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.

增材制造 (AM) 涉及通过逐层添加材料来构建 3D 对象。 纳米/微米颗粒的烧结是许多增材制造工艺中的关键步骤之一。此步骤通常会导致增材制造零件的形状变形，从而阻碍其近净形制造。这项“学术与工业联络机会”(GOALI) 奖项支持综合实验和理论研究，以充分了解增材制造中控制形状扭曲的机制。这种理解将能够识别关键的增材制造工艺参数，以消除不需要的变形，或控制变形以实现新型 4D 打印方法。该项目的成果有可能降低增材制造零件的成本，对航空、汽车和核工业产生积极影响。这项工作实现的精密制造将有助于确立美国在工业 4.0 领域的领导地位。由于增材制造在航空航天工业中用于制造大型零件（例如飞机机翼），该项目的研究成果将成为其制造的关键推动力。近净成形增材制造将消除后处理，从而减少温室气体排放。该项目将与来自贫困学校的 K-12 学生合作，让他们接触基于 STEM 的职业。该项目将通过开发跨学科课程，在先进制造、计算科学和纳米材料等跨学科领域培训多元化的美国劳动力。该项目的重点是确定质量传输机制及其对烧结过程中形状扭曲的相对贡献。基于增材制造工艺。初步研究表明，在烧结过程中零件变形期间，必须进行长程质量传输。 该研究的实验部分将包括纳米和/或微米颗粒 3D 结构的制造、用于观察烧结过程中聚焦离子束 (FIB) 切割切片中颗粒簇运动的操作显微镜，以及广泛的异位观察。烧结。紧密耦合的建模工作将涉及介观相场模型的开发，以发现非均质烧结中远程质量传输的物理机制。此外，还将开发宏观连续体模型，该模型能够模拟全尺寸零件并预测工业相关配置的形状变形和/或残余应力。将开发一个预测模型来量化颗粒尺寸、粘合剂含量、约束条件和温度梯度等参数对零件变形的影响。该研究将建立并通过实验验证设计指南，以最大程度地减少增材制造零件烧结过程中的变形。最后，不均匀烧结将作为一种全新的技术被引入，以实现受控变形，即 4D 打印。该奖项反映了 NSF 的法定使命，并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，被认为值得支持。