Effect of Solution Temperature on Microstructure of TB6 Titanium Alloy

With the continuous development of aviation manufacturing technology, aircraft structural components show the trend of integration, large-scale and complexity, the performance of traditional steel is more and more difficult to meet the design and manufacturing needs. TB6 (nominal composition of Ti-10V-2Fe-3A1) belongs to the near β-type titanium alloys, with excellent overall performance, such as high specific strength, excellent fracture toughness, good corrosion resistance, good high temperature performance, good high fatigue performance, low elastic modulus, etc., in aerospace, ships, weapons loadout, shipboards, ships, weapons loadout, etc., in order to meet the needs of aerospace, aviation, ships, weapons loadout, etc., in the aviation industry. TB6 titanium alloy is widely used in aerospace, shipbuilding, weaponry, etc. TB6 titanium alloy is used in the manufacture of large-size, high-strength forgings, but still get a good match of toughness, fatigue resistance, and therefore become a candidate for aircraft rotor systems, landing gear, fasteners and other important parts. Solid solution aging treatment is the main heat treatment method for TB6 titanium alloy, which can significantly improve the mechanical properties of the alloy. Solid solution treatment is the first and the most critical step, so we focused on the phase composition and microstructure of TB6 titanium alloy under different solid solution temperatures and the variation rule of microstructure with temperature, in order to provide a basis for the selection of solid solution temperature in industrial production.
(1) The solid solution treatment of TB6 titanium alloy bar, with the increase of solid solution temperature, the volume fraction of primary a-phase decreases. When the content of primary a phase is low, the pinning effect decreases and the 8 matrix phase grows sharply. (2) solid solution temperature of 760, 780 ° C, TB6 titanium alloy rods in the primary α-phase content is higher, the size is larger, can play a role in pinning grain boundaries, at this time, the B matrix phase grain size is very small (<5um) (3) solid solution temperature of 820 ° C, TB6 titanium alloy rods in the primary α-phase has completely disappeared, the 8 matrix phase appeared in a large number of needle-like thermally induced α " martensitic phase.