Joining of CFRT-steel hybrid parts via hole-forming and subsequent pin caulking

Abstract In times of increasing global warming, the awareness necessity for significant CO 2 reduction is growing. Especially in transport and aerospace sector, lightweight construction has potential to achieve emission goals by reducing overall vehicle weight. Thereby, adding fibre-reinforced composites materials such as steel aluminium used weight savings. Furthermore, continuous-fibre-reinforced thermoplastics (CFRTs) begin replace more traditional thermoset due their easier bulk production uncomplicated storage. Hybrid parts often consist a CFRT higher strength metal component. Here, joining process poses main challenge, different chemical physical properties components. current state art, riveted bolted joints are commonly used, leading increased auxiliary elements requiring precise bolt holes destroying load-bearing fibres. Joining with cold formed pin structures an innovative versatile process, which avoids need elements. These pins subsequently inserted warm component then caulked create form-fitting hybrid joint. To obtain fundamental understanding this hole-forming pin-caulking, investigated study. First, IR-radiation regard suitable parameters resulting fibre morphology. The consequently mechanically characterized. Second, caulking-process iteratively upsetting measuring geometry. Based on these findings two caulking degrees defined samples mechanical well microscopic investigations manufactured. created first via micro-sections reflected light microscopy identify possible damage component, can result from process. characterisation under shear load extraction loads normal sample surface conducted tests compared bearing samples.