Quantum mechanically guided design of ultra strong and damage tolerant glasses

钴基大块非晶合金具有高的机械强度和刚度以及良好的软磁性能。Co43Fe20Ta5.5B31.5表现出5185 GPa的强度和268 GPa的弹性模量[Inoue等人，Nat.板牙. 2003年]。金属玻璃的发展主要基于唯象玻璃形成规律。由于玻璃态材料的量子力学计算具有挑战性，迄今为止，大多数金属玻璃的拓扑描述都是基于反向蒙特卡罗方法。因此，金属玻璃的基本物理和化学材料设计原则尚未确定。本计画的目的在于辨识并了解这些原理，以实现未来高强度、高刚度、高韧性金属玻璃的知识化设计。基于从头算分子动力学模拟[Hostert等人，J.物理学：Cond. Mater. 2011]测定、合成和表征了适合实验的Co 43 Fe 20 Ta5.5B31.5-xNMx（NM = C、N、O）和Co 43 Fe 20-yTMyTa5.5B31.5（TM = Zr、Nb、Mo、Hf、W）金属玻璃合金系统的刚度和韧性。我们系统地探讨了化学组成对电子结构、拓扑结构、刚度和韧性的影响。我们将使用薄膜组合方法合成Co基金属玻璃。它使一个多组分系统在有限数量的实验有效的调查。将从头算分子动力学数据与刚性、弹塑性转变、密度和化学序的实验数据进行了比较。拓扑和化学有序分析原子探针层析成像（LEAP 3000 X HR）和选区电子衍射。可以预见，基于这种理论和实验相结合的研究策略的基本物理和化学的设计原则，需要实现未来的知识为基础的设计具有高强度和刚度以及韧性的金属玻璃可以确定。

Co-based bulk glassy alloys have high mechanical strength and stiffness as well as good soft magnetic properties. Co43Fe20Ta5.5B31.5 exhibits a strength of 5185 GPa and an elastic modulus of 268 GPa [Inoue et al., Nat. Mater. 2003]. Metallic glasses were developed mostly based on phenomenological glass forming rules. As quantum mechanical calculations of materials in the glassy state are challenging, most topological descriptions of metallic glasses are so far based on reversed Monte Carlo approaches. Hence, basic physical and chemical materials design principles for metallic glasses have not been identified. This project aims at identifying and understanding these principles to realize future knowledge-based design of metallic glasses with high strength and stiffness as well as toughness. Based on ab initio molecular dynamics simulations [Hostert et al., J. Phys.: Cond. Mater. 2011] stiffness as well as toughness of Co43Fe20Ta5.5B31.5-xNMx (NM = C, N, O) and Co43Fe20-yTMyTa5.5B31.5 (TM = Zr, Nb, Mo, Hf, W) metallic glasses alloy systems suitable for experiments are determined, synthesized and characterized. We systematically explore the influence of the chemical composition on the electronic structure, topology, stiffness and toughness. We will synthesize Co-based metallic glasses using a thin film combinatorial approach. It enables the efficient investigation of a multi-component system in a limited number of experiments. The ab initio molecular dynamics data are compared to the experimental data of the stiffness, the elastic plastic transition, the density and the chemical order. Topological and chemical ordering is analyzed by atom probe tomography (LEAP 3000X HR) and by selected area electron diffraction. It is envisioned that based on this combined theoretical and experimental research strategy the basic physical and chemical design principles required to realize future knowledge-based design of metallic glasses with high strength and stiffness as well as toughness can be identified.