摘要
磁粉芯在工程应用中会遇到体积变化引起的开裂、磁性能低等问题,目前未见关于这方面的研究。通过在羰基铁粉磁粉芯(包含磁环、磁片和一体成型电感)中加入不同含量KH550硅烷偶联剂,研究其成型性、磁性能和力学性能,并利用SEM、TMA和LCR等测试分析偶联剂对磁粉芯性能影响的作用机理。研究表明偶联剂能将树脂“约束”在磁粉表面,并在固化过程中带动磁粉颗粒重排,从而增加磁粉芯的膨胀系数。添加0 wt.%和0.1 wt.%偶联剂的磁粉芯具有负的膨胀系数,容易收缩开裂。当偶联剂含量达到0.3 wt.%、0.5 wt.%和0.7 wt.%时,树脂固化过程中磁粉芯的膨胀系数升高,从而增加磁粉芯的体积,有效抑制磁粉芯的开裂倾向。但是,体积的增加会降低磁粉芯的密度、磁导率、Q值和力学性能,增加损耗。综合考虑磁粉芯的成型性和其他性能,偶联剂添加的最佳比例是0.3 wt.%。揭示了偶联剂对磁粉芯膨胀系数等综合性能的影响规律,可为高性能磁粉芯的工程化应用提供重要理论依据。
Magnetic powder cores,also known as soft magnetic composite materials(SMCs),consist of metal magnetic powders coated with an insulating layer formed through a specific pressing process.In engineering applications,magnetic powder cores may be subjected to issues such as cracking,reduced magnetic permeability,and diminished mechanical strength.The insulation coating of the magnetic powder core includes inorganic and organic coatings.Coupling agents,a type of polymer composite additive,have both inorganic and organophilic molecular groups,allowing them to modify the surface of the magnetic powder and serve as a“bridge”between the inorganic and organic coating layers.The gap between academic and industrial research on the cracking and expansion coefficients of magnetic powder cores leads to a poor understanding of the underlying mechanisms.The moldability,magnetic properties,and mechanical properties of carbonyl iron powder(CIP)magnetic powder cores(including magnetic rings,magnetic discs,and molding inductors)with different contents of the KH550 silane coupling agent were investigated in this study.Scanning electron microscopy(SEM),thermomechanical analysis(TMA),and LCR techniques were used for analysis.The SEM images of the magnetic powder core sections indicate that increasing the amount of coupling agent reduces powder agglomeration,which increases the area percentage of the nonmagnetic phase and porosity.With an increase in the coupling agent content,the area percentage of the nonmagnetic phase increased from 18.4%to 31.4%.Notably,the magnetic disc experimental outcomes,influenced by the coupling agent content,thickness,molding pressure,and curing rate,revealed that a higher curing rate,increased thickness,and higher molding pressure made the magnetic discs more susceptible to cracking.However,coupling agents can reduce the cracking tendency of the molding inductors and magnetic rings,thereby enhancing their moldability.The density of the magnetic discs is influenced by both the molding pressure and coupling
作者
余红雅
袁涵
李竞舟
刘仲武
郭宝春
杨建民
陈榕寅
YU Hongya;YUAN Han;LI Jingzhou;LIU Zhongwu;GUO Baochun;YANG Jianmin;CHEN Rongyin(Dongguan Mentech Optical&Magnetic Co.,Ltd.,Dongguan 523330,China;School of Materials Science and Engineering,South China University of Technology,Guangzhou 510640,China;South China Institute of Collaborative Innovation,Dongguan 523808,China)
出处
《中国表面工程》
EI
CAS
CSCD
北大核心
2024年第2期260-268,共9页
China Surface Engineering
基金
东莞市引进创新科研团队项目(2020607231010)
广东省自然科学基金(2021A1515012464)。
关键词
羰基铁粉
KH550偶联剂
膨胀系数
磁粉芯
一体成型电感
carbonyl iron powder
KH550 coupling agent
expansion coefficient
magnetic powder core
molding inductor
