Self-Affine Scaling Studies of Fractography

Abstract

Applying variation-correlation method to images of fractography obtained from the scanning electron microscope (SEM), it has been found that there exists a fractal characteristic length within which the fractured surfaces are fractal. Investigation shows that the fractal characteristic length can represent the statistical maximum size of texture of the SEM image. Multi-magnification fractal analysis has shown that fractography cannot be described by a single fractal dimension but rather a series of fractal dimensions. Fractal study on the fractured surfaces of gray iron with different grain size has shown that there exists a positive relationship between tensile strength and fractal dimension. However, no essential relationship between impact toughness and fractal dimension for HP26Cr35Ni alloy could be obtained. Fractal dimension is sensitive to changes of mechanical properties caused by geometric factors such as grain size and is suitable to quantitatively describe the irregularity of fractography. For a given fracture mode, fractal dimension is not universal.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2000
Accession Number
ADP010906

Entities

People

  • J. M. Li
  • L. Lu
  • M. O. Lai

Organizations

  • National University of Singapore

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Correlation Analysis
  • Electron Microscopes
  • Elements
  • Engineering
  • Fractography
  • Grain Size
  • Graphitic Materials
  • Materials
  • Mechanical Properties
  • Microstructure
  • Production Engineering
  • Scanning Electron Microscopes
  • Tensile Strength
  • Tensile Testing
  • Thermal Shock
  • Three Dimensional
  • Toughness

Readers

  • Metallurgy
  • Wave Propagation and Nonlinear Chaotic Dynamics.

Technology Areas

  • Microelectronics