OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 24 No. 4 2022 Results and discussion The changing of aluminum content in AlxCoCrFeNi alloys system makes it possible to control the phase composition of materials. Well known, that difference of the phase composition has a signifi cant effect on the mechanical properties of the alloys. Figure 1 shows the compression curves of the studied alloys. The Al0.6CoCrFeNi alloy has a higher ductility compared to the AlCoCrFeNi alloy. At the maximum applied stress of ~2,500 MPa, the deformation of the AlCoCrFeNi alloy was 30 %, and the deformation of the Al0.6CoCrFeNi alloy was 53 %. According to the optical metallography results, the structure of the alloys also underwent signifi cant changes after plastic deformation (Figure 2). In both cases, a change in the shape of the grains is observed. Furthermore, the plastic deformation of the Al0.6CoCrFeNi alloy with a compression ratio of 53 % (Figure 2d) does not lead to appearance of cracks. However, in the case of the AlCoCrFeNi alloy (Figure 2, c), fracture traces appear even after compression by 12 %. Well known that residual stresses are balanced in different volumes of the deformed body and affect to the position and shape of the diffraction peaks. Macrostresses are balanced in the macro-volumes of the material and lead to a change of the positions of the diffraction maxima and the shape of the diffraction rings. Microstresses are balanced within several crystallites or blocks and lead to a change in the shape (width) of the diffraction peaks. Static stresses are balanced within groups of atoms and lead to an increase of diffuse scattering and, accordingly, an increase of the background intensity. In terms of the mechanical properties of the designed product, macrostresses are the most important since it can lead to warpage. a b Fig. 1. Compression curves of AlCoCrFeNi (a) и Al0.6CoCrFeNi (b) alloys
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