AZ31镁合金化学镀镍镀层分析

以H_3PO_4+HNO_3酸洗与NH_4HF_2+H_3PO_4活化为前处理工艺,对AZ31镁合金进行化学镀镍研究。应用扫描电子显微镜(SEM)、能谱分析(EDS)、X射线衍射仪(XRD)与X射线光电子能谱分析仪(XPS)等方法对化学镀镍层进行形貌、成分分布、相结构以及元素分析。结果表明:化学镀镍层表面平整光亮,镀层为高磷非晶结构。化学镀镍层表面,镍主要以单质镍(26.75%)、NiO(32.96%)以及Ni(OH)_2(40.29%)形式存在,磷主要以单质磷(20.17%)、PO2-4(17.37%)以及PO_4~(3-)(62.46%)形式存在;化学镀镍层内部,镍基本为金属单质镍,磷主要以单质磷(74.11%)以及PO_4(2-)(25.89%)形式存在。

Analysis of Electroless Nickel Plating on the Surface of AZ31 Magnesium Alloys

The electroless nickel plating on AZ31 magnesium alloy was studied, basing on the pretreatment process of H3PO4+HNO3 pickling and NH4HF2+H3PO4 activation. The morphology, composition distribution, phase structure and elemental analysis of electroless nickel plating coating were investigated through scanning electron microscope (SEM), energy dispersive analysis of X-ray(EDS), X-ray diffractometer (XRD), x ray photoelectron spectroscope(XPS). The results indicate that the surface of the electroless nickel plating coating is smooth and bright, the structure of deposits is amorphous with high content of phosphorous. The occurrence mode of nickel on the surface of deposits is pure nickel(26.7%), NiO(32.96%)and Ni(OH)2(40.29%), and occurrence mode of phosphorus is pure P(20.17%), PO42- (17.37%)and PO43-(62.46%). Furthermore, the occurrence mode of nickel in the intermediate layers of the coating is almost 100% pure nickel, and occurrence mode of phosphorus is pure P (74.11%) and PO42-(25.89%).