CAREER: Understanding Bond Formation, Microstructural Development and Mechanical Properties in Cold Spray Additive Manufacturing – A Unified Experimental and Numerical Approach

职业：了解冷喷涂增材制造中的键形成、微观结构发展和机械性能——统一的实验和数值方法

• 批准号: 2145326
• 负责人: Mostafa Hassani
• 金额: $ 64.87万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-01 至 2027-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2145326&HistoricalAwards=false
• 关键词: CAREER; Understanding; Bond; Formation; Microstructural; CAREER; Understanding; Bond; Formation; Microstructural

Melting-based additive manufacturing (AM) has been utilized for high-value metallic component manufacture. Limitations exist, however, due to the high process temperatures, (often beyond the melting point of component materials), and the large associated thermal gradients and rapid cooling rates. On the other hand, non-melting metal AM such as cold spray technology, in which tiny powder particles are accelerated to a supersonic speed to collide, bond to and build up underlying materials upon impact, may considerably alleviate the melting-rooted challenges. This Faculty Early Career Development (CAREER) award supports research in developing a fundamental understanding of the process-microstructure-property relationships for cold spray AM using novel high-speed single-particle impact testing, complemented by multi-scale numerical modeling, to study individual bonded particles, the building blocks of the cold spray process, and then expand to a part-level study. The research will enable reliable and performance-oriented processing design for cold spray AM, with a potential to strengthen the Nation’s defense and other industries through enabling sustainable and agile manufacturing and repair at the point of need. The knowledge gained may also be translated to other solid-state joining or additive technologies for aerospace, construction and energy applications. The team will engage K-12 students and educators through hands-on activities with a designed additive manufacturing toolkit. The project will also promote participation from underrepresented minority students in advanced manufacturing through 10-week summer camps in a research laboratory.The overall goal of this CAREER project is to establish a unified framework to understand and predict the critical velocity, impact-induced microstructural development, micro-scale bond strength, and macro-scale mechanical properties of cold-sprayed deposits. Laser-induced micro-scale projectile impact testing will be conducted with high-resolution imaging to produce well-defined high-velocity individual bonded particles, with microstructures and properties characterized by advanced electron microscopy and micro-mechanical measurements. Both the first layer impacts and particle impacts on subsequent layers will be systematically investigated. The role of the impact velocity, oxide layer thickness, particle size and temperature, and impact angle in the characteristics of bonded interfaces and local bond strengths will be scientifically revealed. Further, finite element modeling incorporating a dislocation-based constitutive model, oxide layer fracture, and cohesive bonding will be established, which will be used to predict the impact-induced microstructure changes and bond strengths. The micro-scale simulations will inform a macro-scale model to calculate the mechanical properties of cold-sprayed specimens. Different sources of statistical effects resulting from the distribution of particle sizes, temperatures, and oxide layer thicknesses will also be considered in the multi-scale model.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.

基于熔化的添加剂制造（AM）已用于高价值金属组件制造。但是，由于过程温度高（通常超出了组件材料的熔点）以及大型相关的热梯度和快速冷却速率，因此存在局限性。另一方面，非融化金属AM，例如冷喷雾技术，其中微小的粉末颗粒被加速到超音速速度，以碰撞，结合并在撞击后建立潜在的材料，可能会考虑减轻融化根深蒂固的挑战。这项教师早期职业发展（职业）奖支持研究在对冷喷雾过程中的过程中的基本理解中，使用新型的高速单粒子冲击测试，通过多尺度数值建模完成，以研究单个粘结的颗粒，以研究冰上喷雾过程的基本块，然后扩展到部分层面研究。这项研究将为Cold Spray AM提供可靠和以性能为导向的加工设计，并通过在需要时实现可持续和敏捷的制造和维修，从而增强国家的防御和其他行业。获得的知识也可以转化为其他固态加入或上瘾的技术，用于航空航天，建筑和能源应用。该团队将通过动手活动与K-12学生和教育工作者一起使用设计的其他制造工具包。该项目还将在研究实验室的10周夏令营中促进代表性不足的少数群体学生的参与。该职业项目的总体目标是建立一个统一的框架，以了解和预测影响的关键速度，影响诱导的微观结构发展，微观尺度债券强度，以及巨大的债券强度以及冷藏量的宏观机械性能。激光诱导的微尺度弹丸撞击测试将使用高分辨率成像进行，以产生明确定义的高速单个键合颗粒，其显微结构和特性以先进的电子显微镜和微机械测量为特征。第一层的影响和粒子对后续层的影响都将被系统地研究。影响速度，氧化层厚度，粒径和温度以及粘结界面特征和局部粘结强度特征的影响角度的作用将得到科学揭示。此外，将建立编码基于脱位的宪法模型，氧化物层断裂和凝聚力键合的有限元模型，该模型将用于预测影响诱导的微观结构变化和键强度。微型尺度模拟将告知宏观尺度模型，以计算冷喷雾标本的机械性能。多尺度模型也将考虑粒径，温度和氧化物层厚度的分布所产生的统计效应的不同来源。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛影响的评估标准来评估通过评估来获得的支持。