Fig. 1. Structural formula of PA66

Fig. 2. Dimension of CFRTP tensile part

Fig. 3. Schematics of laser direct-joining of aluminum alloy-CFRTP. (a) Laser direct joining process; (b) joint made by laser direct joining; (c) microstructural morphology of aluminum alloy

Fig. 4. Macroscopic morphologies of direct-bonding joints of aluminum alloy-CFRTP under different laser powers. (a)(b) 900 W; (c)(d) 1100 W; (e)(f) 1300 W

Fig. 5. Melting width of CFRTP versus laser power

Fig. 6. Interface bonding of aluminum alloy-CFRTP under different laser powers. (a) 900 W; (b) 1100 W; (c) 1300 W

Fig. 7. Magnified morphologies of interface bonding of aluminum alloy-CFRTP under different laser powers. (a) A area in|Fig. 6; (b) b area in Fig. 7(a); (c) B area in Fig. 6; (d) d area in Fig. 7(c); (e) C area in Fig. 6; (f) f area in Fig. 7(e)

Fig. 8. Effect of laser power on tensile shear properties of joints of aluminum alloy-CFRTP

Fig. 9. Load-displacement curves of joints of aluminum alloy-CFRTP under different laser powers

Fig. 10. Morphologies of fracture surfaces of joints of aluminum alloy-CFRTP under different laser powers. (a) 900 W; (b) 1100 W; (c) 1300 W

Fig. 11. SEM morphologies of fracture surfaces of CFRTP side for laser power of 1100 W. (a) A area in Fig.10 (b); (b) b area in Fig.11(a); (c) c area in Fig.11(b)

Fig. 12. Line scanning results of interface of aluminum alloy-CFRTP under different laser powers. (a) Location of line scanning for laser power of 900 W; (b) 900 W; (c)1100 W; (d) 1300 W

Fig. 13. XPS results of interface of aluminum alloy-CFRTP for laser power of 1100 W. (a) Survey spectrum; (b) fine spectra