The lightweight design of automotive construction materials has become of paramount importance to not only reduce the carbon footprint of their final products but also to conserve valuable and depleting resources. The existing approaches of substitution and structure re-designing with traditional materials have reached their limits and there exists an urgent need to explore the non-metallic but equally functional set of materials to achieve stricter fuel saving targets. Quite recently, lightweight fibre-reinforced plastics (FRP) have become the material of choice due to their flexibility, functionality, and formability into intricate hybrid and multi-part designs. Generally, the FRPs are employed in areas dominated with tensile stress, whereas metals find their utility in compressive stress areas of automotive applications.
Carbon fibre used more on engine block
Recently, carbon fibers are being used as the reinforcement for plastic matrices, as these composites have most weight reduction potential, and have higher stiffness compared to glass counterparts―commercial grade carbon fibers offers a modulus of 230 GPa, which is three times higher compared to E-glass fibers (70 GPa) with a specific gravity only of 70% of E-glass fibers  . However, the high cost seems a hindrance to mass scale exploitation of this wonder material. Recent advances in manufacturing low-cost carbon fiber and its recycling has opened up new venues for lightweight automotive manufacturing.
“With the BMW i3, we get a reduction of 250-350 kilos [550-770 pounds] from carbon fiber,” says Daniel Schafter, head of production of Concept BMW I, “and that more or less compensates for the weight of the battery.”
Carbon fiber, being twice as strong and 30% lighter compared to glass fiber   has been used in automotive applications for some time. However, due to very high cost, these materials are usually employed in high-end products like sports vehicles or luxury cars. The hybrid design of carbon and glass fiber reinforced composites have been recently introduced with encouraging results. Hybrid composite structures have been developed using varying ratio of glass and carbon weaved fabric in epoxy matrices and it is shown that, when employing at the exterior, composite laminates having 50% ratio of carbon fiber reinforcement exhibits optimum flexural properties and alternating carbon/glass lay-up arrangement ensures best compressive strength.
Commercial products arising from research in this area has already been developed by a number of companies. Quantum Composites (Bay City, Mich., USA), a subsidiary of The Composites Group, has very recently launched a hybrid Carbon-glass fiber composite material, believed to be a high-strength, cost effective and lightweight substitute for conventional metal and glass fiber applications in the automotive industry. This brand named Hybrid material, AMC-8590-12CFH is suitable for fast-cure compression molding to manufacture complex parts on mass-scale
As amazing as the car looks on the exterior, it’s really what’s inside that excites us. Lamborghini used a carbon fiber reinforced polymer monocoque:
Very recently, Department of Energy USA in association with various universities and research institutes has launched the Institute for Advanced Composites Manufacturing Innovation (IACMI); the University of Tennessee, Knoxville, and Oak Ridge National Laboratory being founding research partners. Funded through $70 million in federal and $180 million in non-federal funds, IACMI will focus on increasing production capacity of carbon fiber and developing less expensive but advanced fiber-reinforced polymer composites for automotive and other industrial sectors  . Incorporating short and nanofibers can certainly exploit the fullest potential of high strength carbon material in hybrid design as a measure to have better properties and economize the formulation. Fua et al.  have reported 20% increase in ultimate tensile strength of short carbon fibre-polypropylene composites compared to similar glass fibre-filled samples. Although synthesis of nano carbon fiber and their composites have been reported highly energy intensive, up to 12 times more energy consuming compared to steel, overall life cycle studies have shown net savings in energy due to lightweight body parts used in vehicles . Hybrid formulations, where carbon fiber is selectively incorporated into glass or other reinforcement fibers to enhance performance along lading paths in automotive applications, is one option to offset the high cost of carbon fibers. However, a true potential of this otherwise excellent lightweight material can be realized until economically sustainable manufacturing methods are not introduced.
About the Authors:
Muhammad Pervaiz, Center for Biocomposites and Biomaterials Processing, Faculty of Forestry, University of Toronto, Toronto, Canada
Suhara Panthapulakkal, Center for Biocomposites and Biomaterials Processing, Faculty of Forestry, University of Toronto, Toronto, Canada
Mohini Sain, Center for Biocomposites and Biomaterials Processing, Faculty of Forestry, University of Toronto, Toronto, Canada and Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, KSA
Jimi Tjong, Center for Biocomposites and Biomaterials Processing, Faculty of Forestry, University of Toronto, Toronto, Canada, Faculty of Forestry, University of Toronto, Toronto, Canada and Powertrain Engineering Research and Development Centre, Ford PERDC Engineering, Windsor, Canada
Cite this Article:
Pervaiz, M. , Panthapulakkal, S. , KC, B. , Sain, M. and Tjong, J. (2016) Emerging Trends in Automotive Lightweighting through Novel Composite Materials. Materials Sciences and Applications, 7, 26-38. doi: 10.4236/msa.2016.71004.