Structure and Mechanical Properties of Al–Ca–Mn–Fe–Zr–Sc Eutectic Aluminum Alloy after Warm Equal Channel Angular Pressing

Recently developed multicomponent eutectic alloys based on Al–Ca are promising for practical application, since they are characterized by low density and high corrosion resistance and are hi-tech in casting and easily deformed in annealed state. These alloys are strengthened by alloying with Mn, Fe, Zr, Sc, and other elements. The ultrafine grained state in aluminum alloys is achieved by severe plastic deformations, for instance, equal channel angular pressing (ECAP), significantly improving their mechanical properties. In this regard, this work is aimed at analyzing the influence of warm ECAP on the structure, mechanical properties, and thermal stability of eutectic aluminum alloy, wt %: Al–3.5Ca–0.9Mn–0.5Fe–0.1Zr–0.1Sc. ECAP is performed on as-cast alloy specimens with a diameter of 20 mm (400°C, route BC, channel intersection angle: 110°, number of passes N = 6). It is been demonstrated that, as a consequence of ECAP, a developed substructure is generated in the alloy with a high density of dislocations and deposition of Al6(Mn, Fe) and Al3Sc nanosized particles, accompanied by the fragmentation of primary Al6(Mn, Fe) coarse particles and eutectic Al4Ca particles. Such a change in structure during ECAP leads to the significant strengthening of the alloy: its strength increased 1.5–2.0 times and relative elongation decreased 1.3 times in a specimen of longitudinal cross section, slightly changing in the transversal one in comparison with the initial state.