中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 10 No. 3 June 2000 |
erosion of molten silica①
（1. Department of Materials Engineering and Applied Chemistry,
National University ofDefense Technology, Changsha 410073, P.R.China;
2. Biomaterials Engineering Center,
Wuhan University of Technology, Wuhan 430070, P.R.China）
Abstract:Si2N2O ceramics was fabricated from powder by hot-pressing in N2atmosphere. The resistance of the ceramic sample to oxidation and erosion of molten silica was investigated. The bulk density and open porosity of the ceramic sample were measured according to the Archimedes principle in water. Then fracture surface of the sintered body was observed by SEM. The results and analysis indicate that the resistance of Si2N2O ceramics to oxidation and erosion of molten silica increases when its density increases and/or its open porosity decreases. Moreover, they also reveal that the oxidation process is an unsteady dispersing process with oxygen as the constant source, and the resistance to erosion of molten silica related to the quantity of grain boundary in unit surface area. The lowest mass gain is 2.4g/m2after oxidizing at 1000℃for 100 h in air, while the lowest mass loss is 2.9 g/m2after 40 h erosion in molten silica.
Key words: silicon oxynitride; ceramics; chemical stability
