Status and prospect of magneto-optical image sensing non-destructive testing technology

JI Yu-kun, GAO Xiang-dong, ZHANG Nan-feng, ZHANG Yan-xi, YOU De-you, XIAO Xiao-ting, SUN You-song
(1.Guangdong Provincial Welding Engineering Technology Research Center, Guangdong University of Technology,
Guangzhou 510006, China; 2.Huangpu Custons Technical Center, Dongguan 523076, China)

Abstract: Aiming at the technical problems in the process of detecting the defects of ferromagnetic workpiece,a new magnetooptical image sensing nondestructive testing technology based on Faraday effect was introduced. A basic principle and experimental system of MOI sensing NDT was expounded, and based on the discussion of the mechanism of magnetic circuit and excitation mode, the law of magnetic field excitation and the technical difficulties of finding the best excitation were summarized.The algorithm of extracting defect information from MOI and the model of neural network were analyzed, and the key problem how to combine MOI sensing detection with artificial intelligence was pointed out.The characteristics of several main NDT technologies were listed, and the applications of MOI sensing NDT in aerospace and welding were summarized. At last the main problems and development direction of MOI sensing NDT technology were summarized. The results indicate that the MOI sensing NDT technology has unique advantages and provide a new research direction for the realization of highprecision NDT automation, imaging and intelligence.
Key words: magneto-optical image(MOI); Faraday effect; non-destructive testing(NDT); ferromagnetic workpiece