Effect of pre-deformation on microstructures and mechanical properties of high purity Al–Cu–Mg alloy

The effects of pre-deformation following solution treatment on the microstructure and mechanical properties of aged high purity Al–Cu–Mg alloy were studied by tensile test, micro-hardness measurements, transmission electron microscopy and scanning electron microscopy. The micro-hardness measurements indicate that compared with un-deformed samples, the peak hardness is increased and the time to reach peak hardness is reduced with increasing pre-strain. Additionally, a double-peak hardness evolution behavior of cold-rolled (CR) samples was observed during aging. The results of TEM observation show that the number density of S′(Al2CuMg) phase is increased and the size is decreased in CR alloy with increase of pre-strain. The peak hardness and peak strength of the CR alloy are increased because of quantity increasing and refinement of S′ phase and high density dislocation.