The Effect of Current Surging on the Electrodeposition of Microcracked Chromium

Summary

The influence on the microcracking of chromium of raising the plating current density from a base level to a higher or surge level at a controlled frequency has been investigated. Optimum values of the respective current densities, as well as the proportion of time occupied by surging, have been established in both laboratory and pilot-scale tests. The results indicate that the plating time required to develop a uniform microcrack pattern under steady current conditions is reduced substantially by the application of current surging. A tentative explanation of the observations is advanced based on a comparison of the relative effects of an unsurged current density on chromium thickness and crack pattern.