镁合金化学镀中预处理氟化镁膜的特征与作用.pdf 全文

  本文关键词：镁合金化学镀中预处理氟化镁膜的特征与作用，由笔耕文化传播整理发布。

第 17 卷第 5 期 中国有色金属学报 2007年 5 月 Vol.17 No.5The Chinese Journal of Nonferrous Metals May 2007 文章编号:1004-0609200705-0789-06 镁合金化学镀中预处理氟化镁膜的特征与作用 国 栋,樊占 国,杨中 东, 赵 林,高 鹏 东北大学 材料与冶金学院,沈阳 110004 摘 要:对镁合金的表面前处理工艺进行研究,探讨氟化镁在化学镀层中的存在形式及作用。结果表明:酸浸使 镁合金表面形成一层氧化物膜;活化过程生成的氟化镁不具备反应活性,对镁合金基体有保护作用,使之免于受 镀液的过度腐蚀;对化学镀层断口进行 SEM元素分布分析显示氟化镁层集中存在于镁合金基体与 Ni-P镀层之间; 但过度活化会导致化学镀层孔隙率升高,以 3.5%NaCl 溶液为介质的动电位极化测试表明,过度活化会导致化学 镀层耐蚀性下降。 关键词:镁合金;化学镀;耐蚀性;氟化镁 中图分类号:TG 174.4 文献标识码:A Effects and characteristics of MgF during electroless nickel plating 2 of magnesium alloys GUO Dong, FAN Zhan-guo, YANG Zhong-dong, ZHAO Lin, GAO Peng School of Materials and Metallurgy, Northeastern University, Shenyang 110004, China Abstract: Pretreatment of magnesium alloy surface was studied. Effects of MgF in Ni-P coatings were emphatically 2 discussed. The results show that a magnesium oxide layer is formed after acid etching, and the potential differences of different phases of magnesium alloys are reduced due to the presence of oxide layer. MgF layer is formed after activation 2 which can protect magnesium substrate from corrosion of plating bath. The elemental distribution of cross section of Ni-P coating was investigated by scanning electron microscopy. The MgF layer exists between the magnesium alloy substrate 2 and the Ni-P coating. Excessive activation can raise the porosity of Ni-P coating, and the potentiodynamic polarization indicates that excessive activation

  本文关键词：镁合金化学镀中预处理氟化镁膜的特征与作用，由笔耕文化传播整理发布。