Abstract
Surface coated composite powders made by the mechanical powder modification system were prepared in order to investigate the basic sintering behavior of the composite powder, as well as the strengthening and function enhancement of the porous sintered materials made from the composite powder. The sintering behavior of fine alumina or fine titania coated alumina powder was examined. Alumina powder coated with fine alumina powder ground away from coarse alumina material powder surface during surface modification process was also examined. The results obtained were summarized as follows:
(1) It was possible to coat the alumina mother powder surface with the fine powder of alumina or titania by the mechanical powder modification system.
(2) It was possible to coat with fine alumina powders ground away from coarse alumina material powder surface during the surface modification process.
(3) The sintered compacts made from surface coated composite powders show markedly high bend strength compared with that made from untreated powder. The strength of the compact made from alumina coated powder was double, and that made from titania coated powder was 8-fold that of the compact made from untreated material powder.
(4) Porosity and pore size distribution hardly changed, even if the strength was improved by the modification of the powder.
These results show that this method is effective for the fabrication of high-strength porous sintered compacts.
