Composite Microstructure and Formation Mechanism of Calcium Phosphate Conversion Coating on Magnesium Alloy

A simple chemical conversion coating was adopted to deposit zinc calcium phosphate (ZCP) coating and strontium doped ZCP (SZCP) coating on AZ31 magnesium alloy to induce biocompatibility and reduce the degradation rate. The surface morphology, chemical composition and functional groups of the coating were characterized by Scanning Electron Microscopy with Energy Dispersive X-Ray Spectroscopy (SEM-EDS), X-Ray Diffraction (XRD) studies and Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy respectively. SZCP coating formed at 20 min deposition time produced crack free surface with a high degree of crystallinity with barrier property, which ultimately retards the dissolution of magnesium in Simulated Body Fluid (SBF). The corrosion resistance of AZ31 magnesium alloy was improved by SZCP coating as evident from hydrogen evolution test (HET). Cytotoxicity evaluation with L969 cells showed that Sr doped ZCP coatings showed less toxicity on resorbable magnesium alloys.

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Formation Mechanism and Properties of Titanate Conversion Coating on AZ31 Magnesium Alloy

Journal of The Electrochemical Society ◽

10.1149/2.091205jes ◽

2012 ◽

Vol 159 (5) ◽

pp. C226-C232 ◽

Cited By ~ 34

Author(s):

Y. C. Yang ◽

C. Y. Tsai ◽

Y. H. Huang ◽

C. S. Lin

Keyword(s):

Magnesium Alloy ◽

Formation Mechanism ◽

Conversion Coating ◽

Az31 Magnesium Alloy

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Preparation and corrosion behaviors of calcium phosphate conversion coating on magnesium alloy

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2016.08.065 ◽

2016 ◽

Vol 307 ◽

pp. 99-108 ◽

Cited By ~ 47

Author(s):

Yingchao Su ◽

Yunting Guo ◽

Zilong Huang ◽

Zhihui Zhang ◽

Guangyu Li ◽

...

Keyword(s):

Magnesium Alloy ◽

Calcium Phosphate ◽

Conversion Coating ◽

Corrosion Behaviors

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Research on Cerium Conversion Coating on ZM5 Magnesium Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.936.1082 ◽

2014 ◽

Vol 936 ◽

pp. 1082-1085

Author(s):

Rong Xia Zhu ◽

Guo Mian Gao ◽

Zheng Miao

Keyword(s):

Corrosion Resistance ◽

Magnesium Alloy ◽

Formation Mechanism ◽

Potentiodynamic Polarization ◽

Conversion Coating ◽

Experimental Results ◽

Specimen Surface ◽

Potentiodynamic Polarization Curves ◽

Corrosion Behaviors ◽

Cerium Salt

The conversion coating formed by immersion in a solution containing cerium salt on ZM5 magnesium alloy was studied and the corrosion resistance was evaluated as well. These micrographs of specimen surface were investigated by metallographic microscope. The corrosion behaviors of ZM5 magnesium alloy and conversion coating were assessed by means of potentiodynamic polarization curves and immersion tests. The experimental results indicated that a yellow-brown conversion coating was formed subsequently on the specimen surface. The results of electrochemical measurements and immersion tests revealed that the cerium conversion coating possessed better corrosion resistance than the substrate. In this study, cerium conversion coatings formed on ZM5 magnesium alloy were characterized and the formation mechanism was discussed.

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