Experimental and numerical investigations on locally foamable extrusions for additive manufacture of functional hybrid components

拟议项目的主要目标是生产混合功能组件，该组件由挤压铝型材组成，部分由增材制造聚合物定制。在这种情况下，成功地在不同材料类别的金属和聚合物之间建立高质量的键仍然是一个关键的挑战。因此，应在此建议中开发一种新的工艺方法，这将使挤出型材表面局部发泡。铝型材外围区域的开放多孔结构将提供压痕和凹痕，从而通过形式闭合在聚合物组件和金属表面之间建立牢固的连接。为了全面了解这一过程，需要对影响粘结强度的主要因素进行数值模拟和实验模拟。这些参数包括聚合物挤压的参数，以及型材表面几何孔结构的可控修改，这些可以通过挤压铝合金的发泡行为来调节。合适的孔隙大小和孔隙分布应首先使用模拟工具开发，然后将通过改变铝合金的成分和研究挤压的工艺变量来实验实现。数值模型应通过使用x射线显微镜的计算机断层扫描对实际孔隙结构进行测量来验证。功能混合部件的性能也将使用金相分析和机械测试进行评估。

The main objective of the proposed project is the production of hybrid functional components consisting of extruded aluminum profiles that are partly customized by additively manufactured polymers. In this context, the successful creation of a high-quality bond between the different material classes of metals and polymers remains a critical challenge. Hence, a new process approach shall be developed within this proposal, which will enable local foaming of the extruded profile’s surface. The open-porous structure in the peripheral region of the aluminum profile will then provide indentations and undercuts to establish a strong connection between the polymer component and the metal surface by form-closure. In order to gain comprehensive understanding of the process, the main factors influencing the bond strength shall be modeled numerically and experimentally. These include the parameters of polymer extrusion as well as the controlled modification of the geometrical pore structure at the surface of the profile, which can be adjusted by the foaming behavior of the extruded aluminum alloy. Suitable pore sizes and pore distributions shall be developed using simulation tools initially, which will then be realized experimentally by modifications of the composition of the aluminum alloy and an investigation of the process variables of extrusion. The numerical models shall be validated by measurements of the actual pore structures using computed tomography scans with an x-ray microscope. The properties of the functional hybrid components will also be evaluated using metallographic analyses as well as mechanical tests.