Eddy-current induced thermography—probability of detection study of small fatigue cracks in steel, titanium and nickel-based superalloy

Detecting surface features on conducting specimens through an insulation layer using a capacitive imaging technique

“…These techniques include the eddy current technique [9,10], the AC field measurement (ACFM) method [11], the magnetostrictive sensor technique [12], the non-contact AC potential drop method using a high impedance electric potential sensor [13], the magnetic flux leakage method [14], etc. In recent years, there have been several notable advances in the above mentioned NDE technique stemming from research to detect corrosion and other types of defects in metallic components, such as the pulsed eddy current approach [15][16][17][18], the magneto-optical imaging of eddy current [19], the transient-pulsed thermography technique [20], the eddy current induced thermography [21,22], etc.…”

Defect Characterization Based on Eddy Current Technique: Technical Review

“…On a different study, a uniform Eddy current probe with 23 arrayed detectors was designed to measure signals from six mechanical fatigue cracks initiated into type 316L austenitic stainless steel plates [52]. Weekes et al [53] used the induction PECT for detection of fatigue cracks in steel, titanium, and Waspaloy.…”

“…The fast crack profile reconstruction methods using transient time and spectral components of PEC signals were carried out on EDM slots of 3 mm, 4 mm, 6 mm, 6 Advances in Mechanical Engineering [18][19][20][21][22][23] E m p l o y e d E C p r o b e s [27] EC probe mounted in a planar probe [28] Optimized EC array technique Fatigue crack [51] EC with operating frequency range between 200 Hz and 100 kHz [52] A uniform EC probe with 23 arrayed detectors [53] I n d u c t i o n P E C T [2,54,55] Eddy current [56] EC with an array probe [57] EC-giant magnetoresistive (EC-GMR) sensor system Corrosion [47,[58][59][60][61][62]71] Eddy current [63,72] P E C [66] Electromagnetic acoustic transducer-Eddy current (EMAT-EC) dual probe Material microstructure [67] Eddy current Estimation of pearlite [68][69][70] Eddy current and 8 mm depth [77]. The method provided initial approximate profiles for crack shape reconstruction using different PEC signals such as amplitude, phase, real and imaginary values of spectral components, and transient slices using reconstruction mean square errors (MSE) which reduces the computing time.…”

Eddy Current Thermography Testing on Lack of Fusion (LOF) Defect of Carbon Steel Welded Sample

“…Eddy current thermography technique can be used for surface and subsurface defect detection of conductive parts (Yang et al 2011). Joule heating process associated with the eddy current flow permits the detection of flaw in the material (Weekes et al 2012). The method of inspection comes in package with the infrared technology to capture the distribution of heat on components being tested in the form of two-dimensional images and video images.…”

“…Previously, fine defect such as surface, subsurface, or within a complex geometry defect were detected and presented in signal forms by using conventional NDT method. The principal of defect detection using ECT techniques introduces the eddy current path that disrupted by the presence of defect (Yang et al 2011) will be interpreted further in terms of signal due to the variation in current density (Weekes et al 2012). The defect localized around the region consequent the increment and decrement of joule (Ohmic) heating process.…”