Electrodeposition of titanium diboride coatings. Report of investigations 1976. [4130 steel]

The report describes a method for electrodeposting titanium diboride from a molten salt bath. Initially, the electrolyte is a mixture of LiBO/sub 2/, NaBO/sub 2/, Na/sub 2/TiO/sub 3/, Li/sub 2/TiO/sub 3/, and TiO/sub 2/. The cell is operated at 900C in a dry, inert atmosphere with consumable anodes of titanium or hot-pressed titanium diboride (TiB/sub 2/) powder. Agitation of the electrolyte is essential. Current densities may be 6 to 9 amperes per square decimeter (A//sup 2/ with titanium anodes and 9 to 30 A//sup 2/ with titanium diboride anodes. A current density of 6 A//sup 2/ is equivalent to a plating rate of about 35 micrometers per hour (..mu..m/h). The adherence of the TiB/sub 2/ deposit varies with the substrate material. It is most adherent on molybdenum and on 4130 steel that has been preplated with copper and nickel, less adherent on nickel, and still less adherent on lnconel and on 4130 steel without the preplate. Cathode and anode reactions are suggested. (GRA)