Effects of coarse Al2CuLi phase on the hot deformation behavior of Al–Li alloy

Abstract The effects of coarse T1 phase (Al2CuLi), produced by homogenization, on the hot deformation behavior of Al–Li alloy was studied using uniaxial compression. Stress-strain curves, constitutive equations and processing maps were established, and the microstructure was observed by EBSD, SEM and TEM. The homogenized alloy with coarse T1 phase presents lower flow stresses and significantly lower deformation activation energy than the solution treated alloy. Besides, the homogenized alloy exhibits the same hot-working region with the solution treated alloy, and possesses lower power dissipation efficiencies. The EBSD investigation confirms the formation of massive recrystallized grains in the homogenized alloy at 340–460 °C, revealing the coarse T1 phase can promote dynamic recrystallization through particles stimulated nucleation. In contrast, the solution treated alloy is softened dominantly via dynamic recovery at 340–490 °C. This work not only merits the beneficial effects of the coarse T1 phase but also suggests the feasibility of obtaining accelerated recrystallization kinetic and good workability during hot working of Al–Li alloys.