钛酸铝-堇青石复相陶瓷的制备和性能研究

Preparation and Properties of Aluminum Titanate-Cordierite Composite Ceramics

本研究以MgO为稳定剂,以堇青石为增强剂,通过固相反应法成功制备了钛酸铝-堇青石复相陶瓷,并系统研究了MgO和堇青石以及烧结温度对复相陶瓷物相组成、显微结构、烧结性能和热力学性能的影响。结果表明,MgO的引入促进了钛酸铝晶粒的合成和长大,降低了烧结温度,并通过形成Mg_(x)Al_(2(1-x))Ti_((1+x))O_(5)固溶体提高了钛酸铝陶瓷的热稳定性。堇青石在烧结致密化和力学性能方面起着重要作用。在1325℃烧结条件下,MgO含量为8.00%、堇青石含量为15.00%的样品表现出良好的性能,体积密度为3.49 g/cm^(3),气孔率仅为2.2%,抗弯强度达到66.8 MPa,热膨胀系数为2.6×10^(-6)K^(-1)(室温至1000℃)。研究结果为设计和制备具备优异综合性能的高温结构陶瓷提供了新的思路。

In this study,aluminum titanate-cordierite composite ceramics were successfully prepared by solid-state reaction method,with MgO as a stabilizer and cordierite as a reinforcement.The effects of MgO,cordierite,and sintering temperature on the phase composition,microstructure,sintering performance,and thermodynamic properties of the composite ceramics were systematically investigated.The experimental results show that the introduction of MgO promotes the synthesis and growth of aluminum titanate grains,reduces the sintering temperature,and improves the thermal stability of aluminum titanate ceramics by forming a solid solution of Mg_(x)Al_(2(1-x))Ti_((1+x))O_(5).Cordierite plays an important role in sintering densification and mechanical properties.Under the sintering condition of 1325℃,the sample(MgO content of 8.00%,cordierite content of 15.00%)exhibits excellent performance,with a bulk density of 3.49 g/cm^(3),a porosity of only 2.2%,a flexural strength of 66.8 MPa,and a thermal expansion coefficient of 2.6×10^(-6)K^(-1)(room temperature to 1000℃).The research results provide new insights for the design and preparation of high-temperature structural ceramics with excellent comprehensive performance.