粉煤灰漂珠/镍-钴-磷磁性复合材料的制备与表征

摘要

A magnetic composite of fly ash cenospheres/Ni-Co-P was prepared by electroless plating. The effects of Ni2+-to-Co2+ molar ratio, NaH2PO2H2O concentration and pH on the composition and deposition rate of Ni-Co-P coating were studied. The optimal process parameters are as followers: molar ratio of Ni2+ to Co2+ 1∶1, NaH2PO2H2O 0.20 mol/L, and pH 9.0. The obtained Ni-Co-P alloy coatings were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and vibrating sample magnetometer. The results showed that the cenospheres are completely coated by uniform and compact Ni-Co-P alloy coatings. The structure of as-plated coating transfers from amorphous phase to crystalline after heat treatment at different temperatures, the cenosphere/Ni-Co-P composite exhibits soft magnetic properties, and its magnetic performances can be significantly improved by increasing the cobalt content in coating and the heat treatment temperature.%采用化学镀法制备得到漂珠/Ni-Co-P磁性复合材料.研究了Ni2+和Co2+的摩尔比、NaH2PO2.H2O浓度和pH对镀层成分及镀覆速率的影响,得到漂珠表面化学镀Ni-Co-P合金的最佳工艺为:n(Ni2+):n(C02+)=1:1,NaH2PO2·H2O 0.20 mol/L,pH=9.0.利用扫描电镜、能谱仪、X射线衍射仪及振动样品磁强计对化学镀前后漂珠的表面形貌、成分、结构及磁性能进行了表征.结果表明,化学镀后漂珠表面包覆了均匀致密的Ni-Co-P合金镀层.经不同温度热处理后,镀层由非晶相结构转变为晶相结构.漂珠/Ni-Co-P复合粉体具备软磁材料的特性.随着镀层钴含量的增大和热处理温度的升高,复合粉体的磁性能得到明显改善.