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）涉及通过在材料层上添加层来构建3D对象。 纳米/微米粒子的烧结是许多AM工艺中的关键步骤之一。这一步往往会导致形状变形的AM零件，阻止他们的近净形制造。这个赠款机会学术联络与工业（GOALI）奖支持综合实验和理论研究，以充分了解控制AM形状变形的机制。这样的理解将使关键AM工艺参数的识别，以消除不期望的失真，或控制失真，以实现4D打印的新方法。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。这项工作所实现的精密制造将有助于确立美国在工业4.0中的领导地位。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因素。近净形增材制造将消除后处理，从而减少温室气体排放。该项目将与来自弱势学校的K-12学生合作，让他们接触到基于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养多样化的美国劳动力。该项目的重点是确定基于烧结的AM过程中的质量传输机制及其对形状变形的相对贡献。初步研究表明，在烧结变形过程中，长程传质是可行的。 该研究的实验部分将包括制造纳米和/或微粒的3-D结构，操作显微镜观察烧结过程中聚焦离子束（FIB）切割部分中颗粒簇的运动，以及烧结后的广泛非原位观察。一个紧密耦合的模拟工作将涉及一个中尺度相场模型的发展，以发现在非均匀烧结的长程传质的物理机制。此外，将开发一个宏观尺度连续模型，该模型具有模拟全尺寸零件和预测工业相关配置的形状变形和/或残余应力的能力。将开发一个预测模型，以量化参数（如粒度、粘合剂含量、约束和温度梯度）对零件变形的影响。该研究将建立和实验验证设计准则，以尽量减少AM部件烧结过程中的变形。最后，非均匀烧结将作为一种全新的技术引入，以实现受控的变形，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。