Abstract:

We examined the influence of the energy (current density і) and temporal (duration of pulse ton and pause toff, the ratio of ton/toff) parameters of the electrolysis on the composition and morphology of the Fe-Co-Mo coatings. An increase in the pulse duration contributes to the enrichment of alloy with molybdenum in proportion to the increasing current density. At the ratio of pulse/pause ton/toff>1–2, the composition of an alloy changes towards an increase in the content of iron. We demonstrated a tendency of the enrichment of coatings with a high-melting component and a decrease in the content of iron with an increase in the current density. It is shown that with an increase in the current density, the surface of coatings changes from the fine-grained to the globular structure. It was established that at fixed ton/toff, the power yield grows with an increase in the pulse duration over the entire interval of current densities. With an increase in the current density (at ton/toff=const) we observe a reduction in the process efficiency. It was found that the most optimal for obtaining the soft magnetic Fe-Co-Mo coatings is the current amplitude of 3 A/dm2, the duration of pulse 2–5 ms and of pause 10–20 ms. Current at amplitude of 5 A/dm2 is recommended when obtaining materials with the content of a high-melting component larger than 15 аt. %. It is shown that the regime of the unipolar pulse current makes it possible to obtain the Fe-Co-Mo coatings with the content of iron of 58–46 аt. %, cobalt – 34–43 аt. % and molybdenum – 6–17 аt. %. The results obtained create prerequisites to control the composition and properties of the Fe-Co-Mo coatings with a wide range of content of the alloy-forming components. Author Biographies Iryna Yermolenko, National Technical University “Kharkiv Polytechnic Institute” Kyrpychova str., 2, Kharkiv, Ukraine, 61002 PhD Research Laboratory 

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