Effects of Testing Temperatures and Thermal Treatments on Flexural Strength of Si3N4-MoSi2-BN Composites

✍ Scribed by V. Medri; S. Guicciardi; V. Dupont; C. Melandri; A. Bellosi

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 625 KB
• Volume: 8
• Category: Article
• ISSN: 1438-1656
• DOI: 10.1002/adem.200600084

✦ Synopsis

The machinability of ceramic materials can be improved by the addition of hexagonal‐BN. Si~3~N~4~/h‐BN composites are suitable as rotor seals for gas turbine engines in the ranges 1000°C–1300°C. Oxidation resistance and strength retention can be improved by the addition of MoSi~2~ up to 1500°C. Strength retention is due to the formation of a surface borosilicatic glassy phase and the partially oxidized sub‐surface region which prevent extensive bulk damage.