Micro-structuring and macro-structuring of deep drawing tools for dry forming condition

干成形条件下拉深工具的微观结构和宏观结构

基本信息

批准号：
244947573
负责人：
Professor Dr.-Ing. Eckhard Beyer
金额：
--
依托单位：
Professur für Formgebende Fertigungsverfahren
依托单位国家：
德国
项目类别：
Priority Programmes
财政年份：
2013
资助国家：
德国
起止时间：
2012-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/244947573?language=en
关键词：
Micro structuring macro deep drawing

项目摘要

Large friction forces in forming processes reduce the process limits. Generally, lubricants are therefore used to reduce friction and enlarge the process window. However, the technological advantages of lubricants are accompanied by negative economic and ecological effects. Therefore, the elimination of lubricants from deep drawing processes by means of an integrated concept of a protective coating and micro- and macro structuring of the tool is studied and analysed during this project. Within the first phase, the different technologies of the integrative approach were fundamentally analysed and the deep-drawing process with tool structuring was experimentally verified. The general feasibility was demonstrated for axially symmetric parts. In the second funding period, the process principle has been further improved. For a time efficient process design an analytical model has been developed describing the influence of input parameters on the risk of wrinkling and bottom cracks. Furthermore, a feasibility study regarding high-strength steels indicated additional advantages of a macro-structured deep drawing process over standard processes. The reduction of friction forces was pursued by investigating coating technology and micro-structuring of tools and the wear behaviour of coated and structured surfaces and the interaction with blank and tool surface were investigated. All technologies were transferred to the design of a modular tool for non axially symmetric parts. Based on these results, the third research phase has the goal to implement an industrially relevant lubricant free deep drawing process for complex parts and high strength materials. The main approach remains an integrative application of different processes in the areas of macro-structuring, coating and micro-structuring. The enhancement of the macro-structuring into three-dimensional geometries is a key factor, because it allows the direct control of the material flow in tangential and radial direction, and therefore the systematic adjustment of stresses as well as bending and unbending to specifically set part characteristics. An adjusted semi-analytical model is used for designing the macro-structures and choosing process parameters. The corresponding high requirements of the forming process regarding friction and wear of the tools will be addressed with a combined approach of coating and micro-structuring. The goal is to improve on previous results by adjusting the coating and structuring processes. Specifically, a new coating with a fluor modified ta-C layer will be implemented and the chromium bonding layer will be substituted by a nitration process. Additionally, the DLIP process will adjusted by shortening pulse times and homogenising the laser beam in order to improve the quality of the micro-structure while minimising negative effects on the substrate. All technologies will be integrated and verified using the modular deep drawing tool from the second funding phase.

成型过程中的大摩擦力减少了过程限制。因此，通常使用润滑剂来减少摩擦并扩大工艺窗口。然而，润滑油的技术优势也伴随着负面的经济和生态影响。因此，在该项目中，通过保护涂层以及工具的微观和宏观结构的集成概念来消除深拉工艺中的润滑剂。在第一阶段中，从根本上分析了集成方法的不同技术，并对带有工具结构的拉深工艺进行了实验验证。轴对称零件的一般可行性得到了证明。第二期资助期间，流程原则得到进一步完善。为了实现高效的流程设计，我们开发了一个分析模型，描述输入参数对起皱和底部裂纹风险的影响。此外，一项有关高强度钢的可行性研究表明，宏观结构拉深工艺相对于标准工艺具有更多优势。通过研究涂层技术和工具的微观结构来减少摩擦力，并研究涂层和结构化表面的磨损行为以及与毛坯和工具表面的相互作用。所有技术都转移到了用于非轴对称零件的模块化工具的设计中。基于这些结果，第三研究阶段的目标是针对复杂零件和高强度材料实施工业相关的无润滑剂拉深工艺。主要方法仍然是宏观结构、涂层和微观结构领域不同工艺的综合应用。将宏观结构增强为三维几何形状是一个关键因素，因为它允许直接控制切向和径向方向的材料流动，因此可以系统地调整应力以及弯曲和不弯曲以专门设置零件特征。调整后的半解析模型用于设计宏观结构和选择工艺参数。成型工艺对工具摩擦和磨损的相应高要求将通过涂层和微结构的组合方法来解决。目标是通过调整涂层和结构化工艺来改进之前的结果。具体来说，将采用带有氟改性ta-C层的新涂层，并通过硝化工艺取代铬结合层。此外，DLIP 工艺将通过缩短脉冲时间和均匀化激光束进行调整，以提高微结构的质量，同时最大限度地减少对基板的负面影响。所有技术都将使用第二阶段融资的模块化拉深工具进行集成和验证。