A novel crack detection methodology for green-state powder metallurgy compacts using an array sensor electrostatic testing approach

摘要

This paper briefly reviews a new instrumentation approach developed for the electric resistivity testing of green-state P/M compacts. Rapid testing of the green-state specimens is made possible through a special-purpose sensor configuration, which incorporates a matrix of 10 by 10 spring-loaded needle contact with pin spacings of 0.1 inches. The sensor permits the detection of hairline flaws with surface openings as small as 20 microns.