Development of the Microstructure Based Stochastic Life Prediction Models

Abstract

The microstructural features of 7050 T7451 aluminum alloy in the vicinity of fatigue cracks and on the crack path were studied to determine which of them influence fatigue crack propagation. The studies included characterization of the full spectrum of microstructural and fracture surface features starting from the largest ones such as roughness and grain type to the smallest such as second phase particles and dislocations. Of all the features studied, only the second phase particles were shown to have a definite influence by causing crack deflection. The number of particles encountered by the fatigue cracks were significantly higher than the expected average. The fatigue crack path was predominately transgranular and there was no changes in the dislocation and precipitation structures in the crack affected zone.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1993
Accession Number
ADA269880

Entities

People

  • Annetta J. Luevano
  • Jimin Zhang
  • Marek A. Przystupa

Organizations

  • University of California, Los Angeles

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Alloys
  • Aluminum
  • Aluminum Alloys
  • Bulk Materials
  • Crack Propagation
  • Cracks
  • Deflection
  • Dislocations
  • Electron Microscopes
  • Electron Microscopy
  • Geometry
  • Grain Boundaries
  • Materials
  • Microscopes
  • Particles
  • Precipitation
  • Roughness

Fields of Study

  • Materials science

Readers

  • Computational Modeling and Simulation
  • Materials Science (Mechanical Engineering).