锂辉石对红柱石基复相陶瓷烧结性能的影响

Influence of the Spodumene on Sintering Behavior of the Andalusite-matrix Composite Ceramics

以红柱石、微米级PSZ(部分稳定氧化锆)、苏州土、滑石为主要原料,添加适量锂辉石,采用反应烧结法制备了红柱石基复相陶瓷。研究了锂辉石的添加量对红柱石基复相陶瓷烧结性能和力学性能的影响。利用X射线衍射仪、扫描电子显微镜以及万能试验机表征样品的物相组成、微观结构和力学性能。结果表明:在1400℃烧结温度下保温2 h获得了性能优良的红柱石基复相陶瓷,样品吸水率为0.28%,气孔率为0.74%,体积密度为2.61 g/cm^3,抗折强度达96.08 MPa;随着锂辉石添加量的增大,样品的体积密度增大。XRD、SEM分析结果表明,复相陶瓷的主晶相为莫来石和锆英石晶体,锆英石和α-方石英均布在莫来石的骨架中,提高了复相陶瓷的机械性能和断裂性能。红柱石复相陶瓷是一种有广阔应用前景的高温结构陶瓷材料。

Andalusite-matrix composite ceramic materials were fabricated, mainly using andalusite, superfine PSZ, Suzhou clay, and talc as raw materials with the addition of spodumene. The effect of the spodumene content on the sintering behaviour and mechanical properties of the andalusite-matrix composition was analyzed. The composition, microstructure and mechanical properties of the samples were characterized by scanning electron microscope, X-ray diffractometer and universal testing machine, respectively. The results showed that the water absorption was 0.28%, the porosity was 0.74%, the bulk density was 2.61 g/cm^3, and the bending strength was 96.08 MPa, when the samples were obtained by firing at 1400 ℃ for 2 h; the densification of the samples was reduced with the increase of the spodumene content. X-ray diffraction peaks suggested fully developed mullite and zircon phases obtained by reaction sintering of andalusite and PSZ. The microstructure containing mullite as a continuous predominant phase in which zircon grains were homogeneously distributed improved almost all the mechanical and fracture properties. The andalusite composite ceramics could be one of the most promising materials for high temperature structural applications.