More than batteries: the Aerospace Industry will Play an ever Larger Role in the Development of Graphite and Graphene
Graphite has found many new industrial applications over the past few decades. Graphite is used as an additive in the production of steel, in mechanical lubricants and in a variety of automotive products. In last two years, graphite has been the object of renewed interest, an aspect reflected in sharply rising prices for this commodity in world markets, due to evolving lithium-ion battery technology driven by demand for energy efficient products, particularly the rapid development of electric vehicles. The future of nuclear energy, as a result of meltdown concerns raised by the 2011 Fukushima reactor disaster, revolves around pebble bed reactors, which use graphite as the moderator. Such has been the advancement of technology that the graphite derived material graphene, when used in a super-capacitor, could soon make chemical batteries obsolete. Industry analysts have estimated that thanks to evolving battery technology demand alone, graphite demand could grow by as much as 400% over the next decade, especially high carbon content (> 95%) large flake graphite, which will require the opening of many new graphite mines a year. It is this type of graphite that will be able to fetch the highest prices, whereas lower grades, finer flake, will continue to be used in such items as lubricants or pencils. However, lower grades of graphite, like its carbon relative ‘carbon fiber’, will see increased demand from the aerospace industry. Woven graphite, a material introduced to the market in the past decade, is a veritable alternative to carbon fiber and Kevlar; both of which have been used extensively in military and civilian aircraft applications. The Boeing 787, which has just begun commercial operation, has a fuselage and wings that make wide use of graphite carbon reinforced polymers. The Japanese firm Mitsubishi has designed the wings for Boeing 787 using a graphite epoxy composite. The American space exploration agency, NASA, has predicted that future aircraft will trade aluminum for graphite and carbon fiber composites. Graphene is even stronger than graphite, which makes it ideal for aerospace applications. Its strength and low density makes it essential in reducing aircraft weight and, therefore, fuel consumption. Graphite has already fulfilled this role but graphene offers all of graphite’s advantages with the additional benefit of even greater strength and strain control.
The latter aspect provides unprecedented safety gains, as the ability to monitor material strain can help predict part failure and avoid potentially disastrous accidents. The problem of how to produce large enough quantities of graphene is close to being resolved and the aerospace industry will soon begin conducting large scale experimentation to devise methods of adopting this new material in regular production. Meanwhile, graphite will see demand grow from airplane manufacturers such as Boeing and Airbus (like Boeing, Airbus has also unveiled an airliner, the A350 XWB, making large use of composites featuring graphite). Graphite is also one of the best materials to make turbofan jet engine shaft seals thanks to its strength, low weight and excellent heat resistance. The main shaft in a turbofan engine rotates at near supersonic speed, generating a lot of heat, which can cause lubricant to leak if the seals fail. Graphite seals are more resistant than traditional ones; they generate less friction and ideal in such high temperature environments. Graphite and graphite coated composites can also be used in aircraft gearboxes and typically in any application where a high speed rotating shaft is involved. Graphene will probably replace all of the carbon fiber presently being used in the aerospace industry and the aerospace sector will lead the efforts to develop this new and stronger material. Quelle: http://www.graphiteblog.com/2012/04/...-of-graphite-and-graphene.html |