MRI: Acquisition of a Plasma Focused Ion Beam System for Dynamic In-situ Micro-Mechanical Testing Over Cryogenic and Elevated Temperatures

MRI：获取等离子体聚焦离子束系统，用于低温和高温动态原位微机械测试

• 批准号: 2215267
• 负责人: Helen Chan
• 金额: $ 129.83万
• 依托单位: Lehigh 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: 2022-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2215267&HistoricalAwards=false
• 关键词: MRI; Acquisition; Plasma; Focused; Ion

Direct observation of deformation behavior at the micro/nano scales can lead to significant advances in our understanding of the deformation mechanisms in materials by correlating microstructural changes with load-displacement characteristics. For example, the propagation of a crack-tip that would lead to a catastrophic failure of a component, or deformation/temperature-induced phase transformations and crystallinity changes are important processing phenomena that can lead to failure in materials. The plasma focused ion beam (FIB) in this project allows researchers to efficiently extract samples from specific sites of interest in materials for micromechanical testing, which can be performed using a state-of-the-art micromechanical testing device integrated within the same FIB instrument. It is possible to observe both microstructural and crystallographic changes that occur during deformation using this system, and these changes can be directly correlated with localized stress-strain data. The equipment will benefit a wide variety of funded research activities at Lehigh across sectors of materials science ranging from ceramics, metals/alloys, 3D-printed materials, polymers and biomaterials. In addition, the rapid material removal rate achievable in the plasma FIB accelerates the fabrication of a wide range of nanostructures such as tooling for micro/nano injection molding, as well as enable large-scale internal characterization of various samples including highly sensitive biomaterials and soft polymers at cryogenic temperatures. The instrument also supports research projects from other universities, government labs and industry through liaison programs already established at Lehigh. The techniques and knowledge developed using this system are shared with Lehigh students as well as numerous industry/government attendees of the Lehigh Microscopy Schools. The system as specified consists of (1) a plasma focused ion beam (FIB) instrument, integrated with (2) a state-of-the-art in-situ micromechanical testing device with testing capability over a wide temperature range and (3) a high speed electron backscattered diffraction (EBSD) camera. The system will be able to simultaneously acquire many types of data, including highly sensitive transmission Kikuchi diffraction patterns, during mechanical testing. The rapid milling rate of the Xe-ion based plasma FIB, which is ~10–100 times greater than conventional Ga-ion systems, markedly increases the fabrication throughput of micromechanical test samples, and hence addresses what is currently a severe limitation, namely the ability to test a statistically significant number of samples. In-situ mechanical testing within the FIB at temperatures from minus 130 to 1000 degrees C will enable the correlation of deformation processes (such as slip and microcrack/void nucleation) with microstructural features at the nm scale. Furthermore, the load-displacement signals can be sampled at 1.2 MHz, which is much faster than the typical frame rates encountered in SEM imaging. This information will be complemented by digital image correlation, which will be used to quantify localized deformation. These capabilities are highly advantageous, but what makes the requested instrumentation truly unique is the ability to simultaneously extract real time EBSD data during mechanical testing, which is made possible by a novel test platform geometry. Moreover, the efficiency of serial cross-sectioning for the characterization of multi-component materials, as well as specific features such as interfaces and boundaries in materials and devices, is improved tremendously. The sample sectioning capability at cryogenic temperatures is especially useful for cross-sectional observation of soft materials such as polymers and biological samples, and for thin-specimen preparation to allow more detailed observation in a transmission electron microscope.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.

通过将微观结构变化与载荷位移特性联系起来，直接观察微/纳米尺度的变形行为可以使我们对材料变形机制的理解取得重大进展，例如，裂纹尖端的扩展会导致裂纹扩展。组件的灾难性故障，或变形/温度引起的相变和结晶度变化是重要的加工现象，可能导致材料故障。该项目中的等离子体聚焦离子束 (FIB) 允许。研究人员可以从材料中感兴趣的特定位置有效地提取样品进行微机械测试，这可以使用集成在同一 FIB 仪器中的最先进的微机械测试设备来进行，可以观察微观结构和晶体学的变化。使用该系统在变形过程中发生变化，这些变化可以与局部应力应变数据直接相关，该设备将使理海大学跨材料科学领域的各种资助研究活动受益，包括陶瓷、金属/合金、此外，等离子 FIB 可实现快速的材料去除率，从而加速 3D 打印材料、聚合物和生物材料的制造，例如微/纳米注射成型工具，并实现大规模内部表征。该仪器还通过利哈伊大学已经建立的联络计划支持其他大学、政府实验室和工业界的研究项目，包括在低温下的高敏感生物材料和软聚合物。该系统与 Lehigh 学生以及 Lehigh 显微镜学校的众多行业/政府参与者共享。该系统由 (1) 等离子体聚焦离子束 (FIB) 仪器组成，并与 (2) 集成。具有宽温度范围测试能力的最先进的原位微机械测试设备和（3）高速电子背散射衍射（EBSD）相机该系统将能够同时获取多种类型的数据，包括高灵敏度的传输。 Kikuchi 衍射图案在机械测试过程中，基于 Xe 离子的等离子体 FIB 的快速铣削速率比传统 Ga 离子系统高约 10-100 倍，显着提高了微机械测试样品的制造吞吐量，从而解决了以下问题：目前是一个严重的限制，即在 FIB 内在 -130 至 1000 摄氏度的温度下测试技术上大量样品的能力将能够实现变形的相关性。此外，负载位移信号可以以 1.2 MHz 的频率进行采样，这比 SEM 成像中遇到的典型帧速率要快得多。数字图像相关性将用于量化局部变形，这些功能非常有利，但所需仪器的真正独特之处在于能够在机械测试期间同时提取实时 EBSD 数据，此外，通过新颖的测试平台几何形状，可以极大地提高多组分材料以及材料和器件中的界面和边界等特定特征的连续横截面的效率。低温下的切片能力对于聚合物和生物样品等软材料的横截面观察以及薄样品制备特别有用，以便在透射电子显微镜中进行更详细的观察。该奖项反映了 NSF 的法定使命，并被视为值得支持通过使用基金会的智力价值和更广泛的影响审查标准进行评估。