Fe基软磁复合材料的断裂性能研究

基于两步热处理法进行了Fe基软磁复合材料的制备研究,成功制备出具有较高抗弯强度的软磁复合材料(SMCs),研究并分析了微观组织结构与抗弯强度的内在关系。将Fe粉表面钝化增加了Fe与具有优异介电性能的有机硅环氧树脂的结合键,提高了材料的抗弯强度,其强度达到45.3 MPa。能谱(EDS)及有限元方法(FEM)分析表明,SMCs制备中产生的孔洞及裂纹主要分布在树脂层及树脂-Fe界面,在外加载荷作用下,裂纹影响孔洞外缘的应力分布,并朝着共同断裂失效的方向扩展,故对SMCs的强度产生不利影响。为了提高SMCs的强度,需要保证树脂涂覆完整,并进一步提高树脂层本身及树脂与纯铁的粘结强度,采用热压方式减少材料中的孔洞数量。

Study on the Fracture Properties of Fe-based Soft Magnetic Composites

The soft magnetic composites (SMCs) with higher flexural strength were prepared successfully by two-step heat treatment method and the relationship between the microstructure and flexural strength was investigated.The strength achieves the better value 45.3 MPa for the increase of the binding bonds between passivated iron powders and organosilicon epoxy resin (OER) with excellent dielectric properties.Energy dispersion spectrum (EDS) and finite element method (FEM) results showed that the pores and cracks produced during the SMCs preparation process were mainly distributed in the resin layer and resin-Fe interface.Under the external load,the stress distribution of the pore edge was affected by the crack,and made them expand toward the same failure direction,resulting in a negative effect on the strength of SMCs.Our work suggests that the improve of the SMCs' strength depends on the integrity of the coating resin,the further enhancement of resin/iron adhesive strength and resin layer's strength,as well as the use of hot pressing to reduce pores.