Aerospace Advanced Composites in Automobiles

by : brianreuter

There is currently very little potential for advanced-composite technology in high-volume automotive applications. That is not to say that advanced composites have not been or will not be used in the distant future (more than 10 years). For example, advanced composites (e.g., carbon fiber) are currently used in several specialty road cars, concept cars, and in many racing cars. However, these are not produced in high-volume or for use in large parts.

In the United States and Europe, the barrier to acceptance of advanced composites in the automotive industry is price vs. performance. While parts integration and large parts are a potential advantage for engineered and advanced composites over metal (steel included), the cycle times and material costs for advanced composites may still present a barrier to full-scale acceptance in the automotive industry in the near future.

Advanced composites, which are composed of oriented, high-performance fibers (e.g., carbon) in a high-performance resin matrix (e.g., epoxy), provide enhanced structural, electrical, and thermal properties to numerous aerospace applications. The materials are costly, and the fabrication processes are slow. The number of units that are produced is small when compared to high-volume automotive applications. Advanced composite technology is technically appreciated by the automotive industry but is currently not accepted because of formidable costs.

The cost of high-performance fibers (specifically carbon fiber) has been a continuing barrier to full-scale adaptation of advanced composites. Guideline experts estimate that carbon fibers used in the less sophisticated aerospace applications can cost $15 to $60/lb, whereas those used in sporting goods could cost $8 to $15. For carbon fibers to be a feasible option to be used in industrial applications (automotive, oil well tubes, etc), they should cost around $5/lb. However, the realistic threshold for the cost of carbon fibers is probably $6 to $8/lb. Even if some of the giants in the automotive industry can force down the price point of carbon fibers by buying in large volumes, no carbon fiber producer is expected to be able to fulfill the entire demand on time.

Engineered composites, which are composed of unoriented, discontinuous or continuous, low-cost fibers (e.g., glass) and a commodity thermoplastic matrix (e.g., polypropylene) or thermoset matrix (e.g., polyester) are well established in the automotive industry. The cost of materials is low and the fabrication times are relatively fast, ranging from a few seconds (thermoplastic GMT) to a few minutes (thermoset SMC).

Several developments in the field of engineered composites may help expedite the adaptation of advanced composites in the automotive industry. For example, oriented, continuous fiber preforms have been introduced, which will reduce fabrication time for resin infusion processes (RTM, VARTM, SRIM, and RRIM). A second example is the development of new machinery to mix and inject long glass fibers in the form of sheets. This process could provide a serious threat to both GMT and long fiber pellets.

Separately, the carbon fiber industry is reacting to the pressure to reduce fiber cost. A certain amount of progress is being made, but the optimum volumes to achieve the lowest costs are still a few years away.