Pore Formation and Polymer Thermal Debinding during Vapor-Induced Phase Separation-Enabled Metal Printing

蒸汽诱导相分离金属打印过程中的孔形成和聚合物热脱脂

• 批准号: 2315811
• 负责人: Yong Huang
• 金额: $ 53.12万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-10-01 至 2026-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2315811&HistoricalAwards=false
• 关键词: Pore; Formation; Polymer; Thermal; Debinding

Metal additive manufacturing has been of great interest for the fabrication of complex metallic components ranging from automobile parts to jet engines to medical implants. Despite its advantages over conventional metal fabrication methods, current metal additive manufacturing technologies are subject to challenges including handling metal powders, which can be explosive, and fabricating parts with heterogeneous materials to enhance part properties. This project aims to explore a room-temperature polymer binder-assisted metal printing technology, which uses suspension inks made of metallic powders and dissolved polymer. The new process has two advantages: (1) using metal-polymer suspension inks reduces the hazards of handling and inhaling metallic powders for machine operators; and (2) heterogeneous materials can be deposited by adjusting the metal composition of suspension inks. Simultaneously this project will stimulate science-based manufacturing education to broaden the participation of underrepresented and minority students in STEM and prepare a manufacturing workforce for the fast-evolving manufacturing industry.Of various metal printing technologies, powder bed fusion (PBF) and directed energy deposition (DED) are the most common modalities. PBF and DED are energy-driven high-temperature printing processes and require handling metal powders before and after printing. Advances in bound powder extrusion allow the use of metal powders pre-bound in the form of a filament, which, however, limits the choices of materials. The vapor-induced phase separation-enabled three-dimensional printing technology (VIPS-3DP) utilizes metal-polymer suspensions as build materials and VIPS as the solidification mechanism. The resultant metal-polymer green parts are further processed for polymer thermal debinding and sintering to get final metallic parts. The objective of this research is to study the effect of the VIPS-induced solidification of polymer binder on the formation of an interconnected pore space in metal-polymer green parts during printing and the effect of the resulting interconnected pores on the crack occurrence during polymer thermal debinding. The research will be implemented via two tasks: (1) theoretical modeling of the porous microstructure evolution and thermal debinding processes, and (2) experimental characterization of printed green, brown, and final parts in terms of their microstructure and mechanical properties. The resulting knowledge of the VIPS-induced porous microstructure and its effect on thermal debinding may lead to new sustainable metal additive manufacturing technologies.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.

对于从汽车零件到喷气发动机再到医疗植入物的复杂金属组件的制造，金属添加剂生产引起了极大的兴趣。尽管当前的金属添加剂制造技术比传统的金属制造方法具有优势，但仍面临挑战，包括处理金属粉末，这些粉末可能具有爆炸性，并用异质材料制造零件以增强零件的性能。该项目旨在探索室温聚合物粘合剂辅助金属印刷技术，该金属印刷技术使用由金属粉和溶解的聚合物制成的悬架油墨。新工艺具有两个优点：（1）使用金属聚合物悬架油墨可减少机器操作员的处理和吸入金属粉的危害； （2）可以通过调节悬浮墨水的金属成分来沉积异质材料。同时，该项目将刺激基于科学的制造教育，以扩大代表性不足和少数族裔学生在STEM中的参与，并为快速发展的制造业准备制造劳动力。各种金属印刷技术，粉末床融合（PBF）和定向能量沉积（DED）是最常见的模态。 PBF和DED是能源驱动的高温打印过程，需要在打印前后处理金属粉末。结合粉末挤出的进步允许以细丝形式使用金属粉末，但是，这限制了材料的选择。蒸气诱导的相分离启用的三维印刷技术（VIPS-3DP）利用金属 - 聚合物悬架作为建筑材料和VIP作为固化机制。将最终的金属 - 聚合物绿色零件进一步处理，以进行聚合物的热脱落和烧结以获得最终的金属零件。这项研究的目的是研究聚合物粘合剂的VIP诱导的凝固对印刷过程中金属聚合物绿色部分中相互联系的孔隙空间的影响，以及所得互连孔对聚合物热脱粒过程中裂纹的影响。这项研究将通过两个任务实施：（1）多孔微结构演化和热脱线过程的理论建模，以及（2）在其微观结构和机械性能方面对印刷绿色，棕色和最终部分进行实验表征。 由VIPS诱导的多孔微观结构及其对热脱线的影响可能导致新的可持续金属添加剂制造技术的知识。该奖项反映了NSF的法定任务，并被认为值得通过基金会的知识分子优点和更广泛的影响标准通过评估来进行评估。