Additive manufacturing with polymers is typically performed using techniques such as stereolithography, selective laser sintering (SLS), or fused deposition modeling. SLS of unmodified powders with CO₂ lasers represents the state of the art in powder-based polymer additive manufacturing. In the presented work, thermoplastic polyurethane was successfully processed for the first time with a powder feed technique, which is similar to the well-known laser metal deposition. The powder material was doped with carbon black in order to increase the absorptivity of the powder material for laser radiation in the near-infrared range. Various geometries were produced using a standard laser cladding setup with a modified powder feeding system and an Nd:YAG laser. The powder material and the generated structures were characterized by scanning electron microscopy. Structural properties, e.g., porosity, were controlled by different fabrication strategies and process parameters. Furthermore, hybrid structures consisting of metal and polymer parts were successfully produced in the same experimental setup by using two different powder feeders.

中文翻译：

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通过激光聚合物沉积直接生成 3D 结构

聚合物增材制造通常使用立体光刻、选择性激光烧结 (SLS) 或熔融沉积建模等技术进行。含有 CO ₂的未改性粉末的 SLS激光代表了基于粉末的聚合物增材制造的最新技术。在目前的工作中，热塑性聚氨酯首次成功地采用粉末进料技术进行加工，这类似于众所周知的激光金属沉积。粉末材料掺杂有炭黑，以增加粉末材料对近红外范围激光辐射的吸收率。使用标准激光熔覆装置、改进的粉末进料系统和 Nd:YAG 激光器生产各种几何形状。通过扫描电子显微镜表征粉末材料和生成的结构。结构特性，例如孔隙率，由不同的制造策略和工艺参数控制。此外，