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为了获得无氰镀镉-钛合金的最佳后处理工艺,利用金相显微镜、电化学工作站和盐雾试验测试了三种钝化膜的外观及耐蚀性,并进行了比较。实验结果显示,三种钝化工艺获取的钝化膜经96 h中性盐雾试验后,均未出现白锈;电化学测试结果显示低铬钝化工艺获取的钝化膜自腐蚀电流密度最大,重铬酸钠钝化工艺获取的钝化膜自腐蚀电流密度最小。从环保和耐蚀性方面考虑,建议选用重铬酸钠+硝酸钝化工艺作为无氰镉-钛合金镀层的后处理工艺。
In order to obtain the best post-treatment process of cyanide-free cadmium-titanium alloy, the appearance and corrosion resistance of the three passivation films were tested by metallographic microscope, electrochemical workstation and salt spray test, and compared. The experimental results showed that white rust was not observed on the passive film obtained by the three passivation processes after 96 h neutral salt spray test. The electrochemical test results showed that the passivation film obtained by the low-chromium passivation process had the highest self-corrosion current density , Passivation of sodium dichromate passivation film to obtain the smallest self-corrosion current density. From the environmental protection and corrosion resistance considerations, it is recommended to use sodium dichromate + nitric acid passivation process as cyanogen-free cadmium - titanium alloy after-treatment process.