(1. 中南大学 粉末冶金国家重点实验室，长沙 410083；
2. 昆明理工大学 材料科学与工程学院，昆明 650093)
摘 要: 采用溶胶-凝胶法，通过控制正硅酸乙酯(TEOS)和3-氨丙基三乙氧基硅烷(APTES)偶联剂的加入量，在Fe85Si9.6Al5.4粉末表面包覆SiO2绝缘层。采用X射线衍射(XRD)、傅氏变换红外光谱(FTIR)、X射线光电子能谱(XPS)、扫描电镜(SEM)和磁力显微镜(MFM)对粉末的微观结构及成分进行表征，采用振动样品磁强计(VSM)测试粉末的磁性能。结果表明：利用硅烷偶联剂对Fe85Si9.6Al5.4粉末表面改性后再加入TEOS，能在Fe85Si9.6Al5.4粉末表面包覆一层约1~2 μm厚的絮状非晶SiO2；随着TEOS和APTES添加量的增多，SiO2包覆层的厚度也随之增加，饱和磁化强度Ms在0.86~0.90 T之间变化，Hci基本不变；当添加6 mL TEOS、1 mL APTES时，得到的包覆粉末包覆效果及性能最佳，饱和磁化强度Ms达到0.90 T，矫顽力Hci为1 114 A/m。
关键字: Fe-Si-Al粉末；软磁复合粉末；溶胶-凝胶法；SiO2绝缘包覆层
（1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. School of Materials Science and Engineering, Kunming University of Science and Technology,
）
Abstract:Silica insulation coatings were prepared on the surface of Fe85Si9.6Al5.4 powder by sol-gel method through controlling the additions of tetraethyl orthosilicate (TEOS) precursor and (3-Aminopropyl) triethe-oxysilane (APTES) coupling agent. The microstructures, composition and magnetic properties of the material were characterized by X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), magnetic force microscopy (MFM) and vibrating sample magnetometry (VSM). The results show that the compact amorphous silica layers with a thickness of 1-2 μm are coated on the surface of the Fe85Si9.6Al5.4 powder after surface modification by APTES and then followed by addition of TEOS. The thickness of silica layer increases with increasing the addition of TEOS and APTES, and the saturation magnetization (Ms) varies between 0.86 T and 0.90 T, with coercivity basically unchanged. The optimal coating effect and properties can be obtained by adding 6 mL TEOS and 1 mL APTES, with saturation magnetization and coercivity reaching 0.90 T and 1 114 A/m, respectively.
Key words: Fe-Si-Al powder; soft magnetic composite powder; sol-gel method; SiO2 insulation coatings
