Fractographic Investigation of Subcritical Crack Growth at Inherent Flaws in Polycrystalline Ceramics.

Abstract

Variations in intergranular and transgranular fracture along radii extending from fracture origins in hot pressed (H.P.) alumina, 96% alumina and H.P. silicon nitride were studied. The percent intergranular fracture (PIF) was plotted versus stress intensity factor (K sub I) for various distances from the fracture origins assuming smooth crack fronts and the absence of localized stresses. The observed variations were analyzed in relation to single crystal and polycrystal K sub IC values. The results were used to suggest fractographic criteria for subcritical crack growth boundaries in these materials. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1978
Accession Number
ADA065417

Entities

People

  • Dominique M. Richard
  • Henry P. Kirchner
  • Robert M. Gruver

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Acoustic Emissions
  • Blood Coagulation Factors
  • Ceramic Materials
  • Crack Propagation
  • Crystal Lattices
  • Crystal Structure
  • Crystals
  • Fracture (Mechanics)
  • Grain Size
  • Materials
  • Materials Engineering
  • Materials Laboratories
  • Materials Science
  • Mechanics
  • Stress Corrosion
  • Stress Intensity Factors
  • Transitions

Readers

  • Materials Science and Engineering.
  • Powder metallurgy of Titanium alloys.