High Temperature Heterogeneous Materials

Abstract

Experimental and supporting analytical methodologies for the determination and assessment of the integrity of interfaces in composite materials at both room and high temperatures are presented. Experimental test techniques developed in the program are described and supporting analytical methods to assist in the determination of interface fracture toughness from experimental measurements are presented. The test techniques consist of the tensile test on a thin coated fiber and four point bend of a bimaterial bar and were chosen on the basis of their suitability for use at high temperatures. An experimental study of crack tip shielding/antishielding by impurities in alpha-silicon carbide is described. This investigation required the application of stress during high temperature (1873 K) anneals. A novel stress fixture, based on thermal expansion mismatch, was designed, constructed and utilized to achieve this in-situ stressing of the crack specimens at high temperatures.

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Document Details

Document Type
Technical Report
Publication Date
Jul 22, 1994
Accession Number
ADA329853

Entities

People

  • B. Moran
  • J. Weertman
  • K. T. Faber
  • Leon M. Keer

Organizations

  • Northwestern University

Tags

Communities of Interest

  • Air Platforms
  • Cyber
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Ceramic Materials
  • Composite Materials
  • Crack Tips
  • Engineering
  • Fiber Reinforced Composites
  • Films
  • Finite Element Analysis
  • Fracture (Mechanics)
  • Geometry
  • High Temperature
  • Materials
  • Materials Science
  • Mechanics
  • Reliability
  • Shear Strength
  • Shear Stresses
  • Silicon Carbide

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Structural Health Monitoring of Composite Structures.
  • Thin Film Deposition Science.