Inducing TiAl3 in titanium alloys by electric pulse heat treatment improves mechanical properties

Titanium alloy is well known with its susceptibility to adiabatic shear banding, which limits its application unavoidably. In the current study, the electric pulse heat treatment is employed to modulate lamellar microstructure of a newly developed titanium alloy Ti–6Al–4V–4Zr–Mo. It is found that novel lath-shaped and nano-sized TiAl3 precipitations are formed within alpha plates. Diffusion of Al atoms, promoted by the electric pulse, and subsequent local atom accumulation attribute the underlying formation mechanism of TiAl3, which induces an unusual refinement effect by dividing the alpha plates into much tinier pieces, and provides an intriguing effect to dramatically reduce the susceptibility to adiabatic shear banding.

► EPH treatment is employed to modulate microstructure of titanium alloy.
► TiAl3 precipitations induce an unusual refinement behavior for alpha plates.
► Diffusion and accumulation of Al atoms attribute the formation mechanism of TiAl3.
► The susceptibility to adiabatic shear banding is reduced significantly.