镁合金浸锌前处理对化学镀镍层的影响  

The Influence of Zinc-dipping Pretreatment Technological Conditions on the Electroless Nickel Coating on Magnesium Alloy

作　　者：管秀荣[1] 朱宏达 史敬伟[1] 邵忠财[1] 戴诗行 GUAN Xiu-rong;ZHU Hong-da;SHI Jing-wei;SHAO Zhong-cai;DAI Shi-hang(School of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang 110159, China)

机构地区：[1]沈阳理工大学环境与化学工程学院,沈阳110159

出　　处：《表面技术》2018年第4期140-144,共5页Surface Technology

基　　金：辽宁省自然科学基金(201602648)~~

摘　　要：目的优化出镁合金浸锌前处理的处理液络合剂及工艺条件。方法研究镁合金浸锌前处理处理液的络合剂,确定出适用的络合剂,并在最佳络合剂的条件下,研究前处理液pH值和温度的变化对化学镀镍层的影响。采用电化学测试、扫描电子显微镜(SEM)和X射线衍射(XRD)对化学镀镍层进行耐蚀性评价,并对其微观形貌进行表征,确定出最佳络合剂和工艺条件。结果通过对镀镍层厚度的测量及SEM微观形貌观测,确定最优的前处理液络合剂为苹果酸。在该条件下确定最佳的工艺条件为:pH=10,温度80℃。所制得的化学镀镍层的自腐蚀电位为-0.6 V,与镁合金基体的腐蚀电位-1.47 V相比,提高了0.87 V,腐蚀电流密度由镁合金基体的1.26×10^(-4) A/cm^2下降到1.26×10^(-6) A/cm^2,自腐蚀电流密度降低了2个数量级。镀层的钝化区间在-0.6~0.2 V,且结合力好,外形美观。结论镁合金浸锌前处理处理液的最佳络合剂为苹果酸,最佳工艺条件为pH=10、温度80℃。The work aims to optimize the complexing agent of zinc-dipping pretreatment solution before zinc-dipping and the process conditions of zinc-dipping pretreatment. The main method is, studying zinc-dipping complexing agent before processing, determined the best complexing agent, and under the best conditions, studying the influence of pH value and temperature in the former treatment solution on the electroless nickel plating layer. The corrosion resistance of electroless nickel coating was evaluated by electrochemical test, scanning electron microscope （SEM） and X ray diffraction （XRD）. The best complexing agent and technological conditions were determined. Through the measurement and SEM observation of the micro- structure of nickel plating layer thickness, to determine the optimal complexing agent is malic acid; In this condition to deter- mine the optimal processing conditions is pH=10, temperature is 80℃, the electroless nickel plating layer of the corrosion po- tential is -0.6 V, compared with the corrosion potential of magnesium alloy substrate potential -1.47 V, improved 0.87 V, the corrosion current decreased from 1.26×10^-4A/cm^2 to 1.26×10^-6 A/cm^2, the corrosion current density is reduced by 2 orders of, the passivation interval of the coating was -0.6-0.2 V, plating layer with good adhesion, beautiful appearance. In conclusion, the optimum complexing agent for the pretreatment solution of magnesium alloy is malic acid. The optimum technological condi- tions are pH=10 and temperature 80℃.

关 键 词：镁合金 浸锌 前处理 化学镀镍 苹果酸 

分 类 号：TQ153[化学工程—电化学工业]