Fig. 1. Principle of nanosecond laser texturing and grid pattern of micro-texture

Fig. 2. Schematic of laser joining of CFRP to TC4

Fig. 3. Schematic of tensile-shear testing on TC4/CFRP laser bonded joint

Fig. 4. Three-dimensional morphologies of micro-texture with various widths on TC4 surface. (a) Untreated TC4; (b) micro-texture width of 0.1 mm; (c) micro-texture width of 0.2 mm; (d) micro-texture width of 0.3 mm; (e) micro-texture width of 0.4 mm; (f) micro-texture width of 0.5 mm

Fig. 5. Surface roughness of TC4 with different micro-texture widths

Fig. 6. Contact angle of melted CFRP on TC4 surface with various micro-texture widths

Fig. 7. Macroscopic morphologies of typical laser joined joint of CFRP to TC4. (a) Top view; (b) back view

Fig. 8. Optical morphologies of typical laser joined TC4/CFRP joints near interface with various micro-texture widths.(a) Untreated TC4; (b) micro-texture width of 0.1 mm; (c) micro-texture width of 0.2 mm; (d) micro-texture width of 0.3 mm; (e) micro-texture width of 0.4 mm; (f) micro-texture width of 0.5 mm

Fig. 9. SEM morphologies and elements distributions of typical laser joined TC4/CFRP joint. (a)(b) Untreated TC4; (c)(d) micro-textured TC4

Fig. 10. Fitting curves of Ti2p XPS peaks of TC4/CFRP laser joining interface with laser micro-texture

Fig. 11. Shear fore of TC4/CFRP joint with various micro-texture widths

Fig. 12. Three-dimensional fracture images of typical TC4/CFRP joint

Fig. 13. Scanning electron microscopy (SEM) images and element distributions of typical TC4/CFRP joint fracture

Fig. 14. Schematic of laser joining mechanism

Table 1. Chemical composition of TC4 sheet

Table 2. Parameters employed in laser texturing TC4 sheet surface

Table 3. Parameters of TC4 and CFRP laser joining