The approach for joining thermosetting matrix composites (TSCs) proposed in this study is based on the use of a low melting co-cured thermoplastic film, added as a last ply in the stacking sequence of the composite laminate. During curing, the thermoplastic film partially penetrates in the first layer of the thermosetting composite, leading to macro-mechanical interlocking as the main connection mechanism between the thermoplastic film and the underlying composite. After curing, the thermosetting composite joints with the thermoplastic modified surface can be assembled by welding. Welding of the TSC-TSC joints is performed by ultrasonic and induction welding. The weld strength is investigated by morphological characterization of cross sections and failure surfaces and by mechanical testing. The effect of the thermoplastic film thickness on the welding process and on its outcome is also analyzed. Both induction and ultrasonic welding mostly result in good-quality welded joints. The welding process used as well as the initial thickness of the thermoplastic film are found to have a significant effect on the final thickness of the weld line and on the location of failure. Thicker thermoplastic films are found to ease the welding processes.

本研究中提出的连接热固性基体复合材料（TSC）的方法基于使用低熔点共固化热塑性薄膜，该薄膜作为复合层合物的堆叠顺序中的最后一层添加。在固化过程中，热塑性薄膜部分穿透热固性复合材料的第一层，从而导致宏观机械互锁，这是热塑性薄膜与下面的复合材料之间的主要连接机制。固化后，可以通过焊接组装具有热塑性改性表面的热固性复合材料接头。TSC-TSC接头的焊接通过超声波和感应焊接进行。通过横截面和失效表面的形态表征以及机械测试来研究焊接强度。还分析了热塑性薄膜厚度对焊接过程及其结果的影响。感应焊接和超声波焊接都可以产生高质量的焊接接头。发现所使用的焊接工艺以及热塑性膜的初始厚度对焊接线的最终厚度和故障位置具有显着影响。发现较厚的热塑性薄膜可简化焊接过程。