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Instrumentation Development for Crack Detection of Surface and Subsurface Defects in Green-State P/M Compacts Through Multiprobe Electric Resistivity Testing

  • Reinhold Ludwig
  • Gene Bogdanov
  • William Michalson
  • Diran Apelian
Chapter
Part of the Review of Progress in Quantitative Nondestructive Evaluation book series (RPQN, volume 18 A)

Abstract

Over the past two years an electrostatic instrumentation approach has been pursued whereby direct current is injected into green-state powder metallurgy (P/M) compacts followed by subsequent recording of the voltages on the surface. Owing to the fact that P/M specimens are moderate to low conducting samples, even small currents can produce a significant voltage distribution across the surface that can be recorded by an array of sensing probes arranged in a planar or non-planar configuration [1–4]. The presence of flaws, manifesting themselves in conductivity contrasts, can be sensed as a different voltage distribution when compared to the unflawed baseline voltage response.

Keywords

Flaw Type Voltage Distribution Subsurface Flaw Flawed Sample Hairline Crack 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. 1.
    J. G. Stander, J. Plunkett, D. Zenger, J. McNeill, and R. Ludwig, “Electric Resistivity Testing of Green-State Powdered Metallurgy Compacts” in Review of Progress in Quantitative NDE, Vol. 16B, pp. 2005–2012, Plenum Press, 1997.Google Scholar
  2. 2.
    S. Makarov, R. Ludwig, and D. Apelian, “Numerical Solution Of A Direct 3D Electrostatic Resistivity Test Of Green-State Metal Powder Compacts,” in Review of Progress in Quantitative NDE, Vol. 17B, pp. 1462–1470, Plenum Press, 1998.Google Scholar
  3. 3.
    R. Ludwig, G. Bogdanov, and D. Apelian, “Non-Destructive Electrostatic Determination Of Surface Breaking And Subsurface Flaws In Green State P/M Compacts,” PM2Tech Conference, Las Vegas, NV, June 1998.Google Scholar
  4. 4.
    J. Stander, J. Plunkett, W. Michalson, J. McNeill, and R. Ludwig, “A Novel Multi-Probe Resistivity Approach to Inspect Green-State Powder CompactsJournal of Nondestructive Evaluation, Vol. 16, No. 4, pp. 205–214, 1997.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1999

Authors and Affiliations

  • Reinhold Ludwig
    • 1
  • Gene Bogdanov
    • 1
  • William Michalson
    • 1
  • Diran Apelian
    • 2
  1. 1.Department of Electrical and Computer EngineeringUSA
  2. 2.Metal Processing InstituteWorcester Polytechnic InstituteWorcesterUSA

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