DMREF-A Combined Experiment and Simulation Approach to the Design of New Bulk Metallic Glasses

*技术摘要*该项目支持为大块金属玻璃(BMG)合金开发一种新的、迭代的合金设计方法，以推进材料基因组倡议(MGI)的目标。这种发展需要一种综合的方法，处理液体中的动力学，这对玻璃化转变是必不可少的，以及晶化，必须避免这种情况，以形成由液体和玻璃的结构连接的平等基础上的玻璃。实现这一目标需要将实验和模拟结合起来，并提供严格的反馈。这些实验包括新型的高热速、高通量闪光DSC，用于测量整个时间-温度-转变曲线和液体脆性，以及涨落电子显微镜(FEM)，用于测量有关纳米级结构有序性的新信息，否则无法获取。模拟包括加速分子动力学以将结构与液体动力学和结晶联系起来，以及开发和发布新的反向结构确定软件工具，该软件工具结合了有限元数据和使用遗传优化和贝叶斯统计的从头算哈密顿方法。新的方法将应用于开发新的、更大的铝基金属玻璃，从Al-Sm和Al-La系统开始，通过少量合金化稳定下来。一个更大的目标是揭示成分、结构、原子动力学和结晶之间的基本新联系；这些将被用来创建通用、直观的簇设计规则，以开发新的BMG。*非技术摘要*大块金属玻璃(BMG)是可以从液体中冷却而不结晶，从而产生玻璃状、无定形固体的合金。如果温度保持在过冷液相区，足够稳定的BMG可以像塑料一样加工，通过吹塑获得净形状、复杂形状的无缝成形，并通过硬掩模压印快速制造大面积的纳米结构。新的应用包括包装、动脉支架、净水以及微型齿轮和弹簧。该项目将开发一种新的方法来发现新的BMG合金，使用最先进的实验和计算工具的迭代战略，以推进材料基因组倡议(MGI)的目标。该方法需要整合实验和模拟，并在四名研究人员之间提供严格的反馈，并具有互补的专业知识，以提供新的科学见解。这种新的计算和实验相结合的方法，结合了纳米级的结构和玻璃形成和晶化的动力学，可能会在产生独特的工具和方法组合方面产生变革性的作用，这些工具和方法可能导致为各种应用设计新的BMG合金的通用方法。该项目支持在协作环境中对学生和博士后进行综合实验和计算材料研究，并为年轻学生和公众开发外展材料和演示。该奖项由材料研究部(DMR)和数学科学部(DMS)资助。

****Technical Abstract****This project supports development of a new, iterative alloy design methodology for bulk metallic glass (BMG) alloys that advances the objectives of the Materials Genome Initiative (MGI). This development requires a comprehensive approach, treating dynamics in the liquid, which are essential to the glass transition, and crystallization, which must be avoided to form a glass, on an equal footing, connected by the structure of the liquid and the glass. Achieving this goal requires the integration of experiments and simulations with tight feedback. The experiments include novel high-thermal-rate, high-throughput flash DSC to measure entire time-temperature-transformation curves and liquid fragility, and fluctuation electron microscopy (FEM) to measure new, otherwise inaccessible information about nanoscale structural order. Simulations include accelerated molecular dynamics to connect structure to liquid dynamics and crystallization along with the development and release of a new reverse structure determination software tool incorporating FEM data and ab initio Hamiltonians using genetic optimization and Bayesian statistics. The new methodology will be applied to develop new, bulkier Al-based metallic glasses, starting from the Al-Sm and Al-La systems, stabilized by minor alloying. A larger goal is to uncover fundamental new connections between composition, structure, atom dynamics, and crystallization; these will be used to create general, intuitive, cluster design rules to develop new BMGs.****Non-Technical Abstract****Bulk metallic glasses (BMGs) are alloys that can be cooled from the liquid without crystallization, resulting in a glassy, amorphous solid. Sufficiently stable BMGs can be processed like plastics if the temperature is held in the supercooled liquid region, resulting in net-shape, seamless forming of complicated shapes by blow molding and rapid fabrication of nanostructures across large areas by hard-mask imprinting. New applications include packaging, arterial stents, water purification, and miniature gears and springs. This project will develop a new methodology for discovering new BMG alloys using an iterative strategy of state-of-the-art experimental and computational tools that advances the objectives of the Materials Genome Initiative (MGI). The method requires the integration of experiments and simulations with tight feedback between the four investigators with complimentary expertise to provide new scientific insights. The novel integrated computational and experimental approach, combining structure up to the nanometer scale and the kinetics of both glass formation and crystallization, may be transformative in yielding a unique combination of tools and approaches that may lead to a general method to design new BMGs alloys for a variety of applications. This project supports the education of students and post-docs in combined experimental and computational materials research in a collaborative environment, and development of outreach materials and demonstrations for younger students and the general public.This award is funded by the Division of Materials Research (DMR) and the Division of Mathematical Sciences (DMS).