Microstructure and properties of ozalate conversion coating on AZ91D magnesium alloy
The oxalate coating formed on AZ91D magnesium alloy by chemical conversion treatment methods in oxalate salt solutions was investigated.The surface morphologies and chemical composition of coating were examined using scanning electron microscopy (SEM) equipped with energy dispersive analysis of X-ray (EDX).Electrochemical impedance spectroscopy (EIS),potentiodynamic polarization curves and salt spray tests were employed to evaluate corrosion protection of the coating to substrate in 5% NaCl solution.The mechanism of coating formations was also considered in details.The results indicate that a compact and dense surface morphology with fine particle clusters of the oxalate coating on magnesium alloy is presented,which mainly consists of oxide or/and organic of Mg,Al and Zn.And the anti-corrosion of the magnesium after oxalate conversion treatment is better than that of the magnesium substrate.The results of salt spray test for oxalate coating is evaluated as Grade 9 according to ASTM B117.The electric resistance of oxalate chemical conversion coating to substrate is below 0.1Ω.
magnesium alloy ozalate conversion coating microstructure corrosion
JIANG Yong-feng ZHOU Hai-tao ZENG Su-min
School of Materials Science and Engineering,Central South University,Changsha 410083,China
国际会议
2009 Frontier Symposium of China Postductors on Materrials Science(2009年中国博士后材料科学前言论坛)
长沙
英文
1416-1422
2009-11-22（万方平台首次上网日期，不代表论文的发表时间）