微弧氧化对铸铝合金在乙二醇水溶液中的耐蚀性能的影响

Effect of Micro-arc Oxidation on Corrosion Resistance of Cast Aluminum Alloy in Water Solution of Ethylene Glycol

分别采用自然氧化和微弧氧化方法在AlSi10Mg(a)铸造铝合金表面获得氧化膜层,利用失重法、扫描电镜、交流阻抗、极化曲线等研究了微弧氧化对铸铝合金在38%乙二醇水溶液中的耐蚀性能的影响。结果表明,通过微弧氧化工艺可在砂型铸造铝合金AlSi10Mg(a)材质表面形成连续致密的膜层;相比铸铝合金的自然氧化成膜,微弧氧化成膜显著提高了铸铝合金表面在溶液中的膜层电阻和电荷转移电阻,也提高了铸铝合金的自腐蚀电位和击穿电位,降低了自腐蚀电流密度和膜层维钝电流密度。AlSi10Mg(a)铸造铝合金经微弧氧化后在38%乙二醇溶液中具有良好的耐蚀性能和膜层稳定性。

The oxidation films were obtained on the surface of AlSi10Mg(a) cast aluminum alloy by natural oxidation and micro-arc oxidation,respectively.The effect of micro-arc oxidation on the corrosion resistance of cast aluminum alloy in 38% ethylene glycol solution was studied by weight loss method,SEM,AC impedance and polarization curve.The results show that a continuous and dense film layer can be formed on the surface of sand casting aluminum alloy AlSi10Mg(a) by micro-arc oxidation process.Compared with the natural oxidation of cast aluminum alloy,the film resistance and charge transfer resistance on the surface of cast aluminum alloy are significantly increased by micro-arc oxidation,the corrosion potential and breakdown potential of the cast aluminum alloy are also increased,and the self corrosion current density and the passive current density of the film layer are decreased.AlSi10Mg (a) cast aluminum alloy has good corrosion resistance and film stability in 38% ethylene glycol solution after micro-arc oxidation.