Deep Drawing Behavior of Unidirectional and Woven CFRP /Al Hybrid Laminates

ABSTRACT CFRP/Al hybrid laminates are promising materials for lightweight car bodies, combining carbon fiber and aluminum alloy benefits to significantly reduce part weight while maintaining high strength and elastic modulus. However, the traditional CFRP/Al laminate forming process is cumbersome and requires substantial equipment investment, posing challenges in meeting the rapid development needs of the automobile industry. To address this, a temperature‐assisted deep‐drawing route for CFRP/Al laminates was established in this study using a specially designed die set, and its forming behavior was systematically evaluated in comparison with different layup architectures. For unidirectional CFRP/Al cylindrical parts, the forming depth increased, and the defect number decreased as the fiber direction diversified (e.g., from [0]° ₆ /Al to [15/30/……/90]°/Al). The helicoidal [15/30/45/60/75/90]°/Al cylindrical part achieved the largest forming depth of 24.06 mm, whereas the woven CFRP/Al cylindrical part reached an even greater depth of 26.06 mm (8.31% higher) and exhibited the fewest forming defects. Fiber folds and delamination defects were observed in the die corner, contributing to the maximum thickness in these regions. In the punch corner of the parts, the fiber and resin were compressed to form a minimum thickness. The microstructural results showed that the warp and weft yarns in the woven prepreg could undergo greater in‐plane shear deformation than those in the unidirectional prepreg, resulting in greater forming depth and quality.