From What Are Airplanes Made?
Airplanes are made from aluminum, titanium, steel and other materials like composites. Composites may consist of carbon fiber, polymers and other materials that are strong, stiff, low weight and corrosion resistant.
As of 2013, Airbus and Boeing both produce planes made from at least 50 percent composite material. Rolls-Royce PLC makes engines for airline companies, and it is developing composites made from plastics and ceramics. Steel is too heavy to use by itself, so twice as much aluminum is used in planes such as Boeing's 787 Dreamliner. Titanium and other lightweight alloys can be more expensive to produce, so they are used in conjunction with aluminum rather than in place of it. For example, Alcoa developed an aluminum-lithium alloy used by Airbus on its A350. Polymers are used to construct things such as the fuselage on Boeing's planes.