Despite the dynamic development of additive manufacturing technologies, including selective laser sintering (SLS), there is still limited information on the impact of key factors in printing strategy, on the properties of three-dimensional (3D) printed parts. Such factors, such as the orientation of printed layers toward the powder bed or elements target dimensions, seem to be particularly important, from both a mechanical and a structural point of view. Besides, the scientific articles mainly focus on the analysis of one type of loading condition in the samples, that is, the uniaxial tensile test, which were printed on industrial SLS printers. This is a considerable limitation because very often not only tensile forces but also compressive forces act on the structural elements. Therefore, this study aimed at evaluating the influence of desktop SLS printed parts' orientation and diameter on their structural and mechanical parameters. The mechanical properties of samples printed from PA12 powder on the desktop SLS 3D printer were tested in uniaxial tensile and compression tests, as well as structural properties were investigated. For the purposes of this article, 5 angular orientations of the samples in relation to the powder bed and three diameters of cylindrical samples were analyzed. The research has shown that in the case of samples subjected to tensile load, the printing strategy is important, and the best mechanical parameters are obtained for parts printed at an angle of 0°, that is, in the powder bed's plane. The highest values of mechanical parameters were obtained for a part oriented at an angle of 0°. In the case of the uniaxial compression test and structural parameters, the parts orientation turned out to be an insignificant factor affecting the tested parameters. However, the diameter of printed elements was proven to have a significant influence; the best geometric and dimensional representation was observed for parts biggest in size.

中文翻译：

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关于打印策略的 PA12 桌面选择性激光烧结打印部件的机械和结构评估

尽管包括选择性激光烧结 (SLS) 在内的增材制造技术在不断发展，但关于打印策略中关键因素对三维 (3D) 打印部件特性的影响的信息仍然有限。从机械和结构的角度来看，这些因素，例如印刷层朝向粉末床的方向或元素的目标尺寸，似乎特别重要。此外，科学文章主要侧重于分析样品中的一种加载条件，即在工业 SLS 打印机上打印的单轴拉伸试验。这是一个相当大的限制，因为通常不仅拉力而且压缩力也作用在结构元件上。所以，本研究旨在评估桌面 SLS 打印部件的方向和直径对其结构和机械参数的影响。在桌面 SLS 3D 打印机上用 PA12 粉末打印的样品的机械性能在单轴拉伸和压缩测试中进行了测试，并研究了结构性能。出于本文的目的，分析了样品相对于粉末床的 5 个角度方向和圆柱样品的三个直径。研究表明，在样品承受拉伸载荷的情况下，打印策略很重要，以 0° 角（即在粉末床平面内）打印的零件可以获得最佳机械参数。对于以 0° 角定向的零件，获得了最高的机械参数值。在单轴压缩试验和结构参数的情况下，部件方向被证明是影响测试参数的一个微不足道的因素。然而，印刷元素的直径被证明具有重大影响；对于尺寸最大的零件，观察到最佳的几何和尺寸表示。