Facile fabrication of cordierite-based porous ceramics with magnetic properties

In this paper, cordierite-based porous ceramics with magnetic properties have been firstly in-situ synthesized by using MgO, Al2O3, and SiO2 powders as raw materials and Fe3O4 as a functional additive. Combining with the foam freeze casting method, near net size fabrication (total linear shrinkage < 2.86%) of the magnetic porous materials was realized by adjusting the amount of Fe3O4. The porosity, compressive strength, and saturation magnetization of the prepared materials were 83.9%-87.8%, 1.51-2.65 MPa, and 1.2-5.8 emu/g, respectively. The phase composition and microstructure evolutions during sintering were investigated briefly. The results showed that the synthesis temperature of cordierite was lowered about 100 degrees C due to the addition of Fe3O4. Except for the main phase-cordierite, Mg-Al-Fe spinel and alpha-Fe2O3 also existed in the final materials. The lattice parameters of the Mg-Al-Fe spinel and the amount of alpha-Fe2O3 changed obviously with the change in the sintering temperature and Fe3O4 amount, which mainly influenced the magnetic properties of the prepared materials. Thus, a facile fabrication method of the cordierite-based porous ceramics with the magnetic properties has been put forward in this paper.