Structural integration of force sensors by selective laser melting (AddKraft)

选择性激光熔化(SLM)用于集成传感器的附加制造有望为轻量化建筑、过程监控和医疗技术等不同应用中的结构集成带来巨大的好处。与传统加工相比，这些都是自由成形的形状，可以用激光熔化材料制成密封外壳，并且传感器易于个性化。虽然首次实现了SLM封装的执行器模块，但还没有可持续的方法来增加力传感器的制造。在本项目中，研究了用于力传感器的添加剂制造的变形元件和封装的基本性能。这些元素的制造过程分为三个步骤。首先，使用SLM过程建立结构变形单元的一部分。将暂停构建过程，并将带有施加的力传感器的衬底元素插入预构建变形元素中。在最后一步中，构建过程将继续，直到元素完成。本项目将回答以下研究问题：零件的表面粗糙度和几何精度是否足以集成传感器元件？有可能实现变形元件和传感器元件之间的伸长率的可重复转移吗？有可能控制变形元件和传感器基板中基于热致残余应力的工艺吗？旨在控制残余应力和变形的改进的SLM工艺管理是本项目的基础。现场过程监测将用于测量建造过程的热历史，并预测残余应力和变形元素的变形行为。为了实现传感器元件与变形体之间的焊接，将研究新的工艺参数和界面几何形状。必须开发新的变形体几何形状以利用SLM工艺的优势。在传统变形体的基础上，将提出新的概念，同时考虑到SLM过程的可能性和限制。在此基础研究之后，将构建完整的单维和三维传感器元件，并将在长期研究中测试其功能和性能。

The use of selective laser melting (SLM) for additive manufacturing of integrated sensors promises substantial benefits for structural integration in different applications like light weight construction, process monitoring and medical technologies. These are free shape forming compared to conventional machining, the possibility for hermetic enclosures made of the laser-melted material and easy individualization of the sensors. While there are first realizations of SLM-capsuled actuator modules, there are no sustainable approaches for additive manufacturing of force sensors. In this project, the fundamental aptitude of additive manufactured deformation elements and encapsulations for force sensors is investigated. The manufacturing process of the elements is divided in three steps. First a part of the structural deformation element is build using the SLM process. The build process will be paused and a substrate element with an applied force sensor will be inserted in the pre-build deformation element. In the last step the build process will be resumed until the element is finished. The following research questions will be answered in this project: Is the surface roughness and the geometrical accuracy of the parts sufficient enough to integrate sensor elements? Is it possible to achieve a reproducible transfer of elongation between the deformation element and the sensor element? Is it possible to control the process based thermally induced residual stresses in the deformation element and the sensor substrate? A modified SLM process management which aims to control residual stresses and deformations acts as a base for this project. In situ process monitoring will be used to measure the thermal history of the build process and predict the residual stress and the deformation behaviour of deformation elements. To realize welding between the sensor element and the deformation body new process parameters and interface geometries will be investigated. New deformation body geometries have to be developed to exploit the advantages of the SLM process. Based on traditional deformation bodies new concepts will be developed while taking the possibilities and restrictions of the SLM process into account. After this basic research complete single- and three-dimensional sensor elements will be build and their functionality and properties will be tested in long term studies.