氧化铝-钛酸铝复相陶瓷的抗热震性能

Thermal shock resistance of alumina-aluminum titanate ceramic

为了提高氧化铝陶瓷的抗热震性,将具有低膨胀系数的钛酸铝加入到Al2O3中,通过无压烧结工艺,制备出了氧化铝钛酸铝复相抗热震陶瓷.结果表明,钛酸铝加入量为w(钛酸铝)=20%,烧结温度为1 510℃时,陶瓷样品能够承受1 500℃温差(空冷)的热震破坏,并且是制备氧化铝钛酸铝复相陶瓷的最佳成分.采用SEM对陶瓷进行组织结构分析,发现在基体内部形成长柱状固溶体,并呈无规则分布状态.这样的显微组织有利于缓解热应力和提高强度,对提高陶瓷的抗热震性具有重要作用.

In order to improve the thermal shock resistance of alumina ceramics, aluminum titanate with low thermal expansion coefficient was added into Al2O3 powder, and the alumina-aluminum titanate ceramic with good thermal shock resistance was fabricated by means of pressureless sintering technology. The experimental result shows that when the additive amount of aluminum titanate is 20 % and the sintering temperature is 1 510 ℃, the ceramic can endure the thermal shock breakage from the temperature difference of 1 500 ℃ （cooling in air）, and this is the optimal component of alumina-aluminum titanate ceramic. The observations on the microstructure of the ceramic reveal that the solid solution with the shape of column has formed in the matrix, and distributes without any orderliness. Such mierostructure is favorable for abating the thermal stress and enhancing the strength of ceramic, and is one of the most important reasons that the thermal shock resistance of the ceramic can be improved effectivdy.