Proceedings of SerbiaTrib '13

devices „MBZ 1" for shaft coatings and „MBZ 3A" for application in rotating machines weremanufactured (see Figs.3, 4, 5, 6), e.g. the „MBZ 3A" for engine cylinders was produced in 30 items.Unfortunately there is not sufficient use of theadvantages of the deposition of copper frictionalcoatings in the overall practice.coatings, however, improve significantly thewearresistance against hydrogen wear [13].Figure 5. View of the brass-coating device MBZ 3AFigure 7. Hardness in different depth after frictionalcoating deposition on steelFigure 6. The brass-coating device applied in anautomatic machineSome diagrams referring to a part of the basicnew results are presented below. In Fig. 7 is giventhe variation of hardness in depth; so thestrengthening can also be obtained at differentrotation speeds.Fig. 8 shows the reduction of hydrogenconcentration of the friction surface in depth. Thehydrogen wear results from synergetic interactionof various surface phenomena: exoemission,adsorption, frictional destruction, which providehydrogen extraction from the frictional surfaces.Thermal gradient is also formed, as well aselectrical and magnetic fields; this leads tohydrogen diffusion in the metal, hydrogenconcentration in the subsurface layer and rapidwear of this layer [12]. Metal defect formation inthe friction deformed layer also increases the H 2concentration and augments the wear. FrictionalFigure. 8. Reduction of H 2 concentration at thefrictional surface in depthFigure 9. Wear distribution in upper dead point of enginecylinder after different sliding paths: for cylinder withfrictional brass coating (left) and uncoated (right)By means of brass frictional coating in differentconstructions of steel and cast iron it can beobtained not only the 10 - 20 % lowering of frictionforce, but also a changed wear distribution, whichis to be seen, e.g., for the upper death point in24 13 th International Conference on Tribology – Serbiatrib’13