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.

在许多不同的工业领域，例如电子，计算机，医疗设备和汽车制造业，微型零件的制造变得越来越重要和必要。传统上，这些精确的机械零件是通过加工制造的。由于高生产力和成本，净形状或接近净形状的过程（例如金属形成过程）通常更适合小型化。拟议的研究涉及微生物，微动弯曲和深度绘画，微皮剪裁的新型微型形成过程的发展，以及它们在燃料电池堆中使用的金属双极板中复杂微功能的创新生产的合并应用。在微观尺度上，将获得对大变形机制的更广泛，更基本的理解，将在较大部分内形成微零件和微功能方面获得。 新型的微型单轴，平面应变，双轴拉伸和弯曲测试将被开发和使用，以分析实际微型形成过程中存在的不同变形模式，并评估工作硬化，各向异性，塑料不稳定性，形成限制和损坏候选材料的尺寸效应。基于微观结构和有限元（FE）的高级微型形成模型的发展将补充实验工作，以说明微观结构和标本尺寸量表的效果，例如利用最近的应变梯度可塑性理论以及工具 - 分布接触和摩擦。 从上述实验和数值研究中获得的知识将用于形成金属双极板，这是金属双极板，这是汽车燃料电池堆栈的关键组成部分，在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，将使用最近开发的微型多台滚动厂探索形状滚动的新过程。