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.

摘要

堇青石（Mg ₂ Al ₄ Si ₅ O ₁₈）陶瓷由于其低热膨胀系数、高温稳定性和机械性能，已被广泛用作高温填充材料、催化剂载体和绝缘材料。堇青石陶瓷在制备过程中，必须保证合适的烧结温度、保温时间和合适的矿化剂，以提高所得陶瓷的强度和韧性。本文以电熔氧化镁、氧化铝粉、石英砂粉为主要原料，铝酸盐水泥为结合剂，TiO ₂为主要原料，采用浇注烧结法制备堇青石陶瓷。作为矿化剂。研究了烧结温度和保温时间对堇青石陶瓷相组成的影响。本研究确定合适的烧结温度范围为 1350–1400 °C，最佳保温时间为 4 h–8 h。还研究了TiO ₂掺入对堇青石陶瓷的弯曲强度和吸水率的影响。结果表明，TiO ₂的掺入提高了堇青石陶瓷的抗弯强度并降低了其吸水率。当TiO ₂的掺入量增加时，堇青石陶瓷的抗弯强度提高到11.99 MPa，吸水率降低到2.04%达到了 8%。扫描电子显微镜（SEM）表明，TiO ₂的掺入促进了堇青石的形成，细化了晶粒，并起到了增韧作用。