Russia Improves The Durability Of Titanium Alloys Used In Aviation Engine Manufacturing

Russia's Tass news agency reported that researchers at Perm State Scientific Research University of Technology (PNRPU) have discovered a way to improve the durability of titanium alloys used in the manufacture of aircraft engines.

Two-phase titanium alloy is widely used in aviation and engine manufacturing due to its high specific strength and corrosion resistance, but improving its durability is an urgent task in the development and production of gas turbine engine parts, such as compressor blades and roulette wheels, which will withstand large tensile loads during operation.

At present, two—phase sub-microcrystalline titanium alloy has been widely used worldwide to manufacture gas turbine engine components operating under high cyclic loads and high temperature environments of 201-351℃. However, so far, the fatigue strength of titanium alloys in this operating temperature range has not been studied. Scientists from the School of Mechanics and Technology of Perm University of Technology studied the properties of Ti-6Al-4V alloy composed of aluminum, vanadium and titanium, and evaluated the condition of the alloy at a maximum temperature of 351℃.

According to the researchers, the test was carried out using hot-rolled Ti-6Al-4V alloy bars with a diameter of 20 mm. They underwent standard heat treatment: hardened at a temperature of 966℃ and annealed at a temperature of 676℃ for 4 hours; after that, at a temperature of 651℃, the bars were processed in four equal-diameter angle squeezes; and finally, mechanical tensile tests were performed at room temperature and a temperature of 351℃.

All samples used for fatigue testing were made by turning and mechanical polishing, and the microstructure of the material was analyzed in the longitudinal cross-section of the rod using a transmission electron microscope.

Compared with coarse crystal alloys, Ti-6Al-4V ultrafine crystal alloys obtained by equal diameter angle extrusion exhibit higher tensile strength and higher strength at an operating temperature of 351℃. The research was conducted in accordance with the national mandate within the framework of the Academic strategic Leadership Plan “Innovation-2030”. Perm University of Technology received a grant of 100 million rubles from the ”Initiative-2030" program in 2021. "First Initiative-2030" is the largest state plan to support and develop higher education institutions in Russian history. Its goal is to build more than 100 advanced modern universities and national science, technology and socio-economic development centers in Russia by 2030.