Grain refinement in laser remelted Mg-3Nd-1Gd-0.5Zr alloy
Grain refinement in laser remelted Mg-3Nd-1Gd-0.5Zr alloy
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DOI：
10.1016/j.scriptamat.2020.03.006
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发表时间：
2020-07
影响因子：
6
通讯作者：
Duyao Zhang;D. Qiu;Suming Zhu;M. Dargusch;D. StJohn;M. Easton
中科院分区：
文献类型：
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作者：
Duyao Zhang;D. Qiu;Suming Zhu;M. Dargusch;D. StJohn;M. Easton
在基于激光的增材制造中，柱状晶粒通常具有高冷却速率和陡峭的热梯度。在这里，我们证明了细，完全等轴晶可以实现在Mg-3 Nd-1Gd-0.5Zr（EV 31）合金激光表面重熔。熔池中的晶粒从74 μm显著细化到3.5 μm，这可以归因于生长限制效应，即在凝固过程中由Zr溶质形成的成分过冷与激光表面重熔施加的高冷却速率相结合。这一新发现可用于控制增材制造应用中的晶粒形态和合金设计。
Columnar grains are normally favoured with the high cooling rate and steep thermal gradient in laser-based additive manufacturing. Here, we demonstrate that fine, fully equiaxed grains can be achieved in Mg-3Nd-1Gd-0.5Zr (EV31) alloy by laser surface remelting. The grains in the melt pool are remarkably refined from 74 µm to 3.5 µm, which can be attributed to the growth restriction effect, i.e. the constitutional supercooling formed by Zr solute during solidification in combination with the high cooling rate imposed by laser surface remelting. This novel finding could be applied for the control of grain morphology and alloy design for additive manufacturing applications.