为了进一步提高碳纤维增强热塑性复合材料与轻量化金属之间的连接强度,提出一种新型超声波自熔铆焊方法.该方法通过超声波焊接将短碳纤维增强尼龙6(CF/PA6)熔化并压入铝合金板上预制的通孔内,从而实现CF/PA6与铝合金的连接,连接机制为机械自锁.实验结果表明,随着孔数增加,焊接的整体力学性能有所增加,最优焊接能量为 2 000 J,最高剪切强度为(58.9±7.1) MPa.依据焊接功率和焊头位移信号,可将超声波自熔铆焊过程分为3个阶段:压紧阶段、导能筋嵌入阶段和充孔阶段.当能量一定时,随着孔数增加,导能筋会更早嵌入CF/PA6中,且焊接时间缩短.相对于焊接能量,孔数对焊接过程的影响更大.得益于机械自锁的连接机制,该方法对金属种类没有限制,具有较为广阔的应用前景.

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.