在中温碱性条件下对AZ91D镁合金进行直接化学镀镍,对镀层的表面结构和形貌、能谱成分进行了分析,采用极化曲线方法测试了镀层耐蚀性能。XRD衍射分析表明,镀层表面为Ni-P固溶体并呈现晶态;SEM及EDS能谱分析表明,镀层表面致密均匀,有少量因反应速率过快引起的气孔存在,镀层表面磷的浓度为3.28%,属于低磷镀层;动电位极化曲线测试表明镀层的腐蚀电位高于镁合金基体,对镁合金基体起到一定的保护作用。
A direct electroless plating on AZ91D magnesium alloy has been prepared in alkaline solution with medium temperature.The coating has been analyzed on surface structure and morphology, Spectral components. The corrosion resistance of coating has been tested by dynamic potential polarization.The structure of the coating was Ni-P solid solution and presented as crystalline state by X-ray diffraction;SEM and EDS spectrum analysis indicated:the surface of coating was compact and homogeneous, a small quantity of pore existed because of high reaction rate, the surface of coating contained 3.28mass%phosphorus and belonged to low phosphorus coating;By dynamic potential polarization it has shown that the free corrosion potential of the coating was higher than that of magnesium matrix, it played a pole of protection of magnesium matrix.