Fused filament fabrication (FFF) is a common additive manufacturing method for polymers that has been widely adopted due to its low cost and ease of use. However, FFF remains limited in high performance applications due to the weak mechanical properties of the welds between printed fibers, including for parts manufactured from acrylonitrile butadiene styrene (ABS). This study uses atomic force microscopy (AFM) to obtain high resolution nanomechanical maps of the distribution of butadiene particles around weld interfaces in FFF-ABS specimens. From quantitative image analysis, a decrease in the average size and density of the polybutadiene particles is observed within a 5–10 µm region across multiple welds. We find that the lack of craze-inducing polybutadiene particles within the weld zone promotes brittle fracture between printed fibers and results in a reduced weld strength as measured by trouser tear experiments. To improve the fracture toughness of FFF-ABS, methods to promote particle migration into the weld region during or after printing could be considered.

熔融长丝制造（FFF）是一种常见的聚合物增材制造方法，由于其低成本和易用性而被广泛采用。但是，由于在印刷纤维之间的焊缝的机械性能较弱，FFF在高性能应用中仍然受到限制，包括用于由丙烯腈丁二烯苯乙烯（ABS）制造的零件。这项研究使用原子力显微镜（AFM）来获得FFF-ABS标本中焊缝界面周围丁二烯颗粒分布的高分辨率纳米力学图。通过定量图像分析，发现在多条焊缝的5-10 µm区域内，聚丁二烯颗粒的平均尺寸和密度降低了。我们发现，在焊接区内缺乏引起裂纹的聚丁二烯颗粒会促进印刷纤维之间的脆性断裂，并导致降低的焊接强度（如通过裤子撕裂实验测得）。为了提高FFF-ABS的断裂韧性，可以考虑在印刷过程中或印刷后促进颗粒迁移到焊缝区域的方法。