Effect of Alloying on the Microstructure and Properties of Molybdenum-Containing Coatings

This study examines the microstructure and properties of molybdenum-containing coatings deposited by non-vacuum electron beam cladding of molybdenum and amorphous boron powder mixtures. Chromium and titanium served as alloying elements in the experiments. The resulting coatings demonstrated thicknesses of 1.5–2 mm. The Mo-B coatings with chromium additions formed chromium-alloyed α-Fe solid solution along and Fe3B-type borides, while titanium alloying produced α-Fe solid solution and Fe2B borides. The chromium-modified MoBCr coatings exhibited superior hardness and high-temperature oxidation resistance compared to titanium-containing variants. The microhardness increased by a factor of 2.5 relative to AISI 5140 steel base material. The oxidation resistance of MoBCr coatings improved twofold through formation of dense Cr2O3-based oxide films that effectively block oxygen and metal ion diffusion during oxidation processes.