环保型电解质对镁合金氧化膜性能的影响

Effects of environmentally friendly electrolytes on properties of anodic coatings formed on magnesium alloys

采用四因素三水平正交实验,系统研究硅酸钠(Na2SiO3)、植酸(C6H18O24P6)、碳酸钠(Na2CO3)和硼酸钠(Na2B4O7)对AZ91HP镁合金氧化膜性能的影响。结果表明,电解液组成和用量对氧化过程和氧化膜性能影响很大。影响氧化最终电压、氧化膜厚度和耐蚀性的因素从大到小依次分别为:C6H18O24P6>Na2B4O7>Na2SiO3>Na2CO3、Na2B4O7>Na2SiO3=Na2CO3>C6H18O24P6和C6H18O24P6>Na2B4O7>Na2SiO3>Na2CO3。最佳耐蚀性时的环保型工艺配方为:Na2SiO3 8 g/L,C6H18O24P6 5 g/L,Na2CO3 25 g/L,Na2B4O7 10 g/L,并且氧化膜层耐蚀性与厚度之间不存在简单的相关性。

The effects of four factors （Na2SiO3, C6H18O24P6, Na2CO3 and Na2B4O7） with three levels on the coating properties of micro arc oxidation formed on AZ91HP magnesium alloys were systematically studied by orthogonal experiment. The results show that the compositions and concentrations of electrolytes considerably affect the coating properties. The orders of affecting final voltage, coating thickness and corrosion resistance are separately ranked as C6H18O24P6〉Na2B4OT〉Na2SiO3〉Na2CO3, Na2B4OT〉Na2SiO3 = Na2CO3〉C6H18O24P6 and C6H18O24P6〉Na2B4OT〉 Na2SiO3〉Na2CO3. The environmentally friendly process with the best corrosion resistance is Na2SiO3 8 g/L, C6H18O24P6 5 g/L, Na2CO3 25 g/L, Na2B4O7 10 g/L, There is not simple pertinence between the coating corrosion resistance and coating thickness.