Carbon composites move from track to production

The side blades of the new Audi R8 use CFRP and CFRP/GRP clam shell panels made by Fischer Composite Technology in Austria

From October fans of Renault’s Mégane F1 Team R26 car will be able to buy one of 450 limited edition road going versions. Each car has a lacquered CFRP bonnet, which the company claims saves 7.5kg of weight.

Earlier this year, General Motors launched its performance Corvette ZR1 at the Geneva Motor Show. The vehicle features a raised, all-carbon-fibre bonnet with an integrated clear polycarbonate window to provide a clear view of the top of the engine, as well as CFRP front fenders.

The side blade on Audi’s latest high performance R8 model also uses carbon fibre. The part is produced by Fischer Composite Technology in Austria, using Huntsman’s Araldite resin in a resin transfer (RTM) process. The company is producing around 4,000 blade sets a year.

Each of the 900mm by 500mm side blades is produced from two RTM shells. Fixing devices are integrated into the inner shell component to enable the side blade to be mounted onto the car. A combination of glass and carbon fibre is used for the outer shell, however, to ensure a Class A visible surface is achieved. UV protection is provided through application of a clear, high gloss lacquer.

RTM is also used to manufacture the CFRP body for the Roadster sport electric car from US company Tesla Motors. It is now taking orders from European customers prepared to pay the more than €100,000 needed to secure delivery of a stylish all-electric car capable of accelerating from 0-100 km/hr within 3.9s and covering a range of up to 350km from a single charge.

Tesla obtains high specific bending stiffness by having the CF as close to the surface as possible, the panels consisting of a sandwich structure, with two CF layers separated by a middle layer of glass and PP “that presses the carbon against the face of the tool and keeps it close to the surface of the panel”. A smooth surface for painting is obtained by spraying a paint primer on the inside of the tool.

In June this year, Toray opened a €15.8m automotive centre at Nagoya in Japan to develop low cost CFRP composites for body panels and hybrid vehicles. It will very likely have vehicles such as Toyota’s 1/X concept car in mind. Launched at the Tokyo Motor Show last year, it utilised a CFRP body frame to deliver the same interior space as the Prius hybrid car but at one third of the weight.

The NICE Car Company has its sights set on electric drive. Its Super Light Electric Concept was developed with the Cranfield Power and Drive Systems group in Shrivenham in the UK and results in a car weighing less than 400kg including batteries. Shown at the London Motor Show, the car is designed around a “carbon fibre cell” and is claimed to provide a range of more than 160km.

KTM of Austria showed its door- and boot-less CFRP bodied X-Bow car at the Geneva Motor Show. Designed in Italy by Dallara, production in Graz of the first 100 cars has been delayed again but the slip in delivery dates to the second half of this year has not dampened KTW’s enthusiasm, with chairman Werner Wilhelm telling EPN’s sister publication Automobilwoche: “We think that we can sell 2,000 vehicles a year”.

The 75kg carbon fibre monocoque body and seat shells are produced by carbon fibre moulding specialist Wethje in Germany, in which KTM’s majority shareholder Cross Industries has a shareholding.