CFRTS butt joint forming with Metal-Assistant-Clamping (MAC) laser rotational welding method

Carbon Fiber Reinforced Thermosetting Composites (CFRTS) are crucial materials for lightweight manufacturing in the aerospace industry. To achieve high-quality butt joining between CFRTS, the Metal-Assistant-Clamping (MAC) laser rotational welding method is proposed. In this method, two TC4 titanium alloy plates were clamped at the docking position of the CFRTS butt joint, and the TC4 titanium alloy plates were joined with the CFRTS using laser rotational welding technology. Laser cleaning and micro-textures as interface pretreatment were applied to enhance the joining strength. The impact of laser cleaning on the strength of the CFRTS butt joint was examined, revealing that epoxy resin on the CFRTS surface was effectively removed, leading to an increase in bonding strength between the CFRTS and TC4 titanium alloy. The micro-textures, mechanical properties, and failure mechanism of CFRTS butt joints were investigated. The results indicate that the interface pretreatment created mechanical interlocks and chemical bonds between the CFRTS and TC4 alloy, further strengthening the CFRTS butt joint. The failure of the CFRTS butt joint was observed to occur between the Polyamide-6 (PA6) resin and the surface carbon fibers of the CFRTS, predominantly through CFRTS interlayer tearing.