Effect of pickling on plating porosity and related electrochemical test

Abstract

In many previous studies, it was stated well that acid pickling could improve the density and adhesive strength of plating. In this work, it focused on the relationship observed between the pickling time and the porosity of plating. A group of field emission SEM, EDX and profilograph detections showed that the parent metal surface profile and chemical constituent were both changed after the pickling process. Two kinds of electrochemical tests were adopted and gave a quantitative analysis to the porosity of plating. A three-dimensional nucleation model was established to explain how the porosity of plating was influenced by overvoltage and three kinds of interfacial tension. Coupled with previous investigation, it finally revealed that the pickling time should be restricted in a proper condition or the plating porosity would be increased.