为满足装饰行业中富锡处理的需求,在紫铜表面进行化学镀锡,沉积时间从5 min增至40 min,制备出厚度为0.15～0.76 μm的锡镀层。采用扫描电子显微镜(SEM)分析锡镀层的微观形貌,用X射线荧光光谱仪(XRF)分析镀层的厚度,使用能谱仪(EDS)和X射线光电子能谱仪(XPS)分析镀层的化学元素,通过电化学工作站测试锡镀层的交流阻抗谱和Tafel极化曲线来比较镀层的耐蚀性。结果表明:随着沉积时间的延长,锡镀层表面Sn含量不断升高,镀层增厚,锡镀层表面由大量的SnO2和少量的金属Sn构成。沉积时间对锡镀层的微观形貌和耐腐蚀性能有一定影响;随着沉积时间从5 min延长至40 min,锡镀层的微观形貌发生变化,耐腐蚀性能不断变差,20 min耐蚀性最差,40 min时耐蚀性比20 min略微升高。
In order to meet the demand for tin-rich treatment in the decoration industry, electroless tin plating experiment was carried out on the surface of red copper. The thickness of the tin coating ranged from 0.15 to 0.76 μm as the deposition time varied from 5 to 40 min. Scanning electron microscope (SEM) was used to analyze the microstructure of the tin coating. X-ray fluorescence spectrometer (XRF) was used to analyze the thickness of the coating. The chemical elements of the coating were investigated using energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The corrosion resistance of the tin coating was compared using an electrochemical workstation, which measured the electrochemical impedance spectroscopy (EIS) and Tafel polarization curves of tin coatings. Results showed that as the deposition time prolonged, the Sn content on the surface of the tin coating continuously rose, leading to a thicker coating. The surface of the tin coating was composed of a large amount of SnO2 and a small amount of metallic Sn. The deposition time was found to have a certain impact on the microstructure and corrosion resistance of the tin coating. As the deposition time was extended from 5 to 40 min, the microstructure of the tin coating underwent changes, and its corrosion resistance progressively deteriorated. Corrosion resistance was lowest at 20 min, showing slight improvement at 40 min compared to 20 min.
