Study on Sintering Properties and Crystallization of Fused Quartz Ceramic Materials Containing BN-B<sub>4</sub>C

Abstract

Different dosages of BN-B4C compound additive have been introduced for preparing specimen with fused quartz granule (d50=10μm). Fused quartz ceramic materials were fabricated in reduction atmosphere at various temperatures for 1h. The characterizations were carried out by thermal expansion ratio, apparent porosity, cold modulus of rupture (CMOR) and SEM as well as by X-ray diffraction (XRD). The effect of BN-B4C on the sintering, crystallization and properties of fused quartz was investigated. The result reveals that with increase of the temperature, the apparent porosity and CMOR of specimens decrease. The specimen C sintered at 1300°C possessed a maximum CMOR (22.31 MPa). The specimen C sintered at 1350°C has more compact microstructure. The lowest thermal expansion ratio of the specimens sintered at various temperatures was obtained when the dosages of compound additive is 3%. With increasing BN-B4C content, the role on inhibiting crystallization was improved. The specimens containing 3 wt% BN-B4C had obvious effect on inhibiting crystallization of the specimens sintered at various temperatures.