Owing to their strength, resistance to corrosion and their ability to withstand high temperatures without getting deformed, titanium alloys are used to make critical parts of aircraft, rockets and missiles among others. One important application of this metallic material is in the manufacture of jet engines.
The jet engine is the lifeblood of today’s modern jet. It moves the aircraft forward and powers many of the jet’s other systems. It works by drawing in air while the jet is moving, compressing it and mixing it with fuel. The heated fuel produces a gas which is ejected, causing the aircraft to move forward at great speed.
Although initially designed in 1921, it was not until 1942 that the first American jet engine was made. Today’s engines weigh over 10,000 pounds and produce over 100,000 pounds of thrust. Because a standard jet engine may have as many as 25,000 parts, it takes about two years to assemble and a testing period of five years before it is actually used commercially. A large part of that is made of titanium.
Over 65 percent of all titanium metal produced is incorporated into the construction of aircraft frames and engines. When Lockheed first produced the SR-71 ‘Blackbird’ in the early 1960’s, 85 percent of the plane was constructed from titanium that was smuggled in from the former Soviet Union. That set the pace for many other commercial and military aircraft construction. Anywhere between 18 and 146 metric tons of titanium is used in the manufacture of most aircraft today. This is especially important in the construction of jet engines which features rotors, hydraulics, nacelles and compressor blades. Almost 50 percent of all alloys used in aircraft parts utilize the titanium alloy 6AL-4v.
To suck in large amounts of air, the jet engine has a large spinning fan with titanium blades. These blades not only increase the engine’s efficiency but reduce noise. Other titanium-made components are the compressor and combustion chamber.
As David Harris of eNotes.com describes, “The intake fan at the front of the engine must be extremely strong so that it doesn’t fracture when large birds and other debris are sucked into its blades.”
Jet engines are made to withstand great temperatures, pressures and the stress associated with both. The middle compressor of these engines are made of aluminum but once the air and fuel mixture reaches the high pressure and high temperature section, the combustor, its chamber and turbine blades are constructed from nickel and titanium alloys. The most intense heat of the engine is felt here.
Harris continues, “Often, both the combustion chamber and the turbine receive special ceramic coatings that better enable them to resist heat. The inner duct of the exhaust system is crafted from titanium while the outer exhaust duct is made from composites – synthetic fibers held together with resins.”
Amazing, isn’t it? So the next time you see a jet, think about titanium – a space age metal that has a thousand and one uses.