莫来石含量对钙长石/莫来石复相多孔陶瓷组织结构与性能的影响

以CaCO₃、SiO₂、α-Al₂O₃为原料, 采用泡沫注凝法制备了不同莫来石含量的钙长石/莫来石复相多孔陶瓷, 研究了莫来石含量对复相多孔陶瓷的体积密度、气孔率、抗压强度、热导率及微观组织和结构的影响. 结果表明, 莫来石含量对气孔率有很大的影响, 烧结过程中液相出现引起的收缩是气孔率下降的主要原因; 在气孔率相近的情况下, 莫来石含量较高试样的抗压强度和热导率也较高, 致密的孔壁、长柱状的莫来石晶粒使得复相多孔陶瓷的抗压强度提高. 所制备的钙长石/莫来石复相多孔陶瓷的开口气孔率介于60.8%~75.2%, 抗压强度为12.94~36.95 MPa, 热导率为0.30~1.33 W/(m·K).

Effects of Mullite Content on the Properties and Microstructure of Porous Anorthite/Mullite Composite Ceramics

Porous anorthite/mullite composite ceramics with different mullite contents were fabricated by foam-gelcasting method, using CaCO₃, SiO₂, α-Al₂O₃ as raw materials. Effects of mullite content on bulk density, porosity, compressive strength, thermal conductivity and microstructure of the porous composite ceramics were researched. Mullite content has great effect on the apparent porosity of the porous anorthite/mullite composite ceramics. As a result of the appearance of liquid phase in the sintering, the sample shrunk, which is the main reason for the porosity decrease. Compressive strength and thermal conductivity increase with the mullite content under the condition of the similar porosity. Dense pore wall and rod-like mullite grain are benefit for compressive strength of porous anorthite/mullite composite ceramics. The apparent porosity of the prepared porous anorthite/mullite composite ceramics is in the range of 60.8%-75.2%, the compressive strength is between 12.94 MPa and 36.95 MPa, and the thermal conductivity is in the range of 0.30-1.33 W/(m·K).