Influence of structure to plastic deformation resistance of aluminum alloy 1560 after groove pressing treatment

As a result of groove pressing treatment the influence of structural changes was investigated in the samples made of rolled sheet of an aluminum alloy 1560 in the presented research work. Mechanical properties of material was investigated experimentally in quasi-static uniaxial tensile tests at a speed of deformation of s(-1) in the as-received condition and after severe plastic deformation by groove pressing technique. Change of microhardness value of rolled sheet 1.5 mm in thickness has been determined in a sample after four cycles of groove pressing in comparison with a sample in as-received condition. It was determined that after four treatment cycles, yield strength and fracture resistance of rolled alloy sheet increased in 1.4 and 1.5 times, respectively, and microhardness value increased in similar to 2.7 times. Hardening of the studied alloy was accompanied by relative reduction of ultimate strength deformation from 21% in a sample made from aluminum alloy 1560 in as-received condition to 16.7% in a sample made of aluminum alloy 1560 after four groove pressing cycles. Analysis of change results in the grain structure was made by electron backscatter diffraction method. Groove pressing technique processing of aluminum alloy 1560 leads to the formation of bimodal grain structure, which consists of coarse elongated grains and aggregates of micron and submicron sizes with an equiaxial shape. The obtained data are consistent with the experimental data of strength characteristics increase of aluminum alloy 1560 by comparison with other methods of severe plastic deformation.