冷冻干燥法结合淀粉固化制备莫来石多孔陶瓷

发布时间：2018-07-23 08:43

【摘要】：以高岭土、氢氧化铝为原料,淀粉为造孔剂和粘结剂,Y_2O_3为烧结助剂,采用冷冻干燥法结合淀粉固化工艺制备了具有连通开孔结构的莫来石多孔陶瓷。研究了淀粉添加量对浆料前驱体的流变性能、多孔陶瓷的气孔率、孔径分布、显微结构以及力学性能的影响。结果表明:当淀粉含量由15.84vol%增至20.59vol%,浆料前驱体的粘度增加明显;随着剪切速率的增加,浆料前驱体的粘度先显著降低然后趋于稳定,表现为剪切稀化行为。随着淀粉含量的增加,所得多孔陶瓷的孔径尺寸减小,孔径分布趋于均匀,从双峰分布向单峰变化,孔隙率缓慢增加,维持在61.5%~66.2%范围内,当淀粉含量增加到15.84vol%时,抗压强度达到最高值9.5 MPa,孔隙率也达到65.7%。但当淀粉含量进一步增加后,抗压强度有下降的趋势。
[Abstract]:With kaolin and aluminum hydroxide as raw materials, starch as pore-making agent and adhesive Y _ 2O _ 3 as sintering assistant, mullite porous ceramics with connected porous structure were prepared by freeze-drying method and starch curing process. The effects of starch content on the rheological properties, porosity, pore size distribution, microstructure and mechanical properties of the slurry precursor were studied. The results showed that the viscosity of the precursor increased obviously when the starch content increased from 15.84vol% to 20.59vol.With the increase of the shear rate, the viscosity of the precursor decreased significantly and then tended to stabilize, showing a shear-thinning behavior. With the increase of starch content, the pore size of the porous ceramics decreases, and the pore size distribution tends to be uniform. The porosity increases slowly from the bimodal distribution to the single peak, and keeps at 61.5% and 66.2%, while the starch content increases to 15.84vol.%. The compressive strength reached the maximum value of 9.5 MPA, and the porosity reached 65.7 MPA. However, when the starch content increased further, the compressive strength decreased.
【作者单位】：海南大学材料与化工学院南海海洋资源利用国家重点实验室;
【基金】：国家高技术研究和发展计划(863计划)(2015AA034103) 国家自然科学基金(51362008) 海南省自然科学基金创新研究团队项目(2016CXTD001);海南省自然科学基金项目(20155201)
【分类号】：TQ174.1

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