ПРОГРЕССИВНЫЕ ТЕХНОЛОГИИ В МАШИНОСТРОЕНИИ THE ADVANCED TECHNOLOGIES IN MECHANICAL ENGINEERING B. Szeptycka, J. Senatorski INFLUENCE OF AN NANOSTRUCTURAL ELECTROPLATED COMPOSITE COATINGS ON THE TRIBOLOGICAL PROPERTIES OF THE STEEL SURFACE This paper present a result of tribological investigations of the nanostructural electroplated composite coatings deposited on the steel surface. <...> This layers consist the following componets: Ni-B, Ni-SiC and Ni-PTFE. <...> The roughness of the coatings Ni-SiC was measured using tester TR 100. <...> Siemens D500 X-ray diffractometer with CuK , radiation was used to determine the dimension of nickel [111] crystallites and microstress. <...> The microhardness of the deposited layers was measured using a Vickers’ method at a load of 0.01 and 0.05 kg. Roughness of the composite coatings was small, and it was connected with content of dispersion particles in coating and the dimension of nickel [111] crystallites. <...> Microhardness increased considerably with decreasing grain size. <...> The improved microhardness of nanocrystalline composite coatings may be due to their finer nanostructure. <...> The results of this experiments, i.e. wear resistance and coefficient of friction, show very positve effect of application nanostructural electroplated coatings for steel surface treatment. <...> This study has shown that the wear resistance is proportional to the microhardness, the roughness, the size of nickel grain and the particle contents in composite coatings. <...> Strengthening the nanocrystalline nickel matrix with ceramic and polymer particles gave a positive effect in the form of high wear resistance. <...> A common approach entails supplying energy to a material in such a way as to bring it into a highly unstable state, and then lowering this energy to a metastable state. <...> A new approach to processing a material into a metastable state is based on decreasing its grain size to nanometers. <...> Electroplated nanocrystalline nickel coatings have a number of merits that were decisive in the choice of In comparison the direction of our studies. with large-grain coatings, electroplated nanocrystalline nickel coatings are characterized by greater strength, microhardness [1], diffusion coefficient, electrical resistance, specific heat, thermal expansion coefficient, 118 Проблемы машиностроения и автоматизации, № 1 – 2007 plasticity, adhesion, corrosion [2] and wear resistance, lower elasticity modulus, exceptionally soft magnetic properties [3,4,5], thermal stability up to 573 K. <...>