电流密度对硫酸盐光亮镀锡的影响

在电流密度为0.01~0.05 A/cm^2的条件下进行光亮锡镀。研究了电流密度对阴极过电位、电流效率及镀层厚度的影响,并用SEM和XRD对镀层的表面形貌和晶粒的择优取向进行了表征。结果表明:随着电流密度的增大,阴极过电位和镀层厚度不断增加,电流效率先增大后减小。在较低的电流密度下得到的镀层表面较为均匀、致密;当电流密度高于0.03 A/cm^2时,镀层表面出现较多孔隙,粗糙度增加。不同电流密度下,晶粒的择优取向不同。当电流密度高于0.03 A/cm^2时,晶粒的择优取向由(101)晶面和(211)晶面向(220)晶面转变。

Effect of Current Density on Bright Tin Electroplating from Sulfate Bath

Bright tin coatings were prepared from sulfate bath at the current density of 0.01~0.05 A/cm^2.The effect of current density on cathode overpotential,current efficiency and thickness of coatings was investigated,and the morphology and preferred orientation of grains were characterized by SEM and XRD.The results showed that with the increase of current density,the cathode overpotential and thickness of coatings increased,and the current efficiency increased firstly and then decreased.Uniform and compact coating was prepared at a lower current density.When the current density exceed 0.03 A/cm^2,many pores were found on the surface of coating,and the roughness increased.Different current density result in difference of preferred orientation of grains.When the current density exceed 0.03 A/cm^2,the preferred orientation changes from(101)and(211)crystal faces to(220)crystal face.