Effect of heat treatment on zinc whisker growth from electrodeposited coatings

The effects of simple heat treatments on electrodeposited zinc coatings formed on mild steel substrates were examined. It was found that over a temperature range of 50-200°C for 1 and 24 h periods zinc whisker growth was evident. The additional effects of electrodeposited coating thickness and subsequent chromium-based passivation processes were also examined in terms of their effect on whisker growth. Individual whisker morphologies were investigated utilising a field emission gun scanning electron microscopy (FEGSEM) and focused ion beam field emission gun scanning electron microscopy (FIB-FEGSEM).