Professor Chen Guang of Nanjing University of Science and Technology under the support of the National 973 Program and other long-term research, has made strides in the new type of aerospace materials titanium aluminum alloy. On June 20th, relevant results were published online on Natural Materials. Its room temperature tensile plasticity, yield strength, high temperature creep resistance, and temperature capability are among the leading international performance indicators, exceeding 1-2 orders of magnitude for similar materials in the United States. In 2007, the Boeing 787 was successfully tested. This new type of aircraft can save 20% of fuel, reduce nitrogen oxide (NOx) emissions by 80%, and significantly reduce noise, raising global concerns. This aircraft engine developed by the United States General Electric (GE) company, the use of Ti-48Al-2Cr-2Nb (hereinafter referred to as 4822) alloy instead of nickel-based superalloy to create the last two low-pressure turbine blades. This is the first time that titanium-aluminum alloys have been used in aero engines. The 4822 alloy used by GE is also not perfect. Its room temperature tensile plasticity is less than 2%. Although it is enough to disregard other intermetallic compounds, it is still too brittle compared with nickel-based alloys. Therefore, GE used it on the end-stage two-stage blade with the lowest ambient temperature and risk factor, so that even if it breaks, it will not cause the entire aircraft to lose control. The Americans did this by stressing that the density of titanium alloys is only half that of nickel-based alloys. In aircraft engines with a weight-per-gram reduction unit, GE has reduced the weight of a single engine by about 200 pounds, making it a sensational development in aviation and materials. Therefore, titanium-aluminum alloy is now recognized as the best new lightweight structural material to replace nickel-base superalloys. Professor Chen Guang's research results achieved three major breakthroughs in material properties: First, the tensile plasticity at room temperature and the yield strength are greatly improved, reaching as high as 6.9% and 708 MPa, respectively, and the tensile strength is as high as 978 MPa, achieving an excellent combination of high strength and high plasticity. The second is excellent creep resistance. Third, the capacity of bearing temperature has been greatly improved. The aero-engine is hailed as the heart of the aircraft and is constrained by the lack of basic research capabilities. At present, China’s civil aviation engines basically rely on imports. Although military fighter engines have made some progress, the key performance indicators are still far behind those of developed countries. Among them, the turbine blade is the most critical core component in the aeroengine. Its temperature bearing capacity directly determines the performance of the engine, especially the thrust-to-weight ratio. Although traditional Ni-base alloys have good performance in all aspects, its biggest drawback is that it is too heavy, which directly leads to an increase in the energy efficiency ratio of the engine. Therefore, scientists from all over the world have never stopped their efforts to find suitable materials for aeroengines. “Generation material generation engine.†Kang Jianxiong, deputy director of the turbine design department of the China Aviation Power Machinery Research Institute, said that PST titanium and aluminum alloys used at temperatures above 900°C can already compete with nickel-base alloys. It can be used not only in blades, but also in blades. It is also expected to be used in components such as turbine disks and high-pressure compression turbines. A new type of material, from the laboratory to the aircraft, has a long way to go. According to estimates by Chen Guang, PST titanium aluminum alloy has 5 to 10 years of application. (Reporter Zhang Hao)
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My new titanium alloy is expected to be used in aero engines