Study of the Possibilities for Electroless Nickel-Cobalt Coating on Titanium Alloys for Electrical Spark Deposition

Abstract

The paper concerns the study of the possibilities for electroless plating of a nickel-cobalt-phosphorus alloy on titanium and titanium alloy TiAl6V4 substrates when pre-galvanic activation is used. The creation of a nickel alloy coating will allow for further electrospark deposition with less erosional impact on the substrate and better adhesion of the hardalloyed coating to the titanium and titanium alloy. The impact of the pre-copper plating and the use of cobalt in the pre-activation of the surface on the percentage of phosphorus in the electroless coating were evaluated. Scanning electron microscopy and X-ray energy dispersive microanalysis methods, as well as microhardness testing were used to assess the quality of the applied coatings.