中文摘要：

以 Q235钢片为基体，采用湿法超声机械镀制备 Zn-Al复合镀层。用扫描电子显微镜及其配备的能谱仪分析了锌-铝复合镀层的表面形貌、断面形貌和元素组成，并用测厚仪、贴滤纸法和划格试验分别对镀层的厚度、孔隙率和结合力进行表征。结果表明，湿法超声机械镀Zn-Al复合镀层是由锌粉和铝粉颗粒相互镶嵌、填充所形成的致密堆积体，表面均匀、平整，与基体的结合强度高。镀层主要由锌、铝、锡和铁组成，铝的质量分数低于施镀前混合粉体中铝粉的质量分数。在考虑施镀过程中金属粉的损耗后，所得Zn-Al镀层的厚度满足预定的厚度（30μm）要求。

英文摘要：

Zn–Al composite coating was prepared on Q235 steel substrate by ultrasonic-based wet mechanical plating. The surface morphology, cross-sectional morphology, and elemental composition of the coating were analyzed by scanning electron microscopy and energy-dispersive spectroscopy. The thickness, porosity, and adhesion strength of the coating were characterized using thickness tester, ferroxyl test, and cross-cut test, respectively. The results showed that the Zn–Al composite coating prepared by ultrasonic-based wet mechanical plating is a compact stacked layer mutually inlaid and filled by zinc and aluminum particles, with uniform and smooth surface and strong adhesion to the substrate. The Zn–Al coating consists mainly of zinc, aluminum, tin, and iron. The mass fraction of aluminum in the coating is lower than that of aluminum in the particle mixture before plating. The thickness of Zn–Al coating reaches the expected value （30μm） after considering the loss of metal particles during the plating process.