Plastic properties of aluminium alloy semi-products made by the methods of severe plastic deformations

摘要

The paper presents the results of the investigation of the influence of forming semi-products by the methods of severe plastic deformations (SPD), such as: equal-channel angular pressing (ECAP) or hydrostatic extrusion (HE) on the mechanical properties of aluminium as well as 5483 and 7475 alloys. Plasticity of the materials has been determined in a compression test; the influence of deformation speed on the character of the work-hardening curve has also been determined. In previous investigations, the limit temperature of forming not causing significant grain growth has been found to be 250 °C . That is why the work-hardening curves have been determined only up to that temperature. Semi-products after the processes of ECAP and HE have higher hardness and yield stress as compared to the classic commercial alloys. The materials under investigation are plastic and make it possible to form products at a temperature lower than that of recrystallization.