Effect of near isothermal forging on the microstructure of Ti3Al/TC11 welding interface

Abstract

The as-forged Ti3Al-based alloy and TC11 titanium alloy were welded by electron beams in vacuum, and then they were processed using near isothermal forging and gradient heat treatment. The experimental results show that the near isothermal forging processing parameters have little effect on the phase constitution of the weld. The weld consists of Ti2AlNb, MoNb, Nb3Al, and TiAl3 phases as well as the two main phases of α and α2. However, the near isothermal forging processing parameters have significant effect on the shape, size, and volume fraction of α and α2 phases of the welding interface. The sizes of the α and α2 phases increase as the strain rate decreases. Because the distortion energy of the lattice and the volume fraction of the grains occurring in dynamic recrystallization increase with an increase in deformation, the sizes of the α and α2 phases of the welding interface decrease.