Influence of additives on morphology, orientation and anti-corrosion property of bright zinc electrodeposit

The use of new combination of additives such as cetyltrimethylammonium bromide (CTAB), benzoic acid (BA) and 2-bromo-3-chloro-5, 5-dimethylcyclohex-2-enone (BCD) develops bright zinc electrodeposit on mild steel. The additives combination has a synergistic effect on improving faradaic efficiency as well as throwing power of optimized bath. The morphology, orientation and anti-corrosion property of zinc electrodeposit has been systematically studied in absence and presence of individual and mixture of additives. The presence of all the three additives such as CTAB, BA and BCD in plating bath form nanocrystalline, bright zinc coating with (100), (110) preferred orientation with smaller surface roughness and superior anticorrosion property. The presence of any two additive mixtures out of three as well as single additive gave deposit with lower corrosion resistance. The influence of brightener BCD concentration on morphology, orientation and anti-corrosion property of bright zinc coating in optimum bath has been examined.