Wollastonite and Calcium Phosphate Biocoatings with Zn- and Cu-Incorporation Produced by a Microarc Oxidation Method

Abstract

Investigations of wollastonite and calcium phosphate biocoatings with Zn-and Cu-incorporation produced by a microarc oxidation method were presented. Dependences of coating properties on the microarc oxidation parameters were revealed. A variation of the process parameters allowed us to produce wollastonite-calcium phosphate coatings with a plate-like structure, thickness of 25–30 μm, roughness of 2.5–5.0 μm, and enhanced strength properties. Coatings based on substituted hydroxyapatite deposited under voltages of 200–250 V have an X-ray amorphous structure. An increase of oxidation voltage to 300 V leads to the formation of crystalline phases in the coating, such as CaHPO4 and β-Ca2P2O7. The maximum content of 0.4 at% zinc and 0.1 at% copper was obtained for coatings based on Zn-and Cu-substituted hydroxyapatites, consequently, deposited under oxidation voltage of 250 V.