[Aviaport website, September 2, 2022] Tas News Agency, Russia, reported that researchers at PNRPU have discovered a method to improve the durability of titanium alloys used to make aircraft engines.
Two-phase titanium alloys are widely used in aerospace and engine manufacturing due to their high specific strength and corrosion resistance. However, improving their durability is an urgent task in the development and production of gas turbine engine components, such as compressor blades and discs, which are subject to high tensile loads during operation.
At present, two-phase sub-microcrystalline titanium alloys have been widely used worldwide to fabricate gas turbine engine components operating under high cyclic loads and high temperatures ranging from 1 to 351 degrees Celsius. So far, however, no research has been carried out on the fatigue strength of titanium alloys in this operating temperature range. Scientists from the College of Machinery and Technology, Pelmer University of Technology, studied the properties of a Ti-6Al-4V alloy consisting of aluminum, vanadium, and titanium and evaluated the condition of the alloy at 351 C.
The researchers introduced that the test was carried out on 20 mm diameter hot-rolled Ti-6Al-4V alloy bars, which were subjected to standard heat treatment: hardening at 966 C and annealing at 676 C for 4 hours; After that, the bar is processed by four equal-diameter angular extrusions at 651 C. Finally, mechanical tensile tests are carried out at room temperature and 351 C.
All samples used for fatigue testing are made by turning and mechanical polishing and the microstructure of the material is analyzed in the longitudinal section of the bar using transmission electron microscopy.
Compared with coarse-grained alloy, Ti-6Al-4V superfine-grained alloy obtained by isometric angular pressing shows higher tensile strength and higher strength at 351 C. The study was conducted within the framework of the Academic Strategic Leadership Plan Initiative-2030 in accordance with national tasks. In 2021, Palmer University of Technology received a grant of 100 million rubles for the Initiative-2030 program. "Initiative-2030" is the largest national plan in the history of Russia to support and develop higher education institutions. Its goal is to build more than 100 advanced modern universities in Russia by 2030, as well as the National Center of science, technology, and social economic development.
