Flaw Tolerant Oxide Ceramic Composites

 

This set of technologies takes up the problems associated with ceramics in oxidizing environments. By strengthening materials and slowing the growth of cracks it is possible to produce flaw tolerant oxide ceramic composites.

The University of Illinois has developed a suite of technologies for strong, tough, flaw-tolerant, oxide ceramic composites that achieve a more graceful failure. These technologies address the brittleness and unreliability of ceramics in oxidizing environments. The purpose of these technologies is to slow crack growth in ceramic composites, as a means of toughening the materials. Rather than propagating straight through the material at high speed, the crack takes a zigzag path, doing work while it propagates, ultimately wearing itself out and making the resulting material flaw tolerant.

Applications

  • Aerospace
  • Automobiles and heavy equipment
  • Military
  • Superconductors
  • Structural ceramics
  • Electronics

Benefits

  • Reduced Sensitivity to Oxidation: composites are formed with no oxidation-sensitive materials
  • Improved Mechanical Properties: the resulting composites have high strength, high toughness, improved flexural strength, and are creep resistant damage tolerant due to crack deflection.
  • Improved Thermal Properties: composites are resistant to high temperatures up to 2,000 C and stable even at temperatures over 1,600 C in an oxidizing environment
  • Less expensive Platelet technology uses sintering rather than hot pressing, expensive fibers are unnecessary
  • Reduced Dependence on Thermal Mismatch: interfacial debonding in transformation weakening technologies is less dependent upon mismatch of thermal expansion coefficients
  • Toughening crack propagation and debonding activate a variety of synergistic toughening mechanisms