Abstract
Abstract
Cold isostatic pressing, where a rubber bag is filled with ceramic powder, sealed and subjected to hydrostatic pressure, is a method of forming ceramic components with near-net shape. One problem associated with the pressing of complex shapes is that the compact may be cracked after pressing, leading to rejection of the component. In this paper the role of the rubber bag during decompression is investigated using the finite element method. Simulations of both the compaction and the decompression stages of the pressing process are presented and the results demonstrate that excessive distortion of the rubber bag can lead to tensile stresses within the compact that are sufficient to cause cracking of the compact. Methods for alleviating this problem including the modification of the bag geometry are discussed.