Fused filament fabrication (FFF) is a process where thermoplastic materials are heated to its melting point and then extruded, layer by layer, to create a three dimensional printed part. Printing occurs in a layered manner, which leads to creation of voids (air gaps) in the 3D printed parts. These voids act as centers for crack initiation, propagation and therefore resulting bulk mechanical properties are lower. This paper focuses on microstructural characterization and analysis of fused filament fabricated tensile test coupons made from acrylonitrile butadiene styrene polymer, at various design conditions. Comparable tensile modulus with injection molded specimens was obtained for FFF design condition that is, slice height (0.1778 mm), raster width (0.4064 mm), raster to raster air gap (−0.0015 mm), contour to raster air gap (−0.0508 mm) and raster angle (0°). Scanning electron microscope studies provided an understanding as to why FFF processed specimens yielded lower failure strain and an insight into the presence of intralayer voids in specimens having lower tensile modulus. The study confirmed that though bulk mechanicals were affected by the combined effect of inter, intra and interfacial voids, intravoids had a predominant influence.

中文翻译：

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3D打印的丙烯腈丁二烯苯乙烯热塑性塑料零件的组织和力学性能检查

熔融长丝制造（FFF）是一种过程，其中将热塑性材料加热到其熔点，然后逐层挤出，以形成三维印刷件。打印以分层的方式进行，这会导致在3D打印的部件中产生空隙（气隙）。这些空隙充当裂纹萌生，扩展的中心，因此导致的整体机械性能较低。本文致力于在各种设计条件下对由丙烯腈-丁二烯-苯乙烯聚合物制成的熔融长丝制备的拉伸测试试样的微观结构进行表征和分析。对于FFF设计条件，获得了与注塑样品可比的拉伸模量，即切片高度（0.1778 mm），光栅宽度（0.4064 mm），光栅与光栅气隙（-0.0015 mm），轮廓与光栅气隙（-0）。0508毫米）和光栅角度（0度）。扫描电子显微镜研究提供了有关为何FFF处理的样品产生较低的破坏应变的理解，以及对具有较低拉伸模量的样品中存在层内空隙的理解。这项研究证实，尽管整体力学受界面空隙，内部空隙和界面空隙的综合影响，但空隙是主要的影响因素。