Application Of High Temperature, High Strength And High Toughness Titanium Alloy in Airplane
High-Strength titanium alloy refers to titanium alloy with room temperature strength greater than 1000MPa after heat treatment. Foreign high-strength titanium alloy research and development is mainly based on the United States and Russia, and the products have been widely used. China's high-strength titanium alloy research has gradually transformed from imitation to independent research and development. For example, the TB10 alloy (Ti-3Al-5Mo-5V-2Cr) studied by Beijing General Institute of Nonferrous Metals Research has typical properties: Rm = 1360MPa, KIC = 67MPa m1/2, which has been used in aerospace structural parts, aircraft fuselage and wings. Innovative development of Ti-1300, Ti-5322 and other high-strength titanium alloys by Northwest Nonferrous Metals Research Institute. Ti-1300 has a tensile strength of more than 1350Mpa, an elongation of more than 8 %, and a fracture toughness of more than 55MPa. m1/2. Ti-5-3-2-2 tensile strength exceeds 1300MPa, elongation exceeds 7%.
Aerospace airplane require titanium alloy to have excellent high temperature resistance. The first high-temperature titanium alloy in the world is Ti-6Al-4V titanium alloy developed in the United States. Ti-6Al-4V titanium alloy has both α+β two-phase characteristics and it is widely used in aerospace. In order to maximize the strengthening effect of Al solution heat, elements such as Sn, Zr, Mo and Si are also added to titanium alloys, and alloys such as IMI679, Ti6242 and IMI685, Ti6242S, IMI834, Ti1100, BT36 have been developed successively.
At present, the international advanced high-temperature titanium alloys are mainly Ti1100 titanium alloys developed in the United States(Ti-6Al-2.75 Sn-4.0 Zr-0.4 Mo-0.45 Si-0.07 O2-0.02 Fe), which can be used at temperatures up to 600℃,which has lower toughness and greater fatigue crack propagation rate; British I MI 83 4(Ti -5.5Al-4Sn-4Zr-0.3Mo-1Nb-0.5Si-0.06C). At the same time, it has excellent high temperature creep performance and fatigue performance,and the use temperature is 590℃; BT36(Ti-6.2 Al-2Sn-3.6Zr-0.7Mo-0.15Si-5W), BT18Y(Ti-6.5 Al-2.5 Sn-4Zr-0.7 Mo-1Nb-0.25Si), Ti633G(Ti-6.5Al-3Sn-3Zr-1Nb-0.3Mo-0.3Si-0.2 Gd) and Ti18(Ti-6Al-2Sn-4Zr-4Mo-1W-0.2 Si) alloys, the use temperature are 600℃, 550 ~ 600℃, 550 ℃.
China's development of high-temperature alloys are mainly Ti55(Ti-5.5 Al-4Sn-2Zr-1Mo-0.25 Si-1Nd), the Ti60(Ti-5.8 Al-4.8Sn-2Zr-1Mo-0.35Si-0.85Nd)and Ti600(Ti-6Al-2.8 Sn-4Zr-0.5Mo-0.4Si-1Y),which uses the temperature was 550℃, 600℃, and 650℃.
Application of High Toughness Damage Tolerance Type Titanium Alloy on Engine Blades
The typical high-strength and high-toughness titanium alloy is Ti-62222S alloy developed in the United States. This titanium alloy has good strength, plasticity and fracture toughness matching, high fatigue crack propagation resistance, deep hardenability, high elastic modulus, good creep resistance at medium temperature, room temperature fracture strength and yield strength are greater than 1300MPa and 1200MPa, on the other hand, its high temperature performance is also very good.
TC21(Ti-6Al-2Sn-2Zr-2Mo-2Cr-1Nb-0.1Si) is an innovative high-strength and high-toughness damage tolerance titanium alloy developed in China. The titanium alloy has good strength, plasticity, fracture toughness and crack propagation rate matching. It is a very promising high-strength and high-toughness damage-tolerant structural titanium alloy. Under the premise of ensuring high strength at room temperature, the fracture toughness can be as high as 90MPa. m1/2. Now, the most active field of titanium application is aerospace.
