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

政治和环境的要求要求在现代轻量化设计结构中使用适应材料。加入这些不同的材料对现有技术的发展和进步提出了挑战。巨大的潜力为本项目所研究的剪力咬合技术提供了创新。单阶段工艺提供了连接具有显著不同材料特性的材料组合的机会，而无需额外的连接元件或预打孔和回收该预制孔。组合的内部和外部冲头初始化模侧脆性材料中的切割操作以及冲头侧延性连接伙伴中的拉拔过程，以创建成形和力配合接头。这减少了所需的加工时间，并避免了在多阶段加工过程中可能出现的定位误差。第三个供资阶段的重点是调查和改进剪切咬合过程的稳健性以及剪切咬合接头性能的可预测性。为了评价刀具相关设计的优劣，从刀具磨损和刀具材料的抗力两个方面分析了刀具相关设计中的活跃因素。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成形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。第二个重点是对工艺设计的评价。为此，将先前分析的单元素样品替换为多元素样品，以考察邻接点对节理形成的影响。一个基本的方法是识别径向材料流对连接特性的影响，并设置稳健连接过程的限制。分析了接缝距离、板材厚度和附加工艺偏差对接缝成形的影响。对所述材料组合的多元素样品进行了连接强度和腐蚀行为测试。最后的研究主题是关于工艺安全性和测试材料组合的剪切咬合过程的审查。因此，项目前两个阶段的调查结果与工具和过程方面的结果相结合，并从过程可靠性的角度进行评估。具体地说，考虑了接头的失效模式，以便能够预测接头性能。这些发现的可转移性将通过安排不同的冲头侧面铝合金来评估。最后确定了该项目，总结了结果，并对剪切咬合过程进行了全面审查。

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.