Enhanced interlaminar mechanical behavior of advanced fiber metal laminates via nano Al2O3‐IPN formation and surface pre‐treatments

• Published in: Polymer composites 2023-09, Vol.44 (9), p.5514-5526
• Main Authors: Gupta K, B. N. V. S. Ganesh, Patnaik, Satyaroop, Dasari, Srinivasu, Ray, Bankim Chandra, Prusty, Rajesh Kumar
• Format: Article
• Language: English
• Subjects: Aluminum; Aluminum oxide; Delamination; Energy measurement; Fiber-metal laminates; Flexural strength; Fracture toughness; Glass fiber reinforced plastics; interface/interphase; Interfacial shear strength; Interpenetrating networks; Mechanical properties; mechanical testing; Metal surfaces; Microscopy; nanoparticles; Polymers; Shear strength; Strain energy release rate; Surface energy; Surface roughness; surface treatments; Tensile strength
• ISSN: 0272-8397; 1548-0569
• DOI: 10.1002/pc.27505

The inferior delamination resistance and out‐of‐plane performance of fiber metal laminates (FMLs) are of serious concerns. This work employs two modification methods, namely metal surface's chemical pre‐treatment and nano Al2O3 embedded interpenetrating polymer network (IPN) formation for improving the delamination resistance of aluminum and glass fiber‐reinforced polymer (GFRP) composite‐based FMLs. The synergetic effect of the two modification techniques resulted in high degrees of improvement in delamination resistance that were ~28% for critical strain energy release rate during mode‐I interlaminar fracture toughness (ILFT), that is (GIC) and ~37% for GIIC. Simultaneously, the flexural strength, tensile strength, and interlaminar shear strength improved by ~23%, ~17%, and ~24%, respectively. Scanning electron microscopy, atomic force microscopy, and surface energy measurement studies showed that the chemical pre‐treatment significantly influenced the surface morphology, surface roughness, and surface energy responses of aluminum, respectively. Fractographic study validated the effect of modification methods on the failure behavior under various testing modes. The addition of nano Al2O3 to the IPN network and chemical etching of aluminium surfaces increased the interfacial adhesion between the constituents leading to the superior interlaminar mechanical performance of FMLs.