Mechanical joining of dissimilar materials by shear clinching processes without pre-punching (shear clinching)

通过剪切铆接工艺机械连接异种材料，无需预冲孔（剪切铆接）

• 批准号: 227633773
• 负责人: Professorin Dr.-Ing. Marion Merklein
• 金额: --
• 依托单位: Laboratorium für Werkstoff- und Fügetechnik (LWF)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/227633773?language=en
• 关键词: Mechanical; joining; dissimilar; materials; shear

Political and environmental requirements demand the use of adapted materials in modern lightweight design structures. Joining these dissimilar materials challenges the development and advancement of existing technologies. Great potential offers the innovative shear-clinching technology which is investigated in this project. The single-stage process offers the opportunity to join material combinations with significantly different material properties without additional joining elements or pre-holing and retrieval of this pre-hole. The combined inner- and outer punch initialize a cutting operation in the die-sided brittle material as well as a drawing process in the punch-sided ductile joining partner for creating a form- and force-fitting joint. This reduces the required process time and avoids possible positioning errors that occur during multi-stage processes. The third funding phase focuses on investigating and improving the robustness of the shear-clinching process and the predictability of the properties of a shear-clinched joint. Therefore, three key research areas are set.To evaluate the tool-related design, the active elements are analyzed in terms of tool wear and the resistance of the tool materials. In addition to the identification of the process limits, the influence of process and batch-related deviations on the quality of the joint formation and the tool wear are examined. Based on these results the tool elements are adjusted for high local stresses and wear tests are carried out. The second focus is the evaluation of the process design. For this purpose, the previously analyzed single-element samples are replaced by multi-element samples to examine the influence of neighboring points on joint formation. An essential approach is identifying the influence of the radial material flow on the characteristic joint properties and set limits of a robust joining process. The influences on the joint formation of joint distance, sheet thickness and additional process based deviations are analyzed. Multi-element samples of the described material combinations are tested concerning joint strength and corrosive behavior.The final research topic is the review of the shear-clinching process regarding process safety and tested material combinations. Therefore, the findings from the first two phases of the project are combined with the tool- and process-sided results and evaluated in terms of process reliability. In particular, the failure modes of the joints are taken into account for enabling a prediction of the joint properties. The transferability of these findings will be evaluated by arranging different punch-sided aluminium alloys. The project is finalized with the summary of the results and a holistic review of the shear-clinching process.

政治和环境要求在现代轻量化设计结构中使用适应性材料。将这些不同的材料结合起来对现有技术的发展和进步提出了挑战。本项目所研究的新型剪切夹紧技术潜力巨大。单级工艺提供了连接具有明显不同材料性能的材料组合的机会，而无需额外的连接元件或预孔和回收该预孔。组合的内外冲床初始化了模具侧脆性材料的切割操作，以及冲床侧韧性连接伙伴的拉伸过程，以创建形状和力配合接头。这减少了所需的工艺时间，并避免了在多阶段工艺中可能发生的定位错误。第三个资助阶段的重点是研究和提高剪切-夹紧过程的鲁棒性和剪切-夹紧接头性能的可预测性。因此，本文设置了三个重点研究领域。为了评估与刀具相关的设计，从刀具磨损和刀具材料阻力的角度分析了有效元素。除了确定工艺极限外，还检查了工艺和批次相关偏差对接头形成质量和刀具磨损的影响。根据这些结果，调整了刀具元件以适应高局部应力并进行了磨损试验。第二个重点是工艺设计的评价。为此，将先前分析的单元素样本替换为多元素样本，以研究相邻点对节理形成的影响。确定径向材料流对接头特性的影响，并确定坚固连接工艺的极限是一个重要的方法。分析了接头间距、板材厚度和附加工艺偏差对接头形成的影响。对所述材料组合的多元素样品进行了连接强度和腐蚀性能测试。最后的研究课题是从工艺安全性和测试材料组合的角度对剪切-夹紧工艺进行综述。因此，项目前两个阶段的发现与工具和过程方面的结果相结合，并根据过程可靠性进行评估。特别地，为了预测接头的性能，考虑了接头的破坏模式。这些发现的可转移性将通过安排不同的冲孔边铝合金来评估。项目最后总结了结果，并对剪切-夹紧过程进行了全面审查。