Study On The Fabrication And Corrosion Behavior Of Myristic Acid Calcium Coating On Pure Magnesium

This article took mixture solvents of myristic acid ethanol solution and calciumchloride watery solution as conversion solution, and used chemical transformation toobtain myristic acid calcium coating on pure magnesium surface successfully. Theimpact of technology parameters on coating's composition, microstructure andcorrosion-resistance with two preparation methods was researched.The coating with good corrosion resistance can be obtained by immersing puremagnesium in the mixed solution directly. This paper studied the influence of reactiontemperature, reaction time, proportion of ethanol and water in mixed solution as well asconcentration on myristic acid and calcium chloride on coatings. By X-ray diffraction,scanning electron microscopy, this paper studied on coating's composition, andcorrosion resistance of the coating was mainly characterized by potentiodynamicpolarization curve. The research showed that volume ratio of ethanol and water inconversion solution had a huge effect on the coating's morphology, and it was better forthe formation of the myristic acid calcium when the appropriate ratio of ethanol to wateris100/100. Reaction temperature had a great influence on corrosion resistance ofcoating, it was easier to obtain good corrosion resistance of the coating at60?.Another way to obtain tetradecanoic acid calcium coating on pure magnesium surface was to use etradecanoic acid ethanol solution soak pure magnesium, and to dropwisecalcium chloride watery solution. The impact of concentration, steeping time and reacti-on temperature of myristic acid on coating was researched. Among them, concentrationof tetradecanoic acid was the important affecting factor. The coating's corrosion resis-tance was good when the concentration of myristic acid was0.10mol/L. While reactiontemperature had little influence on the coating's corrosion resistance.By studying coating's development, it was known that myristic acid calcium grewon pure magnesium surface in pieces structure, and transformation fluid provided corefor myristic acid calcium on the pure magnesium's corrosion. The corrosion behavior ofcoating in salt water was studied by electrochemical impedance spectroscopy. Theresults showed that the coating blocked corrosive medium spreading to pure magnesiumand played a major role in protecting pure magnesium.