Ultrafine grained bulk ceramic composites consolidated from nanostructured composite powders by pressure less sintering

摘要

Nanostructured alumina-titania composite powders which are microsized particles composed of nanosized grains were prepared from nano alumina and titania powders with nanodopants (zirconia and ceria) by ball milling, spray drying and heat treating. Then, the as prepared nanostructured composite powders were consolidated into ultrafine grained alumina-titania bulk ceramic composites through powder compacting and pressure less sintering. The addition of nanodopants leads to a finer grain size in the ceramic and improves the densification of bulk ceramic composite. The active mechanisms of nanodopants were discussed in detail.