Enhanced Interfacial Adhesion and Mechanical Properties of Glass Fiber/Ti3523 Fiber Metal Laminates via AGO / PDA Synergistic Modification

ABSTRACT Fiber metal laminates (FMLs) are promising aerospace structural materials, but weak fiber–matrix interfacial adhesion is one of the key limitations restricting their mechanical performance. In this study, a hierarchical rigid–flexible interfacial architecture was constructed on glass fiber (GF) surfaces using a flexible polydopamine (PDA) interlayer and rigid aminated graphene oxide (AGO) nanosheets for Ti3523/GF FMLs. The effects of nominal AGO loading on the flexural properties and Mode II interlaminar fracture toughness were investigated. At a nominal AGO loading of 0.3 wt%, the flexural modulus and Mode II interlaminar fracture toughness increased by 107.3% and 239.1%, respectively, compared with the unmodified laminates. The enhancement is attributed to improved stress transfer, crack‐path regulation, and multiple energy‐dissipation mechanisms enabled by the rigid AGO/flexible PDA hierarchical interface. Unlike previous PDA/GO interfacial modification studies primarily focused on conventional fiber‐reinforced polymer composites, this work establishes a rigid AGO/flexible PDA hierarchical interphase specifically for the relatively unexplored Ti3523/GF fiber‐metal laminate system and further reveals the critical role of AGO loading in regulating crack propagation and Mode II fracture resistance. These findings provide an effective interfacial design strategy for improving the mechanical performance of titanium‐based fiber‐metal laminates.