Localized epoxy curing technology for enhanced aviation composite bonding /

The bonding process of composite materials in aerospace applications significantly impacts the structural integrity and energy efficiency of manufactured components. Traditional curing methods, such as oven and autoclave curing, are energy-intensive, costly, and unsuitable for handling large composite components, posing scalability challenges [1,2]. These methods often result in inefficient energy use due to the need for prolonged curing cycles and non-homogeneous heat distribution in the bonding areas [3,4]. This study explores an innovative bonding method using carbon nanotube (CNT)-enhanced epoxy adhesives, combined with localized Joule heating as an alternative to traditional curing methods. In this investigation, CNT-enhanced epoxy adhesives were applied exclusively to the bonding area of single-lap specimens reinforced with glass fibre-reinforced polymers (GFRP). CNT concentrations ranging from 0.25 to 1 wt% were evaluated. A resistive heating method enabled localized curing, with precise monitoring of temperature, electrical resistance, and thermal distribution across the bonding area. Mechanical performance of the bonded specimens was characterized by lap-shear testing in accordance with ISO 4587 standard. This localized curing approach has shown significant potential for enabling efficient adhesive polymerization while ensuring uniform heat distribution in the bonding area. Results indicate that optimal CNT concentrations (0.5 wt%) achieve a balance between thermal conductivity and mechanical strength, while higher concentrations lead to performance degradation due to agglomeration and void formation. This method offers a scalable, energy-efficient alternative for composite bonding, paving the way for advancements in aerospace manufacturing and other industries requiring high-performance composites.