Titanium alloy precision casting – an advanced method of near net forming of titanium alloy parts

Titanium alloy has many advantages, such as low density, high specific strength, high temperature resistance, corrosion resistance, weldability and so on. It is the best material for lightening and improving the comprehensive performance of aerospace vehicles. Titanium products are widely used in many fields, such as petroleum, chemical industry, ship, biomedicine, sports and leisure, automobile industry and so on.

At present, some important parts of advanced large-scale aeroengine, such as rb199 intermediate gearbox and cf6-80c fan gearbox, are made of large-scale complex thin-walled titanium alloy integral structure precision casting. On the fuselage of military aircraft, the titanium consumption of the world’s advanced fighters, such as the B-2 bomber of the United States, mirage 2000 of France and cy-27ck fighter of Russia, has reached more than 20%. The titanium consumption of China’s fighter aircraft is also increasing, such as the titanium consumption of the J-8 series which began to serve in the 1980s is 2%, and that of the new generation fighter aircraft is 10% – 30%.

Casting is an important technology of hot forming of metal parts. Titanium alloy precision casting is an advanced method of near net forming of titanium alloy parts. This method ensures the structural integrity of the parts, simplifies the machining amount, reduces or omits the assembly welding of parts, improves the assembly efficiency, stabilizes the quality, and reduces the cost of using titanium. Due to the high chemical activity of titanium at high temperature, the quality control in the process of liquid metal forming is very difficult. Titanium alloy precision casting is a high-tech product which integrates the technology of metal materials, chemical ceramics, vacuum metallurgy, high-precision processing and testing, high-resolution nondestructive testing, computer-aided design and manufacturing technology and numerical simulation technology. At present, only a few countries in the world have mastered the technology. The technology of special-shaped thin-walled titanium alloy precision casting represents the high difficulty and high level of titanium alloy precision casting technology. In the mid-1980s, PCC, Howmet and other companies in the United States began to study the investment casting technology of large-scale thin-walled integral titanium alloy structural parts, and successively established and expanded the production conditions and scale of the investment casting of large-scale thin-walled integral titanium alloy structural parts, and successfully developed the large-scale thin-walled integral titanium alloy intermediate casing, fan casing and high-pressure compressor of F-100, cfm-56, cf6-80 and f-119 engines Case and other large thin-walled integral precision cast titanium alloy parts.

The application of domestic titanium alloy castings in the field of aviation began in the mid-1980s. After years of development and technical transformation, the domestic titanium alloy casting level is mainly higher in Beijing Institute of aeronautical materials, Baimu high tech, Anji precision casting, the Seventh Five Year Research Institute of China Shipbuilding Heavy Industry, Shenyang Casting Institute, etc. at present, there are relatively complete research and production lines. From the ninth five year plan to the eleventh five year plan, it broke through the key technology of integral precision casting of large and complex titanium alloy components for aeroengines and aerospace vehicles, and provided technical support for model development. With the application of domestic aerospace titanium alloy precision casting, it promoted the improvement of domestic titanium alloy precision casting technology level, and titanium alloy precision casting is approaching or reaching foreign quality Quantity level.