铝合金表面电镀金层出现花斑的原因分析及解决措施

Cause analysis on formation of piebald defect on gold coating electroplated on surface of aluminum alloy and countermeasures

从人、机、料、法、环几个方面分析了导致铝合金表面电镀金层出现花斑的原因,并通过工艺试验进行排查。确定了酸性化学镀镍过程中搅拌力度不够和基体镀前发生锈蚀是主要原因。在酸性化学镀镍过程中应对溶液进行有效搅拌,并且在每步工序之后充分清洗零件。必要时在混酸腐蚀后打磨工件或采取工序间防锈措施。

The causes of piebald defect formed on gold coating electroplated on the surface of aluminum alloy were analyzed from several respects including man, machine, material, method and environment, and was found out through process tests. It is identified that the main causes are insufficient agitation during acidic electroless nickel plating and rust formation on substrate prior to plating. The bath must be agitated sufficiently during acidic electroless nickel plating and the substrates washed completely after every procedure. Polish the workpiece after etching with mixed acid solution or take proper rust-proof measures during procedures if necessary.