasma spraying, microstructure, porosity Acknowledgement: The work was supported by project No INNOTECH – K2/IN2/9/181851/NCBR/13

Protective coatings are used today in many applications for reducing friction and wear of tools in hot-working process e.g. metal die casting, hot forging, metal die plastics injection. The main goal of undertaken investigation was to evaluate usability of those coatings for improving wear resistance of metal die applied in investment casting process for wax injection. The (Ti,Al)N and (Al,Cr)N PVD coatings were deposited onto X37CrMoV5-1 hot-work tool steel and their mechanical and tribological properties are characterized in the paper. Based on the results of microscope examinations, scratch test, hardness measurement the similar properties of (Ti,Al)N and (Al,Cr)N coatings were found. Moreover it was established that type of steel surface machining before coating deposition, i.e. grinding, electrical discharge machining (EDM) and milling, did not affect coating properties. Thin coatings replicate steel base roughness parameters as Ra, Rz and Rmax with over 95% of correlation. Based on tensile test results of wax/coated steel samples and wax/uncoated steel samples the lowest wax adhesion to (Ti,Al)N coating was confirmed.

The thermo-chemical treatment routes for Renè77 superalloy were developed comprising low activity and high activity aluminizing by CVD method. The influence of the treatment on the oxidation resistance in air and creep resistance of the alloy was examined. The cyclic oxidation tests at 1100°C for 500 cycles were carried out. Creep tests were performed at 982°C at the stress level of 124 and 151.7MPa. The chemical and phase composition of the surface layer was analyzed after aluminizing. It was found that aluminide coating enhanced oxidation resistance of the Renè77 superalloy without deterioration of its mechanical properties.