超声辅助及纳米颗粒加入对常温磷化过程的影响

Effects of ultrasonic assistance and nanoparticle addition on phosphating process at room temperature

磷化处理是通过在金属表面上发生化学与电化学反应使其表面上形成一层具有防腐蚀作用的不溶性磷化膜,广泛用于金属表面预处理过程中。重点研究了磷化过程中采取超声辅助、加入一定量的纳米SiO2颗粒等辅助操作对常温磷化过程的影响,扫描电镜检测以及硫酸铜点蚀实验、氯化钠浸蚀实验结果表明超声辅助及纳米颗粒加入有助于提高磷化膜的致密性和耐腐蚀性,2种辅助方式同时采用会对磷化过程产生明显的协同效应,所得磷化膜耐硫酸铜点蚀时间和耐氯化钠溶液腐蚀时间分别达到了125 s和95 min,耐腐蚀能力优于采取单个辅助方式所得磷化膜。

Phosphating is a course of forming insoluble and corrosion-resistant phosphating film on the surface of metal through chemical and electrochemical reactions.It is widely used in the pretreatment of metal surface.In this paper,specific focus was given on the effects on phosphating process at room temperature with some auxiliary operation,such as assistance of ultrasonic wave,adding a certain amount of nano-SiO2.The surface morphology of phosphating films were observed by scanning electron microscopy(SEM),and the corrosion resistance of phosphating films were detected through copper sulfate spot corrosion experiment and sodium chloride etching experiment.The results indicated that the compactness and corrosion resistance of phosphating films were improved effectively by ultrasonic assistance and adding nanoparticles.Furthermore,obvious synergistic effect was discovered on the phosphating process when the two auxiliary methods were used simultaneously.That is,corrosion resistance time against copper sulfate spot corrosion and sodium chloride etching of the resulting phosphating film reached up to 125 seconds and 95 minutes,respectively.And that means the corrosion resistance of phosphating film assisted by both ultrasonic and adding nanoparticles was superior to the other cases that only one measure was adopted.