| Popis: |
Problem. The functional properties of composite electrolytic coatings Co-Mo-WОх, Co-W-ZrО2, Co-Mo-ZrО2, besieged in galvanostatic mode from pyrophosphate-citrate electrolytes are discussed. The effect of the temperature and acidity of the electrolyte on the microstinity of coatings has been proved. It was established that the content of refractory metals does not affect the microhardness of cobalt coatings with such metals, however, dependence on the conditions of the electrical sanction was detected. Goal. The goal is investigation of the effect of electrolysis parameters on the qualitative composition and microhardness of cobalt-based composite coatings with heavy metals. Methodology. The electrical equipment was made at a unipolar current when varying the density of current and temperature. The morphology of the surface was investigated using the Zeiss Evo 40xvp. The study of the phase composition of the coatings was carried out using X-ray analysis using the Siemens D500 powder diffractometer in the emitting of copper with graphite monochrome. The micro-hardness of composite coatings Cо-Mo-WOx, Co-Mo-ZrO2 and Co-W-ZrO2, as well as substrate material was determined as 0.2 kg and an exposure time as 10 s. Results. The increase in the micro-hardness of the covers relative to the ranging components is proven, with the highest indicator of the Cо-Mо-WOх systems (1100kg/mm2), and the micro-affirmation of the Cо-Mо-ZrО2 and Cо-W-ZrО2 is up to 550 kg/mm2. Originality. The effect of electrolysis parameters on the functional properties has been established, in frequency the micro-hardness of composite coatings on the mock-up of cobalt will allow the sphere of use of such coatings. The connection between the composition and morphology of cobalt covers and their physico-mechanical and physical and chemical properties is experimentally established. Based on the studies, it was found that the optimal for the formation of composite electrolytic coatings with cobalt alloys is the span pH = 8–9. Practical value. The compositional coatings of the Cо-Mо-WOх with the overall content of tight components of 25–34 mass% allow to recommend them as wear-resistant coatings for applying parts to products that work in aggressive media at high temperatures. |
