基于RSM-BBD的新型锡镍铜合金电镀添加剂的制备

Preparation of New TiN-Nickel-Copper Alloy Electroplating Additives Based on RSM-BBD

目的制备一种电镀锡镍铜合金添加剂,利用此种添加剂制得黑色、光亮并且综合性能良好的锡镍铜合金镀层。方法基础镀液组成为:33.28 g/L氯化镍,29.33 g/L氯化锡,5 g/L硫酸铜,265 g/L焦磷酸钾,6 g/L L-半胱氨酸,20 mL/L乙二胺,40 g/L柠檬酸三铵。工艺条件为:pH=8.5,温度40℃,电流密度1.3 A/dm2,电镀时间5 min。以此基础镀液为基础,在单因素试验的基础上,应用响应曲面法设计三因素(糖精钠、1.4-丁炔二醇和硫脲)三水平试验,以镀层60°光泽度为响应值,通过回归分析,得到了各个因素参数对响应值的影响规律,并且通过优化分析得到了电镀添加剂的最佳配方。利用百格刀、维氏硬度计对最佳配方制备的镀层的附着力、表面硬度进行分析,用交流阻抗法研究添加剂对锡镍铜合金镀层耐蚀性的影响,利用SEM、EDS对表面形貌及成分进行分析。结果经过响应面试验优选出的最佳添加剂配方为:0.4 g/L 1.4-丁炔二醇,3.5 g/L糖精钠,0.06 g/L硫脲。采用该添加剂配方,在上述基础镀液及工艺条件下,可获得镀层表面平整、光亮的枪黑色试片。该镀层的60°光泽度达到200 GU,附着力的ISO等级为1,ASTM等级为4B,维氏硬度为280.56HV1.0。通过电化学分析结果得知,镀层的耐腐蚀性良好。结论复合添加剂可以制备出平整且光泽度较高的枪黑色镀层,且镀层结合力好,硬度以及耐腐蚀性都有明显的改善,可以满足工业要求。

The purpose is to prepare a copper-tin alloy electroplating additive,and use this additive to prepare a tin-nickel-copper alloy coating with bright black and good overall performance.The method adopted is that the basic composition of the plating solution:nickel chloride 33.28 g/L,tin chloride 29.33 g/L,copper sulfate 5 g/L,potassium pyrophosphate 265 g/L,L-cysteine 6 g/L,and ethylenediamine 20 mL/L,triammonium citrate 40 g/L.The process conditions are pH=8.5,temperature of 40℃,current density of 1.3 A/dm2,and plating time of 5 min.Based on the bath and the single factor test,the response surface method was used to design three factors(saccharin sodium,1.4-butynediol and thiourea)and three levels test in response surface method with the 60°gloss of the coating as response value.Through regression analysis,law of effect of each component parameter of the electroplating solution on the response value was obtained,and the best formula of the electroplating additive was obtained through optimization analysis.The adhesion and surface hardness of the coating prepared with the best formula were analyzed by cross-cut tester and a Vickers hardness tester,the effect of additives on the corrosion resistance of tin-nickel-copper alloy coatings was studied by AC impedance method,and the surface morphology and composition were analyzed by SEM and EDS.According to the test analysis of response surface design,the optimal additive formula selected solution formula was as follows:0.4 g/L for 1.4-butynediol,3.5 g/L for saccharin sodium and 0.06 g/L for thiourea.By adopting the additive formula,under the above-mentioned basic plating solution and process conditions,a smooth and bright gun black test piece can be obtained.The 60°glossiness of the coating reaches was 200 GU,the ISO grade of adhesion is 1,the ASTM grade is 4B,and the Vickers hardness is 280.56HV1.0.The electrochemical analysis shows that the coating has good corrosion resistance.In conclusion,the compound additive can prepare a flat and high gloss gun black coating,and the coating has good adhesion,with a significant improvement in hardness and corrosion resistance,which can meet industrial requirements.