Carbon Nanotube Network Heater for Joining and Repair

Adhesive bonding has been widely used on aircraft manufacturing for enhanced performance and fuel efficiency, as well as for patch repair to restore structural integrity of the part. Conventional joining methods for part... [ view full abstract ]

Adhesive bonding has been widely used on aircraft manufacturing for enhanced performance and fuel efficiency, as well as for patch repair to restore structural integrity of the part. Conventional joining methods for part manufacturing of metal-metal and thermosetting matrix composite-composites, or metal-composite parts include autoclave or oven curing. Heating blanket, heating lamps and induction heating have been used for adhesively bonded repair. Al these heating methods involve heating one substrate or both. These conventional methods not only may require expensive capital investment and high energy consumption, the bondline temperature profile and bond quality could also be affected by temperature gradient of substrates, heat sinks behind the skin and other factors. Such issues could be of particular concern as the aerospace industry is pushing towards joining or repairing thicker loading-bearing components, or bonding higher temperature composites.
In this paper, a carbon nanotube network heater approach for joining and repair is described. What distinguishes this method from the conventional ones lie the fact that heat is induced directly into the bondline, without the need of transferring heat through substrate(s). It has been demonstrated that this approach offers precise temperature and viscosity control at the bondline, and ultra-low energy consumption. These advantages in conjunction with potential bondline fracture toughness enhancement by using nano-scale materials as network heater makes this approach an attractive alternative for joining and repair of aircraft structures.