磷化温度对铝合金磷化膜性能的影响

Effect of Phosphating Temperature on the Performance of Phosphating Film on Aluminium Alloy

采用锌系磷化液对LY12硬铝合金进行磷化处理。通过测量膜质量、硫酸铜点滴试验、极化曲线测试等考查了磷化温度对磷化膜性能的影响,利用SEM、EDS等分析手段,对磷化膜的表面形貌、化学成分进行分析。结果表明,当磷化θ为50℃时,磷化膜外观颜色呈浅灰色,均匀光亮,膜面质量达5.18g/m2,硫酸铜试验耐蚀t为57s,铝合金磷化膜的腐蚀电位最大,腐蚀电流最小,线性极化电阻最大,耐蚀性最好。

Phosphating was applied to LY12 duralumin alloy with zinc phosphating solution.The influence of phosphating temperature on the performance of phosphating film was investigated by using coating weight,CuSO4 solution dropping and electrochemical tests.The surface morphology,chemical composition of films were observed and determined by SEM and EDX techniques.The results showed that the phosphating film prepared under 50 ℃ phosphating temperature was light grey,bright and uniform with coating weight of 5.18 g/m2,corrosion time of 57 s in the CuSO4 solution dropping test.Meanwhile,this phosphating film had a higher corrosion potential and linear polarization resistance,a lower corrosion current density and a better corrosion resistance.