Preparation and Properties of Cordierite Ceramics Obtained via a Pouring-Sintering Method

Abstract

Due to their low thermal expansion coefficient and high-temperature stability and mechanical properties, cordierite (Mg2Al4Si5O18) ceramics have been extensively used as high-temperature filler materials, catalyst carriers, and insulating materials. During the preparation of cordierite ceramics, it is important to ensure an appropriate sintering temperature, holding time, and proper mineralizer to enhance the strength and toughness of the obtained ceramics. In this paper, cordierite ceramics were prepared by a pouring and sintering method using electrically-fused magnesia, alumina powder, and quartz sand powder as the main raw materials, aluminate cement as the binding agent, and TiO2 as the mineralizer. The effects of sintering temperature and holding time on the phase composition of cordierite ceramics were investigated. This study determined that the appropriate sintering temperature range was 1350–1400 °C and the optimal holding time was 4 h–8 h. The effects of TiO2 incorporation on the flexural strength and water adsorption of cordierite ceramics were also studied. The results indicated that the incorporation of TiO2 increased the flexural strength and reduced the water adsorption of cordierite ceramics. The flexural strength of cordierite ceramics increased to 11.99 MPa, and the water adsorption rate decreased to 2.04% when the amount of incorporated TiO2 reached 8%. Scanning electron microscopy (SEM) revealed that the incorporation of TiO2 promoted the formation of cordierite, refined the grains, and played a toughening role.