Composite Use in the Automotive Sector

Composite Materials in the Automotive Sector Composite materials have been utilized across many sectors from the past to the present, and the history of composites extends back to ancient times. In ancient times, fragile materials were reinforced by adding plant and animal fibers, creating the first examples of composite materials, making them more durable. Composite materials, formed by combining two or more materials at the macro level to bring together the best properties of each in a single material, have been used for years in numerous sectors ranging from aviation to defense, from space to automotive. The use of composites in the automotive sector first emerged in 1945 with the automobile called Stout 46. Over the years, as the automotive sector adopted sustainability goals, an increase in composite usage has been observed.

History of Composite Use in the Automotive Sector

In 1945, the Stout 46 automobile was first manufactured using composites. The Stout 6, recognized as the world's first composite prototype automobile with a fiberglass body and pneumatic suspension, was developed by Owens Corning and William Stout. The first commercial example of a car using composites emerged in 1953. That year, MFG launched the Chevrolet Corvette, the first automobile to have fiberglass body panels. By 1960, Sheet Molding Compound (SMC) had been invented. Thus, SMC began to be used in automobiles. One of the first examples was the Chrysler Station Wagon launched in 1968; this automobile featured an SMC rear air deflector. In 1972, the Corvette converted its body panels to SMC. It is known that composite materials are utilized in Formula 1 racing cars. The first example of this emerged in 1981. The British automotive company McLaren launched the first Formula 1 vehicle with a carbon fiber monocoque body in 1981. Over the years, particularly an increase has been observed in the use of SMCs in the automotive sector. Many automotive companies have utilized SMC in body panels, front systems, and other components. In 1987, SMC was used in a bumper beam of an automobile in North America, becoming the first structural part using SMC. By 2013, one of the world's largest automotive companies launched the first mass-production automobile made largely of composite materials. With this development, the use of composite materials in mass-production vehicles has steadily increased. Today, the fact that composite materials are lightweight and more environmentally friendly solutions increases their usage.

Types of Composite Materials Used in Automobiles

The types of composite materials in the automotive industry vary depending on where in the vehicle these materials will be utilized. Looking at composite materials used in the automotive sector, by fiber type, glass fiber, carbon fiber, or natural fiber composites are used. By resin type, thermoset or thermoplastic composites are utilized. When examined by fiber type, glass fiber composites have the largest market share in the automotive sector. These composite materials have quite low thermal resistance and high strength. At the same time, glass fiber-reinforced composites also demonstrate resistance to chemical materials and moisture. In the automotive sector, one reason for the use of glass fiber-reinforced composite materials, thanks to these properties, is that they are low-cost, easily available, and processable. Particularly in mass production, their low cost provides manufacturers with a significant advantage. Carbon fiber-reinforced composite materials are strong and lightweight. However, these composite materials are expensive, which is why they are mostly used in sports and high-end vehicles. Natural fibers are more commonly used in automobile trunks, headliners, and seat backs. Today, with sustainability gaining importance, natural fibers are being used more frequently. For example, natural fibers have begun to be used in body structures in motorsports. The areas where composite materials are most utilized in vehicles are external structures such as fenders, bumpers, door panels, and hoods. The reason for this is that composite materials provide the properties sought for vehicle external structures, such as chemical resistance and tensile strength. At the same time, composite materials generally have lower maintenance costs and longer service life. For this reason, composites are being utilized on vehicle exteriors to extend the lifespan of the vehicles. When examining resin types, thermoset and thermoplastic composites come to mind. Both of these composite materials have variable application areas in vehicles. Demand from the automotive sector for thermoset materials is higher, and thermoset composites are used in many areas from headlight housings to external and internal components. In addition, thermoplastics have become a material with increasing usage rates because they are recyclable. Should the costs of thermoplastics decrease, a rise in market demand for these materials is anticipated.

Sustainability and Composites in the Automotive Sector

The climate crisis experienced globally has increasingly embedded the concept of sustainability into our lives. Companies work toward sustainability goals in their production areas; increasing the use of renewable energy; recycling waste, among other matters. The automotive sector has been affected by the situation the world finds itself in. With this impact, the production of electric vehicles has increased; many companies have begun initiatives to reduce vehicles' carbon emissions to zero. Looking at the European Union's targets on this matter, they aim to reduce automobiles' carbon dioxide emissions by 50% by 2030. Consumers are certainly affected by environmental processes, and for this reason, consumer demand for environmentally friendly and low carbon emission vehicles is rising. In line with these demands, composite usage in the automotive sector has increased.

The reasons for using composites in line with sustainability goals are as follows:

• Composites can be shaped more easily and in the desired form. Thanks to this, assembly times in vehicles are shortened, which reduces energy expenditure. • Composites are much lighter compared to many materials. The reduction of weight in automobiles leads to reduced total costs and fuel consumption. Thus, vehicles achieve fuel savings and lower carbon emissions. • Composites provide innovative battery integration solutions for electric vehicles, contributing to the development of next-generation automobiles. • Composites provide fuel storage tanks suitable for new-generation hydrogen-powered vehicles. Thanks to these properties, it is anticipated that the use of composite materials in the automotive sector will increase even further over the years. When examining the distribution of composite materials by sector, it is seen that the automotive sector leads with a 28% share in 2019. According to conducted research, the automotive composites market, which has shown continuous growth since 1980, will grow further in the future.   References: https://www.sutori.com/en/story/history-of-automotive-composites--1yJrnDNy2bwyet92mgYPVa47 https://kalkinmaguncesi.izka.org.tr/index.php/2021/06/17/otomotiv-sektorunde-kompozit-malzeme-kullanimi/ The future use of structural composite materials in the automotive industry, Dr. Joe Carruthers   Prepared by: Nilsu Kotil