A novel method of preparation of metal ceramic coatings

This paper presents a relatively new technique for producing metal ceramic coatings on metal surfaces by a combination of plasma electrolytic deposition from a liquid medium with an electric spark discharge. The technique has some advantages compared with the separate two techniques. Particularly, the advantages are low discharge voltage and preservation of the coatings by the liquid medium. The effectiveness of the new technique is shown in this paper by coating a high speed steel, W9Mo5Cr4V2, with a metal ceramic electrode in an aqueous solution of urea. In addition, the effects of the on/off voltage pulse ratio on thickness, hardness and wear resistance of the coatings were investigated.