Enhancing Fracture Performance of Non‐Conductive Composite Adhesively Bonded Joints With Magnetically Aligned MWCNT/Fe₃O₄ Hybrid Nanofillers

ABSTRACT The Mode‐I fracture behavior of non‐conductive composite adhesively bonded joints (ABJs) reinforced with multi‐walled carbon nanotube/iron oxide (MWCNT/Fe₃O₄) hybrid nanofillers aligned in different directions was studied using double cantilever beam (DCB) tests. Fe₃O₄ nanoparticles were chemically coated onto MWCNTs to explore the practical potential of these produced magnetically controllable nanofillers in high‐tech industries that require precise nanofiller alignment in specific directions. Nanofillers were aligned within the ABJ adhesive layer using a low magnetic field at 0°, 45°, and 90° relative to the crack growth path, verified by Raman spectroscopy. ABJs with 90° alignment exhibited the highest fracture energy, surpassing unreinforced and randomly dispersed specimens by 136% and 41%, respectively. In contrast, 0°‐alignment showed the lowest fracture energy, while 45° alignment demonstrated intermediate performance. Cohesive zone modeling simulated the ABJ damage behavior, and the effects of nanofiller alignment on macro and microscale fracture mechanisms were assessed using optical and scanning electron microscopy.