Papers by Author: Juan Li Yu

Abstract: In this paper, highly porous Si3N4 ceramics with high strength, homogeneous microstructure were fabricated by introducing a proper amount of nanometer carbon in the Si3N4 slurry by gel-casting. Scanning electron microscopy, X-ray diffraction, Archimedes water-displacement method and three-point bending tests were employed to analyze the microstructures and mechanical properties of the sintered bodies. It was shown by the XRD analysis that SiC particles were formed in the sintered bodies. The pillar β- Si3N4 morphology, homogeneous microstructure and the SiC particles as a reinforcement phase are the contributing factors for high porosity and good mechanical behavior.

Abstract: Porous Si3N4 ceramics by gel casting preparation has received considerable attention because of its excellent performance. In the paper, orthogonal experimental design L16(45) was used to investigate the preparation of porous Si3N4 ceramics by gel casting preparation. Three variables including solid loading, monomer content and the ratio of crosslinking agent to monomer were studied. Through range analysis and variance analysis, the results suggest that the ratio of crosslinking agent to monomer has significant influences on both the flexural strength and porosity of Si3N4 sintering body. For the flexural strength of Si3N4 sintering body, the order of significance levels was as follows: the ratio of crosslinking agent to monomer, solid loading and monomer content. For the porosity of Si3N4 sintering body, the order of significance levels was as follows: the ratio of crosslinking agent to monomer , monomer content and solid loading.