Fabrication of low cost shirinkage-free porous sialon ceramics

• Published in: Journal of Ceramic Processing Research, 10(5) pp. 581 - 588
• Main Authors: B.S.B. Karunaratnea, Hai-Doo Kim
• Format: Journal Article
• Language: English
• Published: 세라믹연구소 01.10.2009
• Subjects: 재료공학
• ISSN: 1229-9162; 2672-152X

The possibility of fabricating shrinkage-free sialon ceramics from natural aluminosilicates by simultaneous carbothermal reduction and nitridation (CRN) was explored. X-ray diffraction studies confirmed that the products synthesized contained sialon as the major crystalline phase. The average linear shrinkage of sialon pellets produced by CRN at 1450℃ from bentonite and kaoline was about 9-18%. However, it is interesting to report that the study with kyanite led to an important discovery of the possibility of synthesizing sialon samples by CRN to have zero shrinkage after sintering. This has an important implication as many industrial applications demand close dimensional tolerance of fired ceramic bodies such as honeycomb structures. The volume expansion associated with the transformation of kyanite to mullite around 1350℃ is responsible for compensating the sintering shrinkage which would otherwise occur during CRN. The resulting porosity of sialon pellets was more than 60%. KCI Citation Count: 5