The materials used in manufacturing of aircraft have changed significantly from the construction of the first aircraft. With its objective of flying using air support while, resisting gravitational forces, the materials used for construction of aircraft must have a small weight, high specific strength, heat resistant, fatigue load resistant, crack resistant and corrosion resistant. Back in the days, aircrafts were constructed using wood and fabrics. But aircrafts that are made up of wood and fabric were subject to rapid deterioration and high maintenance. Thus, the search for better materials began. Now, aluminium, steel, titanium and composite materials are preferred in the construction of aerospace structures.
Materials used in manufacturing of aircrafts
Aluminium is used due to its low density (2.7 g/cm3), high strength properties, good thermal and electric conductivity, technological effectiveness and high corrosion resistance. But because aluminium loses its strength at high temperatures, it is not used in the skin surface of an aircraft.
Steel is an alloy of iron and carbon and can be three times stronger and heavier than aluminium. It is usually used in a landing gear due to its strength and hardness as well as in the skin surface of aircrafts due to its high heat resistance.
Titanium and its alloys are commonly used in the construction of aircraft due to its high strength properties, high temperature resistance and high corrosion resistance compared to steel and aluminium. Despite being expensive, titanium is used in aircraft construction due to its excellent material properties. It is used in panel and swivel wing assemblies, hydraulic systems and other parts.
Product manufacturing company also favors composite materials in the production of aircrafts due to their high tensile strength, high compression resistance, low weight and high resistance to corrosion. Composite materials are composed by a base material and resin that strengthens the material as a whole. Composite materials improve fuel efficiency and performance of the aircraft as well as lessen direct operating costs of aircrafts. The most common composite material used is fiberglass that is made up of glass fibers as the base material and a resin matrix. The disadvantages of using composite materials, however, include high cost and immediate repair are needed in case of damage. It is also important to avoid fire when using composite materials because the resin used weakens and causes release of toxic fumes.
Future materials for aircraft building
Magnesium had been gaining popularity again due to new developments regarding its corrosion and flammability properties. Magnesium is a lightweight metal but was banned in aircraft construction because it easily catches fire. Now, various research studies made progress in developing magnesium alloys that can meet aerospace corrosion and flammability requirements and succeeded in lifting the ban of magnesium usage. Due to its low weight property, high strength and ductility, magnesium alloys improve efficiency of the aircraft.
Nano Adaptive Hybrid Fabric (NAHF-X) or fuzzy fibers have good structural, electrical and thermal properties. Once incorporated into resin products, it will have the ability to be produced in continuous sheets to desired sizes like other fabrics. Fuzzy fibers can be used in small Unmanned Aerial Vehicles (UAVs) where weight will be reduced when the conductive “skin” of fuzzy fiber serves for the aircraft’s power, sensor systems and communications.
Fiber metal laminates (FML) have high strength, low density and high elasticity modulus with improved toughness, corrosion resistance, good fire resistance and fatigue properties. Furthermore, fiber metal laminates have low weight compared to other metallic structures. Lesser amounts of FML is needed to build a component compared to other materials. With these properties, cost is dramatically reduced in the construction and maintenance of aircrafts.
Other materials that can improve the performance and reduce cost of aircraft manufacturing are CentrAl reinforced aluminum (CentrAl) and ceramic matrix composites (CMCs). CentrAl has 25% more tensile strength than high-strength aluminum alloys, high fatigue resistance and highly damage-tolerance. It also has a lighter weight compared to aluminum alloys that will decrease the weight of the aircraft and lower the fuel consumption. CMCs have high resistance to temperatures that exceed the properties of other materials. Its utilization in CFM LEAP high-bypass turbofan engine has reduced fuel consumption by 16%.
Various studies are still being implemented in order to find materials that will be highly suitable with the requirements needed for materials used in the construction of aircraft and will reduce overall costs while improving the efficiency of the aircraft.