Microstructure and Properties of Fe-6.5wt%Si Alloys Cores with Core-Shell Structures Prepared by Mechanical Alloying and Spark Plasma Sintering Methods

Abstract

In this work, the Fe-6.5wt%Si alloy cores with core-shell structures were prepared by Mechanical Alloying and Spark Plasma Sintering methods. The microstructure and magnetic properties of the samples were investigated with differential scanning calorimetry, X-ray diffraction, scanning electron microscopy and vibrating sample magnetometer. The results show that the synthesis of the Fe-6.5wt%Si powder with core-shell structures can be completion during mechanical alloying process. And the coreshell structure, Fe-6.5wt%Si as core and SiO2as shell, apparently exists in the sinter cores. The relative densities of sintered cores would ascend with increasing the sintering temperature. The Ms offered upgrade tendency with increasing the sintering temperature, while the Hc curves evolve with almost opposite phases. For the core sintered at 1050 °C, the following magnetic data were observed: Ms = 167.84 emu/g, Mr = 2.26 emu/g, Hc = 11.77 Oe, ρ = 2 μΩm and P15/400 = 2.47 W/kg.