Rossi Arianna, Morettini Giulia, Moretti Michele, Capponi Lorenzo
Industrial Department, University of Perugia, 06125 Perugia, Italy.
Materials (Basel). 2022 May 14;15(10):3530. doi: 10.3390/ma15103530.
The fused filament fabrication (FFF) process is widely used for producing prototypes and functional parts for diverse applications. While FFF is particularly attractive due to its cost-effectiveness, on the other hand, the fabricated parts have limitations in terms of large manufacturing time and reduced mechanical properties. The latter is strongly influenced by the fabrication process parameters, which affect the interlayer bonding and the adhesion between consecutive layers. Several works presented in the literature analysed the correlation between mechanical properties and process parameters. It was demonstrated that an increase in the fabrication feed rate causes slippage between filament and the feeding system, which leads to a decrease in the extruded material flow, and thus in part density. This work aims to investigate how the limitation of the slippage phenomenon affects the mechanical properties of parts fabricated using the FFF process. A prototype machine, equipped with a closed-loop control system on filament transport, was used to fabricate samples for tensile tests and dynamical mechanical analysis. Samples fabricated enabling the filament transport control showed an increase both in ultimate tensile strength and elongation at break for those fabricated with disabled control, whilst a decrease in stiffness was observed. In addition, the results showed that the use of a filament transport control system on a FFF machine increases the possibility of fabricating high value-added parts.
熔融长丝制造（FFF）工艺被广泛用于生产各种应用的原型和功能部件。虽然FFF因其成本效益特别有吸引力，但另一方面，制造的部件在制造时间长和机械性能降低方面存在局限性。后者受到制造工艺参数的强烈影响，这些参数会影响层间结合以及连续层之间的附着力。文献中提出的几项研究分析了机械性能与工艺参数之间的相关性。结果表明，制造进给速度的增加会导致长丝与进给系统之间打滑，从而导致挤出材料流量减少，进而导致部件密度降低。这项工作旨在研究打滑现象的限制如何影响使用FFF工艺制造的部件的机械性能。一台配备了长丝传输闭环控制系统的原型机被用于制造用于拉伸试验和动态力学分析的样品。与未启用控制制造的样品相比，启用长丝传输控制制造的样品的极限抗拉强度和断裂伸长率均有所提高，同时观察到刚度有所降低。此外，结果表明，在FFF机器上使用长丝传输控制系统增加了制造高附加值部件的可能性。
