(1. 湖南科技大學(xué) 機(jī)電工程學(xué)院，湘潭 411201；
2. 江西科技師范大學(xué) 材料與機(jī)電學(xué)院，南昌 330013)
摘 要: 在含6 g/L氫氧化鈉和15 g/L植酸鈉的基本溶液中，分別加入4種鈣鹽研究鈣鹽，對(duì)Mg-1.0Ca合金微弧氧化膜性能影響。使用SEM、EDS和XRD分析陶瓷氧化膜的表面形貌、成分及結(jié)構(gòu)，通過(guò)點(diǎn)滴實(shí)驗(yàn)和動(dòng)電位極化曲線來(lái)判定氧化膜的腐蝕降解速率。結(jié)果表明：CaCO3可稍微增加氧化膜的鈣含量，使氧化膜厚度由3.4 μm增加到8.8 μm，且明顯改善表面微孔均勻性。點(diǎn)滴實(shí)驗(yàn)和動(dòng)電位極化曲線分析表明：CaCO3能顯著提高氧化膜的耐蝕性能，其點(diǎn)滴時(shí)間由75 s提高至116 s，自腐蝕電流密度由3.898 μA/cm2降低至1.473 μA/cm2，且自腐蝕電位由-1.538 V升高至-1.465 V。
關(guān)鍵字: 鎂鈣合金；微弧氧化；腐蝕降解速率；鈣鹽
（1. College of Electro-mechanical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China;
2. School of Materials and Electromechanics, Jiangxi Science and Technology Norma）
Abstract:Four kinds of calcium salts were separately added into a base solution of 6 g/L NaOH and 15 g/L sodium phytate, and their influences on the property of anodic coatings formed on Mg-1.0Ca alloys were investigated. The surface morphologies, chemical compositions and structures were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffractometry (XRD). The dropping test and potentiodynamic polarization tests were applied to evaluate the corrosion degradation rate of anodic coatings. The results demonstrate that CaCO3 can slightly increase the calcium content. The coating thickness increases from 3.4 μm to 8.8 μm and the coating porous uniformity of anodic coatings is obviously improved. The dropping test and potentiodynamic polarization curve analysis shows that CaCO3 can significantly improve corrosion resistance of the anodic coatings. The drop time is extended from 75 s to 116 s, and the self-corrosion current density is reduced from 3.898 μA/cm2 to 1.473 μA/cm2，while the corrosion potential is improved from -1.538 V to -1.465 V.
Key words: magnesium-calcium alloys; micro arc oxidation; corrosion degradation rate; calcium salt
