工艺参数对2024铝合金HEDP阳极氧化膜耐蚀性的影响

Effects of process parameters on corrosion resistance of anodic oxide film prepared in a HEDP electrolyte on 2024 aluminum alloy

采用羟基乙叉二膦酸(HEDP)溶液对2024铝合金进行阳极氧化。研究了HEDP浓度、温度、电流密度和时间对氧化膜耐蚀性、表面形貌和元素组成的影响。结果表明,所得阳极氧化膜由较厚的多孔层和较薄的阻挡层组成,其主要成分为非晶态的Al_(2)O_(3)。较佳的阳极氧化工艺条件为:HEDP 0.2 mol/L,温度(25±5)℃,电流密度0.83 A/dm^(2),时间30 min。在该条件下所得多孔膜孔径较小,耐蚀性较佳。

2024 aluminum alloy was anodized in a 1-hydroxyethylidene-1,1-diphoshonic acid(HEDP)electrolyte.The effects of HEDP concentration,temperature,current density,and treatment time on the corrosion resistance,surface morphology,and elemental composition of oxide film were studied.The results showed that the anodic oxide film was composed of a thick porous layer and a thin barrier layer,and its main component was amorphous Al_(2)O_(3).The optimal anodization conditions were determined as follows:HEDP 0.2 mol/L,temperature(25±5)℃,current density 0.83 A/dm^(2),and time 30 min.The porous film obtained thereunder featured small pore size and good corrosion resistance.