新型铝合金三价铬复合转化膜工艺研究

发布时间：2018-06-06 20:44

  本文选题：铝合金 + 三价铬　； 参考：《电镀与涂饰》2015年21期

【摘要】：为克服非六价铬铝合金转化膜耐蚀性能不佳的问题,以Cr(NO_3)_3·9H_2O、Na_2MoO_4·2H_2O、NaH_2PO_4·2H_2O为主要成膜物质,采用单因素法对转化液组分及转化条件进行优化,在5052铝合金表面制备三价铬复合转化膜。利用扫描电镜、能谱仪分析了复合膜的形貌及成分,并通过硫酸铜点滴试验、中性盐雾试验和动电位极化曲线测量研究其耐蚀性能。结果显示:以15 g/L Cr(NO_3)_3·9H_2O、10 g/L Na_2MoO_4 2H_2O、10 g/L NaH_2PO_4·2H_2O、0.15 g/L NH_4HF_2组成转化液,在pH为3.3、温度为40℃的条件下反应10 min,所得复合膜的耐蚀性较佳。该复合膜由Cr、Mo、P、O、Al、Mg等元素组成,在3.5%Nacl溶液中的腐蚀电位较基体正移了196 mV,腐蚀电流密度远小于基体。经此钝化液处理的样品在中性盐雾试验168 h后才发生点蚀。
[Abstract]:In order to overcome the problem of poor corrosion resistance of non-hexavalent chromium aluminum alloy conversion film, taking Crgno _ 3H _ 2O _ 3H _ 2O _ 3 _ 3H _ 2O _ (3) H _ (2) O _ (2) O ~ (2 +) Na _ (2Mo) O _ (42) H _ 2O as main film-forming material, single factor method was used to optimize the composition of conversion solution and conversion conditions, and trivalent chromium composite conversion film was prepared on the surface of 5052 aluminum alloy. The morphology and composition of the composite film were analyzed by scanning electron microscope (SEM) and energy spectrometer (EDS). The corrosion resistance of the composite film was studied by copper sulfate drop test, neutral salt spray test and potentiodynamic polarization curve measurement. The results show that the conversion solution composed of 10 g / L Na2MoO _ 42H _ 2O _ 2 10 g / L NaH _ 2P _ 2H _ 2O _ 2O _ (10 g / L) and 0.15 g / L S _ (NH _ 4HF _ 4) _ 2 is prepared by 15 g / L CrCrNo3 / L _ (10) / L Na2MoO _ (4) H _ (2) H _ 2O _ 2. The corrosion resistance of the composite film is better when the pH is 3.3 and the temperature is 40 鈩，

本文编号：1988045