Preparation and characterization of DPCD coating on Mg-Ca-Zn magnesium alloy by a phosphating treatment

摘要

A dicalcium phosphate dihydrate (CaHPCy 2H_2O, DCPD) coating was prepared to reduce the biodegradation rate of Mg-Ca-Zn alloy. The substrate was immersed into a solution with Ca(N03)2'4 H20 0.1 mol/L and Na3PC>4 0.1 mol/L to obtain calcium phosphate coating. Surface morphology was observed by scanning electron microscopy (SEM). Phase and chemical composition were determined by X-ray diffraction (XRD) and EDX. The biodegradable behavior was investigated by immersion tests. The results showed that calcium phosphate coating consisted of many flake particles and with immersion time increasing, the coating thickness increased and became more uniform and smooth. The coating can reduce the biodegradation rate of Mg alloys in Hank's.