工艺参数对干压各向异性永磁铁氧体性能的影响

Effect of process parameters on the properties of dry-pressed anisotropic permanent ferrite

采用陶瓷法制备干压各向异性锶永磁铁氧体材料。用X射线衍射(XRD)、扫描电子显微镜(SEM)、粒度测试仪和测磁仪对样品的显微结构、密度与磁学性能进行研究。通过对湿压与干压成型工艺对比,湿压与干压产品的性能差异源于密度差异。通过优化摩尔比n、一次添加SiO2含量、磁粉粒度等工艺参数,将干压成型磁体的密度提高至4.90g/cm3。一次添加适量的SiO2有利于提高磁体密度和改善干压磁粉成型特性。通过优化工艺,制备出的干压产品典型性能为:Br=397mT,Hcb=235kA/m,Hcj=241kA/m,(BH)max=28.9kJ/m3。

Dry-pressed anisotropic Sr-ferrite materials were prepared by ceramic technology. The crystal structure, density and magnetic properties were studied by means of X-ray diffraction（XRD）, scanning electron microscope（SEM）, particle size analyzer and permanent magnet material measuring instrument, respectively. Comparison of wet- and dry-pressing process indicates that difference in magnetic properties comes from difference in their density. The density of dry-pressed magnet is increased to 4.90g/cm3 by optimizing the molar ratio n, SiO2 content, particle size and so on. Suitable amount of SiO2 addition is advantageous to improve density and mold characteristic. Through optimizing the process, dry-pressed magnet material was prepared with typical magnetic properties of Br=397mT, Hcb=235kA/m, Hcj=241kA/m, （BH）max=28.9kJ/m3.