采用自主研发的预处理方法,制定了2种镁合金摩托车零件的电镀工艺。对于形状复杂的AZ91D零件(如发动机外壳),工艺流程为:机械抛光-除蜡一-学除油-crO3+HNO3酸洗-氢氟酸活化-化学镀镍-电镀焦铜-CuNi/Cr镀层。对于形状简单的AM60零件(如轮毂),工艺流程为:机械抛光-除蜡-化学除油-一步酸洗活化-浸锌-预镀镍-电镀焦铜-CuNi/Cr镀层。近2年的试验结果表明,所获得的镀层光亮,结合力好,耐蚀性高,可用于镁合金零件室外环境下的腐蚀防护。
Two electroplating processes for Mg alloy motorcycle parts were developed based on self-developed pretreatment methods. The process flow is as follows: mechanical polishing-dewaxing-chemical degreasingpickling with CrO3 and HNO3-activating with hydrofluoric acidelectroless Ni plating-pyrophosphate Cu plating Cu/Ni/Cr plating for AZ91D parts with complicated shape (such as engine case), and mechanical polishingdewaxing-chemical degreasing-one-step pickling/ activating-Zn immersion-Ni pre-plating-pyrophosphate Cu plating-Cu/Ni/Cr plating for AM60 parts with simple shape (such as wheel hub). The results obtained in almost two years test showed that the coating is bright and has good adhesion and high corrosion resistance, suitable for the outdoor corrosion protection of Mg alloy parts.