Fatigue Behavior of P/M 7091 and I/M 7475 Aluminum Alloys

Abstract

The fatigue behaviors, tensile properties, microstructures, and fractographic features of powder metallurgy 7091-T7E69 and ingot metallurgy 7475-T7351 aluminum alloys were studied and compared. In this study, the fatigue tests were performed under constant amplitude and FALSTAFF and MINI-TWIST spectrum loadings. The P/M 7091-T7E69 aluminum alloy has greater tensile strength but lower fracture toughness than the I/M 7475-T7351 aluminum alloy. The dominant microstructure difference between these two alloys is the extra phases in P/M 7091-T7E69 aluminum alloy: Cobalt aluminide or (Co, iron)2Al9 spheroids and numerous oxide particles along prior powder boundaries (PPB) as well as within the powders. The fatigue crack growth path is tortuous in the P/M 7091-T7E69 aluminum alloy but straight in the I/M 7475-T7351 aluminum alloy.

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Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1989
Accession Number
ADA221790

Entities

People

  • Eun U. Lee

Organizations

  • Naval Air Warfare Center Warminster

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Force
  • Aircrafts
  • Alloys
  • Aluminum Alloys
  • Amplitude
  • Electron Microscopes
  • Electron Microscopy
  • Fatigue Tests (Mechanics)
  • Intensity
  • Materials
  • Mechanics
  • Microscopes
  • Microscopy
  • Microstructure
  • Particles
  • Tensile Properties
  • Tensile Strength

Fields of Study

  • Materials science

Readers

  • Materials Science (Mechanical Engineering).
  • Powder metallurgy of Titanium alloys.