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

金属轻质材料在交通工程的许多领域都被用来提高动态范围、优化资源和减少排放。铝构件的制造方法有焊接、粘接和螺丝连接。摩擦钻削作为一种随后制造螺纹的成形工艺，提供了利用局部材料膨胀在轻质型材中生产可用螺纹深度大于型材厚度的内螺纹的机会。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，将开发一种可靠的用于铝和镁合金AlSi10 Mg和AZ91的摩擦钻削概念，以通过螺纹成形的方式生成可拆卸的接头。螺纹成形的优点是它是一种非切割过程，与攻丝相比，它可以在边界区域导致加工硬化。将使用先进的摩擦钻削工艺，在该工艺中，工件将被前端展开。使用范围明显扩大，型材连接可以在不增加设计特点的情况下实现连接。应通过应用优化的测量传感器技术应用试验方法，通过适量的试验试件来表征内螺纹的准静态和循环材料特性。选定的与工艺相关的参数在制造过程中会发生变化，并与机械表征方法进行比较评估。结果的反馈使资源优化和高效的螺纹加工成为可能。拟议的研究项目的目标包括整体开发、表征和优化一种创新的摩擦钻削工艺，并随后在铝和镁合金中制造螺纹。特别是基于模型的过程-结构-性质-关系的相关性有待研究。内螺纹与工艺有关的几何和组织性能与机械性能相关，因此，基于结构的损伤机理分析导致对最佳工艺参数设计的理解。

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.