CAREER: In Operando Investigation of Laser Powder-fed Directed Energy Deposition: Process Physics, Microstructure Evolution, and Mechanical Properties

职业：激光送粉定向能量沉积的操作研究：过程物理、微观结构演化和机械性能

• 批准号: 2046523
• 负责人: Atieh Moridi
• 金额: $ 63.69万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-01 至 2026-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2046523&HistoricalAwards=false
• 关键词: CAREER; Operando; Investigation; Laser; Powder

The disruptive innovation of additive manufacturing relies on its ability of mass customization of complex-shaped products that are impossible or difficult to make by conventional manufacturing methods. However, poor processing repeatability is one of the major obstacles to its widespread use, especially for critical load-bearing metallic components. The huge variability, for laser powder-fed direct energy deposition in particular, is due to extremely high heating and cooling rates, which occur during stochastic interactions of the powder flow stream with a shape-changing liquid metal pool and cause far-from-equilibrium and highly dynamic phenomena that are extremely challenging to study. This Faculty Early Career Development (CAREER) award supports the study of using high-energy, high-speed x-rays to achieve fundamental understanding of the aforementioned transient phenomena. Experiments at different time and length scales will be performed to establish process and characteristic relationships to predict quality, repeatability and properties of additively manufactured parts. The educational and outreach activities aim to promote a full participation of women and underrepresented minorities in advanced manufacturing and to develop a well-trained, diverse and sustainable manufacturing workforce. Over the project course, the PI will work with middle school girls, undergraduate women and underrepresented minorities through organizing workshop series on additive manufacturing with hands-on activities, attending lunch series and mentoring students in a 10-week summer program, respectively.The main research objective of this project is to transform the powder-fed direct energy deposition by understanding the fundamental physics of the process. A custom-built directed energy deposition apparatus will be interfaced with the facility at Cornell High Energy Synchrotron Source to perform unique experiments. Synchrotron hard x-ray imaging and diffraction techniques with unprecedented spatial and temporal resolutions are combined to study the powder flow stream, melt pool dynamics and non-equilibrium phase transformation of titanium and nickel-based alloys, as well as pore formation. Moreover, experiments with time-resolved x-ray measurements will be conducted to investigate the influence of cyclic heat treatments, intrinsic to additive manufacturing, to the microstructure and residual stress evolution. Correlations between compositions, processing parameters, process signatures and the resultant microstructure, porosity and residual stresses will be established. The findings will be used to overcome the long-lasting limitations of additive manufacturing by i) reducing anisotropy within the accessible process parameter range by promoting equiaxed solidification, ii) minimizing residual stresses and distortions by managing the heat accumulation during the process, iii) maximizing the process efficiency while minimizing melt pool discontinuities and iv) constructing process maps with the best combination of part properties.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.

增材制造的颠覆性创新依赖于其对传统制造方法无法或难以制造的复杂形状产品进行大规模定制的能力。然而，较差的加工重复性是其广泛使用的主要障碍之一，特别是对于关键的承载金属部件。特别是对于激光送粉直接能量沉积来说，巨大的变化性是由于极高的加热和冷却速率造成的，这种变化发生在粉末流与形状变化的液态金属池的随机相互作用期间，并导致远离平衡和高度动态的现象，这对研究来说极具挑战性。该学院早期职业发展（CAREER）奖支持使用高能，高速X射线的研究，以实现对上述瞬态现象的基本理解。将进行不同时间和长度尺度的实验，以建立过程和特性关系，从而预测增材制造零件的质量、可重复性和性能。教育和外联活动旨在促进妇女和代表性不足的少数群体充分参与先进制造业，并培养训练有素、多样化和可持续的制造业劳动力。在项目过程中，PI将与中学女生，本科女生和代表性不足的少数民族合作，分别通过组织增材制造系列研讨会和实践活动，参加午餐系列和指导学生参加为期10周的暑期课程。该项目的主要研究目标是通过了解该过程的基本物理原理来改变粉末直接能量沉积。一个定制的定向能量沉积装置将与康奈尔高能同步加速器源的设施连接，以进行独特的实验。同步辐射硬X射线成像和衍射技术与前所未有的空间和时间分辨率相结合，研究粉末流，熔池动力学和非平衡相变的钛和镍基合金，以及孔隙的形成。此外，将进行时间分辨X射线测量实验，以研究增材制造固有的循环热处理对微观结构和残余应力演变的影响。将建立成分、工艺参数、工艺特征与所得微观结构、孔隙率和残余应力之间的相关性。这些发现将用于克服增材制造的长期局限性，方法是：i）通过促进等轴凝固在可获得的工艺参数范围内降低各向异性，ii）通过管理工艺期间的热积累来最小化残余应力和变形，iii）使工艺效率最大化，同时使熔池不连续性最小化，以及iv）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。

项目成果

Metastability mediated grain size control in PH 17-4 stainless steel fabricated using Laser-Powder Bed Fusion (LPBF)

使用激光粉末床熔融 (LPBF) 制造的 PH 17-4 不锈钢中亚稳态介导的晶粒尺寸控制

• DOI: 10.1016/j.mtla.2023.101857
• 发表时间: 2023
• 期刊: Materialia
• 影响因子: 3.4
• 作者: Singh, Kaushalendra K;Moridi, Atieh
• 通讯作者: Moridi, Atieh

Additive manufacturing of functionally gradient refractory coatings using substrate dilution and in-situ carbide formation

• DOI: 10.1016/j.msea.2023.145952
• 发表时间: 2023-11
• 期刊: Materials Science and Engineering: A
• 作者: Poulomi Mukherjee;Ashlee Gabourel;S. Firdosy;Douglas C. Hofmann;Atieh Moridi

Effect of solidification pathway during additive manufacturing on grain boundary fractality

• DOI: 10.1016/j.addlet.2023.100149
• 发表时间: 2023-05-19
• 期刊: ADDITIVE MANUFACTURING LETTERS
• 作者: Wakai，Akane;Das，Amlan;Moridi，Atieh
• 通讯作者: Moridi，Atieh

Laser based directed energy deposition system for operando synchrotron x-ray experiments

用于操作同步加速器 X 射线实验的激光定向能量沉积系统

• DOI: 10.1063/5.0081186
• 发表时间: 2022
• 期刊: Review of Scientific Instruments
• 影响因子: 1.6
• 作者: Dass, Adrita;Gabourel, Ashlee;Pagan, Darren;Moridi, Atieh
• 通讯作者: Moridi, Atieh

Dendritic deformation modes in additive manufacturing revealed by operando x-ray diffraction

原位 X 射线衍射揭示增材制造中的枝晶变形模式

• DOI: 10.1038/s43246-023-00404-0
• 发表时间: 2023
• 期刊: Communications Materials
• 影响因子: 7.8
• 作者: Dass, Adrita;Tian, Chenxi;Pagan, Darren C.;Moridi, Atieh
• 通讯作者: Moridi, Atieh