以铝片为基底,研究了不同添加剂对氯化物镀铁体系镀层形貌的影响。实验发现,糖精主要起柔韧剂作用,可避免镀层开裂;强还原荆抗坏血酸主要稳定镀液中的Fe2+,避免Fe3+对镀层性能的影响,同时抗坏血酸也在一定程度上对镀层有整平作用;十二烷基硫酸钠可提高镀液对镀层的浸润性能,有利于电镀过程的传质,同时使电镀过程中产生的氢气快速逸出,形成致密平整的微观表面。通过将上述添加剂加入到氯化物镀铁体系,使镀层致密光亮,铁晶粒均匀、细小致密,镀层性能优良。
The influence of different additive agents on surface morphology of iron coatings derived from the chloride electroplating bath has been investigated using aluminium plates as the substrates. It is found that the saccha- rin plays a flexible role to avoid the formation of cracking iron coating. As a strong reducing agent, ascorbic acid main- ly keeps the stability of Fe2+ in plating baths to prevent the occurrence of the harmful results on surface morphology of iron coatings. In addition, the ascorbic acid is also a leveling agent for the iron coatings in a certain extent. The addi- tion of lauryl sodium sulfate to the plating baths benefits the wettability of baths on coatings, which can improve the mass transfer of iron element from baths to substrates. Meanwhile, the hydrogen bubbles forming in the plating process rapidly escape from the cathode surface, leading to the formation of compact smooth surface in microstructure. As a result, the iron coatings present the excellent properties in compact and bright coating and uniform and fine iron grains with the addition of different additive agents to iron electroplating baths.