Effects of Energy Director Types on the Interface Morphology and Tensile Properties of Ultrasonically Welded CF/PAEK Joints

This study investigates the impact of ultrasonic welding amplitudes and time on the properties of carbon fiber reinforced polyaryletherketone (CF/PAEK) composite joints. To enhance the performance of CF/PAEK ultrasonic welded joints, a hybrid energy director (ED) was proposed, which was composed of the interfacial microgroove and resin film or metal mesh. This study investigated the effect of different types of ED on the forming quality, shear failure load, and fracture interface microstructure of single lap joints made of CF/PAEK. The results indicated that the hybrid ED with resin film offers a distinct effect on enhancing the strength of ultrasonic welded joints. The hybrid ED with resin film essentially improves the tensile properties of the joint, with the strength and toughness increased by 35.8% and 174.3%, respectively. This strengthening effect is primarily attributed to the added resin film providing adequate interfacial resin. Sufficient resin is filled into the interior of the microgroove, ultimately forming a mechanical anchoring structure to strengthen the joint strength.