Crack-Growth Resistance in Transformation-Toughened Ceramics
Abstract
Crack-growth resistance in transformation-toughened ceramics is studied by modeling the region surrounding an advancing crack tip as a zone which has undergone a uniform dilatational phase transformation. This zone is allowed to evolve around advancing crack tip under conditions of increasing far- field load while the tip is maintained at a critical stress intensity necessary for fracture. This procedure leads to the surprising conclusion that maximum toughening occurs for finite amounts of crack advance. The discovery of enhanced fracture toughness zirconia-enriched ceramics has led to a flurry of experimental and theoretical analyses. It has been well established that the high stresses near a crack tip can cause small zirconia particles, typically one micron or less in diameter, to undergo a phase transformation from a tetragonal to a monoclinic crystal structure.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1989
- Accession Number
- ADA206849
Entities
People
- Bernard Budiansky
- David M. Stump
Organizations
- Harvard University