机械镀锌-铝复合镀层的结构分析

采用金相显微镜、扫描电镜、能谱仪分析了混粉法机械镀锌-铝复合镀层的结构、形貌和化学成分分布。结果表明，机械镀锌-铝镀层主要是由尺寸不等的锌粉颗粒相互参杂、填充，形成致密结构体；锌粉颗粒之间的间隙填充着更小尺寸的锌粉和夹杂物，镀层中部分锌粉颗粒发生变形；片状铝粉在镀层中不均匀分布，铝粉和锌粉没有明显的包裹、缠绕；镀层中Fe，Sn，Zn的含量分布正常，且Al的含量比施镀前混粉中Al的含量低得多。

Structure analysis of mechanical plated Zn-Al composite coatings

The structure,morphology and composition distribution of mechanical plated Zn-Al composite coatings obtained by blending metal powders were analyzed with metallomicroscope,scanning electron microscope(SEM) and energy spectrometer.The results show that the coating is mainly composed of zinc particles of different size intermixing and filling reciprocally,and therefore a dense structure is formed;the interspaces of these zinc particles(some are distorted) are filled with smaller size of zinc powder and impurities;the distribution of sheet aluminum powder in the coating is uneven and no apparent wrap and intertwist are found between aluminum powder and zinc powder;the distribution of Fe,Sn and Zn content in the coating is normal,while the aluminum concentration is much lower than that in mixed powders before plating.