Sc and Sc–Zr effects on microstructure and mechanical properties of Be–Al alloy

Abstract

Herein, we investigated the effects of Sc and Sc–Zr on the microstructure and mechanical properties of Be–Al alloy, showing that Sc alloying resulted in Be grain refinement and reduced the secondary dendritic arm spacing (SDAS) of these grains by 1/3, whereas Sc–Zr alloying further decreased the SDAS to 7.5 µm and afforded equiaxed/cellular-like morphology with further refined Be grains. The above alloying resulted in the formation of intermetallic compounds (Be 13 Sc, Be 13 Zr, and Al 3 (Sc 1– x Zr x )), increasing the macrohardness of the Be–Al alloy, with the microhardness and elastic modulus of the Be phase increasing to a larger extent than those of Al. Importantly, Sc–Zr alloying resulted in better microstructure modification and mechanical reinforcement than Sc alloying.