Abstract In recent years, significant advancements in Fused Filament Fabrication (FFF) have enabled this technology to become one of the most leading techniques of Additive Manufacturing (AM) for the production of functional products. The poor mechanical properties of manufactured parts have traditionally imposed considerable limitations on use of FFF processes. These shortcomings have been overcome using new advanced filaments with nanoparticle reinforced components, short-length and continuous fibres, and other composite material processing technologies. Polymers reinforced with graphene nanoplatelets (GNP) have been an effective solution for improving electrical, thermal, and mechanical properties. However, the geometric properties of functional products manufactured with GNP reinforced polymers have not been analysed in spite of being crucial for the manufacture, assembly, and service life of functional products. The aim of this study was to compare an improved PLA polymer (PLA-3D) with a GNP reinforced PLA composite (PLA-Graphene) by analysing the geometric properties of dimensional accuracy, flatness error, surface texture, and surface roughness. The effect of the 3D printing parameters − build orientation (Bo), layer thickness (Lt), and feed rate (Fr) − on the geometric properties of two PLA-based filaments were evaluated. The results showed dimensional accuracy was mainly affected by the build orientation, where an increase in the layer area on the X-Y plane showing the highest dimensional deviation owing to the longer displacements of the extruder accumulating positioning errors. The dimensional accuracy along the Z-axis was not affected by any of the printing parameters nor the accumulation of layers, with results close to nominal ones. The flatness error and surface roughness were strongly conditioned by building orientation, with the best results obtained in the flat orientation. Neither of the compared materials showed significant variations between them in geometric properties, with similar results in the tested printing conditions.

中文翻译：

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FFF技术应用于增材制造的未增强PLA与PLA-石墨烯复合材料几何性能对比研究

摘要 近年来，熔丝制造 (FFF) 的重大进步使该技术成为用于生产功能性产品的增材制造 (AM) 的最领先技术之一。制造零件的机械性能差传统上对 FFF 工艺的使用施加了相当大的限制。这些缺点已经通过使用具有纳米粒子增强组件、短长度和连续纤维以及其他复合材料加工技术的新型先进长丝来克服。用石墨烯纳米片 (GNP) 增强的聚合物已成为改善电、热和机械性能的有效解决方案。然而，尽管对功能产品的制造、组装和使用寿命至关重要，但尚未分析使用 GNP 增强聚合物制造的功能产品的几何特性。本研究的目的是通过分析尺寸精度、平面度误差、表面纹理和表面粗糙度的几何特性，比较改进的 PLA 聚合物 (PLA-3D) 与 GNP 增强的 PLA 复合材料 (PLA-石墨烯)。评估了 3D 打印参数 - 构建方向 (Bo)、层厚度 (Lt) 和进给速率 (Fr) - 对两种 PLA 基长丝的几何特性的影响。结果表明，尺寸精度主要受构建方向的影响，其中 XY 平面上层面积的增加显示出最高的尺寸偏差，这是由于挤出机的较长位移积累了定位误差。沿 Z 轴的尺寸精度不受任何印刷参数或层积聚的影响，结果接近标称值。平面度误差和表面粗糙度受建筑方向的强烈影响，在平面方向上获得了最好的结果。两种比较材料在几何特性上均未显示出显着差异，在测试打印条件下的结果相似。平面度误差和表面粗糙度受建筑方向的强烈影响，在平面方向上获得了最好的结果。两种比较材料在几何特性上均未显示出显着差异，在测试打印条件下的结果相似。平面度误差和表面粗糙度受建筑方向的强烈影响，在平面方向上获得了最好的结果。两种比较材料在几何特性上均未显示出显着差异，在测试打印条件下的结果相似。