提高压铸铝外壳化学镀镍层质量工艺

Technics for improving die-cast aluminum case electroless nickel coating quality

电连接器铝外壳压铸件直接化学镀镍所得镀层耐蚀性差。通过化学镀镍镀前处理──喷丸(对要求高的工件还需要机械抛光)和镀后处理──铬酸盐钝化后浸涂金属防护剂或液体石蜡,改善了基体铝外壳的表面状态,减少了镀层的孔隙率。盐雾试验表明,采用新工艺所得镀层的抗盐雾能力大大增强。对电连接器压铸铝外壳化学镀镍新工艺流程进行了介绍。

The corrosion resistance of direct electroless nickel on die-cast aluminum case of the electronic connector is bad. The surface state of aluminum case on substrate is improved and the porosity of coating is decreased by pretreatment process of peening （for demanding workpiece mechanical polishing is needed.） and post-treatment of immersion coating with metal protective agent or liquid paraffin after chromate passivation. Salt spray test showed that the coating＇s salt spray resistance is increased significantly by the present new process, The new process flows of the electroless nickel for the die-cast aluminum case of electronic connector are described.