The Influence of Micro-Crack Interaction on the Strength of Polycrystalline Ceramics

• Published in: Key engineering materials 2003-01, Vol.243-244, p.357-362
• Main Authors: Sakaida, Yoshihisa, Kawamoto, Hiroshi, Cao, Jianwu, Nagano, Yasuo
• Format: Article
• Language: English
• ISSN: 1013-9826; 1662-9795; 1662-9795
• DOI: 10.4028/www.scientific.net/KEM.243-244.357

Fine element simulations of two-dimensional polycrystalline structures with micro-cracks were performed to study the influence of micro-cracks interaction on the four-point bending strength of polycrystalline ceramics. The micro FEM model, which was considered in the middle bottom of a four-point bending macro FEM model, was constructed from SEM micrograph of an Al2O3-10 vol%ZrO2 ceramics, in which the crystallographic information was given to each grain randomly. One micro-crack was introduced in the micro FEM model as a basic case to simulate the four-point bending strength. The strength was determined by the average stress in a one-grain size distance from the crack tip. Two types of micro-cracks were introduced in the model as a second micro-crack, and the strength were compared with the basic case. For the case that the second crack is parallel to the first crack and apart from the first crack in horizontal direction, the strength increasing with the second crack closer to the first crack. For the case that the second crack is parallel to the first crack and apart from the first crack in vertical direction, the strength decreasing with the second crack closer to the first crack.