Investigation of chemical reactions in TiB2/Si3N4 composites

✍ Scribed by Bor-Yuan Shew; Jow-Lay Huang

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 909 KB
• Volume: 159
• Category: Article
• ISSN: 0921-5093
• DOI: 10.1016/0921-5093(92)90406-q

✦ Synopsis

Various contents of TiB 2 particles were added to Si3N 4 with 6 wt.% Y203 and 2 wt.% AI203 as sintering additives. Samples were sintered at different temperatures (1850, 1800 and 1750 °C) and in different atmospheres (9 atm N2, ] atm N z and 1 atm argon) to investigate the effects of sintering conditions. TiN was found in every TiB2-containing sample through the reaction between N 2 and TiB/near TiB 2 surfaces. This reaction becomes more prominent as the temperature or N z pressure increases. The source of nitrogen gas for the reaction could be the dissociation of Si3N 4 or the ambient atmosphere. Micropores are commonly observed near the reaction zone. Further chemical characterization and mechanical testing work should be conducted in order to understand more about the chemical reaction and to investigate its effects on mechanical properties.