MICROSTRUCTURAL AND PHYSICAL CHARACTERIZATION OF CORDIERITE-MULLITE CERAMICS REFRACTORIES

Abstract

The morphologies of the synthesized cordierite and mullite samples as well as their physical-mechanical properties were investigated and characterized by x-ray diffraction spectroscopy (XRD). The cordierite and mullite was shown to be successfully synthesized by XRD results and represented phases of mullite cordierite and alumina, indicating the creation of materials having interesting combinations of sample ceramics refractories properties. After sintering at 1300°C and 1350°C temperatures, physical properties, such as shrinkage (varied from 10.1 ~ 13.1% and 10.4 ~ 13.6%), bulk density (range of 2.33 ~ 2.41 g/cm³ and 2.22 ~ 2.36 g/cm³), water absorption (varied from 0.07 ~ 5.49% and 0.01 ~ 4.12%), apparent porosity (varied from 0.51 ~ 12.87% and 0.15 ~ 9.15%), flexural strength (range of 37.7 ~ 43.5 MPa and 40.6 ~ 56.9 MPa), thermal expansion coefficients (4.89 ~ 6.60x10-6/°C and 4.72 ~ 6.17x10-6/°C), respectively. The microstructure of cordierite and mullite ceramics refractories in sintered samples, in which consists of short cordierite and mullite grains by SEM imaging. It was found that a new sample sintering at 1350°C. They are most suitable for the manufacture of refractory materials.