Effect of Network Formation on the Creep of Platelet-Reinforced Ceramics

摘要

The addition of SiC platelets to alumina is knownto decrease the strain rate by up to one order of magnitude ascompared to pure alumina with an otherwise identicalmicrostructure. In order to investigate the role of plateletinteractions on this process we have made composites usingdifferent processing routes, which results in different degrees ofplatelet orientation. The more interesting effects are observed inthe material with the most random orientation. The experimentalevidence suggests that a strong platelet network develops. Thisbuilds in large internal stresses following the hot pressing. Thesestresses drive the creep process until they are able to relax. Thisprocess has been followed in detail by means of neutron diffraction.