Atomistic Studies of Concentrated Multicomponent Nickel-Based Alloys Utilizing Atom-Probe Tomography and Vacancy-Mediated Lattice Kinetic Monte Carlo Simulations

利用原子探针断层扫描和空位介导的晶格动力学蒙特卡罗模拟对浓多组分镍基合金进行原子研究

• 批准号: 1610367
• 负责人: David Seidman
• 金额: $ 45万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1610367&HistoricalAwards=false
• 关键词: Atomistic; Studies; Concentrated; Multicomponent; Nickel

Non-Technical AbstractThis research program is focused on how phase separation occurs in nickel-aluminum based alloys, which are the physical bases of all nickel-based superalloys and which may contain up to 12 different alloying elements, with each element serving a particular purpose. Nickel-based superalloys are utilized for turbine blades and disks, which are at the heart of both military and commercial jet engines as well as natural gas-fired turbine engines that produce electricity, and which operate at extremely elevated temperatures. To study these materials at an atomic scale in this technologically important class of alloys, extensive utilization will be made of the Northwestern University Center for Atom-Probe Tomography. Atom-Probe Tomography is a unique technique that allows characterizing materials at the sub-nano to nanoscale. Applying this technique to nickel-aluminum based alloys will allow understanding the development of the final microstructure, which is of great significance and technological importance for controlling the physical and mechanical properties of a material at microscopic and macroscopic length scales. This work will help train the next generation of materials scientists in this state of the art technique. Technical AbstractThe kinetic pathways in the different stages of alloy phase separation (nucleation, growth and coarsening) of concentrated multicomponent nickel-based supersaturated solid-solutions are critical for understanding the development of the final microstructure, which is of great significance and technological importance for controlling the physical and mechanical properties of a material at microscopic and macroscopic length scales. To study the temporal evolution of phase separation, the PI will perform correlative experiments utilizing ultraviolet laser-assisted atom-probe tomography (APT) and vacancy-mediated lattice-kinetic Monte Carlo (LKMC) simulations, which permit understanding this evolution on an atomic scale. This work will also employ microhardness measurements and transmission electron microscopy experiments. The temporal evolution is studied starting with the clustering of atoms to form embryos exhibiting short-range order (SRO), which are the precursors of stable nuclei (precipitates); thus, allowing study of SRO and then precipitates with long-range order (LRO) and observation of growth and coarsening. All of the 10 plus physical parameters, for describing the temporal evolution, are measured via APT and simulated via LKMC simulations. Additionally, the PI will study the evolution during the quasi-steady coarsening regime and compare these results with the Philippe-Voorhees (P-V) mean-field modeling of multicomponent alloys (2013) for selected ternary and quaternary nickel-based alloys, which involves the use of both thermodynamic and mobility data bases. This will yield a realistic approach to quasi-stationary coarsening of a polydispersed distribution of precipitates embedded in a matrix. This multipronged experimental and simulation approach yields information at the atomic scale through the continuum length scale.

非技术抽象的研究计划集中在基于镍铝的合金中如何发生相位分离，这些合金是所有基于镍的超合金的物理基础，并且可能包含多达12种不同合金的元素，每个元素都具有特定的目的。以镍的超级合金用于涡轮叶片和磁盘，它们是军用和商用喷气发动机的核心，以及产生电力且在极高温度下运行的天然气发动机发动机。 为了以原子量的规模研究这些在技术上重要的合金类中，将由西北大学原子 - 探针层析成像中心进行广泛的利用。原子探针断层扫描是一种独特的技术，它允许在纳米级的子纳米处表征材料。 将此技术应用于基于镍铝合金的合金将允许理解最终微观结构的发展，这对于控制材料在显微镜和宏观长度尺度上的物理和机械性能具有重要意义和技术重要性。这项工作将有助于培训这种最先进技术的下一代材料科学家。技术摘要在合金相分离（成核，生长和变高）的不同阶段的动力学途径对理解最终微观结构的发展至关重要，这对于在微观和宏观尺度上控制物质的物理和机械特性具有重要意义和技术重要性。为了研究相分离的时间演化，PI将使用紫外线激光辅助原子螺旋桨层造影术（APT）和空位介导的晶状体型蒙特卡洛（LKMC）模拟进行相关实验，从而可以在原子尺度上理解这种进化。 这项工作还将采用微硬度测量和透射电子显微镜实验。从原子的聚类开始以形成表现出短距离顺序（SRO）的胚胎开始，研究时间进化，这是稳定核的前体（沉淀物）。因此，允许研究SRO，然后以远距离顺序（LRO）和生长和变厚的观察进行沉淀。用于描述时间演化的所有10个Plus物理参数均通过APT测量，并通过LKMC模拟进行模拟。此外，PI将研究准稳态变厚方案期间的演变，并将这些结果与多组分合金（2013）的Philippe-Voorhees（P-V）的均值模型（2013年）进行比较，用于选定的三元和基于镍镍的合金，涉及使用热力学和迁移性数据碱的使用。 这将产生一种现实的方法来使嵌入基质中的沉淀物的多分散分布的准平稳化。这种多收益的实验和模拟方法通过连续长度尺度在原子尺度上产生信息。