网眼多孔陶瓷中缺陷形成的有限元分析  

Finite Element Analysis for Strut Crack formation in Reticulated Porous Ceramics

作　　者：张大凤[1] 蒲锡鹏[1] 

机构地区：[1]聊城大学材料科学与工程学院,山东聊城252059

出　　处：《聊城大学学报（自然科学版）》2005年第4期49-52,共4页Journal of Liaocheng University:Natural Science Edition

摘　　要：根据有机泡沫模板孔筋实际结构,设计了合理的模型,采用有限单元法对脱胶过程中的热应力进行了计算.计算结果表明凹三角形的棱角处最易破坏,随着涂覆厚度的增加,热应力逐渐减小,这样就可以减小热应力对涂覆层的破坏,提高材料的力学性能.在有限元分析的基础上,采用改进的两次离心挂浆工艺制备了网眼多孔陶瓷,增加了模板的涂覆厚度,材料的力学性能得到了显著提高.实验结果与理论计算相吻合,有力证明了有限元计算结果的正确性及其对工艺改进的重要指导意义.A two-dimensional model was built according to the strut cross- section ot template. The thermal stress in the struts during pyrolysis process was simulated and calculated using finite element analysis. The result indicated that the weaker points locate at the strut angles, which is consistent with the experiment. Also extremum of thermal stress decrease with the increasing thickness of slurry coat. So the effective method to avoid the cracks is improving the loading of the slurry and the coat thickness. By two-step centrifuging process, the thermal stress resistance of the coating was promptly improved because of increased coat thickness. Thus the bending strength and thermal shock resistance of the produced reticulated porous ceramics were improved, which further proved the finite element analysis is a powerful assistant means to fleetly design and optimize the ceramic processing.

关 键 词：多孔陶瓷 缺陷 有限元 热应力 

分 类 号：TQ174.75[化学工程—陶瓷工业]