Deforming ceramic oxide materials - to increase hardness and creep resistance

摘要

Ceramic oxide materials are deformed at a temp. at which the temperature-fracture stress curve markedly rises, under a mechanical stress between the stress value at which the displacement-deformation starts, and that at which the material is damaged (by separation of grains, fissures or fracture), with the proviso that the extension (or compression) remains below 0.5%. The applied stress should be gradually increased to the final value within 1-2 mins. to ensure the predominance of the sliding displacements. In the case of sintered alumina, the hardness can be increased by 30%, and the creep resistance by a factor of 10.