Grain Boundary Segregation of Rare-Earth Elements in Magnesium Alloys

By Joseph D. Robson, Sarah Haigh, B. Davis, D. Griffiths. Metallurgical and Materials Transactions. A, 2015

143 citations recorded by the source corpus.

Small additions of rare-earth (RE) elements have been shown to have a powerful effect in modifying the texture of wrought magnesium alloys, giving a highly beneficial effect in improving their formability. Recent work has shown that segregation of RE atoms to grain boundaries is important in producing this texture change. In this work, two Mg-RE systems have been studied Mg-Y and Mg-Nd using high-resolution scanning transmission electron microscopy that permits both imaging and elemental analysis with a spatial resolution of better than 0.1 nm. The Mg-Y alloy, where the solubility and level of addition are relatively high, showed the RE texture change effect. This was accompanied by clustering of Y on the grain boundaries, consistent with previous studies of the Mg-Gd system. The Mg-Nd alloy, where the solubility and level of addition are relatively low, showed no texture change and no segregation. In this case, impurity elements binding the RE into insoluble particles, rendering it ineffective. The results are analyzed by modifying a previous model for the solute drag effect on boundaries expected due to the RE additions. This predicts that both Gd and Y will strongly inhibit boundary motion, with Gd being approximately twice as effective as Y.

Subfields: Aerospace Engineering, Biomaterials, Mechanical Engineering

View Paper: https://www.semanticscholar.org/paper/864f5c8312541a4df01de935d929e2295836901b

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In Aerospace Engineering

1. W. M. Rainforth
2. Junheng Gao
3. Dikai Guan
4. Bradley Wynne
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In Biomaterials

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In Mechanical Engineering

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4. Bradley Wynne
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Citations in the corpus

• Individual effect of recrystallisation nucleation sites on texture weakening in a magnesium alloy: Part 1- double twins (2017, background): “Although solute drag may not retard static recrystallisation effectively at high temperature, it could slow down the recrystallised GBs mobility during the subsequent grain growth stage [1,24,25,39].”