Additive manufacturing (AM) process parameters highly affect the mechanical and fracture properties of additively manufactured carbon fiber reinforced polymer (CFRP) composites. In this work, we study the effect of two process parameters, including build orientation (XYZ, XZY, and ZXY) and raster pattern ( ± 45º and 0º/90º), on the fracture behavior of the CFRP composites fabricated by fused filament fabrication (FFF). The mode I fracture toughness and effective fracture energy of the CFRP composite materials are measured on compact tension samples. The crack growth direction in the FFF-fabricated CFRP composites is found to be controlled by both build orientation and raster pattern. The fracture toughness of the examined CFRP material is sensitive to build orientation, while the effective fracture energy reveals significant dependence on both build orientation and raster pattern. The samples fabricated with the XYZ and ZXY build orientations exhibit 5-fold greater effective fracture energy than the ones with the XZY build orientation. A wide range of fracture energy dissipation mechanisms, including fiber-bridging and fiber pull-out, are identified depending on the process parameters. The reported fracture trends in this study have the potential to provide guidelines for the development of FFF-fabricated CFRP composites with high fracture resistance.

增材制造 (AM) 工艺参数极大地影响了增材制造的碳纤维增强聚合物 (CFRP) 复合材料的机械和断裂性能。在这项工作中，我们研究了两个工艺参数，包括构建方向（XYZ、XZY 和 ZXY）和光栅图案（± 45º 和 0º/90º）对熔丝制造制造的 CFRP 复合材料的断裂行为的影响（ FFF）。CFRP 复合材料的 I 型断裂韧性和有效断裂能在致密拉伸样品上进行测量。发现 FFF 制造的 CFRP 复合材料中的裂纹扩展方向受构建方向和光栅模式的控制。被检查的 CFRP 材料的断裂韧性对构建方向很敏感，而有效断裂能量显示出对构建方向和光栅模式的显着依赖性。以 XYZ 和 ZXY 构建方向制造的样品的有效断裂能比具有 XZY 构建方向的样品高 5 倍。根据工艺参数确定了广泛的断裂能量耗散机制，包括纤维桥接和纤维拉出。本研究报告的断裂趋势有可能为开发具有高抗断裂性的 FFF 制造的 CFRP 复合材料提供指导。包括纤维桥接和纤维拉出，取决于工艺参数。本研究报告的断裂趋势有可能为开发具有高抗断裂性的 FFF 制造的 CFRP 复合材料提供指导。包括纤维桥接和纤维拉出，取决于工艺参数。本研究报告的断裂趋势有可能为开发具有高抗断裂性的 FFF 制造的 CFRP 复合材料提供指导。