Coating engineering of cobalt-tungsten alloys and mapping their properties

Abstract

<p> Theoretical and practical studies of tungsten alloys with iron group metals continue to be carried out worldwide, in the light of versatile applications of these alloys because of the unique combination of tribological, magnetic, and electrical properties. The electrodeposition of Co-W alloys was performed in the citrate-borate solution at pH 5-8; t=20 and 60 °C. The electrochemical corrosion was studied in 0.01 M H2SO4, and stainless steel is selected as a substrate due to its extremely high corrosion resistance in the mentioned media. For the mapping properties the alloys having various content of W (3-36 at.%) and crystallite size varying from polycrystalline (<60 nm) to "amorphous-like” (2-5 nm) have been prepared. Co-W alloys possessing highest corrosion resistance, highest hardness and good wear resistance should contain 13-24 at.% of W, i.e. have a structure close to intermetallic phase Co₃W. </p>