Fatigue of a fine-grained high-strength Al-6Mg-Sc alloy produced by equal-channel angular pressing

Room-temperature mechanical properties of a fine-grained high-strength Al-6Mg-Sc alloy 1570 produced by equal-channel angular pressing (ECAP) have been studied. The alloy was deformed to a true degree of deformation ɛ ∼ 8 at a temperature of 325°C. The average size and the volume fraction of new small grains after ECAP were 1.2 μm and 0.7, respectively. It is shown that the formation of a submicrocrystalline structure makes it possible to increase the yield strength and endurance limit of the alloy 1570 with respect to the microcrystalline and coarse-grained states with small loss in plasticity. The influence of the microstructure which is formed in the process of ECAP on the behavior of the material upon high-cycle fatigue is discussed.