Natural Aging of Aluminum Alloy 2024 After Severe Plastic Deformation

This paper provides a laboratory-level evaluation of the cryogenic strain potential of aluminum alloy 2024 after severe plastic deformation by equal channel angular pressing method. Characteristics of the samples were determined by transmission electron microscopy, tensile tests and microhardness determination. Natural aging at room temperature for 24 days resulted in a change in the microhardness of aluminum samples. Thus, in samples strained at room temperature, the decrease in microhardness occurs by 250 MPa and in samples strained at a cryogenic temperature by 110 MPa. This can be explained by return processes which improve the characteristics of plasticity. As a result, a thermo-mechanical treatment mode was developed for aluminum alloy, including quenching, straining by equal channel angular pressing at liquid nitrogen temperature, followed by natural aging, which allows to obtain samples with certain parameters of structural strength of the alloy.