A process of cyanide-free alkaline copper electroplating with ethylenediamine as major complexing agent was studied on iron substrate. The effects of the amounts of the major and three auxiliary complexing agents on the polarization curve and electrochemical impedance spectrum of the plating bath as well as the appearance and adhesion strength of the copper coating were discussed by orthogonal test. The optimal process conditions were determined as follows: ethylenediamine 55 g/L, auxiliary complexing agent C 30 g/L, auxiliary complexing agent T 30 g/L, and auxiliary complexing agent G 33 g/L. The bath prepared with the optimal formulation features good throwing and covering power as well as＞80% current efficiency. The appearance and thermal shock resistance of more than 100 pieces of samples produced in pilot-scale test were qualified. The cyanide-free alkaline copper electroplating process with ethylenediamine as major complexing agent is a feasible substitute to traditional cyanide copper plating process for pre-plating on iron and steel substrates.%研究了铁基体上以乙二胺为主配位剂的无氰碱性镀铜工艺.用正交试验讨论了主配位剂及3种辅助配位剂的用量对镀液的阴极极化曲线、电化学阻抗谱及铜镀层外观、结合力的影响.确定了最佳工艺条件为:乙二胺55 g/L,辅助配位剂C30g/L,辅助配位剂T30g/L,辅助配位剂G 33 g/L.最佳配方镀液的分散能力、覆盖能力均良好,电流效率达80％以上.中试100多件样品的镀层外观及热震试验结合力均合格.在铁基体上用以乙二胺为主配位剂的碱性镀铜工艺代替氰化镀铜预镀是可行的.
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