The effect of groove texturing direction on laser joining of titanium alloy to CFRTP

Hybrid structure of titanium alloy and carbon fiber reinforced thermoplastic composite (CFRTP) provided a new direction for lightweight and laser had a great prospect for application in joining metal/plastic. In this work, before laser joining TC4 (Ti6Al4V) and CFRTP (PA66), three groove micro-structures in different texturing direction (0°, 45°, 90°) were prepared on the TC4 surface respectively by nanosecond laser. The effect of different groove texturing was studied. Research results showed that the existence of three groove texturing increased the affinity between TC4 and molten CFRTP to the same extent. The resin-carbon fiber mixture adhered to the surface of TC4 after laser texturing increased obviously. However, the groove micro-structure had different impact on the tensile performance of the joint. The maximum tensile shear strength could reach 10.9 MPa, which was increased by 111 % compared with the untreated when the groove micro-texturing direction was perpendicular to the tensile direction (0° texturing) while the 90° textured joint performance was only increased by 42.9 %. The FEA results revealed that micro-texturing provided mechanical resistance for the joint during the tensile process and 0° micro-texturing provided the largest mechanical resistance followed by 45° and 90° micro-texturing.