Smart carbon alliance

Development of a flight-proven prototypes of high performance electric cables based on nanocarbon for aerospace applications

In spite of low oil prices, jet fuel continues to be the largest expense for airlines and operators, accounting for some 31% of airline costs, hence the everlasting race for lighter, more efficient planes or helicopters in order to ensure commercial operator profitability while complying with increasingly demanding emissions limitations (EU Clean Sky initiative): reducing aircraft weight means less fuel consumption, which implies more money and lower carbon footprint (each kilogram weight cut means a savings of roughly 1 million USD over a commercial aircraft lifetime). In addition, the recent explosion of in-flight entertainment demand from airlines, along with cockpit computerization (fly-by-wire, high-definition augmented reality for pilots, real-time structural health monitoring generating various Terabytes per flight of data from embedded sensors), have multiplied the need of embarked cables, although still mostly relying on copper. Copper is regarded as the standard in electrical conductors, second only to silver in conductivity, but far more abundant and therefore economical. The conductivity of copper is 65% higher than that of aluminum which means that the conductor size of similarly rated cables is proportionately smaller.. However, in addition to good performance in terms of conductivity, lighter materials are also sought. Aluminum' s lighter weight would suggest it being favored for the weight-conscious aircraft industry. Its weight is about 1/3 that of copper, and even with its lesser conductivity, it performs better than copper on a per pound basis by a factor of almost 2:1. Despite the above, aluminum proved to be galvanically too aggressive to be placed in direct contact with copper fittings or terminals in the presence of moisture, develops a hard layer of oxides on its surface (and this must be penetrated for a good electrical connection) and is that it cannot be easily soldered or plated to improve solderability. All this may suggest there is no real use for aluminum in electrical systems, let alone on aircraft. Not yet. Carbon Nanotubes are an attractive alternative to conventional conductors used in cables because they combine high strength, thermal and electrical conductivity with low density, which makes them best for applications where weight saving is a key factor. However, reaching electrical performance comparable to metals has been challenging, especially if used as pure nanocarbon wires, hence the second option to use hybridized copper with nanocarbon and benchmark both of them. Although less mature in terms of potential industrialization, the perspective of full nanocarbon based wires opens the door to further improvements and weight savings not only for the aerospace industry, but also for other sectors such as automotive or energy transportation. Recently, one of Airbus cable supplier managed to propose a 5% weight reduction in its latest product generation thanks to the use of metallic alloys and savings on shielding material. Using the promising wonder properties of nanomaterials such as Graphene or Carbon Nanotubes opens the possibility of increasing electrical, thermal and mechanical properties of cables exponentially. The possibility of ultraconductive copper has been proven in the frame of EU FP7 Ultrawire project, by combining copper with nanocarbon to create high performance cables. As part of the project Industrial Advisory Board, Airbus Group is interested in rapidly certifying and onboarding such replacement technology with the objective to reach potential weight reduction up to 50% based on nanocarbon-copper hybridization compared to current cable solutions. Precisely, this project aims at flight-proving a cable prototype based on both technologies (nanocarbon-copper hybridized and full nanocarbon) with aerospace grade specifications as a replacement of the current technology, with an increased level of conductivity and performance (temperature, mechanical properties of an equivalent full copper or metallic alloy cable) for a lower amount of conductive material mass, hence meaning massive weight gains potential for airlines, thanks to the integration of nanotechnology. The result of this international collaborative project between Airbus Helicopters (France), Trek Access Nanotech (Chile), NAWA Technologies (France) and CAMETICS (UK) is to accelerate innovation and catapult nanotechnology onto actual platforms in a safe, efficient and durable manner. Another key benefit of this initiative is to prove to Chilean authorities that there are strategic opportunities beyond copper mining and exportation: high value material transformation and nanomaterials integration could become a major economic opportunity for Chile.
Start date: 
Project Duration: 
Project costs: 
420 000.00€
Technological Area: 
Metals and Alloys
Market Area: 

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