Quantum mechanically guided design of ultra strong and damage tolerant glasses

钴基大块玻璃合金具有较高的机械强度和刚度以及良好的软磁性能。Co43Fe20Ta5.5B31.5的强度为5185 GPa，弹性模量为268 GPa [Inoue et al., Nat. Mater. 2003]。金属玻璃是根据现象学玻璃形成规律发展起来的。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。本项目旨在识别和理解这些原理，以实现未来基于知识的高强度、高刚度和高韧性金属玻璃设计。基于从头算分子动力学模拟[j]。:电导率。确定、合成并表征了适合实验的Co43Fe20Ta5.5B31.5-xNMx （NM = C， N， O）和Co43Fe20-yTMyTa5.5B31.5 （TM = Zr, Nb, Mo, Hf， W）金属玻璃合金体系的刚度和韧性。我们系统地探讨了化学成分对电子结构、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钴基金属玻璃。它可以在有限的实验中有效地研究多组分系统。将从头算分子动力学数据与实验数据进行了刚度、弹塑性跃迁、密度和化学有序度的比较。通过原子探针层析成像（LEAP 3000X HR）和选定区域电子衍射分析拓扑和化学有序。设想基于这一理论与实验相结合的研究策略，可以确定实现未来高强度、高刚度、高韧性金属玻璃知识化设计所需的基本物理和化学设计原理。

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.