Preparation and Characterization of DPCD Coating on Mg-Ca-Zn Magnesium Alloy by a Phosphating Treatment

Abstract

A dicalcium phosphate dihydrate (CaHPO4·2H2O, DCPD) coating is prepared to reduce the biodegradation rate of Mg–Ca–Zn alloy. The substrate is immersed into a solution with Ca(NO3)2·4 H2O 0.1 mol/L and Na3PO4 0.1 mol/L to obtain calcium phosphate coating. Surface morphology is observed by scanning electron microscopy (SEM). Chemical composition is determined by X-ray diffraction (XRD) and EDX. The biodegradable behavior is investigated by immersion tests. The results show that calcium phosphate coating consists 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.

Microstructure of Hydroxyapatite/Collagen Coating on AZ31 Magnesium Alloy by a Solution Treatment

“…One of the most effective ways to improve the poor corrosion resistance of Mg alloys is to form a coating on the surface to isolate the base material from the outer environment. Different kind of calcium phosphates coatings, such as, CaHPO 4 •2H 2 O (DCPD) [1,2], octacalcium phosphate (OCP) [3], beta-tricalcium phosphate (beta-TCP) [4], and hydroxyapatite (HA) [5][6][7], have been prepared on magnesium alloys. A number of studies have been carried out to control the phase composition of calcium phosphate coatings.…”