Materials and Manufacturing

Abstract The relevant FMLs in this work are manufactured from a stainless steel alloy (X10CrNi18-8) and an epoxy-based CFRP prepreg material (Hexcel 8552-AS4). The relevant elastic and thermal material properties are mainly taken from the literature. For the manufacturing of the FMLs, a standard prepreg process known from the aerospace industry is used, and a mechanical pretreatment step for the steel sheets is added. This additional step includes a vacuum suction blasting process and applying a sol-gel layer. Two fundamentally different cure cycles, the manufacturer-recommended cure cycle (MRCC) and a modified (MOD) cure cycle, allow the generation of significant differences in the residual stress states for all types of laminate configurations. Preliminary quasi-static tensile tests on all four relevant laminate configurations prove the reproducibility of the manufacturing processes and a significant influence of the residual stress states on the ultimate tensile strength and the elastic modulus of the manufactured FMLs.