苯酚磺酸体系岛状锡的制备与性能研究

发布时间：2018-06-08 05:43

  本文选题：苯酚磺酸电镀锡 + 低锡板　； 参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：国际市场上锡资源日益紧张,减小镀锡板镀锡量已经成为镀锡工艺的发展趋势。但镀锡量的下降往往带来镀锡板可焊性和耐蚀性的下降。本文试图开发出直接岛状锡和镍系岛状锡两套新型的镀锡工艺,岛状锡镀锡板属于低锡板,但由于其凸起的结构,在相同镀锡量下岛状锡软熔后表现出优于常规低锡板的性能,所以岛状锡镀锡板是一种具有很大发展前景的低锡板种类。本文主要对苯酚磺酸体系电镀岛状锡的工艺及其形成机理进行研究,通过SEM,电化学工作站等方法,确定了直接岛状锡和镍系岛状锡的工艺参数,并考察了其软熔后的焊接性能与耐蚀性能。通过电化学工作站研究了两种岛状锡的成核过程。在使用低添加剂浓度和电流密度的情况下成功制备出直接岛状锡,其工艺参数为:SnSO4浓度为51g/L,添加剂EN+ENSA(α-氧基-萘+α-萘酚磺酸聚氧乙烯醚)浓度为0.5g/L,电镀电流密度为1.4A/dm2。SEM测试显示直接岛状锡颗粒粒径在微米级,最小粒径为0.64μm,最大粒径为3.64μm,平均粒径为1.95μm,锡的覆盖度为53%。镀锡量测试结果表明,直接岛状锡在使用高频感应软熔仪软熔后自由锡含量维持在0.3g/m2以上,利于焊接。在闪镀镍经过热处理后的基体上制备出镍系岛状锡,其工艺参数为:闪镀镍含量为0.05g/m2,热处理的温度为450℃,热处理的时间为45s,SnSO4浓度为51g/L,添加剂EN+ENSA浓度为5g/L,电镀电流密度为2.8A/dm2。SEM测试显示镍系岛状锡锡颗粒粒径在微米级,平均粒径为1.65μm,锡的覆盖度为41%;Tafel曲线和阻抗测试显示镍系岛状锡耐蚀性优于常规低锡板和直接岛状锡,电化学测试显示其在软熔后自由锡含量维持在0.3g/L以上,可焊性优于常规低锡板。对镀锡层锡颗粒沉积处与露铁处分别进行EDS元素分布测试,测试结果表明,与贫碳区相比,富碳区为直接岛状锡沉积的活性区域,直接岛状锡在形成过程更接近于瞬时成核,铁基体在苯酚磺酸镀锡体系中锡的沉积过程为扩散控制。与镀镍量少的地方相比,镀镍量多的的地方为镍系岛状锡沉积的活性区域,镍系岛状锡在形成过程更接近于瞬时成核,镍经热扩散处理后的基体在苯酚磺酸镀锡体系中锡的沉积过程为扩散控制。
[Abstract]:Tin resources are becoming increasingly scarce in the international market, and reducing tin plating on tin plate has become the development trend of tin plating process. However, the solderability and corrosion resistance of tinplate decrease with the decrease of tin plating amount. In this paper, two new tin plating processes, direct island tin and nickel island tin, are developed. The island tin plating plate belongs to low tin plate, but due to its raised structure, the island tin soft melting performance is superior to that of conventional low tin plate under the same amount of tin plating. Therefore, island tin plating plate is a kind of low tin plate with great development prospect. In this paper, the process and formation mechanism of island tin electroplating with phenol sulfonic acid system were studied. By means of SEM and electrochemical workstation, the technological parameters of direct island tin and nickel island tin were determined. The welding and corrosion resistance of the soft melt were investigated. The nucleation process of two kinds of island tin was studied by electrochemical workstation. Direct island tin was successfully prepared with low additive concentration and current density. The technological parameters are as follows: the concentration of SnSO4 is 51g / L, the concentration of additive en ENSA is 0.5g / L, the current density of electroplating is 1.4A / dm2.SEM test shows that the particle size of direct island tin particles is in micron order. The minimum particle size is 0.64 渭 m, the maximum particle size is 3.64 渭 m, the average particle size is 1.95 渭 m, and the covering degree of tin is 53 渭 m. The results of tin plating test show that the free tin content of direct island tin is above 0.3g/m2 after soft melting with high frequency induction soft melt, which is favorable for welding. The nickel insular tin was prepared on the substrate after heat treatment. The technological parameters were as follows: the content of nickel plating was 0.05g / m ~ 2, the temperature of heat treatment was 450 鈩，

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