CAREER: Advancing Laser Powder Bed Fusion with Non-Spherical Powder

职业：推进激光粉末床与非球形粉末的融合

• 批准号: 2339857
• 负责人: Amir Mostafaei
• 金额: $ 61.81万
• 依托单位: Illinois Institute of Technology
• 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: 2024-08-01 至 2029-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2339857&HistoricalAwards=false
• 关键词: CAREER; Advancing; Laser; Powder; Bed

This Faculty Early Career Development (CAREER) award will support research that intends to address the limitations of current additive manufacturing (AM) practices that primarily use expensive and energy-intensive spherical powdered materials. The cold mechanically driven method employs attrition milling with a reciprocating cutter, achieving precise powder size distribution, leading to the production of pore-free metal powders with reduced energy input. The project aims to: (1) enhance powder-spreading dynamics through multimodal particles and a hybrid powder dispenser, and (2) improve laser-powder interaction and microstructure control. If successful, the project outcomes may expand material choices, making production more cost-effective and sustainable across various AM processes such as binder jetting and laser/electron beam powder bed fusion. The project provides research opportunities to a diverse pool of undergraduate students, including those from underrepresented groups and veterans. Through hands-on research experiences, outreach activities, and the creation of video animations, the project will engage underrepresented communities and high school students in the field of metal additive manufacturing. The CAREER research project aims to address three fundamental research problems: (1) Non-spherical powder characteristics, such as morphology and size, impact powder-powder interactions, potentially leading to lower packing density and non-uniform powder beds. This will be addressed by developing a deposition mechanism using multimodal powder sizes and an innovative non-contact electrostatic powder spreader. (2) Laser-powder interaction is affected by characteristics such as shape, morphology, and size distribution. The shift in the stable/unstable keyhole mode due to the shadowing effect of non-spherical powder at higher laser scan speeds will influence the process map, and mechanical interlocking of particles. Comprehensive investigations into laser-powder interactions will be undertaken, using in-situ observations such as synchrotron X-ray imaging and multi-physics modeling. This approach aims to unravel the underlying physics and formulate processing strategies to effectively address anticipated defects. (3) Locally reduced cooling rates from the shadowing effect influence solidification, impacting microstructure and resultant mechanical properties. This will be addressed by adjusting process parameters and applying post-heat treatments, such as hot isostatic pressing, which is expected to achieve equiaxed grain structures for improved strength and ductility comparable to wrought alloys. The research outcomes have the potential to bridge the gap between fundamental understanding and practical applications, fostering a sustainable future for additive manufacturing.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.

该学院早期职业发展（CAREER）奖将支持旨在解决当前增材制造（AM）实践局限性的研究，这些实践主要使用昂贵且能源密集的球形粉末材料。冷机械驱动方法采用往复式刀具进行研磨，实现精确的粉末粒度分布，从而以更低的能量输入生产无孔金属粉末。该项目旨在：（1）通过多峰颗粒和混合粉末分配器增强粉末铺展动力学，以及（2）改善激光-粉末相互作用和微结构控制。如果成功，该项目的成果可能会扩大材料的选择，使生产更具成本效益和可持续性的各种增材制造工艺，如粘合剂喷射和激光/电子束粉末床融合。该项目提供研究机会，以本科生的多元化池，包括那些来自代表性不足的群体和退伍军人。通过实践研究经验、推广活动和视频动画的创作，该项目将吸引代表性不足的社区和高中生参与金属增材制造领域。CAREER研究项目旨在解决三个基础研究问题：（1）非球形粉末特性，如形态和尺寸，影响粉末-粉末相互作用，可能导致较低的堆积密度和不均匀的粉末床。这将通过开发一种使用多模态粉末尺寸的沉积机制和一种创新的非接触式静电粉末散布器来解决。(2)激光-粉末相互作用受诸如形状、形态和尺寸分布的特性的影响。由于非球形粉末在较高激光扫描速度下的遮蔽效应而导致的稳定/不稳定小孔模式的偏移将影响工艺图和颗粒的机械互锁。将利用同步加速器X射线成像和多物理场建模等原位观测，对激光-粉末相互作用进行全面调查。这种方法的目的是解开潜在的物理和制定处理策略，以有效地解决预期的缺陷。(3)阴影效应导致的局部冷却速率降低会影响凝固，影响微观结构和最终的机械性能。这将通过调整工艺参数和应用后热处理（如热等静压）来解决，这有望实现等轴晶粒结构，从而改善与锻造合金相当的强度和延展性。该研究成果有可能弥合基本理解和实际应用之间的差距，促进增材制造的可持续未来。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。