TY - JOUR
T1 - Novel interventional electromagnetic thermography for subsurface defect detection
AU - Miao, Ling
AU - Gao, Bin
AU - Li, Haoran
AU - Lu, Xiaolong
AU - Liu, Lei
AU - Woo, Wai Lok
AU - Wu, Jianhua
PY - 2023/2/1
Y1 - 2023/2/1
N2 - For low-emissivity metal materials, reducing the influence of non-uniform emission in detecting subsurface defects remains a challenge. This paper proposes a novel interventional electromagnetic thermography technique. In particular, a thin water film medium is involved in the detection which enhances the detectability of subsurface defects by utilizing the thermal radiation characteristic and thermophysical parameters of the participating medium. The physical mechanism of the proposed technique is analyzed in solid aspect. Static experiments have been carried out on the ferromagnetic plate with subsurface notches. The obtained results have shown that water film can eliminate the inhomogeneous emission of the detection target while the high emissivity of the water film corrects the temperature distribution. Moreover, dynamic scanning experiments have been conducted on the ferromagnetic plate containing artificial subsurface defects and the non-austenitic stainless-steel plate containing natural subsurface intergranular corrosion defect. The commonly used black paint is added to the dynamic experiment for performance comparison. The comparative experimental results have demonstrated that the proposed technique can effectively identify subsurface defects with burial depth up to 1.0 mm in the ferromagnetic plate. The results are especially more pronounced when the subsurface defects occur at buried depths ranging from 0.4 mm to 1.0 mm where higher thermal contrast and signal-to-noise ratio have been attained. The technique has shown superior detection performance for detecting natural subsurface microcrack.
AB - For low-emissivity metal materials, reducing the influence of non-uniform emission in detecting subsurface defects remains a challenge. This paper proposes a novel interventional electromagnetic thermography technique. In particular, a thin water film medium is involved in the detection which enhances the detectability of subsurface defects by utilizing the thermal radiation characteristic and thermophysical parameters of the participating medium. The physical mechanism of the proposed technique is analyzed in solid aspect. Static experiments have been carried out on the ferromagnetic plate with subsurface notches. The obtained results have shown that water film can eliminate the inhomogeneous emission of the detection target while the high emissivity of the water film corrects the temperature distribution. Moreover, dynamic scanning experiments have been conducted on the ferromagnetic plate containing artificial subsurface defects and the non-austenitic stainless-steel plate containing natural subsurface intergranular corrosion defect. The commonly used black paint is added to the dynamic experiment for performance comparison. The comparative experimental results have demonstrated that the proposed technique can effectively identify subsurface defects with burial depth up to 1.0 mm in the ferromagnetic plate. The results are especially more pronounced when the subsurface defects occur at buried depths ranging from 0.4 mm to 1.0 mm where higher thermal contrast and signal-to-noise ratio have been attained. The technique has shown superior detection performance for detecting natural subsurface microcrack.
KW - Interventional electromagnetic thermography
KW - Medium parameters
KW - Radiation characteristic
KW - Subsurface defect detection
KW - Thin water film
UR - http://www.scopus.com/inward/record.url?scp=85140003438&partnerID=8YFLogxK
U2 - 10.1016/j.ijthermalsci.2022.107960
DO - 10.1016/j.ijthermalsci.2022.107960
M3 - Article
AN - SCOPUS:85140003438
SN - 1290-0729
VL - 184
JO - International Journal of Thermal Sciences
JF - International Journal of Thermal Sciences
M1 - 107960
ER -