Material microstructure and surface considerations in microforming of sheet materials

板材微成型中的材料微观结构和表面考虑因素

• 批准号: 249643-2012
• 负责人: Jain, Mukesh
• 金额: $ 1.75万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=570672
• 关键词: Material; microstructure; surface; considerations; microforming

The manufacturing of micro-parts has become more important and necessary in many different industrial sectors such as electronics, computers, medical devices and automotive manufacturing. Traditionally these precision mechanical parts are fabricated by machining. The net shape or near net shape processes, such as sheet metal forming processes, are often better suited for miniaturization because of high productivity and cost. The proposed research deals with development of novel micro-forming processes of microbending, micro-draw-bending and deep drawing, micro-shearing and their combined application towards innovative manufacturing of complex micro-features within metallic bipolar plates used in fuel cell stacks. A broader and fundamental understanding of the mechanics of large deformation at the micro-scale will be gained in forming of micro-parts and micro-features within larger parts. Novel miniature uniaxial, plane strain, biaxial tensile and bend tests will be developed and utilized to analyze different deformation modes present in real micro-forming processes and to assess the size effects in work hardening, anisotropy, plastic instability, forming limits, and damage development of candidate sheet materials. The experimental work will be complemented by the development of microstructure and finite element (FE) based advanced micro-forming models to account for microstructural and specimen size scale effects such as by utilizing the recent strain gradient plasticity theory as well as tool-sheet contact and friction. The knowledge gained from the above experimental and numerical investigations will be applied towards forming of a metallic bipolar plate, a critical component of automotive fuel cell stack where micro-geometric features in the bipolar plate strongly influence its performance within the fuel cell. For this purpose, a novel process of shape rolling will be explored using a recently developed miniature multi-stand rolling mill.

微型零件的制造在许多不同的工业部门，如电子，计算机，医疗设备和汽车制造中变得越来越重要和必要。传统上，这些精密机械零件是通过机械加工制造的。净成形或近净成形工艺，例如金属板成形工艺，由于高生产率和高成本，通常更适合于小型化。拟议的研究涉及微弯曲，微拉伸弯曲和深拉伸，微剪切及其组合应用到燃料电池堆中使用的金属双极板内的复杂的微特征的创新制造的新的微成形工艺的发展。在微零件和较大零件内的微特征的形成中，将获得对微尺度下的大变形力学的更广泛和基本的理解。 新型微型单轴，平面应变，双轴拉伸和弯曲测试将被开发和利用，以分析不同的变形模式，目前在真实的微成形过程中，并评估尺寸效应的加工硬化，各向异性，塑性不稳定性，成形极限，和损伤发展的候选板材。实验工作将得到补充的微观结构和有限元（FE）为基础的先进的微成形模型的发展，以考虑微观结构和试样尺寸的尺度效应，如利用最近的应变梯度塑性理论，以及工具板接触和摩擦。 从上述实验和数值研究中获得的知识将被应用于形成金属双极板，这是汽车燃料电池堆的关键部件，其中双极板中的微几何特征强烈影响其在燃料电池内的性能。为此，将探索一种新的形状轧制工艺，使用最近开发的微型多机架轧机。