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Ink-based additive manufacturing of high-entropy alloys from oxide and hydride powders

利用氧化物和氢化物粉末基于墨水增材制造高熵合金

基本信息

批准号：
2004769
负责人：
David Dunand
金额：
$ 40万
依托单位：
Northwestern University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-01 至 2024-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2004769&HistoricalAwards=false
关键词：
Ink based additive manufacturing entropy

项目摘要

Non-technical AbstractAdditive manufacturing (3D printing) of metals is revolutionizing US manufacturing for civilian and defense applications, as it allows the creation of complex-shaped objects in a single operation, typically by melting metal powders with a laser. Inspired by polymer 3D printing, this work focuses on a novel 3D printing method - 3D ink-extrusion - to create strong and lightweight metallic objects. A liquid ink containing metal-hydrogen (hydride) precursor powders and a binder is extruded into solid filaments, layer by layer, which is then heated to remove the solvent, binder and hydrogen, leaving behind a skeleton of metal powders. This skeleton is heated at a high temperature to densify the metal powders to form a strong and lightweight metallic structure. This promising approach has many key advantages as compared to the more established manufacturing methods, including lower costs, improved energy efficiency due to room-temperature printing in air, and formation of more robust metal components. The overall goal of this project is to identify and predict the critical parameters of this promising advanced manufacturing method. Furthermore, a web-based free-access video game, PRIMA (Printing Robots with Inks of Metals and Alloys), is being developed for youngsters (grades 6-12) that conveys the design and scientific principles of 3D-printing techniques in order to excite, educate, and motivate them to pursue STEM and manufacturing education and careers.Technical AbstractThis study explores the fundamental physical phenomena associated with a novel additive manufacturing approach, metallic ink-extrusion printing. In this method, inks containing mixed (Co,Cr,Fe,Ni) oxide particles or mixed (Hf,Nb,Ta,Ti,Zr) hydride particles are extrusion-printed into filaments (stand alone or assembled into micro-lattices), which are then reduced/decomposed to metals, inter-diffused to form high-entropy alloys (HEA), and sintered. Systematic studies of the co-reduction (for oxides) or co-decomposition (for hydrides), metal inter-diffusion and porosity evolution are performed as a function of particle composition, size and packing fraction, reducing species (H2 or C) for mechanistic insights. Also, the evolution of pores (remaining from partial sintering or added via foaming/space-holders) during the extrusion, homogenization and sintering of fibers, struts and micro-trusses are examined by both ex situ metallographic techniques and in situ synchrotron x-ray diffraction and tomography. These experimental data allow for the development of diffusion-based models and finite-element models in order to predict and optimize this novel manufacturing approach for specific mechanical properties based on the synthesized micro-lattices, strut porosity, phases, and geometry.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.

非技术摘要金属增材制造（3D打印）正在彻底改变美国民用和国防应用的制造业，因为它可以在一次操作中创建复杂形状的物体，通常是通过用激光熔化金属粉末。受聚合物3D打印的启发，这项工作专注于一种新的3D打印方法- 3D墨水挤出-以创建坚固而轻质的金属物体。将含有金属-氢（氢化物）前体粉末和粘合剂的液体油墨逐层挤出成固体细丝，然后加热以除去溶剂、粘合剂和氢，留下金属粉末的骨架。该骨架在高温下加热以使金属粉末致密化，从而形成坚固且轻质的金属结构。与更成熟的制造方法相比，这种有前途的方法具有许多关键优势，包括成本更低，由于在空气中室温打印而提高了能源效率，以及形成更坚固的金属部件。该项目的总体目标是识别和预测这种有前途的先进制造方法的关键参数。此外，一个基于网络的免费视频游戏，PRIMA（用金属和合金油墨印刷机器人）正在为青少年开发（6-12年级），传达3D打印技术的设计和科学原理，以激发，教育，并激励他们追求STEM和制造业教育和职业。技术摘要本研究探讨了与新型添加剂相关的基本物理现象制造方法，金属油墨挤出印刷。在该方法中，将含有混合的（Co、Cr、Fe、Ni）氧化物颗粒或混合的（Hf、Nb、Ta、Ti、Zr）氢化物颗粒的油墨挤出印刷成细丝（独立或组装成微晶格），然后将其还原/分解成金属，相互扩散以形成高熵合金（HEA），并烧结。系统的研究的共同减少（氧化物）或共同分解（为CO2），金属相互扩散和孔隙度的演变进行作为一个功能的颗粒组成，尺寸和包装分数，还原物种（H2或C）的机制的见解。此外，孔的演变（剩余的部分烧结或添加通过发泡/空间持有人）在挤出，均质化和烧结的纤维，支柱和微桁架的过程中检查两个非原位金相技术和原位同步X射线衍射和断层扫描。这些实验数据允许开发基于扩散的模型和有限元模型，以预测和优化这种新的制造方法，以获得基于合成微晶格、支柱孔隙率、相和几何形状的特定机械性能。该奖项反映了NSF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。