Application of Titanium Alloy Materials for Large Aviation Forgings
Application of Titanium Alloy Materials for Large Aviation Forgings
Titanium alloy for large aviation forgings
Due to its high specific strength, specific stiffness, corrosion resistance and other excellent properties, titanium alloys have been widely used in the aviation industry, and have significant effects on reducing the weight of aircraft structures and improving the service life of parts. Especially for military aircraft, some important structural components such as wing spars, bulkheads, landing gear, etc. are widely processed from titanium alloy forgings, which have high weight, large size and cross-sectional area.
For example, the 8 parts of the main landing gear bracket beams of Boeing B747 aircraft are made of Ti-6Al-4V titanium alloy forgings, each piece weighs 1724kg, has a length of 6.2m and a projected area of 4.1m2. Airbus A380 aircraft has two six-wheel three-axle trolley-type main lifts The load beam of the landing gear is made of Ti-1023 titanium alloy forgings, with a length of 4.255m and a weight of 3210kg. The fourth-generation fighter F22 frame developed by Lockheed in the United States is made of Ti-6Al-4V ELI forgings, with a single piece weighing more than 771kg and a projected area 4.06m2
At present, the main grades of titanium alloys for aviation are TC4, TC18 (BT20), TC21, TA15, TB6 (Ti-55531), etc. Among them, TC18 (BT20) is suitable for the manufacture of large forgings due to its high hardenability, and is currently the most used in China. According to the needs of civil aircraft such as Boeing and Airbus, Russia has developed Ti-55531 titanium alloy on the basis of TC18 (alloy) by reducing the content of Fe, which is easy to segregate. Ti-55531 has high strength, and has excellent hardenability and The wider processing window is currently used on parts such as the A380 aircraft suspension joints and landing gear struts.
China's C919 aircraft has also carried out research and development of domestic materials, and domestic heavy-duty helicopters are also using this material to develop the central part of large helicopter hubs. The data collected so far show that Ti-55531 has higher tensile strength and lower plasticity and fracture toughness than TC21 and TC18.
