Thermo-Mechanical Separation by Atomic Diffusion for Refinement and Recycling of Alloys

通过原子扩散进行热机械分离，用于合金的精炼和回收

• 批准号: 2311311
• 负责人: Jan Schroers
• 金额: $ 57.07万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-01 至 2026-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2311311&HistoricalAwards=false
• 关键词: Thermo; Mechanical; Separation; Atomic; Diffusion

Research supported by this grant focuses on a separation method for efficient recycling of metallic alloys, which is important for achieving a circular economy. Inefficient separation of alloy scrap leads to loss of valuable alloying elements as impurities. Current alloy separation methods are based on chemical processes, which are energy intensive and hazardous. This research develops a thermo-mechanical separation method based on differences in atomic diffusion of the alloying elements in scrap metal. The project develops theory to predict the separation rates of the alloying elements based on the laws governing diffusion for a given alloy of interest. The thermo-mechanical separation process uses moderate temperatures and pressures and is thus less energy intensive. This diffusion-based separation process lays the foundation for the development of an energy-efficient, economic, and environmentally viable method to separate elements from alloys and scrap metal, which has significant impact on the US economy. The project involves students, especially women and under-represented minorities, who are trained in multi-disciplinary research and who become the next generation of skilled engineers and scientists. The students learn advanced materials fabrication and characterization techniques, data analytics and its adaptation for solving materials science problems.Thermo-mechanical separation is the separation of alloying elements from alloys utilizing their differences in diffusion rates under applied temperature and pressure. This research is based on results from a recently developed thermo-mechanical nanomolding process, in which an alloy is extruded through nanocavities at elevated temperatures and large applied pressure gradients. Preliminary results from the thermo-mechanical nanomolding work revealed separation of elements at temperatures above approximately 40% of the liquidus temperature. This thermo-mechanical separation process is essentially controlled by differences in atomic diffusion rates of the alloy constituents. The established pressure gradient, which originates from the applied pressure and nanocavity geometry, motivates diffusion of the elements. Models based on atomic diffusion are developed that quantify the separation rate for different alloys and model predictions are compared against experimentally determined separation rates for alloys with various compositions. For the experiments, alloys are selected based on their technological importance, the element combinations resulting from mining, extraction, and recycling, the criticality of the elements, and limitations of alternative refinement and recycling processes. The outcome of the project is to reveal for which alloys the use of thermo-mechanical separation to separate desired elements is the most effective, impactful, and superior over existing technologies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该赠款支持的研究重点是一种有效回收金属合金的分离方法，这对于实现循环经济很重要。合金废料的效率低下会导致损失有价值的合金元素作为杂质。当前的合金分离方法基于化学过程，这些过程是强化和危险的。这项研究基于废金属合金元素的原子扩散差异，开发了一种热机械分离方法。该项目开发了理论，以根据有关给定利益合金的扩散的法律来预测合金元素的分离率。热机械分离过程使用中等温度和压力，因此能量密集型较少。这种基于扩散的分离过程为开发节能，经济和环境可行的方法奠定了基础，以将元素与合金和废金属分开，这对美国经济产生了重大影响。该项目涉及学生，尤其是女性和代表性不足的少数群体，他们接受了多学科研究的培训，并成为下一代熟练的工程师和科学家。学生学习先进的材料制造和表征技术，数据分析及其用于解决材料科学问题的适应性。这些机械分离是合金元素与合金的分离，利用其在施加的温度和压力下的扩散率差异。这项研究是基于最近开发的热机械纳米芯层工艺的结果，在该过程中，合金在升高的温度和较大的施加压力梯度下通过纳米腔挤出。热机械纳米质量工作的初步结果表明，在高于液体温度的40％以上的温度下，元素的分离。这种热机械分离过程基本上由合金成分原子扩散速率的差异控制。建立的压力梯度源自施加的压力和纳米腔的几何形状，激发了元素的扩散。开发了基于原子扩散的模型，以量化不同合金的分离速率，并将模型预测与具有各种组成合金的实验确定的分离速率进行比较。对于实验，合金是根据其技术重要性（通过采矿，提取和回收利用而产生的元素组合，元素的关键性以及替代性改进和回收过程的局限性）选择的。该项目的结果是揭示了使用热机械分离来分开所需元素的合金是最有效，有影响力和优于现有技术的。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响审查标准来通过评估来支持的。