Effect of forming temperature and fiber orientation on the warm deep drawing formability of TA2/Cf/PEEK laminates

Titanium alloy-based carbon fiber reinforced polyetheretherketone laminates (TA2/Cf/PEEK), as an emerging type of fiber metal laminates, have demonstrated their massive potential in the field of aerospace. Nonetheless, the machining and forming of these laminates have long been a challenge due to the heterogeneity between the composite layers and the metal layers as well as the strain mismatch. In this study, experimental investigation and numerical simulation were conducted in combination to systematically explore the impact of deep drawing temperature and fiber orientation on the warm deep drawing characteristics of TA2/Cf/PEEK laminates. It is revealed that the deep drawing at a temperature slightly above the glass transition temperature (T-g) of the composites can improve the quality of formed parts compared to room temperature and melt temperature (T-m). Moreover, this study illustrates the profound influence of fiber orientation on boundary dimensions, thickness distribution, and stress-strain extension direction of the formed parts. Notably, the (0/45/90/-45) fiber orientation in TA2/Cf/PEEK laminates exhibits pseudo-isotropic behavior, which is effective in mitigating the anisotropy of the composite layers and endowing them with excellent forming properties. Furthermore, the mechanism behind the influence of the intermediate composite's state on the forming quality of FMLs is determined, which provides a reference for further research on the deep drawing of TA2/Cf/PEEK laminates.