Antimicrobial and decorative ion-plated copper-containing ceramic coatings

Abstract

New-generation decorative ceramic coatings have frequently been requested to be diverse in color and scratch resistant, and demonstrate antimicrobial functions. Because long-established silver-containing decorative hard coatings have involved using noble silver metal, incorporating copper into the deposited hard coatings should exhibit antimicrobial functions as well. Such coatings may fulfill the multiple surface functions of decoration, wear resistance, and antimicrobial properties. This study used arc ion plating (AIP) to prepare TiN coating while using magnetron sputtering (MS) to incorporate copper to obtain copper-containing titanium nitride coatings (Cu-containing TiN) on Ni/Cr pre-electroplated Cu–35Zn substrates, a common material for sanitary wares. Experimental results show that the coatings are well crystalline TiN up to a Cu content of 14.35at.%, over which the coatings present fine granular structure and is undetectable by XRD. The surface hardness, wear resistance, and corrosion resistance of the Cu-containing TiN coatings were higher than those of the pre-electroplated Cu–35Zn substrate. Antimicrobial efficacy of the Cu-containing TiN coatings against Escherichia coli (E. coli) was satisfied, according to the JIS Z2801:2000 standard, when the copper content in the deposited films achieved 21.65at.%.