考虑釉面膨胀系数的陶瓷表面微裂纹扩展模拟

Simulation of Microcrack Growth on Ceramic Surface Considering Expansion Coefficient of Glaze

考虑到釉面膨胀系数对陶瓷表面微裂纹的影响,研究设计了一种陶瓷表面微裂纹扩展模拟方法。将釉面视为陶瓷基体材料中包裹的球状颗粒,基于球状颗粒半径趋于无穷大的情形,计算陶瓷材料与界面垂直的表面微裂纹的应力强度因子,然后分析热膨胀系数差对应力强度因子的影响并构建数字模型,建立符合Weibull分布的陶瓷表征单元体。从热传导和热膨胀系数等角度出发,模拟陶瓷表面微裂纹扩展情况。实验结果表明:裂纹扩展长度与膨胀系数成正比,当膨胀系数为10时,陶瓷试件表面微裂纹扩展迅速;陶瓷试件的水平方向应力随着膨胀系数的增加而增加;陶瓷表面微裂纹的长度与宽度与应力强度因子数值成正比。

In order to investigate the effect of the expansion coefficient of the glaze on the microcracks on the ceramic surface, a simulation method of microcracks on the ceramic surface was designed in this work. The ceramic glaze was treated as spherical particles and the radius of spherical particles tended to infinity. Firstly, the stress intensity factors of surface microcracks perpendicular to the interface were calculated. Secondly, the influence of thermal expansion coefficient difference on SIF was analyzed in detail, and a numerical model was established. Subsequently, the Weibull distribution of the ceramic characterization unit was also established. Finally, according to the thermal conductivity and thermal expansion coefficient, the dynamic propagation of microcracks on the ceramic surface was simulated. The results show that the crack growth length and horizontal stress are proportional to the expansion coefficient, and the length and width of microcracks are directly proportional to the value of the stress intensity factor.