Holistic development and characterization of an efficient manufacturing of detachable joints for aluminium and magnesium lightweight materials

金属轻量化材料在交通工程的许多领域被用于提高动态范围、优化资源和减少排放。铝组件是通过焊接、粘合和螺钉连接的方式制造的。摩擦钻孔作为一种后续螺纹制造的成型工艺，可以利用局部材料膨胀，在轻质型材中制造出可用螺纹深度大于型材厚度的内螺纹。此外，与传统的螺纹加工相比，直接制造在节省时间和成本方面具有巨大的潜力。在本研究项目中，应开发一种可靠的铝镁合金AlSi10Mg和AZ91的摩擦钻孔概念，通过螺纹成形产生可拆卸接头。螺纹成形的优点是它是一个非切削过程，与攻丝相比，在边缘区域会导致加工硬化。将使用先进的摩擦钻孔工艺，其中工件前端扩展。操作范围明显扩大，无需额外设计功能即可实现型材连接的连接。测试方法应采用应用优化的测量传感器技术，通过适当数量的测试样品来表征内螺纹的准静态和循环材料行为。所选工艺参数在制造过程中发生变化，并与力学表征方法进行比较评价。结果的反馈可以实现资源优化和高效的螺纹加工。拟议研究项目的目的包括整体开发，表征和优化创新的摩擦钻孔工艺，以及随后的铝和镁合金螺纹制造。重点研究了基于模型的过程-结构-属性关系的关联。内螺纹的几何和微观性能与力学性能密切相关，因此基于结构的损伤机理分析有助于优化工艺参数的设计。

Metallic lightweight materials are used for enhancing the dynamic range, resource optimization andemission reduction in many fields of traffic engineering. Aluminum components are manufactured by means of welded, adhesive and screw joints. Friction drilling, as a forming process with subsequent manufacturing of threads, offers the opportunity to produce an internal thread in lightweight profiles with a usable thread depth larger than the profile thickness, making use of local material expansion. Moreover, the direct manufacturing offers a huge potential for time and cost saving in comparison to conventional thread machining.In this research project a reliable friction drilling concept for aluminium and magnesium alloys AlSi10Mg and AZ91 shall be developed to generate detachable joints by means of thread forming. Thread forming offers the advantage that it is a non-cutting process and leads to work hardening in the border area compared with tapping. An advanced friction drilling process will be used, where the work piece is front-end expanded. The operational range is distinctly extended and joinings for profile connections can be realized without additional design features. Test methods shall be applied by means of application-optimized measurement sensor technology to characterize the quasistatic and cyclic material behavior of internal threads with an appropriate amount of tested specimens. Selected process-relevant parameters are varied during the manufacturing and comparatively evaluated with the mechanical characterization methods. The feedback of the results allows a resource optimized and efficient thread machining.The aim of the proposed research project includes the holistic development, characterization and optimization of an innovative friction drilling process with subsequent thread manufacturing in aluminium and magnesium alloys. Especially the model based correlations of the process-structure-property-relations are to be investigated. The process related geometrical and microstructural properties of internal threads are correlated with the mechanical properties, whereby a structure-based analysis of the damage mechanisms leads to a comprehension of an optimal process parameter designing.