Advances in materials science in recent years have produced multifunctional composites combining traditional strength and stiffness with properties such as flame resistance or sensing capabilities. EU-funded researchers have explored the potential of multifunctional composites for self-healing through work on the IASS (Improving the aircraft safety by self healing structure and protecting nanofillers) project.The novel composites can enhance reliability and service life and decrease accidents by up to 80 %, while slashing operating costs in half. In addition, their adoption decreases the size, weight, cost, power consumption and complexity of aircraft systems. This has important impacts on fuel consumption — also related to operating costs — and associated emissions.To achieve these aims, scientists utilised inexpensive materials in ring-opening metathesis polymerisation-based chemical reactions that induce self-healing. Conductive forms of carbon, including multi-walled carbon nanotubes, carbon nanofibres, graphite forms and graphene sheets were used to form both the conductive network and the catalyst support for the reactions.The team formulated and characterised the epoxy mixture and the nanofillers were embedded in the epoxy matrix as part of the novel self-healing carbon fibre-reinforced composites (CFRCs). Scientists also modified formulations to enhance epoxy hardness and impart flame resistance as well. One of the most promising multifunctional load-bearing systems were used to manufacture a CFRC panel.Self-healing epoxy formulations were tested under various processing conditions. Healing efficiency and dynamic mechanical properties are both critical to increasing the safety and reliability of the panels. These properties were measured and are close to specified requirements. Formulations and panels were also optimised in order to achieve the project’s goals.Exploitation of IASS self-healing multifunctional composites promises major short- and long-term benefits for the aerospace industry and its passengers. Self-healing of damage will keep safe planes in service, drastically reducing both disruptions to passenger travel and operating costs related to maintenance and downtime. This will have major positive impact on the competitive position of the EU aircraft industry and its role in a constantly growing market.
Aircraft, maintenance, self-healing, multifunctional composites, IASS