chapter  3
20 Pages

Major Aircraft Materials and Its Classification

There has been a long history of development of materials for aircraft manufacturing since the rst aircraft was developed in the early 1900s by the Wright Brothers. The choice of aircraft materials available has changed since World War II when aluminum alloys were exclusively used for the body frame, along with some steel in selected areas where strength and stiffness was required; for example, in the landing gear and engine support structural components. In 1950, titanium was introduced for aerospace applications, when extraction of titanium from its ore had been economically developed for production. Titanium has now become a key material for both airframe and engine structures, due to its high specic strength and corrosion resistance compared to aluminum alloys. During the early to mid-1960s, composite materials with boron-based bers impregnated with various polymers were introduced into aerospace applications. The boron ber composites were costly, and difcult to machine. Composite technologies continued to develop successfully into the present day carbon ber composites, commonly referred to as carbon ber reinforced plastic (CFRP). The composite manufacturing industries are constantly working on various matrices with graphite bers, along with the process technologies to produce cost effective and more attractive and efcient materials with lower density, high strength and stiffness, and excellent fatigue characteristics. Thermoset and thermoplastic epoxy-based resin systems have widely been used in making various aircraft components satisfying the engineering requirements for these applications.