Microwave Sintered Porous Mullite Composite

Abstract

In order to aviod much high energy and CO2 generation. Microwave sintering (MS) is always carried out to prepare refractory. In this work，MS was proposed to sinter mullite composite. An insulation structure based on hybrid heating mode was well designed with the wall of high-aluminum refractory and the aided heaters of SiC. The sintered samples under different sintering processing were characterized by appearent porosity detection and volume density. Phase composition was investigated by X-ray Diffraction (XRD) analysis. Surface and fracture Flied Emission Scanning Electron Microscopy (FESEM) was applied to observe pore distribution and grain growth. Sintering profile was provided in this work. It was found that mullite composite could be prepared within 1h at relative lower temperature around 1300°C. Compared with samples prepared by convitional sintering (CS), MS samples presented better densification and more uniform grain growth. Microwave plasma phenomena was explored inside MS samples, however, not found in CS ones.