CAREER: Understanding and controlling the sintering of metal powders with nanoscale additives

职业：了解和控制纳米级添加剂金属粉末的烧结

• 批准号: 2340688
• 负责人: William LePage
• 金额: $ 68.23万
• 依托单位: University of Tulsa
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-08-01 至 2029-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2340688&HistoricalAwards=false
• 关键词: CAREER; Understanding; controlling; sintering; metal

NON-TECHNICAL SUMMARYThis CAREER project connects research on sustainable 3D printing of metals with education efforts to inspire K-12 and college students through hands-on materials science combined with inspiring stories about several highly accomplished Black scientists. The research addresses critical questions surrounding a type of metal 3D printing called binder jet. Metals are central to food, water, transportation, and healthcare, but unfortunately, metal extraction and production generates 10% of global climate change impacts. Therefore, there is a need for doing more with less for metals. Towards this, binder jet is one of the most promising ways to make sustainable metal parts at a large scale. However, binder jet is being held back by knowledge gaps about the science of sintering. Sintering happens when solid pieces of material fuse together over time, such as ice cubes sticking together in a freezer. For binder jet, sintering is critical because it fuses metal powders into the final part. Sintering is highly sensitive to the chemical composition of surfaces, yet there is little understanding about how small changes in surface compositions (such as coatings) influence the sintering of metal powders. To advance binder jet, this work uses a multi-modal approach to understand important physical and chemical processes during sintering. Overall, this research paves the way towards understanding, predicting, and controlling sintering of metals with trace additives, towards sustainable metal manufacturing. The project's integrated research and education efforts have broad impacts around society. The research itself opens new doors for scalable, sustainable metal manufacturing for automotive, aerospace, and beyond. Additionally, this project launches education initiatives that work towards full participation of people from historically underrepresented groups in STEM, along with enhanced STEM education and educator development. These efforts start locally in the Tulsa community by sharing hands-on K-12 modules on sintering, along with captivating stories about highly accomplished Black scientists. The efforts expand globally in collaboration with TeachEngineering.org and NSBE. Overall, the integrated research and education supports the growth of a diverse, globally competitive STEM workforce.TECHNICAL SUMMARYThe research of this project focuses on unlocking new paradigms for the performance and predictability of high-volume, high-efficiency metal parts fabricated by binder jet. The intellectual merit centers on establishing extensive process-structure-property relationships for sintered Al- and Ti-alloy powders with and without trace additives that enhance sintering. In detail, the investigation probes the evolution of particle interfaces, necks, grains, and pores during sintering with nanoscale additives (e.g., enhancing binders, nanoparticles, powder coatings, and infiltrants). The work uses in situ microscopy and spectroscopy to unravel coupled physical and chemical mechanisms, in light of bulk dilatometry, in situ quantification of sintering distortions, and mechanical properties after sintering. Additionally, this work studies important pore/grain-boundary interactions by introducing a new class of nanoscale infiltration, which provides a toolbox to study vacancy diffusion and pore/grain boundary interactions, as well as a new pathway for increasing the density of sintered metals. This work also quantifies part distortion via digital image correlation to calibrate models of binder jet sintering based on the material point method, a powerful way to model the physics of millions of particles. Overall, the research addresses key questions about the combined chemical/physical interactions of additives with the base metal during sintering. This opens new horizons for tailored/designer powders, nanoparticles, coatings, additives, and infiltrants. The research integrates closely with education that seeks to enrich science learning and inspire future STEM leaders. In collaboration with STEM educators in the Tulsa community, the work shares hands-on activities that bring sintering to life for students. Coupled with this hands-on learning is the sharing of stories, posters, and digital media about numerous highly accomplished Black engineers and material scientists. In collaboration with NSBE, these stories are distributed worldwide. Finally, building from the sintering research, a new laboratory module on powder metallurgy is added to the undergraduate curriculum at The University of Tulsa.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.

这个职业项目将金属可持续3D打印的研究与教育工作联系起来，通过实践材料科学，结合几位非常有成就的黑人科学家的鼓舞人心的故事，激励K-12和大学生。这项研究解决了围绕一种称为粘合剂喷射的金属3D打印的关键问题。金属是食物、水、交通和医疗保健的核心，但不幸的是，金属的开采和生产对全球气候变化的影响占10%。因此，有必要用更少的资源做更多的金属。在这方面，粘合剂喷射是最有希望大规模制造可持续金属部件的方法之一。然而，由于烧结科学方面的知识差距，粘结剂喷射一直受到阻碍。当固体材料随着时间的推移融合在一起时，就会发生烧结，比如冰块在冰箱里粘在一起。对于粘结剂喷射，烧结是至关重要的，因为它将金属粉末熔合成最终零件。烧结对表面的化学成分高度敏感，但对表面成分（如涂层）的微小变化如何影响金属粉末的烧结却知之甚少。为了推进粘结剂喷射，本工作采用多模态方法来了解烧结过程中重要的物理和化学过程。总的来说，本研究为理解、预测和控制微量添加剂金属烧结，实现可持续金属制造铺平了道路。该项目的综合研究和教育工作对社会产生了广泛的影响。这项研究本身为汽车、航空航天等领域的可扩展、可持续的金属制造打开了新的大门。此外，该项目还启动了教育倡议，致力于让历史上代表性不足的群体充分参与STEM，同时加强STEM教育和教育工作者的发展。这些努力从塔尔萨当地社区开始，通过分享K-12的烧结实践模块，以及关于非常有成就的黑人科学家的迷人故事。通过与TeachEngineering.org和NSBE的合作，这些努力将在全球范围内扩展。总体而言，综合研究和教育支持多样化，具有全球竞争力的STEM劳动力的增长。技术概述：该项目的研究重点是为粘合剂喷射制造的大批量、高效率金属零件的性能和可预测性解锁新范式。其智力优势集中在建立广泛的工艺-结构-性能关系的烧结铝和钛合金粉末添加和不添加促进烧结的微量添加剂。详细地说，该研究探讨了纳米级添加剂（如增强粘合剂、纳米颗粒、粉末涂层和渗透剂）烧结过程中颗粒界面、颈、颗粒和孔隙的演变。这项工作使用原位显微镜和光谱学来解开耦合的物理和化学机制，根据体膨胀法，烧结变形的原位量化，以及烧结后的力学性能。此外，本工作通过引入一类新的纳米级渗透来研究重要的孔隙/晶界相互作用，这为研究空位扩散和孔隙/晶界相互作用提供了一个工具，也为提高烧结金属的密度提供了新的途径。这项工作还通过数字图像相关来量化零件畸变，以校准基于材料点法的粘结剂喷射烧结模型，这是一种模拟数百万粒子物理的强大方法。总的来说，该研究解决了烧结过程中添加剂与母材化学/物理相互作用的关键问题。这为定制/设计粉末，纳米颗粒，涂层，添加剂和渗透剂开辟了新的视野。该研究与旨在丰富科学学习和激励未来STEM领导者的教育紧密结合。与塔尔萨社区的STEM教育工作者合作，该作品分享了为学生带来烧结生活的实践活动。与这种实践学习相结合的是分享许多非常有成就的黑人工程师和材料科学家的故事、海报和数字媒体。在与NSBE的合作下，这些故事将在全球发行。最后，在烧结研究的基础上，塔尔萨大学在本科课程中增加了一个新的粉末冶金实验模块。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。