Al3003 is an aluminium alloy in which the principal alloying element is manganese. It is one of the most popular general-purpose aluminium alloys, used for applications such as sheet metal work, stampings, fuel tanks, chemical equipment, pressure vessels and electronics, among others. In many of these applications, the assemblies made of this alloy are subjected to thermomechanical loading in a wide range of strain rates and temperatures. This alloy is non-heat-treatable for precipitation hardening and its mechanical properties are commonly enhanced by a combination of work hardening and annealing [1]. At the microstructural level, work hardening is explained by the increase in resistance to dislocation movement caused by the multiplication and accumulation of dislocations produced during plastic deformation [2]. At the same time, this defect density serves as driving force for a series of nonequilibrium transformation phenomena, namely recovery, recrystallisation and grain coarsening, which result in the softening of a previously hardened material. The kinetics of this phenomena is controlled by temperature and holding time [3]. To evaluate and characterize the mechanical response of Al3003 for different thermomechanical histories, a series of uniaxial compression tests at temperatures ranging from the ambient temperature to 550 °C, and at strain rates between  $5 \times 10^{-5} s^{-1}$ to $5 \times10^{-5} s^{-1}$ have been performed, allowing the obtention of behaviour curves like those observed in figure 1. The hardening/softening response will be explained based on the microstructural evolution of the samples as observed by electronic microscopy analysis (SEM, EBSD).