新型铜锡合金电镀添加剂的制备

Preparation of New Copper-Tin Alloy Electroplating Additive

目的制备一种电镀铜锡合金添加剂,利用此种添加剂制得白亮并且综合性能良好的铜锡合金镀层。方法基础镀液组成为:焦磷酸钾250 g/L,焦磷酸铜16 g/L,焦磷酸亚锡12 g/L。工艺条件为:pH 8.5,室温,电流密度0.3 A/dm^2,电镀时间5 min。以此为基础,设计正交试验,以镀层60°光泽度作为判定标准,优选出电镀添加剂的最佳配方。利用百格刀、维氏硬度计、材料表面性能综合测试仪、盐雾试验箱对最佳配方制备的镀层的附着力、表面硬度、摩擦系数、耐蚀性能等进行分析,利用SEM、XRD对其表面形貌及物相进行分析。结果经过正交试验优选出的最佳添加剂配方为:8×10^(-3) g/L聚二硫二丙烷硫磺酸钠(SPS),8×10^(-3) g/L聚乙烯亚胺烷基盐(PN),8×10^(-4) g/L 2-巯基苯并咪唑(M)。采用该添加剂配方,在上述基础镀液及工艺条件下,可获得全范围白亮Hull槽试片。该镀层60°光泽度达到269.7,表面平整,附着力的ISO等级为2,维氏硬度为154.47HV0.2,摩擦系数为0.2,盐雾试验中超过72 h无腐蚀。结论复配添加剂可以制备出光泽度较高的银白色镀层,且镀层结合力好,硬度、耐磨性以及耐腐蚀性都较高,可以满足工业要求。镀层表面平整,物相为Cu_6Sn_5以及Cu_(13.7)Sn。

The work aims to prepare a new electroplating additive to obtain a white bright copper-tin alloy electroplated coating with comprehensive properties.The electrolyte was composed of K4 P2 O7.3 H2 O of 250 g/L,CU2 P2 O7.3 H2 O of 16 g/L and Sn2 P2O7 of 12 g/L.The electroplating was conducted in the above electrolyte(pH=8.5)at ambient temperature and current density of 0.3 A/dm2 for 5 min.An orthogonal experiment was designed to determine the optimal formula of the electroplating additive,and the 60°gloss of coating was used as a criterion.The adhesion,surface hardness,friction coefficient and corrosion resistance of the coating prepared by the optimal formula were analyzed by cross-cut tester,vickers hardness tester,surface performance tester and salt spray device.The surface morphology and phase were analyzed by SEM and XRD.An optimal formula of additive selected by the orthogonal experiment was composed of SPS of 0.008 g/Ls PN of 0.008 g/L and M of 0.0008 g/L.The white bright Hull cell test samples were prepared by the additive formula under the above electrolyte and process conditions.The gloss of the coating at 60°reached 269.7.The electroplated coating showed a smooth surface with adhesion level of ISO grade 2.Vickers hardness of the elec仕opiated coating was 154.47HV0.2,and the friction coefficient was 0.2.The electroplated coating was free from corrosion after the salt spray test for 72 hours.The obtained additive can be used to prepare a bright silvery electroplated coating with high glossiness.The coating has good bonding force,high hardness,and good abrasion resistance and corrosion resistance.The properties of the prepared coating can meet the requirements of industry.The coating surface is smooth and the phase is Cu6Sn5 and Cu13 7Sn.