用于多孔介质燃烧板的刚玉-莫来石复相陶瓷的研究

Study on Corundum-mullite Composite Ceramics for Porous Medium Combustion

多孔介质燃烧技术是实现低排放、稳定燃烧的有效方式,多孔介质燃烧板作为其核心材料需具有优异的抗热震、耐高温和抗氧化性能。刚玉-莫来石复相陶瓷是耐高温、抗热震环境中使用的优选陶瓷材料。本实验以高岭土、α-Al_(2)O_(3)为原料,采用无压烧结工艺,制备了刚玉-莫来石复相陶瓷。通过XRD、SEM、FESEM等现代测试技术研究了不同配比的高岭土对刚玉-莫来石复相陶瓷的相组成、微观结构和性能的影响。结果表明:经1 620℃烧成的复相陶瓷样品C3(w(α-Al_(2)O_(3))∶w(高岭土)=60∶40)抗折强度达107.59 MPa,样品经30次热震(1 100℃~室温)后强度提升至120.75 MPa,提升率为12.23%。样品的相组成为刚玉和莫来石,短柱状的莫来石与刚玉晶粒相互交错生长,赋予样品具有较高的力学性能及抗热震性能。

Porous medium combustion technology is an effective way to achieve low emission, and stable combustion.Porous medium is used as its key material needs to have excellent thermal shock resistance, high temperature resistance and oxidation resistance.Corundum-mullite composite ceramics are the preferred ceramic materials used in high temperature and thermal shock resistant environment.Kaolin and α-Al_(2)O_(3) were used as raw materials to prepare corundum-mullite composite ceramics.The effects of kaolin addition on the phase composition, microstructure and mechanical properties of the samples were investigated by XRD,SEM,FESEM and so on.The results show that the sample C3 is the best, and the bending strength of the sample sintered at 1 620 ℃ is 107.59 MPa.After 30 thermal shock tests(1 100 ℃~ room temperature),the strength of the sample was increased to 120.75 MPa, improvement rate was 12.23%.The sample is composed of corundum and mullite, and the mullite and corundum grains in the samples grow interlacing with each other and the appropriate pores give the ceramic higher mechanical properties and good thermal shock resistance.