水性Al-Zn-Si合金涂层微观组织及腐蚀性能研究

用Al-Zn-Si合金粉末制备热烧结铝锌硅合金涂层，通过盐水浸泡实验和电化学测试研究其耐蚀性能，并结合扫描电镜和X射线衍射分析等手段观察Al-Zn-Si合金涂层显微组织及其在盐水中的腐蚀产物形貌，分析涂层的耐蚀机理。结果表明，Al-Zn-Si合金涂层也具有阴极保护作用，且Al-Zn-Si合金延缓涂层金属粉末的消耗，使牺牲阳极的腐蚀速率减慢。

MICROSTRUCTURE AND CORROSION RESISTANCE OF WATERBORNE Al-Zn-Si ALLOY COATING

A kind of anti-corrosive paint consisted of epoxy silane and lamellar Al-Zn-Si alloy particles was introduced in this paper. Corrosion properties of waterborne Al-Zn-Si alloy coating were tested through salt water immersion method, electrochemical method. Furthermore, the microstructure, corrosion products of the coating were detected by means of SEM, EDS and XRD. The experimental results showed that Al-Zn-Si alloy particles dispersed in coating in the form of flake structure which formed a more effective physical shield, extending the path of the corrosive medium to body; furthermore, in the corrosion processes corrosion product film formed which filled in pores of the coating and had good shielding property; Tafel curves indicated that Al-Zn-Si alloy was a good sacrificial anode material of aluminum. In addition, anti-corrosive mechanism of Al-Zn-Si alloy coating was analyzed which possessed excellent cathodic protection, and its excellent corrosion resistance was related to lamellar Al-Zn-Si alloy powder which had lower dissolution rate, inhibited the corrosion of the coating and prolonged the duration of cathodic protection.