Instrumentation Development for Crack Detection of Surface and Subsurface Defects in Green-State P/M Compacts Through Multiprobe Electric Resistivity Testing
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.
KeywordsLithium Mold Powder Compact Dial
Unable to display preview. Download preview PDF.
- 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.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.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