6061铝合金镧转化膜工艺参数的正交优化

Orthogonal Optimumization of Technological Parameters for Preparation of Lanthanum Conversion Film on 6061 Aluminum Alloy

以稀土转化膜的膜厚和点滴时间作为评价指标,采用正交试验法设计出以La(NO_3)_3·6H_2O和KMnO_4为促进剂的铝合金稀土转化处理液的最佳配方和工艺参数。La(NO_3)_3·6H_2O15 g·L^(-1),KMnO_4 4 g·L^(-1),处理温度为(40±2)℃,处理时间为10 min,pH 3.5,在该工艺条件下制备出的稀土镧盐转化膜具有较好的耐蚀性。比较了最佳工艺参数下形成的转化膜与铝合金基体在3.5%NaCl溶液中的腐蚀速率。结果表明,稀土镧转化膜可以降低6061铝合金的腐蚀速率,提高基体的耐蚀性。

Take the thickness of conversion film and spot test time as assessment criteria, me optltnm tolinum technological parameters of conversion processing solution with La（NO3）s·6H2O and KMnO4 as additives were obtained as follows： La（NO3）s·6H2O15g·L^-1,KMn044g·L^-1,（40±2）℃, 10 min, pH=3. 5. The conversion film formed under the technological conditions has good corrosion resistance. And the corrosion rates of conversion film prepared with optimum process parameters and aluminum alloy in 3. 5% NaCl solution were compared. The results show that rare earth conversion film on aluminum alloy can reduce the corrosion rate of 6061 aluminum alloy, and thus improve the corrosion resistance of aluminum alloy matrix.