Study on the Properties and Microstructure of Ferromagnetic Mullite-Based Composite

抄録

Regarded as an important structural and functional material, mullite is widely researched on electronic, optical and high-temperature structural applications. In this paper, dense ferromagnetic mullite-based composites with 30 mol% α-Fe₂O₃ were obtained at 1400 and 1450°C in the air by pressureless sintering technique, respectively. Due to the excess of solid solution limitation at sintering temperature, some spinel solid solution of iron oxide and Al³⁺ ion separated from the mullite/Fe₂O₃ solid solution matrix with the elevation of sintering temperature, which is confirmed by phase and microstructure analyses. The mechanical, magnetic and high temperature electrical conductive properties of the composite were measured. It is shown that the mechanical properties of composite are comparable with those of monothetic mullite. Furthermore, the composite also behaves ferromagnetic property at room temperature and good electrical conductivity at high temperature, which shows the possibility of adding multiple functions to mullite composite.