Abstract An Mg-15Gd-1Zn (GZ151, wt.%) alloy was fabricated by rotating magnetic field (RMF) casting, and the microstructures were compared with those produced by conventional gravity casting (CGC). The results show that the RMF can cause significant dendritic fragmentation and resultant grain refinement of the as-cast alloy. Compared with the CGC, the RMF makes the distribution of secondary eutectic phase-(Mg, Zn)3Gd more uniform, but does not affect the phase types. Furthermore, the RMF contributes to the formations of kinks of long-period stacking ordered (LPSO) structures and dislocations, which originate from the stress and strain caused by Lorenz force. Under the solution-treated condition, the RMF casting alloy presents higher content and larger size of X phases than those of CGC alloy. Interestingly, for the first time, some curved chain-like structures consisting of short rod-like nanoscale phases were found in the grains. The short rod-like nanoscale phase is composed of many γ' precipitates confined in an elliptical domain.

中文翻译：

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旋转磁场铸造制备的 Mg-15Gd-1Zn (wt.%) 合金的微观结构和纳米相的表征

摘要 采用旋转磁场（RMF）铸造法制备了Mg-15Gd-1Zn（GZ151，wt.%）合金，并与常规重力铸造（CGC）的显微组织进行了比较。结果表明，RMF 会导致显着的枝晶破碎和铸态合金的晶粒细化。与CGC相比，RMF使二次共晶相-(Mg, Zn)3Gd的分布更加均匀，但不影响相类型。此外，RMF 有助于形成长周期堆积有序 (LPSO) 结构和位错的扭结，这源于洛伦兹力引起的应力和应变。在固溶处理条件下，RMF铸造合金呈现出比CGC合金更高的X相含量和更大的尺寸。有趣的是，第一次，在晶粒中发现了一些由短棒状纳米级相组成的弯曲链状结构。短棒状纳米级相由限制在椭圆域中的许多γ'沉淀物组成。