Microstructural Observation Of Complex-Shaped Green Ceramic Compact And Numerical Simulation With Special Consideration On Crack Formation

The microstructure of a die-pressed green ceramic compact with a complex shape was visualized by liquid im-mersion and X-ray micro-computed tomography techniques. Significant microstructural inhomogeneity in terms of the pore distribution and granule shape was observed depending on the sample locations, while cracks were formed only at certain positions. The microstructural differences were explained by the von Mises stress gradient within the compact, which originated from friction between the granule and mold as well as non-uniform pressure delivery because of the complex sample shape. A numerical simulation was performed based on the modified Drucker-Prager/Cap model to explain the origin of the different microstructures, such as pore distri-bution and crack formation.