Non-Oxide Structural Ceramics - Alloy Design for Improved Sinterability and Mechanical Performance
Abstract
Research on non-oxide structure ceramics including silicon nitride, silicon carbide and titanium diboride has been conducted Multiphase silicon nitride composites with melilite and other high nitrogen content grain boundary phases have been prepared. These composites can be sintered to high density and they show improved oxidation resistance. Mechanical properties have been evaluated and found to compare favorably with other silicon nitride materials. Phase relations have also been delineated for various rare-earth containing silicon nitride systems. An in-situ toughened alpha silicon nitride solid solution with a microstructure of elongated grains has been discovered. Compared with conventional silicon nitride, this material has a comparable strength and toughness but has 40% higher hardness. Phase relations of selected rare-earth containing alpha silicon nitride solid solutions have also been delineated. Composites of silicon carbide and titanium diboride have been prepared which also show a microstructure of elongated grains. These materials have improved strength and toughness compared to monolithic silicon carbide. In addition, the electrical conductivity has been improved by the addition of titanium diboride.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 12, 1998
- Accession Number
- ADA345523
Entities
People
- I. W. Chen
- Tseng Ying Tien
Organizations
- University of Michigan