Ultrasonic welding (USW) of thermoplastic composites is considered as an interesting joint technique, which can be cost-effective due to its short welding time. The paper focuses on studying the effect of USW current on strength and quality of welding. In this paper, the welding of thermoplastic unidirectional prepregs glass/polyamide 6 composites laminate with stacking sequence of (0/90/+45/−45/−45/+45/90/0) is conducted by USW. A flat energy director is used to concentrate the interface heat. To examine the interface microstructure, the current-time graph was utilized during welding processes, and the relationship between such interface events, consumed current, weld strength, weldability, and weld quality is fully investigated. Based on the results, the highest welding strength and welding quality of thermoplastic composites can be obtained when the energy director and the first layer of the composite are completely melted and no disorder is observed in the fibers. In addition, the highest joint strength equals to 24.46 MPa, which is obtained after 1830 ms welding time.

中文翻译：

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复合材料层压板 GF/PA6 的超声波焊接：通过电流和强度衡量的可焊性和焊接质量

热塑性复合材料的超声波焊接（USW）被认为是一种有趣的连接技术，由于焊接时间短，因此具有成本效益。本文重点研究USW电流对焊接强度和质量的影响。本文采用USW对堆叠顺序为(0/90/+45/−45/−45/+45/90/0)的热塑性单向预浸料玻璃/聚酰胺6复合材料层压板进行焊接。扁平能量导向器用于集中界面热量。为了检查界面微观结构，在焊接过程中利用电流-时间图，充分研究了界面事件、消耗电流、焊接强度、可焊性和焊接质量之间的关系。结果表明，当导能器和复合材料第一层完全熔化且纤维中没有观察到紊乱时，热塑性复合材料可以获得最高的焊接强度和焊接质量。此外，焊接时间为1830 ms后获得的最高接头强度为24.46 MPa。