Applications of carbon composites in aerospace

In recent years, composite materials have become the most important materials in various fields such as automotive, aerospace, sports, construction, and medical care. Various composite materials such as glass, carbon and Kevlar are often designed and manufactured for use in aircraft components

1.Introduction
Carbon fiber composites are widely used in aerospace industry because of their excellent properties. Carbon composite materials have the characteristics of high strength, light weight, corrosion resistance, high stiffness and high modulus, and are very popular in the aerospace industry. Carbon composites improve the properties of metal alloys, enabling them to meet all extreme conditions. In the aerospace industry, the most important characteristic of carbon composites is fatigue fracture resistance. This feature helps planes take off and land. By replacing traditional metal alloys with carbon composites in aircraft design, the weight of aircraft is reduced. When weight is reduced, fuel consumption is reduced, thus reducing costs. In the aerospace industry, the volume of carbon composite materials in the manufacturing of the Boeing 787 Dreamliner is more than 50%, close to 80%.

2.Composite material classification
2.1. Metal Matrix Composites (MMC)
They are made of metal substrates, primarily aluminum, cobalt, magnesium, iron, copper, and titanium, as well as distributed ceramic or reinforcement phases. The choice of base material depends on the quality and service environment required for the application. The amount of reinforcement material used in the composite may be as high as 50% of the total volume. SiC particles, boron and Al2O3, and Borsic and TiB2 coated carbon can be mixed quickly and efficiently. Due to their excellent strength and corrosion resistance at high temperatures, aluminum and titanium are the two most commonly used metal substrates in the automotive and aerospace industries.

The demand for metal matrix composites is growing. According to the “markets and market” report, the global metal matrix composites market is expected to grow from $467 million in 2020 to $787 million in 2025. The application of metal matrix composites in the automotive and transportation industries as well as the aerospace industry is driving the growth of the metal matrix composites market. Aircraft weight reduction is the most important factor, and the strength-to-weight ratio is also an important factor in the aerospace industry.

2.2. Ceramic Matrix Composites (CMC)
These composites are reinforced by ceramic substrates, such as alumina, carbon and silicon nitride. Ceramics are used in aerospace applications because they have several desirable properties, including high toughness and high-temperature stability, as well as wear resistance. Short and long fibers can be used to achieve specific quality levels. The toughness of short ceramic matrix composites makes them more resistant to fracture expansion, but it is also prone to failure.

2.3. Reinforcement
Carbon, glass, metal and Kevlar fibers are put into the matrix as reinforcing materials. These materials are usually hard, with high strength, stiffness, high temperature resistance and wear resistance. Reinforcement materials come in the form of particles, flakes and whiskers. Their main purpose is to carry the load of the composite material. Fiberglass is now widely used in the manufacture of automotive parts, hulls, sports equipment and architectural decorative panels. Recent studies have shown that silicon carbide particles, boron nitride, alumina and zinc oxide are the best reinforcing materials for polymer matrices to achieve certain mechanical and electrical properties.