Microstructural design of tough ceramics for contact damage resistance. Final report, February 1995--August 1998
The results of research investigating contact damage and fatigue of ceramics is described, with particular attention to microstructural design. The aims were as follows: (1) To develop experimental testing methodologies, using Hertzian contacts, for studying the fundamental short-crack damage properties of tough ceramics, notably in silicon carbide and silicon nitride; (2) To examine the role of critical microstructural variables (grain size and shape, grain boundary phase, interface energy, internal stress) on the nature of the ensuing contact damage; (3) To investigate the effect of the damage on associated mechanical properties, e.g., strength degradation, fatigue resistance, wear resistance; (4) To process and modify ceramic materials in order to improve the above properties; (5) To develop theoretical models of the damage micromechanics; (6) To establish design engineering criteria for materials selection and optimization. The proposed program has led to new insights into the role of micromechanical phenomena in mechanical behavior of tough ceramics, insights that will ultimately bear on practical areas such as bearing mechanics, cyclic fatigue, ceramic design, and coating-substrate technology.
- Research Organization:
- Lehigh Univ., Dept. of Materials Science and Engineering, Bethlehem, PA (United States)
- OSTI ID:
- 679018
- Report Number(s):
- AD-A--365160/XAB; CNN: Contract F49620-95-1-0187
- Country of Publication:
- United States
- Language:
- English
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