Research on fabrication process and impact resistance of CFRTP/stainless steel laminates

Abstract Objectives This study investigates the fabrication process of thermoplastic resin-based carbon fibre/stainless steel (SS) laminates and their low-velocity impact performance under different stacking sequences. Methods Anodic oxidation, short-beam shear tests, and three-point bending tests were conducted to evaluate the interfacial bonding and mechanical strength of the laminates. Among five anodic oxidation parameter sets, 10 V for 300 s produced the best combined mechanical performance. After applying a silane coupling agent at the interface, X-ray photoelectron spectroscopy (XPS) clarified the reinforcement mechanism. Based on optimized SS surface treatment process, unidirectional thermoplastic carbon fibre prepreg tapes and SS foils were used to fabricate fibre metal laminates (FMLs) with different stacking configurations. Low-velocity impact tests were conducted to examine the impact resistance and failure mechanisms of the laminates. Results The optimized SS surface treatment process was defined as mechanical grinding + acetone cleaning + etching in 15 mL/L phosphoric acid solution + anodic oxidation at 10 V for 300 s + treatment with 1 wt% coupling agent. Laminates prepared using this process achieved short-beam shear strength and flexural strength of 57.5 and 1129.4 MPa, respectively. Conclusion the low-speed impact results indicate that the failure modes of carbon fibre/SS FMLs are governed primarily by the thickness of the outer SS layers. The energy absorption capacity is influenced by the thickness of individual SS layers and the number of interfaces between SS and carbon fibre layers.