Question

Applications of composite materials in automotives

Answer 1

Composite materials may someday have big advantages over steel in automobile manufacturing. Composites are being considered to make lighter, safer and more fuel-efficient vehicles. A composite is composed of a high-performance fiber (such as carbon or glass) in a matrix material (epoxy polymer) that when combined provides enhanced properties compared with the individual materials by themselves. Carbon-fiber composites weigh about one-fifth as much as steel, but are as good or better in terms of stiffness and strength. They also do not rust or corrode like steel or aluminum, and they could significantly increase vehicle fuel economy by reducing vehicle weight by as much as 60 percent, according to the Oak Ridge National Laboratory (ORNL). “With composite materials, we get high strength-to-weight and stiffness-to-weight ratios, as well as excellent energy-absorbing capability per mass,” says Dan Adams, professor of mechanical engineering at the University of Utah who is collaborating with ORNL on the development of test methods for automotive composites. “Steel is strong and inexpensive, which is why it’s the material of choice today. But composites can be designed tobe strong and light to provide better safety and fuel efficiency.” Adams says that the strength and stiffness factors are why composites are currently used in aerospace applications, which also require a material that is extremely light. And compared to single-layered steel in cars, multiple-layer composite laminates can be designed to absorb more energy in a crash. “However, the use of these materials in the automotive industry has been very limited partly because of the costs associated with the materials and manufacturing,” he says. Adams and his associates are addressing these issues, along with design safety, as they develop test methods and assess candidate composites for automotive applications.