Powder based laser material deposition (LMD) is a suitable additive manufacturing technology for repair and overhaul of metal parts as well as for the build-up of new parts. This technology is used in industrial applications as automotive, turbomachinery, aviation, or tool making [T. Jambor, “Funktionalisierung von Bauteiloberflachen durch Mikro-Laserauftrag-schweisen,” Ph.D. thesis, RWTH Aachen University, Germany, 2012; I. Kelbassa, “Qualifizieren des Laserstrahl-Auftragschweisens von BLISKs aus Nickel- und Titanbasislegierungen,” Ph.D. thesis, RWTH Aachen University, Germany, 2006; J. Witzel, “Qualifizierung des Laserstrahl-Auftragschweisens zur generativen Fertigung von Luftfahrtkomponenten,” Ph.D. thesis, RWTH Aachen University, Germany, 2014; R. Poprawe, Tailored Light 2 (Springer, Berlin, 2011), pp. 209–224]. The repair of turbine blade tips, for example, requires dimensional accuracy of the deposited volume to achieve sufficient overhang necessary for postweld machining and simultaneously reduces the time and efforts for machining to a minimum. Typically, the repair of a turbine blade tip is carried out layer by layer, and each layer starts with the deposition of a contour track. This contour track is important for outer geometry and therefore for the dimensional accuracy of the volume to be deposited. In order to determine the influence of the contour track on deposit geometry, a basic research in laser material deposition on edges of plates is carried out. During the research presented in this paper, the geometries of single tracks and webs deposited on edges are investigated depending on the distance of the track to the edge of the plate, on the lateral offset of the tracks of two successive layers, and the number of overlapping tracks in one layer. The melt pools are monitored by high-speed videography to analyze melt pool geometry and the characteristics of the powder grain trajectories of the filler metal. In the future, the results of this research will be used to validate a simulation tool that has been developed to simulate LMD on edges with the aim to reduce the number of experimental studies.

中文翻译：

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粉末基激光材料在边缘沉积

粉末基激光材料沉积 (LMD) 是一种适用于金属零件维修和大修以及新零件组装的增材制造技术。该技术用于汽车、涡轮机械、航空或工具制造等工业应用中 [T. Jambor，“Funktionalisierung von Bauteiloberflachen durch Mikro-Laserauftrag-schweisen，”博士。论文，亚琛工业大学，德国，2012；I. Kelbassa, “Qualifizieren des Laserstrahl-Auftragschweisens von BLISKs aus Nickel- und Titanbasislegierungen,”Ph.D. 论文，亚琛工业大学，德国，2006；J. Witzel，“ Qualifizierung des Laserstrahl-Auftragschweisens zur generateerativen Fertigung von Luftfahrtkomponenten，”博士。论文，亚琛工业大学，德国，2014；R. Poprawe, Tailored Light 2 (Springer, Berlin, 2011), pp. 209–224]。例如，涡轮叶片尖端的修复需要沉积体积的尺寸精度，以​​实现焊后加工所需的足够悬垂，同时将加工时间和工作量减少到最低限度。通常，涡轮叶片尖端的修复是逐层进行的，每一层都从轮廓轨迹的沉积开始。该轮廓轨迹对于外部几何形状很重要，因此对于要沉积的体积的尺寸精度很重要。为了确定轮廓轨迹对沉积几何形状的影响，进行了板材边缘激光材料沉积的基础研究。在本文介绍的研究过程中，根据轨道到板边缘的距离，研究了单个轨道和沉积在边缘上的腹板的几何形状，关于两个连续层的轨迹的横向偏移，以及一层中重叠轨迹的数量。熔池通过高速摄像进行监控，以分析熔池几何形状和填充金属粉末颗粒轨迹的特征。未来，这项研究的结果将用于验证一种模拟工具，该工具已开发用于模拟边缘 LMD，旨在减少实验研究的数量。