先驱体转化法制备莫来石毡/氧化锆多孔复合材料的显微结构与力学性能

Mechanical Properties and Microstructure of Mullite Felt/ZrO_2 Porous Composites Prepared by Precursor Infiltration and Pyrolysis

以ZrO2前驱体混合液作为浸渍液,莫来石毡为前驱体附着骨架,采用真空压力浸渍工艺制备出莫来石毡/氧化锆多孔复合材料。研究了不同烧结温度(1 300、1 350、1 400和1 450℃)下该多孔复合材料的物相组成、体积密度、开口气孔率、压缩强度及显微结构。结果表明,烧结之后的多孔复合材料发生了四方相氧化锆到单斜相氧化锆的转变,相转变过程直接导致较低烧结温度(1 300和1 350℃)下制备的多孔复合材料体积密度低于烧结前的;而在较高烧结温度下,晶粒间更加紧密联结并生长出大晶粒,材料致密化程度和压缩强度提高,其中,1 450℃烧结制备的多孔复合材料体积密度为2.16g/cm3,开口气孔率约为46.5%,平均压缩强度达到31.6MPa。

The mullite felt/ZrO2 porous composites were fabricated by a vacuum pressure infiltration technique with ZrO2 precursor mixture as an impregnation liquid and mullite felt as a framework The effect of temperature （i.e.,1 300,1 350,1 400and 1 450 ℃） on the porous composites phase composition,density,open porosity and compressive strength was investigated.The results show that tetragonal ZrO2 can transform into monoclinic zirconia in porous composites after sintering.The densityof porous composites sintered at a lower temperature （i.e.,1 300 or 1 350 ℃） is lower than that of composites without sinte ring.The density and compressive strength of the as prepared mullite felt/ZrO2 porous composites increased with the increaseof sintering temperature.The density of porous composites sintered at 1 450 ℃ is 2.16 g/cm3,and the open porosity and the compressive strength are 46.5％ and 31.6 MPa,respectively.