The Electrodeposition of Tungsten from Aqueous Solutions

A method has been developed for the electrodeposition of metallic tungsten from aqueous solutions. The tungsten deposit is smooth, hard and coherent, having a high luster. Like chromium, the electrodeposited tungsten needs no polishing if the plated article was previously polished. Tungsten has remarkable acid‐resisting properties, which make it desirable as a protective coating for other metals. Several types of solutions have been investigated in regard to their usefulness as tungsten plating baths. Solutions of tungsten salts in organic solvents were found unsuitable for this purpose. Aqueous solutions of an acid nature did not give satisfactory metal deposits. Alkaline solutions containing alkaline tungstates were preferably used as plating . baths. The temperature, cathode current density, and hydrogen ion concentration of the solution must be controlled. Alloys of tungsten and iron, and of tungsten and nickel, were electrodeposited from similar solutions containing very small concentrations of the ions of these second metals. The usefulness of highly alkaline solutions as plating baths for the electrodeposition of other metals is pointed out.