亚微米碳酸钙加入量对莫来石多孔陶瓷结构和性能的影响  

Effects of Submicron-sized CaCO3 on the Microstructures and Properties of Porous Mullite Ceramics Prepared

作　　者：葛胜涛 毕玉保[1] 司瑶晨 张海军[1] GE Shengtao;BI Yubao;SI Yaochen;ZHANG Haijun(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,Hubei,China)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室

出　　处：《陶瓷学报》2019年第5期665-669,共5页Journal of Ceramics

基　　金：国家自然科学基金(51672194,51872210);湖北省教育厅高等学校优秀中青年科技创新团队计划(T201602);湖北自然科学基金创新群体项目(2017CFA004)

摘　　要：以莫来石粉体为原料,以亚微米碳酸钙为添加剂,羧甲基纤维素钠为稳泡剂,Isobam-104为粘结剂,十二烷基硫酸三乙醇胺为发泡剂,固定浆料固含量为52vol.%,先采用发泡注凝成型工艺制备了莫来石多孔陶瓷坯体,再经1400℃保温2h烧结后制得莫来石多孔陶瓷。研究了亚微米碳酸钙的加入量(0-4wt.%)对莫来石多孔陶瓷的线收缩率、孔隙率、体积密度及抗折强度等常温物理性能及隔热性能的影响,并通过XRD、SEM等手段表征了试样的物相组成、显微结构和孔径分布。研究结果表明:碳酸钙的加入对莫来石浆料的稳定性无明显影响;亚微米碳酸钙的加入可在坯体烧结过程中起到造孔剂的作用,同时与莫来石反应生成钙长石,从而降低多孔陶瓷的导热系数,当添加2wt.%的亚微米碳酸钙时,所制备的莫来石多孔陶瓷的导热系数低至0.178 W/(m·K)。Porous mullite ceramics were fabricated at 1400℃ for 2 h by foam-gelcasting method using industrial grade mullite powder as the main raw materials,CaCO3(0-4wt.%)as an additive,Isobam-104 as the dispersing and gelling agent,sodium carboxymethyl cellulose as the foam stabilizing agent,and triethanolamine lauryl sulfate as the foaming agent.The effects of the addition of CaCO3 on linear shrinkages,porosity,bulk density,flexural strength and thermal properties of porous mullite samples were examined,and the phase composition,microstructures and pore size distribution of the resultant porous ceramic were characterized by XRD and SEM.The results indicated:Addition of CaCO3 had no clearly effect on the stability of the mullite slurries;such addition of CaCO3 andin-situ formed anorthite might play a positive role in decreasing the overall thermal conductivity of the final product.Most importantly,they also exhibited a very low thermal conductivity,e.g.,0.178 W-m-1-K-1 at 200℃ with the addition of 2wt.%CaCO3.

关 键 词：莫来石多孔陶瓷 发泡-注凝法 导热系数 

分 类 号：TQ174.75[化学工程—陶瓷工业]