建筑装饰用Cu-Zn合金的表面钝化与耐蚀性能

Surface Passivation and Corrosion Resistance of Cu-Zn Alloy for Building Decoration

为解决建筑装饰用Cu-Zn合金耐蚀性和环保问题,运用缓蚀剂和稀土钝化方式对其处理。采用正交试验法优化了BTA和CeCl3复配方案下Cu-24Zn合金的钝化工艺,并对比分析了单一BTA方案和钝化液中添加KI和OP-10方案下钝化膜的电化学性能。结果表明:正交极差分析结果优化得到的Cu-24Zn合金的钝化工艺参数为A3B1C2D3,即温度65℃、BTA浓度0.1 g/L、时间70 min、CeCl3浓度6 g/L,此优化钝化工艺下处理的Cu-24Zn合金的耐腐蚀性能相较于商用Cu-24Zn合金大幅提升;方案乙中的BTA和CeCl3复配比单一BTA钝化液可以得到更好的钝化效果,且继续向上述正交试验优化方案钝化液中添加KI和OP-10形成的方案丙可以进一步提升Cu-24Zn合金的耐蚀性;经方案丙钝化的Cu-24Zn合金表面形成的致密复合转化膜可以极大提升Cu-24Zn合金的耐蚀性能,且可以起到抑制色变的作用。

In order to solve the corrosive and environmental problems of Cu-Zn alloy for building decoration,the Cu-Zn alloy was processed by inhibitors and rare-earth passivation method. The passivation process of Cu-24Zn alloy under BTA and CeCl3 compound scheme was optimized by orthogonal test,and the electrochemical properties of passivation film under single BTA scheme and adding KI and OP-10 scheme in passivation solution were compared and analyzed. Results showed that the passivation process parameters optimized by orthogonal range analysis were A3B1C2D3,which were as follows: 65 ℃ of the temperature,0.1 g/L BTA,70 min of process time and 6 g/L cerium chloride. The corrosion resistance of the Cu-24Zn alloy treated by the optimized passivation process was much higher than that of the commercial Cu-24Zn alloy. In addition,the BTA and CeCl3 in scheme B could obtain better passivation effect than the single BTA passivation solution. The corrosion resistance of Cu-24Zn alloy could be further improved by adding KI and OP-10 to the passivation solution of scheme B,which was named as scheme C. Moreover,the dense composite conversion film formed on the surface of Cu-24Zn after passivation in scheme C,which could greatly improve the corrosion resistance of Cu-24Zn alloy and inhibit the color change.