The fused filament fabrication (FFF) process of polymer-based composites has been developed due to its capability to make complex geometries and shapes with reasonable mechanical properties. However, the improvement of mechanical properties of the obtained parts and products are still under study and are interesting for designers. There are several strategies to enhance these desired properties of produced pieces, for example optimizing the process parameters and/or using different architecting designs. This paper presents the effect of some overriding process parameters (liquefier temperature, print speed, layer height, and platform temperature) on the temperature evolution and mechanical behavior of PA6 reinforced with chopped carbon fibers produced by FFF. Due to deposition of multilayers, there is a cyclic profile of temperature in the FFF process, which is a considerable note related to fabrication and consequently the strength of the manufactured parts. In parallel with the study of process parameters effect, this cyclic temperature profile has been measured. The preliminary results related to physicochemical and mechanical properties revealed that differences in crystallinity percentage exist and failure stress/strain can be considered as an indicator to evaluate the mechanical properties of FFF manufactured products. Moreover, measuring the temperature profile of the deposited filaments revealed that process parameters have a considerable influence on the cooling process of deposited filaments which itself affects the bonding of adjacent filaments. The higher temperatures led to slower cooling rate. Finally, the results confirm the impact of mentioned parameters roles on the bonding formation in the FFF process and also the subsequent obtained mechanical properties of the printed parts. Therefore, selection of the optimized and suitable process parameters is an important design consideration.

中文翻译：

---

工艺参数对使用熔融长丝制造的聚合物基复合材料的热性能和机械性能的影响

聚合物基复合材料的熔融长丝制造 (FFF) 工艺因其能够制造具有合理机械性能的复杂几何形状和形状而得到开发。然而，获得的零件和产品的机械性能的改进仍在研究中，对设计者来说很有趣。有多种策略可以增强生产件的这些所需属性，例如优化工艺参数和/或使用不同的架构设计。本文介绍了一些重要的工艺参数（液化器温度、打印速度、层高和平台温度）对 FFF 生产的短切碳纤维增强 PA6 的温度演变和机械性能的影响。由于多层沉积，在 FFF 过程中存在温度的循环曲线，这是与制造相关的重要注意事项，因此与制造零件的强度有关。在研究工艺参数影响的同时，还测量了这种循环温度曲线。与物理化学和机械性能相关的初步结果表明，结晶度百分比存在差异，失效应力/应变可作为评估 FFF 制成品机械性能的指标。此外，测量沉积长丝的温度分布表明工艺参数对沉积长丝的冷却过程有相当大的影响，而沉积长丝本身会影响相邻长丝的粘合。较高的温度导致较慢的冷却速度。最后，结果证实了上述参数对 FFF 工艺中粘合形成的影响，以及随后获得的打印部件的机械性能。因此，选择优化和合适的工艺参数是一个重要的设计考虑。