An ordered metallic glass solid solution phase that grows from the melt like a crystal

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• 作者：Karena W. Chapman ; Peter J. Chupas ; Gabrielle G. Long ; Leonid A. Bendersky ; Lyle E. Levine ; Fr茅d茅ric Mompiou ; Judith K. Stalick ; John W. Cahn
• 关键词：Metallic glass ; Phase transformation ; Pair distribution function analysis ; X-ray scattering
• 刊名：Acta Materialia
• 出版年：January, 2014
• 年：2014
• 卷：62
• 期：Complete
• 页码：58-68
• 全文大小：2690 K

文摘

We report structural studies of an Al-Fe-Si glassy solid that is a solid solution phase in the classical thermodynamic sense. We demonstrate that it is neither a frozen melt nor nanocrystalline. The glass has a well-defined solubility limit and rejects Al during formation from the melt. The pair distribution function of the glass reveals chemical ordering out to at least 12 脜 that resembles the ordering within a stable crystalline intermetallic phase of neighboring composition. Under isothermal annealing at 305 掳C the glass first rejects Al, then persists for approximately 1 h with no detectable change in structure, and finally is transformed by a first-order phase transition to a crystalline phase with a structure that is different from that within the glass. It is possible that this remarkable glass phase has a fully ordered atomic structure that nevertheless possesses no long-range translational symmetry and is isotropic.