摘要
基于冰冻铸造法,采用自主设计的定向凝固装置制备了孔隙率为66.79%的多孔Al2O3陶瓷,探究了不同蔗糖含量对多孔陶瓷微观组织形态的调控规律,发现蔗糖能将小面生长的冰晶改变成非小面生长,从而将层状多孔结构改变为蜂窝状结构,基于这一微观组织的改变和SEM表征,探究了蔗糖含量对多孔陶瓷力学性能的影响规律。结果表明：随着蔗糖含量的增加,多孔陶瓷的微观组织逐渐由层片状向蜂窝状转变,试样的抗压强度呈先升高后降低的趋势,蔗糖浓度由0%（质量分数）增加到1%时,抗压强度由18.90 MPa提高到22.24 MPa,并在蔗糖为含量时达到最大,为25.87 MPa,继续增大蔗糖浓度,抗压强度在蔗糖含量为7.5%和10.0%时分别下降到22.42和21.32 MPa。力学性能变化的原因在于：随着蔗糖含量的增加（0~5%）,层状多孔结构中陶瓷桥的数量增加,使其抗压强度升高;试样中,蜂窝状多孔区和层片状多孔区存在区域边界,边界能有效地限制裂纹在不同区域的扩展。
Porous Al2O3 ceramics were prepared by a self-designed directional solidification device based on the freeze-casting principle. The effect of sucrose content on the microstructures of porous ceramics was investigated. The results show that sucrose can change the faceted growth of ice crystals into non-faceted growth and the layered porous structure into cellular porous structure. The microstructures of porous ceramics gradually change from lamellar to cellular with the increase of sucrose content, and the compressive strength of the samples firstly increases and then decreases. The compressive strength increases from 18.90 to 22.24 MPa as sucrose content is increased from 0%（mass fraction） to 1%, and the maximum strength, 25.87 MPa, is obtained when sucrose content is 5%, and then the compressive strength decreases from 22.42 to 21.32 MPa when sucrose content is decreased from 7.5% to 10.0%. The mechanism is that the number of ceramic bridges in the layered porous structure increases, leading to the increase of the compressive strength, and there are regional boundaries between the cellular porous region and the lamellar porous region, and the boundaries can effectively obstruct the propagation of the crack between different regions when sucrose content increases from 0% to 5%.
作者
郑韬
虎小兵
申洁楠
游家学
王理林
王志军
李俊杰
王锦程
ZHENG Tao;HU Xiaobing;SHEN Jienan;YOU Jiaxue;WANG Lilin;WANG Zhijun;LI Junjie;WANG Jincheng(State Key Laboratory of Solidification Processing,School of Materials Science and Engineering,Northwestern Polytechnical University,Xi＇an 710072,China;School of Materials Science and Engineering,Xi＇an University of Technology,Xi＇an 710048,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2018年第6期785-791,共7页
Journal of The Chinese Ceramic Society
基金
陕西省自然基金(2017JM5112)
国家自然科学基金(51701155)资助
关键词
冰冻铸造法
蔗糖
组织形态调控
力学性能
freeze-casting
sucrose
regulation of microstructure
mechanical property
