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

政治和环境要求要求在现代轻质设计结构中使用适应性材料。连接这些不同的材料挑战现有技术的发展和进步。巨大的潜力提供了创新的剪切铆接技术，这是在这个项目中调查。单级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钻孔和该预钻孔的回收。组合的内冲头和外冲头初始化模具侧脆性材料中的切割操作以及冲头侧韧性接合伙伴中的拉伸过程，以产生形状配合和力配合接合。这减少了所需的处理时间，并避免了在多阶段处理期间可能发生的定位误差。第三个资助阶段的重点是调查和提高剪切铆接过程的鲁棒性和剪切铆接接头性能的可预测性。因此，本研究的重点是三个方面：一是分析刀具材料的耐磨性与刀具磨损的影响因素，以评估刀具设计的优劣;除了识别的过程中的限制，过程和批量相关的偏差对接头形成的质量和工具磨损的影响进行检查。根据这些结果，调整工具元件以适应高局部应力，并进行磨损试验。第二个重点是对过程设计的评价。为此，以前分析的单元素样品被多元素样品取代，以检查相邻点对节理形成的影响。一个基本的方法是确定的径向材料流的特征连接性能和设置一个强大的连接过程的限制的影响。分析了接头间距、板厚和附加工艺偏差对接头成形的影响。对所述材料组合的多元素样品进行了接头强度和腐蚀性能测试。最后的研究主题是审查剪切铆接过程中的工艺安全性和测试材料组合。因此，项目前两个阶段的结果与工具和过程方面的结果相结合，并在过程可靠性方面进行评估。特别是，考虑到关节的失效模式，以便能够预测关节特性。将通过排列不同的冲压侧铝合金来评估这些发现的可转移性。该项目是最后的结果总结和剪切铆接过程的整体审查。

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.