【摘要】 采用碳化硅、烧高岭土、氢氧化铝、滑石为主要原料,石墨为造孔剂制备了碳化硅/堇青石复相多孔陶瓷。研究了烧结温度和烧结助剂二氧化铈对碳化硅/堇青石复相多孔陶瓷气孔率和强度的影响,并分别用XRD和SEM分析晶相组成和断面显微结构表明:制备出的SiC多孔陶瓷的主相是SiC,结合相是堇青石与方石英,多孔陶瓷具有相互连通的开孔结构;在1350℃烧结,并保温3h,当造孔剂含量为15%时,碳化硅/堇青石复合多孔陶瓷性能最佳,其气孔率31.80%,相应的弯曲强度为63.74MPa。在1200℃下,添加不同含量的CeO₂,对烧结样品的相组成有影响,能够降低生成堇青石的温度,在CeO₂含量为3%的样品中,堇青石的峰最明显,但是过量的氧化铈会抑制了堇青石的生成;随着CeO₂加入量的增加,其气孔率和弯曲强度也会随之变化,1200℃下,在CeO₂加入量为4%时其弯曲强度最优。但随着CeO₂的含量的增加,其气孔率逐渐下降。更多还原

【Abstract】 Silicon carbide / cordierite composite porous ceramics were fabricated from silicon carbide,calcined kaolin,aluminum hydroxide,talcum as matrix materials and with graphite as pore-forming. The influence of sintering temperatures and sintering additives ceria on the porosity and flexural strength of silicon carbide / cordierite composite porous ceramics were investigated. The grain phases and the fracture surface micrograph were analyzed with XRD and SEM,respectively. The result showed the main phase that fabricated the porous ceramics,which was proved to have perforated structure that linked one another,is Si C and the bonded phase are cristobalite and cordierite. Sinterred at 1350 ℃ and kept for 3 hours,with the content of pore-forming being 15%,the composite porous ceramic of silicon carbide-cordierite reached its top capability. Meanwhile,the porosity was 31. 8% and the flexural strength was 63. 73 MPa. The addition of CeO₂ led to a drop in the temperature of cordierite formation. When 3wt% CeO₂ was added,the highest content of cordierite was observed. Yet excessive CeO₂ would be inhibited to the reaction. The porosity and the flexural strength were influenced by the amount of CeO₂. When 4wt% CeO₂ was added,highest flexural strength was reached at 1200 ℃. But the porosity of the material was decreased with the increase of CeO₂ addition.更多还原