机械镀锌层的组织结构研究

Microstructure of Mechanfcally Deposfted Zinc Coating

为加深对机械镀锌层组织结构的认识,以球状锌粉为原料,通过机械镀方法制备了锌防护层。运用光学显微镜(OM)、扫描电子显微镜(SEM)及其配备的能谱仪观察了镀层的结构形貌,分析了镀层的化学成分;采用XRD技术分析了镀层的物相组成;采用贴滤纸法对镀层进行了孔隙率测试。结果表明,镀锌层是由锌粉颗粒、空隙、金属锡、金属M等构成的多相混合体系,镀层具有一定的致密度;镀层属于由少量Sn,M和大量Zn构成的金属复合镀层,镀层中没有合金相产生;锌粉颗粒是镀层的主体,部分锌粉颗粒发生团聚。

Zinc coatings were prepared by mechanical deposition. An optical microscope and a scanning electron microscope (SEM) were employed to observe the structure of the coatings. An X-ray diffractometer and energy dispersive spectrometer equipped with SEM were employed to analyze the phase and composition of the coatings. Moreover, the porosity of the coatings was tested by filtration-paper-pasting method. Results showed that the mechanically deposited zinc coating has a dense microstructure and is composed of multiple phases of zinc, interstice, tin, and metal M. And aside from a large amount of Ni and small amounts of Sn and metal M, the composite coating did not contain any new alloy phases, while some zinc powders was agglomerated in the coating.