The Structure and Mechanical Properties of an Al-1.8Mn-1.6Cu Alloy Subjected to Severe Plastic Deformation

The evolution of the structure and properties of an Al-1.8% Mn-1.6Cu alloy under deformation via high pressure torsion at room and elevated temperatures has been studied. The sequence of mechanisms of the formation of an ultrafine-grained structure has been established, and the cycling of the phase transformations, namely, the partial dissolution and precipitation of nanosized particles, has been observed. It has been found that aging, which occurs at the accumulated strain e = 6.9, suppresses the process of the grain growth under deformation at an elevated temperature. The effect of the structural-phase transformations on the strength and ductility of the alloy has been determined. As a result of deformation, the ultimate tensile strength increases by 3 times, and the yield strength increases by 7 times. Dynamic recrystallization results in a decrease in strength and in a considerable increase in the ductility of an alloy.