Effect of scandium on the phase composition and mechanical properties of ABM alloys

The effect of scandium on the composition and mechanical properties of ABM-1 alloys (Al-30% Be-5% Mg) is studied. The scandium content is varied from 0.1 to 0.5 wt %. It is established that, in the studied part of the Al-Be-Mg-Sc system, an aluminum solid solution (Al) and the ScBe₁₃ compound are in equilibrium with a beryllium solid solution (Be). Magnesium dissolves in both the aluminum component and the ScBe₁₃ compound. The strengthening effect related to the decomposition of the solid solution and the precipitation of Al₃Sc cannot be extended to the strengthening of ABM-type alloys. Additions of 0.1–0.15 wt % Sc only weakly improve the mechanical properties of the alloys due to the refinement of beryllium-component grains. At high scandium contents, the strength increases insignificantly due to primary precipitation of ScBe₁₃ and the plasticity decreases simultaneously.