Titanium is an important structural metal developed in 1950s. Titanium alloy is widely used in various fields because of its high strength, good corrosion resistance and high heat resistance. Many countries in the world have realized the importance of titanium alloy materials, and have carried out research and development and obtained practical application. During the 1950s and 1960s, high-temperature titanium alloys for aero-engines and structural titanium alloys for airframes were mainly developed. In 1970s, many corrosion-resistant titanium alloys were developed. Since 1980s, corrosion-resistant titanium alloys and high-strength titanium alloys have been further developed. Titanium alloys are mainly used to manufacture compressor parts of aircraft engines, followed by structural parts of rockets, missiles and high-speed aircraft.
Titanium is a new metal, and its properties are related to impurities such as carbon, nitrogen, hydrogen and oxygen. The purity of titanium iodide is less than 0. 1%, but its strength is low and its plasticity is high. The properties of 99.5% industrial pure titanium are: density ρ=4.5g/ cm3, melting point 1725℃, thermal conductivity λ= 15.24W/(m.K), tensile strength σb=539MPa, elongation δ=25%, and area shrinkage ψ =.