Effect of Zr, Mn and Sc additions on the grain size of Mg–Gd alloy

• Published in: Journal of alloys and compounds 2009-02, Vol.470 (1), p.311-316
• Main Authors: Fang, X.Y., Yi, D.Q., Nie, J.F., Zhang, X.J., Wang, B., Xiao, L.R.
• Format: Article
• Language: English
• Subjects: Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Grain refinement; Materials science; Mg–Gd alloy; Other heat and thermomechanical treatments; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Precipitation; Solidification; Treatment of materials and its effects on microstructure and properties
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2008.02.069

The effect of Zr, Mn and Mn + Sc additions on the grain size of Mg–10Gd alloy has been investigated and the grain refinement mechanisms are also suggested. The results reveal that the addition of Zr results in a significant grain refinement of as-cast Mg–10Gd alloy by generating nucleants. However, it cannot restrict grain growth during homogenization treatment at 520 °C, and completely loss the grain refining effect for extruded alloy sample. Mn has a negligible effect on grain size of as-cast Mg–10Gd alloy, but α-Mn particles precipitate during homogenization treatment, which helps to refine the grains of extruded alloy sample due to α-Mn particles restricting recrystallization grain growth during extrusion. Successful grain refinement can be obtained by the addition of Mn + Sc. It is effective to refine microstructure of as-cast Mg–10Gd alloy, inhibit grain growth during homogenization treatment and also have a significant grain refining effect on extruded Mg–10Gd alloy sample, which are ascribed to the precipitation of a large number of Mn 2Sc particles.