کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7880891 | 1509593 | 2015 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Formation of high-strength βⲠprecipitates in Mg-RE alloys: The role of the Mg/βⳠinterfacial instability
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Aging reactions in Mg-RE alloys strengthen magnesium, due to the formation of metastable βⳠand βⲠprecipitates. We use first-principles calculations to critically assess binary Mg-RE (RE = Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm and Y) aging reactions, metastable phases and interfacial energy. We find the following. (i) Our calculations correctly predict the formation of different variants of βⲠphases for Mg-RE systems across the RE series. (ii) Surprisingly, the Mg/βⳠprismatic interfaces are unstable, with a negative interfacial energy. (iii) This interfacial instability implies the existence of a more energetically stable compound than βâ³, which we show to be the βⲠprecipitate. By exposing the link between Mg/βⳠprismatic interfaces and the βⲠstructure, we propose that βⲠphase formation is due to an energetic preference for an ordered arrangement of Mg and βâ³. (iv) Our Mg/βⳠinterfacial energy results also indicate that atomically thin βⳠplanar Guinier-Preston zones can form as a precursor to βⲠprecipitation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 83, 15 January 2015, Pages 75-83
Journal: Acta Materialia - Volume 83, 15 January 2015, Pages 75-83
نویسندگان
A. Issa, J.E. Saal, C. Wolverton,