Alternating Current Electrophoretic Deposition of Hydroxyapatite Composite Coating on Mg-0.8wt.%Ca-3%wt.%Zn alloy

Abstract

The present work investigates the AC electrophoretic deposition of nano-sized  HAP composite coating on Mg-0.8wt.%Ca-3%wt.%Zn alloy.  Nano HAP powder was prepared using hydrothermal microwave assisted technique. HAP coating is deposited electrophoretically from dispersing medium (ETELAC) forming composite coating on the alloy surface.  Electrophoretic deposition experiments were conducted as single run (S), double run (D) and multirun (M). The properties of HAP coating regarding adhesion, morphology and corrosion behavior were thoroughly investigated.Results show that the best coating regarding the weight gain as well as the morphology was obtained from multi run (M) experiments of  5%HAP and 5% ETELAC at 200 V under 150 rpm stirring.  Electrochemical Impedance (EIS) investigation show that HAP composite coating posses a high corrosion resistance compared to the substrate alloy.  The mechanism of HAP/ETELAC coating formation was thoroughly discussed.