Enhancement of joinability and joint characteristics in mechanical joining processes by tailor heat-treated aluminium semi-finished products

通过定制热处理铝半成品，增强机械连接工艺中的可连接性和连接特性

• 批准号: 454200985
• 负责人: Professorin Dr.-Ing. Marion Merklein
• 金额: --
• 依托单位: Lehrstuhl für Fertigungstechnologie (LFT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2021
• 资助国家: 德国
• 起止时间: 2020-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/454200985?language=en
• 关键词: Enhancement; joinability; joint; characteristics; mechanical

The increasing demands on the automotive industry to reduce the vehicle weight and simultaneously increase the crash safety require new design approaches. A material mix of steel and aluminum with increased strengths provides a possible solution for both problems. However, a material mix is also associated with new challenges for joining technology. In this context the use of mechanical joining processes has been intensively investigated in recent years. However, as it is known from the state of the art, the joining of high-strength materials is not yet unlimited possible. Therefore, the aim of the research project is the enhancement of joinability and the resulting bonding strength of high-strength dissimilar materials by the use of a local short-term heat treatment. The softening effect that occurs during the short-term heat treatment of aluminum alloys of the 7000 series can be used to improve the material flow of the high-strength aluminum material located on the punch side. Based on fundamental scientific investigations, the influence of tailor heat-treated blanks on the joining process and on the bonding strength of the joining point will be analyzed. This represents a new field of application for tailor heat-treated semi-finished products, which until now have only been used to expand the forming limits in part manufacturing. By analyzing the complex material flow in the shear-clinching process, a holistic process understanding will be established. Taking into account the interactions involved, an ideal strength distribution in the joining zone should be determined based on numerical models of the short-term heat treatment and the shear-clinching process. By means of experimental investigations the numerical results should be validated and the mechanical properties and the joint strength should be identified.

汽车行业对减轻车辆重量并同时提高碰撞安全性的需求日益增长，需要新的设计方法。强度更高的钢和铝材料组合为这两个问题提供了可能的解决方案。然而，材料混合也给连接技术带来了新的挑战。在此背景下，近年来机械连接工艺的使用得到了深入研究。然而，如从现有技术中已知的，高强度材料的连接还不是无限可能的。因此，该研究项目的目的是通过使用局部短期热处理来增强高强度异种材料的可连接性和由此产生的结合强度。 7000系列铝合金在短期热处理过程中产生的软化效应可用于改善位于凸模侧的高强度铝材料的材料流动。基于基础科学研究，将分析定制热处理毛坯对连接过程和连接点结合强度的影响。这代表了定制热处理半成品的新应用领域，迄今为止，该半成品仅用于扩大零件制造中的成形极限。通过分析剪切铆接过程中的复杂材料流，将建立整体过程的理解。考虑到所涉及的相互作用，应根据短期热处理和剪切铆接过程的数值模型来确定连接区的理想强度分布。通过实验研究，应验证数值结果并确定机械性能和接头强度。