Abstract
This paper presents some research information on the effects of Zn, Cu and Ni on the microstructure and mechanical properties of as-cast Mg-2Dy (at.%) alloys. The Mg-2Dy alloy is composed of α-Mg and Mg24Dy5 phases. With the addition of 0.5at.%Zn, 0.5at.%Cu and 0.5at.%Ni, respectively, besides α-Mg, the long period stacking order (LPSO) phases containing Zn, Cu, and Ni precipitated in the α-Mg interdentritic boundary. The addition of Ni effectively refined the dendrite arm spacing. The as-cast Mg-2Dy-0.5Ni alloy exhibited the best tensile strengths and elongation. The better mechanical properties were mainly attributed to small secondry dendrite arm spacing (SDAS) and high volume fraction of LPSO phases.