Multiprobe impedance measurement system for nondestructive evaluation and test of "green state" powder metallurgy parts

This paper describes an instrument capable of detecting flaws in "green-sta te" (prior to sintering) powder metallurgy (Prm) parts. The instrument uses a matrix of impedance measurements from a multiprobe array that contacts t he surface of the P/M part. The array of measured data is processed to not only detect the presence of flaws but determine their location, size, and o rientation as well. Experimental results show detection of flaws ranging in size from 10-200 mu m.