空心微珠表面化学镀Ni-Co-P合金

以无机非金属粉煤灰空心微珠为芯材, 利用化学镀工艺对其表面进行金属化改性, 可以得到表面完整包覆的导电粉体, 该粉体具有中空, 质轻, 粒度细, 高强度, 耐高温, 导电性能好等多种优异性能, 可部分代替金属和铁氧体微粉作为电磁波吸收剂. 采用SnCl2和PdCl2进行敏化-活化处理后, 在空心微珠表面化学包覆Ni-Co-P合金层, 利用XRD、EDS、SEM和镶嵌金相等方法对样品进行形貌观察和分析表征, 结果表明, 使用PdCl2作活化剂可以得到优质均匀的Ni-Co-P合金镀层, 镀层光亮, 均匀, 包覆完整. 化学镀后镀层呈非晶态, 450 ℃氢气气氛下热处理后出现结晶相Ni3P和六方晶系的α-Co单质.

Electroless Plating Ni-Co-P Alloy on the Surface of Fly Ash Cenospheres

After surface metallized modification, fly ash cenospheres which have the properties of light, hollow, low density, fine granularity, high intensity, heat-resistant and good conductivity are widely used as the fillings in composite materials and may probably become a new type of microwave absorber to replace the ultrafine metallic and ferrite powders. In this paper, conductive and magnetic cenospheres were fabricated by electroless plating Ni-Co-P alloy films on the surface of fly ash cenospheres after the pretreatment of sensitization and activation by SnCl2 and PdCl2. XRD, EDS, SEM and metallic microgragh analytical methods were utilized to characterize the properties and microstructure of the cenospheres coated with Ni-Co-P films by electroless plating. The results indicate that uniform and high quality Ni-Co-P alloy film with 2～4 μm thickness could be obtained after the activation by PdCl2.