摘要
采用凝胶注模成型工艺制备了ZrO2纤维增韧莫来石复合陶瓷材料。借助透射电子显微镜(TEM)、扫描电子显微镜(SEM)、平板导热仪、单边切口梁法(SENB)等测试手段对样品微观形貌、导热系数、断裂韧性等进行研究;研究了分散剂对凝胶注模浆料团聚体的影响;讨论了ZrO2纤维增韧莫来石复合材料的增韧机理;概述了同时获得高韧性和高强度材料的途径。结果表明:添加ZrO2纤维能够明显提高莫来石的断裂韧性;当ZrO2纤维添加量(体积分数)为25%左右时可使莫来石轻质耐火复合材料兼具较低的热导率(λ=0.35 W.m-1.K-1,298K)和优异的综合力学性能(KIC=7.6MPa.m1/2,σb=270MPa)。
Zirconia fiber/muUite light-weighted composites were prepared by gel-casting technique. The micro- structure, thermal conductivity and fracture toughness were characterized by means of transmission electron micro- scope （TEM）, scanning electron microscope（SEM）, plane table thermo-conductivity meter and single edge notched beam （SENB）, etc. Effect of dispersing agent on agglomeration in gel-casting slurry was studied. The toughening mechanism of mullite light-weighted composites toughened by zirconia fiber was discussed. And the balance of high fracture toughness and high tensile strength were summarized. The results show that adding alumina fiber can advance the fracture toughness of mullite light-weighted composites significantly. The low thermal conductivity（λ=0.35W·m^-1·K^-1, 298K） and high fracture toughness （KIC=7.6 MPa·m^1/2,σb=270 MPa） were obtained simultaneously when the adding quantity of zirconia fiber was controlled around 25 vol%.
基金
江苏省星火计划重点支撑项目(YC110427)
