Process development and sensor-supported process monitoring and control of laser additive manufactured implants with complex external geometries and internal structures

添加制造，特别是基于激光的粉末床熔化技术，使复杂部件和小批量的制造成为可能。因此，这种方法注定要用于制造针对患者的植入物，通过有针对性地使用分级格子结构，可以局部地对其硬度进行分级。因此，SP-1的总体目标是可重复加工由具有可调节、分级孔隙率的Ti-6Al-4V制成的患者专用植入物。为此，必须根据激光粉床熔化的工艺条件，设计相应的力学性能、表面形貌、腐蚀性能和失效性能，并研究它们之间的影响和相互作用。为了局部调整刚度，生成了梯度TPMS格子结构(三周期极小曲面)，并改变其几何参数，以适应有限元模拟(有限元)确定的载荷情况。此外，SP-1还收集了在线工艺监测数据，目的是能够将熔池几何形状和工艺排放与设定的工艺参数、所产生的表面和微观结构以及所产生的部件性能相关联。为了研究表面形貌(如高粗糙度)和复杂的TPMS晶格结构对涂层过程和组织集成的影响，向其他子项目提供了不同的样品。基于细胞和生物相容性研究的结果，提出了迭代地进一步开发表面形貌和晶格结构的挑战。根据实验设计方法(DoE)对实验进行了计划、实施和分析。通过这种方式，开发的经验模型可以显示相关性和相互作用，并可以在未来用于为单个植入物选择合适的工艺设置。

Additive manufacturing, especially the laser-based powder bed fusion technique, enables the manufacturing of complex components and small batches. This method is therefore predestined for the manufacturing of patient-specific implants, which can be locally graded in their stiffness through the targeted use of graded lattice structures. The overall aim of SP-1 is therefore the reproducible processing of patient-specific implants made of Ti-6Al-4V with adjustable, graded porosity. For this purpose, the mechanical properties, surface topography, corrosion and failure properties must be designed accordingly via the process conditions of the laser-based powder bed fusion process and their influences and interactions must be investigated. To locally adjust the stiffness, graded TPMS lattice structures (triply periodic minimal surface) are generated and their geometric parameters are varied, examined and adapted to the load situations determined by FE simulations (finite elements). In addition, online process monitoring data is collected in SP-1 with the aim of being able to correlate the melt pool geometry and process emissions with the set process parameters, the resulting surface and microstructure and the resulting component properties. In order to investigate the influence of the surface topography (e.g. high roughness) and the complex TPMS lattice structures on the coating process and tissue integration, different samples are made available to the other sub-projects. Based on the results of the cyto- and biocompatibility studies, the challenge arises to iteratively further develop the surface topography and the lattice structure. The experiments are planned, carried out and analyzed based on the Design of Experiments approach (DoE). This way a developed empirical model can show correlations and interactions and can be used in the future to select suitable process settings for individual implants.