CRACK DETECTION USING PULSED EDDY CURRENT STIMULATED THERMOGRAPHY

Abstract

This contribution presents results from studies investigating factors that influence the detection of surface breaking cracks using pulsed eddy current thermography. The influences of the current strength and crack orientation in both ferromagnetic and non‐ferromagnetic metals have been investigated. It has been found that crack detection is far more sensitive to crack orientation in non‐ferromagnetic metals than in ferromagnetic metals. The effects of crack size on detectability are presented for a large number of steel, nickel alloy and titanium samples. Results of studies comparing crack images obtained prior and after coating a nickel alloy sample with a thermal barrier coating are presented.