Ultrasonic Self-Fusion Rivet Welding of CF/PA6 to 6061 Aluminum Alloy

Abstract

In order to further improve the strength between carbon fiber reinforced thermoplastic (CFRTP) and lightweight metals, a novel ultrasonic self-fusion riveting method is proposed, in which carbon fiber reinforced polyamide 6(CF/PA6) is melted by ultrasonic welding and pressed into the prefabricated hole on the aluminum alloy plate to realize the join between CF/PA6 and aluminum alloy. The joining mechanism is mechanical self-locking. The results show that the overall mechanical performances increase with the increase of the number of holes. The optimal welding energy is 2 000 J and the maximum shear strength is (58.9 ± 7.1) MPa. According to the welding power and welding displacement signal, the ultrasonic self-fusion riveting process can be divided into the pressing stage, the energy director embedding stage, and the hole filling stage. When the energy is constant, with the increase of the number of holes, the energy director will be embedded into CF/PA6 earlier, and the welding time will be shortened. Compared with the welding energy, the number of holes has a greater impact on the welding process. Because ultrasonic self-fusion riveting mainly realizes the join between CFRTP and metal through mechanical self-locking, this method is not limited by metal types and has a broad application prospect.

Keywords

• ultrasonic plastic welding
• carbon fiber reinforced thermoplastic (cfrtp)
• aluminum alloy
• dissimilar materials joining