Following the carbon rear panel of the Audi R8, which is still in series production, SGL Carbon also worked with Mercedes AMG experts almost two years ago to develop a carbon rear panel and brought it into series production. Coming in at around 1.5 meters wide and 50 centimeters high, the innovative rear wall, is used in the AMG GT 4-Door Coupé sports car model, is 6 kg lighter than the fold-down rear wall made of conventional materials and offers 20% more rigidity.
In cars, the rear wall separates the interior from the trunk and the rear. This means that it is a relatively large component per se, which usually offers further potential for weight savings even in an already optimized vehicle structure. In addition, a particularly rigid rear wall reduces the so-called “twisting” of the body in curves and thus supports sporty handling. In the event of an accident, it also prevents luggage from possibly breaking through from the trunk into the passenger cell.
The use of carbon fibers is ideal for back panels, as they not only have a low weight but also a particularly high tensile strength, which in turn results in a high component rigidity. Increasingly important in development, however, is the implementation of a more advanced, particularly efficient method of series production using fiber composite materials.
The key to this lies in optimized component designs and automated manufacturing concepts, in order to be able to produce components with similar material efficiency as with conventional materials.
Robert Hütter, Director Program Management & Sales in the Composites - Fibers & Materials Business Unit at SGL Carbon.
For this reason, the rear wall of the Mercedes AMG GT 4-Door Coupé is designed as a monolithic component. In addition, it is produced directly in the efficient Resin Transfer Molding (RTM) press process at the SGL Carbon' location in Innkreis, Austria, without requiring any preforming of the carbon fiber mats. Thanks to the very lean component design and the efficient production concept, we have not only achieved particularly fast cycle times, but also an especially high material usage ratio.
“The carbon rear wall of the AMG GT 4-Door Coupé impressively demonstrates how the production of automotive components made of fiber composites can be further tailored to the special features of the material with relatively little effort. Flat components are particularly well suited for this purpose,” explains Hütter.
In addition, the sports car segment is always a good testing ground for possible further expansion into other vehicle classes. In any case, the requirements for rear panels also apply generally to other types of car, albeit to a much lesser extent.