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Постійне посилання на розділhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/35393
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Документ Highly wear-resistant and biocompatible carbon nanocomposite coatings for dental implants(Elsevier, 2016) Penkov, Oleksiy V.; Pukha, Vladimir E.; Starikova, Svetlana L.; Khadem, Mahdi; Starikov, Vadym V.; Maleev, Maxim V.; Kim, Dae-EunDiamond-like carbon coatings are increasingly used as wear-protective coatings for dental implants, artificial joints, etc. Despite their advantages, they may have several weak points such as high internal stress, poor adhesive properties or high sensitivity to ambient conditions. These weak points could be overcome in the case of a new carbon nanocomposite coating (CNC) deposited by using a C60 ion beam on a Co/Cr alloy. The structure of the coatings was investigated by Raman and XPS spectroscopy. The wear resistance was assessed by using a reciprocating tribotester under the loads up to 0.4 N in both dry and wet sliding conditions. Biocompatibility of the dental implants was tested in vivo on rabbits. Biocompatibility, bioactivity and mechanical durability of the CNC deposited on a Co/Cr alloy were investigated and compared with those of bulk Co/Cr and Ti alloys. The wear resistance of the CNC was found to be 250e650 fold higher compared to the Co/Cr and Ti alloys. Also, the CNC demonstrated much better biological properties with respect to formation of new tissues and absence of negative morphological parameters such as necrosis and demineralization. Development of the CNC is expected to aid in significant improvement of lifetime and quality of implants for dental applications.Документ Friction and Wear Characteristics of C/Si Bi-layer Coatings Deposited on Silicon Substrate by DC Magnetron Sputtering(Springer, 2012) Penkov, Oleksiy V.; Bugayev, Yegor A.; Zhuravel, Igor; Kondratenko, Valeriy V.; Amanov, Auezhan; Kim, Dae-EunThe tribological behavior of carbon/silicon bi-layer coatings deposited on a silicon substrate by DC magnetron sputtering was assessed and compared to that of amorphous carbon and silicon coatings. The motivation was to develop a wear resistant coating for silicon using thin layers of amorphous carbon and silicon. Wear tests were conducted by sliding a stainless steel ball against the coating specimens under applied normal loads in the range of 20 * 50 mN. Results showed that the wear rate of the bi-layer coating was strongly dependent on the ratio of thickness between the carbon and silicon layers. The wear rate of the bi-layer coating with 25 nm thick carbon and 102 nm thick silicon layers was about 48 and 20 times lower than that of the single-layer amorphous carbon and amorphous silicon coating, respectively. In addition, the steady-state friction coefficient of the bi-layer coating could be decreased to 0.09 by optimizing the thickness of the layer. Finally, a model for the wear reduction mechanism of the carbon/silicon bi-layer coating was proposed.