Titanium alloys are widely used in aircraft manufacturing titanium is nineteen fifties developed an important structural metal, titanium alloy with high strength, good corrosion resistance, heat resistance and high which are widely used in various fields. Many countries in the world have realized the importance of titanium alloy materials, have carried on the research and development, and the practical application. In twentieth Century 50 ~ 60 age, is the development of high temperature titanium alloy for aircraft engine and airframe structure titanium alloy, 70's developed a number of corrosion resistant titanium alloy, since 80 time, corrosion resistant titanium alloy and high strength titanium alloy has been further development. Titanium alloy is mainly used for the production of aircraft engine compressor components, followed by the Rockets, missiles and high-speed aircraft structure parts

The history of the development of titanium is nineteen fifties developed an important structural metal, titanium alloy with high strength, good corrosion resistance, heat resistance and high which are widely used in various fields. Many countries in the world have realized the importance of titanium alloy materials, have carried on the research and development, and the practical application.

The first practical titanium alloy is the United States in 1954 the successful development of the Ti-6Al-4V alloy, due to its heat resistance, strength, plasticity, toughness, formability, weldability, corrosion resistance and biocompatibility of titanium alloy are better, and become the industry 's trump card in the alloy, the alloy consumption accounted for all of titanium alloy 75% to 85%. Many other titanium alloy can be seen as the modification of Ti-6Al-4V alloy.

In twentieth Century 50 ~ 60 age, is the development of high temperature titanium alloy for aircraft engine and airframe structure titanium alloy, 70's developed a number of corrosion resistant titanium alloy, since 80 time, corrosion resistant titanium alloy and high strength titanium alloy has been further development. Heat resistant titanium alloy using temperature already from 50 time to 400 DEG C to 90 time 600 ~ 650 C. A2 ( Ti3Al ) and R ( TiAl ) based alloy, the titanium in the engine using parts by engine ( cold end of the fan and compressor engine ) to the hot end of the advancing direction ( turbine ). Structure of titanium alloy to high-strength, high plasticity, high tenacity, high modulus and high damage tolerant direction.

In addition, since the nineteen seventies, has also appeared in Ti-Ni, Ti-Ni-Fe, Ti-Ni-Nb shape memory alloy, and in engineering is increasingly widely used.

At present, the world has developed hundreds of titanium alloy, the most famous alloy with 20 to 30, such as Ti-6Al-4V, Ti-5Al-2.5Sn, Ti-2Al-2.5Zr, Ti-32Mo, Ti-Mo-Ni, Ti-Pd, SP-700, Ti-6242, Ti-10-5-3, Ti-1023, BT9, BT20, IMI829, IMI834 [2, 4].

Alloying

Titanium alloy is a titanium based joined other elements of the alloy. Titanium two paramorph: below 882 DEG C for close-packed six party structure alpha titanium, above 882 DEG C for body-centered cubic beta titanium.

Alloy elements according to their phase transition temperature effects can be divided into three categories:

The stable phase, increase the phase transition temperature of elements for the alpha stable elements, aluminum, carbon, oxygen and nitrogen. Aluminum titanium alloy which is the main alloy elements, it can improve the room temperature and high temperature strength, reducing the proportion, increase the elastic modulus has obvious effect.

The stability of beta phase, reduce the phase transition temperature of the elements as beta stable elements, and can be divided into isomorphous and eutectoid type two.

Application of the titanium alloy product

The former are molybdenum, niobium, vanadium, chromium, manganese,; the latter have copper, iron, silicon and other.

The phase transition temperature has little effect on element is the neutral element, zirconium, tin etc..

Oxygen, nitrogen, carbon and hydrogen are the main impurities in titanium alloy. Oxygen and nitrogen in the alpha phase has high solubility, on titanium alloys can be enhanced, but the ductility decreases. Usually provides titanium oxygen and nitrogen content in 0.15 ~ 0.2% and 0.04 ~ 0.05%. The hydrogen in the alpha phase solubility is very small, the titanium alloy dissolved too much hydrogen may produce hydrides, the alloy brittle. Typically hydrogen in titanium alloy is controlled below 0.015%. Hydrogen in titanium solubility is reversible, can be used to remove the vacuum annealing.