镁合金化学转化膜上化学镀镍的研究

Electroless Plating of Nickel on Magnesium Alloy AZ91D with Pre-phosphorization

将化学转化和化学镀镍结合在一起,先对AZ91D镁合金进行化学转化处理,然后在转化膜上进行化学镀镍.并用扫描电镜(SEM)、X射线衍射技术(XRD)研究了镀层表面形貌和组织结构及处理后镁合金的耐蚀性能.结果表明:两种工艺结合得到的镀层使腐蚀电位正移0.83 V,腐蚀电流降低,有效的提高了镁合金耐腐蚀性能.

In order to enhance the anti-corrosion performance of AZ91D magnesium alloy, a composite coating cosisted of pre-phosphorization and electroless plating of nickel was investigated in detail. Firstly, the chemical conversion coating on AZ91 D magnesium alloy was obtained in phosphate-permanganate solutions, and then electroless nickel plating was carried out on the conversion coatings. The surface morphology, phase constituents of the conversion coatings and the plated Ni-coatings were examined by scanning electron microscope （SEM）and X-ray diffraction （XRD）. The results show that a compact, uniform Ni layer with good adhesion was deposited on AZ91 D Mg alloy. The measurements of potentiodymaic polarization indicate that the anti-corrosion property of Mg alloy was improved greatly by the composite coating.