Fig. 1. (a) System structure; (b) Dual linear array laser schematic diagram

Fig. 2. (a) Simulation model, (b) Surface temperature distribution

Fig. 3. (a) Line array laser X gradient; (b) Line array laser Y gradient; (c) Dual linear array laser Xgradient; (d) Dual linear array laser Y gradient

Fig. 4. (a) Line array laser AB, CD, EF temperature gradient; (b) Dual linear array laser AB, CD, EFtemperature gradient

Fig. 4. [in Chinese]

Fig. 5. (a) X gradient background heterogeneity; (b) Y gradient background heterogeneity; (c) Relationship between spot radius and X gradient amplitude; (d) Relationship between spot radius and Ygradient amplitude

Fig. 6. (a) Relationship between center distance and crack gradient; (b) Relationship between dislocation distance and crack gradient; (c) Relationship between laser spacing and crack SNR; (d) Relationship between scanning speed and crack SNR

Fig. 7. Relationship between gradient and laser relative position

Fig. 8. (a) 0.6 mm X gradient image; (b) 3.8 mm Xgradient image; (c) 1 mm Y gradient image; (d) 4 mm Ygradient image; (e) fuse image

Fig. 9. (a) Experimental device; (b) laser power distribution heat map

Fig. 10. Experimental results of cylindrical ferrite