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，因为它允许在一次操作中创建复杂形状的物体，通常是通过使用激光熔化金属粉末。受聚合物 3D 打印的启发，这项工作重点关注一种新颖的 3D 打印方法 - 3D 墨水挤出 - 来制造坚固且轻质的金属物体。将含有金属氢（氢化物）前体粉末和粘合剂的液体墨水逐层挤出成固体细丝，然后加热以除去溶剂、粘合剂和氢气，留下金属粉末的骨架。该骨架在高温下加热，使金属粉末致密化，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，包括更低的成本、由于在空气中进行室温打印而提高的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景的先进制造方法的关键参数。此外，正在为青少年（6-12 年级）开发一款基于网络的免费视频游戏 PRIMA（金属和合金墨水打印机器人），该游戏传达 3D 打印技术的设计和科学原理，以便激发、教育和激励他们追求 STEM 和制造教育和职业。技术摘要本研究探讨了与新型增材制造方法（金属墨水挤出打印）相关的基本物理现象。在这种方法中，含有混合（Co、Cr、Fe、Ni）氧化物颗粒或混合（Hf、Nb、Ta、Ti、Zr）氢化物颗粒的油墨被挤出印刷成细丝（独立或组装成微晶格），然后被还原/分解为金属，相互扩散形成高熵合金（HEA），并进行烧结。对共还原（对于氧化物）或共分解（对于氢化物）、金属相互扩散和孔隙度演变进行系统研究，作为颗粒组成、尺寸和堆积分数、还原物质（H2 或 C）的函数，以实现机械性能见解。此外，通过异位金相技术和原位同步加速器 X 射线检查在纤维、支柱和微桁架的挤出、均质化和烧结过程中孔的演变（部分烧结留下的或通过发泡/空间保持器添加的）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，以便基于合成的微晶格、支柱孔隙率、相和几何形状来预测和优化这种新颖的制造方法的特定机械性能。该奖项反映了通过使用基金会的智力价值和更广泛的影响审查标准进行评估，NSF 的法定使命被认为值得支持。