镁合金基体上不合格镀层的退除方法  

Stripping of unqualified coatings plated on magnesium alloy

作　　者：储荣邦 王宗雄 徐关庆 

机构地区：[1]南京市虎踞北路4号6幢501室,江苏南京210013 [2]宁波市电镀行业协会,浙江宁波315016 [3]长春市南湖大路28号富苑华诚沁园春60A,吉林长春130012

出　　处：《电镀与涂饰》2012年第9期5-7,共3页Electroplating & Finishing

摘　　要：AZ31B—H24镁合金经浸锌预处理后氰化预镀铜及化学镀镍，以铅板为阴极通过电解法于阴极电流密度2～5A／dm。之下采用单纯氢氟酸或氢氟酸＋铬酸酐溶液进行退镀。操作过程中，当电流骤降而电压微升时，金属镀层即完全退除。讨论了退镀液组成及温度对退镀效果的影响。采用5％～55％氢氟酸退除液，以电解方式退除镁合金表面镀铜或镀铜＋化学镍镀层，不会损伤镁合金基体。加入75～150g／L铬酸酐在室温下操作，既可提高退除速率，又可避免只用氢氟酸退除镀层后产生黑色氧化膜的现象。AZ31B-H24 magnesium alloy was treated by zinc immersion, copper pre-plating, and electroless nickel plating successively. The coatings were stripped by electrolysis with Pb sheet as cathode in pure HF or HF＋CrO3 solution at cathodic current density 2-5 A/dm2. The removal of metal coatings is completely finished as indicated by the dramatic current drop and slight voltage increase. The effects of the composition of stripping solution and temperature on the removal of metal coatings were discussed. The removal of copper or copper plus electroless nickel coatings by electrolysis in 5%-55% HF solution will not damage the magnesium alloy substrate. The addition of CrO3 at room temperature not only improves the removing speed, but also eliminates the formation of black oxide film after stripping, which usually occurs when only HF is used.

关 键 词：镁合金 浸锌 预镀铜 化学镀镍 退镀 

分 类 号：TQ135.1[化学工程—无机化工] TG178[金属学及工艺—金属表面处理]