How Composite Fabrication Is Revolutionizing Aircraft Manufacturing
Aircraft that use composite materials are lighter than those made of traditional metals, which improves fuel efficiency. They’re also less susceptible to corrosion and require lower maintenance costs.
What are Composite Materials?
A composite material is a combination of materials that are stronger together than they are individually. Composites can be made of natural or artificial elements with different physical and chemical properties.
Aircraft structures must be strong enough for flight and carry passengers, but they must also be as light as possible to travel quickly. To achieve this, aircraft manufacturers increasingly use composite materials for their construction.
Composites consist of a matrix material, such as plastic, embedded in reinforcing materials like fibers. The matrix material can be a thermoset, such as epoxy resin, or a thermoplastic, such as phenolic.
The reinforcement materials may be extended, thick carbon fibers or short “whiskers” of boron, silicon carbide, or tungsten-boron, depending on the application. These are bonded to the matrix with an adhesive, such as fiberglass, epoxy, or vinyl ester resins. The composite material’s properties are anisotropic, meaning they differ according to the direction of applied loads and forces.
How are Composites Made?
Typically, composites consist of reinforcing materials like carbon fiber and polymer resins, such as epoxies. The resulting hybrid materials have superior strength-to-weight ratios, higher corrosion resistance, and improved fatigue properties, enhancing an aircraft’s specific strength, efficiency, and longevity.
The process of constructing composites varies depending on the material and the desired outcome of the final product. Nevertheless, the most common method is autoclave molding. During this process, multiple prepreg plies (pre-impregnated, uni-directional woven cloths) are laid up over a male mold in the shape of the final part. The fabric is then heat-activated so the resin liquefies, wets all the fibers, and cures into a harsh, rigid result.
Engineers at Mentis Sciences can also orient the fibers in various directions to support specific stresses. For instance, the wing skins of modern jets are trained to withstand longitudinal stress across the span. This results in a better strength-to-weight ratio, reduced fuel consumption and emissions, and lower direct operating costs.
What are the Benefits of Composites?
In their simplest form, composites comprise two materials that combine to create a stronger whole. A first material, such as a high-performance fiber or particle, is reinforced in a second material, usually an epoxy polymer. This combination combines the best qualities of each original component into one unified design element.
The primary benefits of composites include excellent strength-to-weight ratios, reduced maintenance costs, and more. Engineers can also customize the material by adding strengths in specific areas that are needed most. For example, an aircraft tail may require increased tensile strength to withstand flight vibration and load effects.
Another benefit of composites is their ability to resist corrosion, such as deicing salts. This reduces maintenance costs and extends the life of the aircraft.
What are the Challenges of Composites?
Composites offer many advantages to aircraft manufacturers. They can improve the strength-to-weight ratio of aircraft structures and reduce the weight of airframes, resulting in reduced fuel consumption and lower emissions, and they can allow for greater aerodynamic efficiency. They can also help to save time and money during assembly as they don’t require riveted joints like metal parts.
Despite these benefits, the use of composites has its challenges. One issue is that it can be difficult to judge the quality of workmanship in composite panels, as a perfect, well-made panel can look very similar to a flawed, delaminated composite panel.
Another challenge is that composites are poor conductors of heat and electricity and, therefore, have to be insulated to prevent structural damage. Finally, the production process of composites can be slow and labor-intensive. However, with advances in technology and streamlining of processes, composites are becoming increasingly common. With composites, engineers can design innovative new products that are impossible with traditional materials.
