Search academic texts

Information × Registration Number 0222U005402, 0122U002391 , R & D reports Title Influence of stoichiometry and bias stress on microstructure and tribomechanical properties of WN/TiSiN nanolayer coatings with different bilayer thickness popup.stage_title Head Pohrebniak Oleksandr D., Доктор фізико-математичних наук Registration Date 29-12-2022 Organization Sumy State University popup.description2  The object of research is microstructure, elemental composition, physical and mechanical properties of nanostructured coatings based on high-entropy alloys. The purpose of the work is to establish the relationship between the microstructure and physico-mechanical properties during the formation and subsequent modification by high-energy ions of multi-component nanostructured coatings based on HEAs that will have increased hardness, high-temperature stability and wear resistance. The research includes a wide range of experimental methods, namely: RF magnetron sputtering for nitride coatings, scanning electron microscopy, atomic force microscopy and transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, nanohardness and elastic modulus measurements, as well as a pin-on-ball wear test The main result is the knowledge of the relationship between silicon concentration and RF discharge power/bias potential in multilayer structures based on nitrides of high-entropy alloys. The silicon content of the coatings increases with radio frequency power, and all coatings have a smooth surface with very little roughness. The coating structure is a nanocomposite of face-centered cubic (FCC)/amorphous Si3N4. As the RF power increases, the content of the amorphous phase becomes higher, and the crystalline grains decrease in size. The change in structure leads to an increasing trend in the hardness and elastic modulus of the coatings first, and then to a decrease with a peak hardness of 38.1 GPa and a modulus of 451.3 GPa for the coating grown at RF power of 800 W. These results show that the composition and structure of the coatings can be effectively modified by tuning the RF power to achieve the goal of optimizing the properties of the coatings. The scientific novelty consists in the first analyzes of the chemical composition, morphology, microstructure, tribological and mechanical properties of the functional coatings of VESN (AlCrNbSiTi)N and (TiVC Product Description popup.authors Borba-Pogrebnjak Svitlana О. Buranich Volodymyr V. Rogoz Vladyslav M Smyrnova Katerina V. popup.nrat_date 2022-12-29 Close