Stress-Corrosion and Corrosion-Fatigue Susceptibility of High-Strength Aluminum Alloys

Abstract

The 'stress-corrosion-fatigue' performance of several high strength- aluminum alloys was investigated by tests of hydraulic cylinders and other types of specimens. Specimens were prepared from forgings and forging stock of alloys 2014-T6, 7075-T6, 7075-T73, 7079-T6, and X7080-T7 and from premium castings of alloy CH70-T7. Alloy 7075-T73 rated best in the corrosion-fatigue tests; no stress-corrosion cracking occurred in this alloy, and the lives of forged cylinders subjected to repeated loadings to 80% of design stress in a corrosive environment were at least 10 times as long for this alloy as for forged cylinders of alloys 2014-T6, 7075-T6, or 7079-T6. Fractographic examination showed that stress-corrosion cracking as well as fatigue cracking occurred in alloys 2014-T6, 7075-T6, and 7079-T6 in the stress-corrosion-fatigue tests. The investigation demonstrated that stress corrosion and fatigue can interact under certain conditions to produce failures in shorter times and fewer cycles than for either phenomenon occurring by itself.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1970
Accession Number
AD0720857

Entities

People

  • B. W. Lifka
  • Glenn E. Nordmark
  • J. G. Kaufman
  • M. S. Hunter

Organizations

  • Alcoa

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Aluminum Alloys
  • Electron Microscopes
  • Environment
  • Failure Mode And Effect Analysis
  • Fatigue Cracking
  • Fatigue Tests (Mechanics)
  • Fracture (Mechanics)
  • Hydraulic Cylinders
  • Internal Pressure
  • Materials
  • Materials Laboratories
  • Mechanical Properties
  • Mechanical Working
  • Mechanics
  • Stress Corrosion
  • Stress Corrosion Cracking
  • Tensile Strength

Fields of Study

  • Materials science

Readers

  • Pavement Materials Engineering.
  • Structural Health Monitoring of Composite Structures.