Measurement of Small Elastic Anisotropy in Solids Using Laser Induced Ultrasonic Pulses.

Abstract

Nondestructive laser induced short ultrasonic pulse generation together with broadband detection are used to detect and measure the small elastic anisotropy in opaque solids quickly and precisely. This is demonstrated for extruded aluminum alloy type 6061-T6. A single laser-induced acoustic pulse propagation measurement over a path length of 47 mm provides a longitudinal ultrasonic velocity measurement accuracy of 0.02%. The longitudinal velocities at + or - 45 deg from the extruding direction Z are found to be 2% larger than the velocity along Z, indicating that most of the aluminum crystallities are oriented with a principal axis parallel to Z. Thermal annealing of the sample results in a small increase in ultrasonic velocity in all directions with the observed acoustic anisotropy remaining essentially unchanged.

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Document Details

Document Type
Technical Report
Publication Date
Aug 08, 1984
Accession Number
ADA144296

Entities

People

  • A. C. Tam

Organizations

  • International Business Machines Corporation (Armonk, NY)

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Accuracy
  • Acoustic Measurement
  • Aluminum Alloys
  • Annealing
  • Broadband
  • Crystal Structure
  • Detection
  • Elastic Properties
  • Extrusion
  • Laser Applications
  • Laser Beams
  • Lasers
  • Materials
  • Military Research
  • Modulus Of Elasticity
  • Transducers
  • Ultrasounds

Fields of Study

  • Physics

Readers

  • Control Systems Engineering.
  • Metallurgy
  • Optical Physics and Photonics.

Technology Areas

  • Directed Energy