Influence of microstructure on the flow behaviour of metallic materials inside micro- and nanocavities - Nanoimprinting

微观结构对微纳米腔内金属材料流动行为的影响 - 纳米压印

• 批准号: 282202710
• 负责人: Professor Dr.-Ing. Karsten Durst
• 金额: --
• 依托单位: Fachgebiet Physikalische Metallkunde
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/282202710?language=en
• 关键词: Influence; microstructure; flow; behaviour; metallic

Within this project the plastic flow behavior of metals inside micro- and nanocavities is studied. The concept of the proposal is based on nanoimprinting methods, which are applied here to metals. During nanoimprinting a flat punch diamond with cavities is pressed onto the metal and plastic flow processes inside the cavities lead to surface structuring. The scientific program is concerned with how single or multiple grains flow inside small scale cavities during an imprinting process. We aim to use a multiple length scale approach, based on both experiments and simulations to study how the flow process depends on the size of the forming tool with respect to the grain size of the material. By using a systematic variation of grain size, film thickness and work hardening behavior of the material together with various cavity tool dimensions, it is envisaged to lay the scientific basis for controlling the flow behavior at different length scales. Starting from nanocrystalline thin coatings up to fine grained bulk metals, a wide range of grain sizes and film thicknesses is being considered. The deformation mechanism (dislocation motion, subgrain formation, strain gradients, grain boundary sliding, grain rotation) leading to the formation of the extruded material as well as the extrusion height will be analyzed by means of electron microscopy. In-situ deformation experiments inside the electron microscope together with finite element modelling will lead to new insights into the plasticity mechanism. The detailed analysis of the deformation mechanism at different length scales and for various ratios of grain size to cavity size, will be used to develop a deformation mechanism map for microflow processes. The results can give important new insights for applications in the field of surface structuring or the forming of microparts, using metal forming processes.

在这个项目中，研究了微腔和纳米腔中金属的塑性流动行为。该提案的概念是基于纳米压印方法，在这里适用于金属。在纳米压印过程中，将具有空腔的平冲头金刚石压在金属上，并且空腔内的塑性流动过程导致表面结构化。该科学计划关注的是在压印过程中单个或多个颗粒如何在小规模腔体内流动。我们的目标是使用多个长度尺度的方法，基于实验和模拟来研究流动过程如何取决于成形工具的尺寸相对于材料的晶粒尺寸。通过使用材料的晶粒尺寸、膜厚度和加工硬化行为的系统变化以及各种腔体工具尺寸，设想为控制不同长度尺度下的流动行为奠定科学基础。从纳米晶薄涂层到细粒块状金属，正在考虑广泛的晶粒尺寸和膜厚度。将通过电子显微镜分析导致挤压材料形成的变形机制（位错运动、亚晶粒形成、应变梯度、晶界滑动、晶粒旋转）以及挤压高度。电子显微镜内的原位变形实验以及有限元建模将为塑性机制带来新的见解。在不同的长度尺度和各种比例的晶粒尺寸的空腔尺寸的变形机制的详细分析，将用于开发微流过程的变形机制图。结果可以提供重要的新的见解，在该领域的应用程序的表面结构或形成的微型零件，使用金属成型工艺。