Magnetically-Assisted Laser-Induced Plasma Micro-Machining for Flexible and Fast Texturing of Functional Surfaces

用于功能表面灵活快速纹理化的磁辅助激光诱导等离子体微加工

• 批准号: 1563244
• 负责人: Kornel Ehmann
• 金额: $ 30万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1563244&HistoricalAwards=false
• 关键词: Magnetically; Assisted; Laser; Induced; Plasma

Challenges in the energy, environmental, and health sectors present a growing need for flexible and scalable micro-machining processes for applications such as textured surfaces for tissue adhesion and anti-bio-fouling, reduced wear in tooling and engine systems, and functional surfaces for biomedical devices such as needles and implants. This award funds research on a novel micro-machining process that addresses several existing challenges, namely limitations in the machinability of materials, patterning large areas at economically feasible material removal rates, and generating micro-features of different sizes and shapes. A fully realized magnetically-assisted laser induced plasma micro-machining process will be capable of fast and direct generation of micro-features with controlled geometrical characteristics.In magnetically-assisted laser-induced plasma micro-machining, picosecond laser pulses induce a plasma plume within a liquid dielectric. The plasma plume removes material from the workpiece surface by a combination of thermal vaporization and mechanical erosion to create machined features with desired geometry. This project aims to advance processing capabilities in terms of machining rate and precision by utilizing the external magnetic field's influence on the plasma plume through two mechanisms: (1) by increasing its energy density, leading to increased material removal rates; and (2) by modifying its shape, leading to the nearly direct creation of desired micro-feature geometries. The research objective is to understand the interaction between the electromagnetic and thermo-mechanical mechanisms of the process, i.e., interactions between the laser, dielectric, plasma, magnetic field and workpiece material. Methods to achieve this objective include simulations using magneto-hydrodynamic, particle-in-cell and finite element analysis methods to determine the outcomes of each interaction. Experiments with a wide variety of materials, including titanium alloys, silicon, polymers, and transparent, brittle and reflective materials such as glass, will be conducted using a picosecond laser system with a 532 nm wavelength, a computer-controlled array of electromagnets, and focus variation-based metrology. Experimental results will be compared with simulation results in terms of the depth and shape of the generated features and material removal rate.

能源、环境和健康领域的挑战提出了对灵活且可扩展的微加工工艺的需求不断增长，这些工艺适用于组织粘附和抗生物污垢的纹理表面、减少工具和发动机系统的磨损以及用于制造和运输的功能表面等应用。生物医学设备，例如针和植入物。该奖项资助一种新型微加工工艺的研究，该工艺可解决现有的几个挑战，即材料可加工性的限制、以经济可行的材料去除率对大面积进行图案化，以及生成不同尺寸和形状的微观特征。 完全实现的磁辅助激光诱导等离子体微加工工艺将能够快速、直接生成具有受控几何特征的微观特征。在磁辅助激光诱导等离子体微加工中，皮秒激光脉冲在内部产生等离子体羽流。液体电介质。等离子体羽流通过热汽化和机械腐蚀的结合从工件表面去除材料，以形成具有所需几何形状的加工特征。该项目旨在通过两种机制利用外部磁场对等离子体羽流的影响，提高加工速度和精度方面的加工能力：（1）通过提高其能量密度，从而提高材料去除率； （2）通过修改其形状，几乎可以直接创建所需的微观特征几何形状。研究目标是了解该过程的电磁和热机械机制之间的相互作用，即激光、电介质、等离子体、磁场和工件材料之间的相互作用。实现这一目标的方法包括使用磁流体动力学、细胞内粒子和有限元分析方法进行模拟，以确定每次相互作用的结果。将使用波长为 532 nm 的皮秒激光系统、计算机控制的电磁体阵列和各种材料进行实验，包括钛合金、硅、聚合物以及玻璃等透明、脆性和反光材料。基于焦点变化的计量。实验结果将在生成特征的深度和形状以及材料去除率方面与模拟结果进行比较。