The advantages of composite materials over metal during the creation of aircraft are many. For example, as the cost of composites declines, design flexibility continues to improve. As such, year after year, composites are replacing traditional materials (e.g., steel and aluminum). Additionally, fiber-reinforced composites, such as fiberglass and carbon fiber, allow engineers to create new designs. Furthermore, the use of composites in product creation improves the design process and the end product. With these advantages, it is easy to see why the traditional metal materials are being left behind.
Advantages of Composite Materials in Aircraft
1. Composite Materials Offer Strength
Although the strength of metal is equal in all directions, composites can be designed and then engineered to provide strength in specific directions.
The strength of a composite is determined by the ratio of the resin to the reinforcement material (i.e., the fiber). Since there are numerous resins and reinforcement materials available, formulations can be created to meet any strength requirement.
Adding Strength With Reinforcements
Reinforcements help strengthen the resin matrix. Although one type of resin matrix is typically used consistently throughout a composite structure, there are three areas where reinforcements may be added to the laminate.
A synthetic surfacing veil consisting of fiberglass can be used to add strength to the inner surface of a laminate.
The next layer is thicker and consists of chopped fiberglass, which provides hardy backup for the veil layer.
The final layer is the thickest. This structural layer frequently contains fiberglass reinforcements. These reinforcements provide the structural layer with a high glass content (65% reinforcement and 35% resin). This final layer may be created using fabrics, choppable reinforcements or direct draw, single-end rovings.
2. Composites Are Lightweight
Strong, lightweight parts are crucial to numerous industries, including transportation, aerospace and infrastructure. Therefore, carbon fiber is a good option for these industries. For comparison purposes, steel weighs 75% more and aluminum weighs about 30% more than carbon fiber does.
The Importance of Lightweight Materials in the Transportation Industry
The weight of the materials used to construct transportation vehicles such as automobiles and aircraft determines their fuel efficiency. Heavier materials use more fuel than lighter materials do.
Airplane designers are always concerned about the weight of the aircraft because if it is heavy, besides using more fuel, it is unable to reach the speeds that a lighter aircraft can. Today, some airplanes (e.g., the Boeing 787 Dreamliner) have more parts made of composites than they do metal.
3. Composites Are Corrosion Resistant
One of the main functions of the resins used in composites is to protect the fibers that they surround. Unlike metals, composites can be created that are resistant to chemical-laden environments, temperature fluctuations, as well as other environmental factors (e.g., exposure to UV rays). Isophthalic resins and epoxy vinyl ester resins are the core corrosion-resistant resins used today.
Unique composite formulations are created to protect against:
- Acidic environments.
- Caustic solutions.
- High temperatures/Hot environments.
- Oxidizing chemicals.
- Alkaline environments.
- Exposure to UV rays.
- Water environments.
Isophthalic resins are resistant to chemicals and heat, which is why these resins are frequently used while creating aircraft.
Epoxy vinyl ester resins offer the highest resistance to heat, corrosion and water penetration. Therefore, epoxy vinyl ester resins are commonly used to create corrosion-resistant composites for automobiles, aircraft, pipes, tanks and marine vehicles.
4. Epoxy Vinyl Ester and Isophthalic Resins Offer Flexibility
The flexibility of composites is extremely beneficial because it allows materials to be molded into complex shapes. Since composites consist of a blend of resins, additives and reinforcing fibers, they can be customized to meet a range of requirements.
Additionally, these composites can be used to improve aesthetics and add specific properties. Applications for these composites range from vehicle creation to wind blades.
5. Composites Are Durable
Composites have high dimensional stability, which is what allows them to maintain their shape regardless of the environmental factors around them. Additionally, composites are resistant to UV radiation and hold up well when stressed.
Furthermore, composite structures require little maintenance and the structures created with composite materials last for a very long time. Nevertheless, it is difficult to determine a composites’ actual lifespan because original structures created 50 years ago are still in use today.
These five advantages of composite materials have resulted in composites becoming the material of choice for numerous applications, including aircraft construction.
To learn more about the composite material options for aerostructures that are available at TIGHITCO, please call our Charleston, South Carolina, office at 843-376-0409 or our Berlin, Connecticut, office at 860-828-0298. For our office addresses, please click here.
