Evertz Simon, Music Denis, Schnabel Volker, Bednarcik Jozef, Schneider Jochen M
Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, 52074, Aachen, Germany.
Laboratory for Nanometallurgy, ETH Zürich, Vladimir-Prelog-Weg 5, 8093, Zurich, Switzerland.
Sci Rep. 2017 Nov 16;7(1):15744. doi: 10.1038/s41598-017-16117-7.
Metallic glasses are promising structural materials due to their unique properties. For structural applications and processing the coefficient of thermal expansion is an important design parameter. Here we demonstrate that predictions of the coefficient of thermal expansion for metallic glasses by density functional theory based ab initio calculations are efficient both with respect to time and resources. The coefficient of thermal expansion is predicted by an ab initio based method utilising the Debye-Grüneisen model for a Pd-based metallic glass, which exhibits a pronounced medium range order. The predictions are critically appraised by in situ synchrotron X-ray diffraction and excellent agreement is observed. Through this combined theoretical and experimental research strategy, we show the feasibility to predict the coefficient of thermal expansion from the ground state structure of a metallic glass until the onset of structural changes. Thereby, we provide a method to efficiently probe a potentially vast number of metallic glass alloying combinations regarding thermal expansion.
金属玻璃因其独特性能而成为很有前景的结构材料。对于结构应用和加工而言，热膨胀系数是一个重要的设计参数。在此我们证明，基于密度泛函理论的从头算计算对金属玻璃热膨胀系数的预测在时间和资源方面都是高效的。利用德拜 - 格律乃森模型，通过一种基于从头算的方法对一种具有明显中程有序的钯基金属玻璃的热膨胀系数进行了预测。通过原位同步加速器X射线衍射对这些预测进行了严格评估，观察到了极好的一致性。通过这种理论与实验相结合的研究策略，我们展示了从金属玻璃的基态结构预测热膨胀系数直至结构变化开始的可行性。由此，我们提供了一种方法，可高效探究大量金属玻璃合金组合的热膨胀情况。
