Chapter 38. Influence of the Si3N4 Microstructure on Its R-Curve and Fatigue Behavior
- John B. Wachtman Jr
Published Online: 28 MAR 2008
Copyright © 1991 The American Ceramic Society, Inc.
Proceedings of the 15th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 12, Issue 7/8
How to Cite
Tikare, V. and Choi, S. R. (2008) Influence of the Si3N4 Microstructure on Its R-Curve and Fatigue Behavior, in Proceedings of the 15th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 12, Issue 7/8 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470313831.ch38
- Published Online: 28 MAR 2008
- Published Print: 1 JAN 1991
Print ISBN: 9780470375099
Online ISBN: 9780470313831
Silicon nitrides with highly elongated grains have gained much attention as engineering materials for use in high-temperature structural applications. The R-curve and fatigue behavior of a silicon nitride with large, highly elongated grains were compared to those of a silicon nitride with smaller, more equiaxed grains. The former was found to have higher toughess and a slightly rising R-curve which enhanced fatigue resistance, while the latter had constant toughness with crack length. The R-curve was atrributed to crack deflection and grain pull-out. The microstructure did not influence the dynamic fatigue properties of the two ceramics as both had good resistance to dynamic fatigue. The cyclic fatigue resistance of the large-grained Si3N4, however, was surprisingly low.