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

选择性激光熔化（SLM）用于集成传感器的增材制造，有望为轻质结构、过程监控和医疗技术等不同应用中的结构集成带来实质性好处。与传统机械加工相比，这些是自由形状成形，由激光熔化材料制成的密封外壳的可能性以及传感器的简单个性化。虽然有SLM封装的致动器模块的第一个实现，但没有用于力传感器的增材制造的可持续方法。在这个项目中，增材制造变形元件和力传感器的基本能力进行了研究。元件的制造过程分为三个步骤。首先，使用SLM工艺构建结构变形元件的一部分。构建过程将被暂停，并且具有施加的力传感器的基底元件将被插入预构建变形元件中。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？是否可以在变形元件和传感器元件之间实现可再现的伸长传递？是否可以控制变形元件和传感器基板中基于工艺的热致残余应力？一个修改后的SLM工艺管理，旨在控制残余应力和变形作为本项目的基础。现场过程监测将用于测量构建过程的热历史，并预测变形元件的残余应力和变形行为。为了实现传感器元件和变形体之间的焊接，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工艺的优点。在传统变形体的基础上，将开发新的概念，同时考虑SLM过程的可能性和限制。在此基础研究之后，将建立完整的单维和三维传感器元件，并在长期研究中测试其功能和特性。

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.