环保型AZ91D镁合金直接化学镀镍工艺研究

发布时间：2018-01-16 15:18

  本文关键词：环保型AZ91D镁合金直接化学镀镍工艺研究　出处：《表面技术》2015年02期 　论文类型：期刊论文

  更多相关文章： 镁合金 化学镀 前处理 稳定性

【摘要】：目的开发一种无铬、低氟、稳定的镁合金直接化学镀镍工艺。方法通过SEM,EDX及浸泡实验、动电位极化曲线、划格试验等方法 ,以稳定系数和镀速等参数为对象,对比新工艺和传统工艺对镀层或镀液性能的影响。结果在以硫酸镍为主盐的基础液中,添加质量浓度为0.5 mg/L的硫脲,镀液的稳定性可得到明显的提高。在使用硝酸+磷酸酸洗后的镁合金试样表面,获得了良好的腐蚀形貌结构,这种结构有利于增强镀层与基底间的机械咬合作用。新工艺获得的镀层属高P镀层(P的质量分数约为11%),在Na Cl溶液中的自腐蚀电位由-1.5 V正移至-0.5 V,腐蚀电流密度降低了约3个数量级。结论以硫酸镍主盐镀液获得的镀层耐蚀性优于碱式碳酸镍主盐镀液获得的镀层,镀液的最佳p H=5,化学镀镍温度为82℃。
[Abstract]:Objective to develop a direct electroless nickel plating process for magnesium alloys without chromium, low fluorine and stability. Methods SEMX edX, immersion test, potentiodynamic polarization curve and grid test were used. The effects of the new process and the traditional process on the properties of the coating or the plating solution were compared with the parameters of the stability coefficient and the plating speed. The results were found in the base solution with nickel sulfate as the main salt. The stability of the plating solution can be improved obviously by adding thiourea (0.5 mg/L). Good corrosion morphology was obtained on the surface of magnesium alloy after pickling with nitric acid. This kind of structure is helpful to strengthen the mechanical bite between the coating and the substrate. The coating obtained by the new technology belongs to the high P coating, the mass fraction of which is about 11%). The self-corrosion potential in NaCl solution shifted from -1.5 V to -0.5 V. The corrosion current density was reduced by about 3 orders of magnitude. Conclusion the corrosion resistance of the coating obtained from the nickel sulfate main salt plating solution is better than that obtained from the basic nickel carbonate main salt plating solution. The electroless nickel plating temperature is 82 鈩，

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