Abstract: The invention proposed a novel hot pressing flowing sintering method to fabricate textured ceramics. The perfectly 2-dimensional textured Si3N4 ceramics (Lotgering orientation factor fL 0.9975) were fabricated by this method. During the initial sintering stage, the specimen flowed along the plane which is perpendicular to the hot pressing direction under pressure, through the controlling of the graphite die movement. The rod-like ?-Si3N4 nuclei was easily to texture during the flowing process, due to the small size of the ?-Si3N4 nuclei and the high porosity of the flowing specimen. After aligned, the ?-Si3N4 grains grew along the materials flowing direction with little constraint. textured Si3N4 ceramics fabricated by this invention also showed high aspect ratio. Compared to the conventional hot-forging technique which contained the sintering and forging processes, hot pressing flowing sintering proposed is simpler and lower cost to fabricate textured Si3N4.
Type:
Grant
Filed:
August 10, 2015
Date of Patent:
July 18, 2017
Assignees:
DONGGUAN SOUTH CHINA DESIGN AND INNOVATION INST., GUANGDONG UNIVERSITY OF TECHNOLOGY