GOALI: Understanding the Physical Mechanisms of Distortion and Controlling its Effects in Sintering-based Additive Manufacturing Processes

目标：了解变形的物理机制并控制其在基于烧结的增材制造工艺中的影响

• 批准号: 2328678
• 负责人: Rahul Panat
• 金额: $ 65万
• 依托单位: Carnegie-Mellon 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: 2024-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2328678&HistoricalAwards=false
• 关键词: GOALI; Understanding; Physical; Mechanisms; Distortion

Additive Manufacturing (AM) involves building of 3D objects by adding layer upon layer of material. Sintering of nano/microparticles is one of the critical steps in many AM processes. This step often leads to shape distortion of AM parts, preventing their near-net-shape manufacture. This Grant Opportunities for Academic Liaison with Industry (GOALI) award supports an integrated experimental and theoretical research to fully understand the mechanisms controlling shape distortion in AM. Such understanding will enable identification of critical AM process parameters to either eliminate distortions when undesirable, or to control distortions to enable novel methods of 4D printing. The outcomes of this project have the potential to reduce cost of AM parts, positively impacting aviation, automotive, and nuclear industries. The precision manufacturing enabled by this work will help establish American leadership in Industry 4.0. As AM is adopted in aerospace industry for fabrication of large parts (e.g., aircraft wings), research outcomes from the project will be key enablers for their fabrication. Near-net-shape AM will eliminate post-processing, leading to a reduction in greenhouse gas emissions. The project will involve collaboration with K-12 students from disadvantaged schools to expose them to STEM-based careers. The project will train a diverse US workforce in the interdisciplinary areas of advanced manufacturing, computational sciences, and nanomaterials through the development of interdisciplinary curricula.This project focuses on identifying the mass transport mechanism(s) and their relative contributions to shape distortion in sintering-based AM processes. The preliminary studies have demonstrated that a long-range mass transport must be operational during part distortion in sintering. The experimental portion of the research will consist of fabrication of 3-D structures of nano and/or microparticles, operando microscopy to observe movement of particle clusters in Focused Ion Beam (FIB)-cut sections during sintering, and extensive ex-situ observations post sintering. A closely coupled modeling effort will involve the development of a mesoscale phase-field model to discover the physical mechanisms of long-range mass transport in non-homogeneous sintering. In addition, a macroscale continuum model will be developed that has capabilities to simulate full scale parts and predict shape distortion and/or residual stresses for industrially relevant configurations. A predictive model will be developed to quantify the effect of parameters such as particle size(s), binder content, constraints, and temperature gradients on part distortion. The research will establish and experimentally validate design guidelines to minimize distortion during sintering of AM parts. Lastly, inhomogeneous sintering will be introduced as a completely new technique to achieve controlled distortion, i.e., 4D printing.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.

添加剂制造（AM）涉及通过在材料层上添加层来构建3D对象。 纳米/微粒的烧结是许多AM过程中的关键步骤之一。此步骤通常会导致AM零件的变形，从而阻止其近乎净形状的生产。这项与行业联络的赠款机会（Goali）奖支持了一项综合的实验和理论研究，以完全了解AM中控制形状失真的机制。这种理解将使关键的AM过程参数能够在不希望的情况下消除扭曲，或者控制扭曲以启用4D打印的新方法。该项目的结果有可能降低AM零件的成本，从而积极影响航空，汽车和核行业。这项工作实现的精确制造将有助于在行业4.0中建立美国领导力。正如AM在航空航天行业所采用的用于制造大型零件（例如飞机机翼）一样，该项目的研究结果将是其制造的关键推动力。近网状AM将消除后处理，从而减少温室气体排放。该项目将涉及与弱势学校的K-12学生合作，以使他们接触基于STEM的职业。该项目将通过跨学科课程的开发在高级制造业，计算科学和纳米材料的跨学科领域培训各种各样的劳动力。该项目着重于确定基于杀伤的AM过程中的大规模运输机制及其对形状畸变的相对贡献。初步研究表明，在烧结的部分变形过程中，远程质量转运必须是运行的。 该研究的实验部分将包括制造纳米和/或微粒的3-D结构，操作数学显微镜，以观察烧结过程中聚焦离子束（FIB）切割部分中粒子簇的运动，并在烧结后进行了广泛的前Situ观测。紧密耦合的建模工作将涉及中尺度相位场模型的开发，以发现非均匀烧结中远程质量转运的物理机制。此外，还将开发一个宏观连续模型，该模型具有模拟全尺度零件并预测工业相关配置的形状失真和/或残留应力的功能。将开发一个预测模型，以量化参数的影响，例如粒径，粘合剂含量，约束和温度梯度对部分变形。该研究将建立并通过实验验证设计指南，以最大程度地减少AM零件烧结期间的失真。最后，将引入不均匀的烧结作为实现受控失真的全新技术，即4D打印。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智力优点和更广泛影响的审查标准通过评估来支持的。