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This study examines the effect of electron beam treatment (EBT) of Co-Cr substrate on the film growth mechanism, mechanical properties, and surface topography of TiN/TiO 2 coatings deposited by reactive magnetron sputtering. The obtained results and processes that occurred during the deposition are discussed in the context of crystallographic principles, and special attention is paid to the crystallographic orientation and growth mechanism studied by X-ray diffraction (XRD). The mechanical properties were investigated by means of nanoindentation and wear tests. The surface topography was evaluated using atomic force microscopy (AFM). The results obtained in the present study showed that polycrystalline TiN and anatase TiO 2 phases were present in all cases. Electron beam treatment of Co-Cr substrate tended to form a reorientation of the microvolumes from (111) to (200) of TiN, leading to a change in the growth mechanism from three-dimensional (Volmer-Weber) to layer-by-layer (Frank-van der Merwe). It was found that the electron beam treatment process did not significantly affect the thickness of the coatings and the deposition rate. The treatment process led to an increase in surface roughness. The higher surface roughness after the EBT process should be appropriate to support cell growth and adhesion on the surface of the deposited bilayer coating. It was demonstrated that EBT of the substrate caused a decrease in hardness of the deposited coatings from 10 to 5 GPa. The observed decrease in hardness was attributed to the change in the preferred crystallographic orientation and film growth mechanism. The hardness of the bilayer coating after the application of EBT of the Co-Cr substrate was much closer to that of human bones, which means that severe stress shielding effect could not be expected. The evaluated coefficient of friction (COF) exhibited significantly lower values in the case of EBT of the substrate compared to the untreated Co-Cr material.resistance, which depends mostly on the surface properties and can be overcome by appropriate surface modification technologies [4].During the last decades, considerable attention has been paid to surface manufacturing of materials by high-energy fluxes (HEFs) (i.e., electron and laser beams). In these technologies, the electrons or photon fluxes interact with the surface of the sample, heat the treated area, and form a thermal distribution. The rate of heating and cooling can be characterized by quite high values (about 10 5 -10 6 K/s), which lead to some structural changes in the functional properties [5][6][7][8][9][10]. The authors of [11] demonstrated an innovative approach for controlling the surface topography and tribological behavior of biomedical alloys, such as Ti6Al4V, by means of electron beam surface treatment. Other researchers [12,13] have successfully demonstrated the possibilities for enhancing the wear and corrosion properties of steel by the formation of carbon fiber-reinforced Ni-based composite coatings via laser cladding. Laser beam technologie...

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In this study, we present the results of Young’s modulus and coefficient of friction (COF) of Ti–Ta surface alloys formed by electron-beam surface alloying by a scanning electron beam. Ta films were deposited on the top of Ti substrates, and the specimens were then electron-beam surface alloyed, where the beam power was varied from 750 to 1750 W. The structure of the samples was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). Young’s modulus was studied by a nanoindentation test. The coefficient of friction was studied by a micromechanical wear experiment. It was found that at 750 W, the Ta film remained undissolved on the top of the Ti, and no alloyed zone was observed. By an increase in the beam power to 1250 and 1750 W, a distinguished alloyed zone is formed, where it is much thicker in the case of 1750 W. The structure of the obtained surface alloys is in the form of double-phase α’and β. In both surface alloys formed by a beam power of 1250 and 1750 W, respectively, Young’s modulus decreases about two times due to different reasons: in the case of alloying by 1250 W, the observed drop is attributed to the larger amount of the β phase, while at 1750 W is it due to the weaker binding forces between the atoms. The results obtained for the COF show that the formation of the Ti–Ta surface alloy on the top of Ti substrate leads to a decrease in the coefficient of friction, where the effect is more pronounced in the case of the formation of Ti–Ta surface alloys by a beam power of 1250 W.

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