A process for improving the impact strength of brittle ceramic materials, such as aluminum, silicon carbide and silicon nitride

摘要

A method of improving the impact resistance of bodies of polycrystalline ceramic such as alumina, silicon nitride and silicon carbide, and bodies produced by the method. The body is provided with a layer of a low elastic modulus polycrystalline ceramic material which has microcracks therein, formed by such factors as thermalexpansion coefficient anisotropy, differences in thermalexpansion coefficients between phases of the material, and by changes in volume during phase transformations in the material. The layer can be applied by preforming the layer and then applying, or by hot pressing the material of the layer onto the body.