镁合金表面电镀前处理新工艺

常用的镁合金电镀前预处理时需预镀锌、预镀铜,还需使用氰化物,不仅污染环境,且预处理工艺复杂.为此,研究了AZ91D镁合金焦磷酸盐体系电镀铜的前处理工艺.分析了酸洗、活化、浸锌液主盐、配位剂、浸锌温度、浸锌时间等工艺参数对浸锌层质量的影响,确定了前处理工艺的优化条件.采用增重法测试了浸锌层的膜重,用电化学方法研究了镁合金的浸锌过程及浸锌层的耐蚀性能,用划痕、热震和锉刀法测试了经该前处理后所得镀铜层与基体的结合力.结果表明:采用该工艺电镀铜所得镀层细致、光亮,镀层与基体结合力良好,对镁合金基体有较好的防护作用.

New Process for Electroplating Pretreatment of Magnesium Alloy

The pretreatment process for the copper electroplating of AZ91D magnesium alloy was studied in a pyrophosphate bath.The influences of process parameters including acid pickling, activation, major salt of zinc-immersion solution,complexing agent, temperature and time on the quality of zincimmersion coating were analyzed and examined.The pretreatment conditions were optimized.Moreover the mass of the zincation film was measured by weight-gain method, the zincation process of magnesium alloy and corrosion resi...