Characterization of High Cycle Fatigue Behavior of a New Generation Aluminum Lithium Alloy (Preprint)

Abstract

The high cycle fatigue life characteristics of an Al-Li alloy was studied as a function of microstructure. For the parent microstructure, fatigue life decreased with an increase in the grain size. No such effect was however noted at high stresses. This decrease in fatigue life was correlated with the lower crack initiation life arising due to small crack effect. Under multiaxial stress conditions, the alloy exhibited intergranular type of cracking. The cross-linking of intergranular cracks (in T8 condition) caused a further deterioration in fatigue life. Additionally, planar type of slip movements (in T3 condition) in stage-I crack propagation was observed. The slip planarity depended on both the sample texture and the nature of precipitates. Fractographic and textural evidences for this are presented.

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 2011
Accession Number
ADA550829

Entities

People

  • J. A. Baumann
  • P. S. De
  • R. S. Mishra

Organizations

  • Missouri University of Science and Technology

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Alloys
  • Crack Propagation
  • Electron Microscopy
  • Elements
  • Fatigue Life
  • Friction Stir Processing
  • Grain Size
  • Lithium Alloys
  • Materials
  • Materials Science
  • Mechanical Properties
  • Metals
  • Microscopy
  • Stress Concentration
  • Stress Strain Relations

Fields of Study

  • Materials science

Readers

  • Powder metallurgy of Titanium alloys.
  • Structural Health Monitoring of Composite Structures.