TABLE OF CONTENTS Titanium is an attractive structural material due to its high strength, low density, and excellent corrosion resistance. However, even though titanium is the fourth most abundant element in the earth's crust, due to its high melting point and extreme reactivity, the cost of titanium is high. The high cost includes both the mill operations (sponge production, ingot melting, and primary working) as well as many of the secondary operations conducted by the user. The primary reasons for which titanium alloys are used in aerospace applications include: [1]
Weight savings. The high strength-to-weight ratio of titanium alloys allows them to replace steel in many applications requiring high strength and fracture toughness. With a density of 0.16 lb/in. [3], titanium alloys are only about as heavy as steel and nickel based superalloys, yielding excellent strength-to-weight ratios.
Fatigue strength. Titanium alloys have much better fatigue strength than aluminum alloys and are frequently used for highly loaded bulkheads and frames in fighter aircraft.
Operating temperature capability. When the operating temperature exceeds about 270 F, aluminum alloys lose too much strength and titanium alloys are often required.
Corrosion resistance. The corrosion resistance of titanium alloys is superior to both aluminum and steel alloys.
Space savings. Titanium alloys are used for landing gear components on commercial aircraft where the size of aluminum components would not fit within the landing gear space envelope.
Due to their outstanding resistance to fatigue, high temperature capability, and resistance to corrosion, titanium alloys comprise approximately 42% of the...
