Effect of Fe3SiAl12 particles on the fracture structure of cylindrical specimens of 6101 aluminum alloy in coarse- and ultrafine-grained states under static tension

This work presents a comparison of the fracture surface structure of cylindrical specimens after static tension to failure at room temperature in two structural states of the Al 6101 alloy: the coarsegrained structure was studied after standard heat treatment, and the ultrafine-grained structure was studied after equal-channel angular pressing according to the conform scheme (ECAP-С). In the coarse-grained (CG) state, the alloy was subjected to thermal quenching and aging to improve the elastic-plastic properties, which entailed a change in the structure, physical and mechanical properties and phase composition. To obtain the ultrafine-grained (UFG) structure, the ECAP-С method was used, which also has a great effect on improving the strength and other characteristics of the material. In earlier studies, the phase composition of the Al 6101 alloy was shown for both states. In this paper, this study is supplemented by a new result: inclusions of Fe-based particles along the interfaces of fracture pits were considered. Their overwhelming majority relative to other inclusions for the coarse-grained state was shown, which makes them one of the main causes of direct destruction, along with other factors. Studies of fractures in the UFG state did not reveal a predominant accumulation of these particles; this allowed us to conclude that when creating the UFG structure, the Fe-based particles are crushed and redistributed, and their influence is no longer one of the main factors of destruction under static loads.