Microstructure evolution and mechanical properties of vanadium-bearing Ti–22Al–26Nb alloys obtained by controlled cooling from a single B2 region

To investigate the role of Vanadium element in Ti₂AlNb-based alloy, Ti–22Al–26Nb-xV (x = 0, 2, 8) alloys were cooled from the B2 single-phase temperature (1300 °C) at controlled process parameters. The isothermal preheating in the B2 single-phase zone contributes to the homogenization of microstructure and the elimination of micro-segregation in subsequent microstructure evolution. Two typical microstructures after temperature-controlled cooling experiments can be obtained: B2+O two-phase and α₂+B2+O three-phase microstructures. The effects of Vanadium content and cooling rate on phase transformation and microstructure evolution were analyzed. The crystallographic relationship between B2, α₂ and O phases was identified as follows: {011}_B2/β//{0001}_α2, <111> _B2/β//<11 2‾ 0>_α2, {110}_B2/β//{001}_O, < 1‾ 11> _B2/β//<1 1‾ 0>_O, {0001}_α2//{001}_B2/β, <11 2‾ 0>_α2//<110> _O. Last, the compression tests of these heat-treated samples were performed, and the microstructure-dependent mechanical properties were discussed.