| Summary: | A novel approach for metal surface modification and finishing is proposed and developed based on the in situ mechanochemical processing of metal oxides in reducing media. As typical examples of the new coating process, mechanochemical deposition of pure chromium and titanium coatings on steel and aluminum substrates was chosen. The possible mechanisms of the formation of the mechanochemically deposited layer under impact conditions and some mechanical properties have been investigated. We identify the so-called welding mechanism as the most probable mechanism for coating formation under mechanical impact conditions. Hardness of the coating was chosen as a key property, since it is indicative of the work-hardened state of the material in the layer, the grain size and hence the coating strength. Hardness was measured by multiple load indentation, allowing the variation with of hardness with depth to be studied. The data was interpreted using the work-of-indentation model, and suggests that the coating shows a considerable hardness increase compared to the bulk property of the same material, but also a moderate increase compared to the substrate. The coating is therefore thought likely to provide improved wear resistance.
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