Detection and evaluation of backside crack in spot-welding component of heat-resistant alloy using electromagnetic field distortion

Issue title: Proceedings from the 17th International Symposium on Applied Electromagnetics and Mechanics (ISEM 2015)

Guest editors: Fumio Kojima, Futoshi Kobayashi and Hiroyuki Nakamoto

Article type: Research Article

Authors: Kim, Jungmin^a | Kim, Sejin^a | Le, Minhhuy^a | Lee, Jinyi^{a; *} | Park, Jongwoon^b

Affiliations: [a] Department of Control and Instrumentation Engineering, Chosun University, Gwangju, Korea | [b] Aero Technology Research Institute, ROKAF, Deagu, Korea

Correspondence: [*] Corresponding author: Jinyi Lee, Department of Control and Instrumentation Engineering, Chosun University, Gwangju 501-759, Korea. Tel.: +82 62 230 7101; E-mail:jinyilee@chosun.ac.kr

Abstract: A method for inspecting far-side fatigue cracks is proposed. These cracks occur in the spot-welding components of a heat-resistant alloy, used in aircraft engine components. For measurement without contact, an electromagnetic field is applied to the object. The distortion of the field owing to far-side fatigue cracks in the spot-welding area is measured with a linearly integrated giant-magneto resistance sensor array. Artificial far-side cracks can be detected where there is a slit-type crack around the spot-welding area. A probability of detection (POD) is used to analyze the detection performance of the inspection system. Crack with lengths of 3.699 mm and 4.647 mm were inspected with 90% POD and 90/95 POD with confidence bound, respectively.

Keywords: Fatigue crack, inconel, magnetic camera, eddy current, sensor array, imaging, heat-resistant crack

DOI: 10.3233/JAE-162146

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 52, no. 3-4, pp. 1193-1199, 2016