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Utilization of additive manufacturing (AM) is widespread in many industries due to its unique capabilities. These material extrusion methods have been developed extensively for manufacturing polymer and polymer composite materials. The raw material in filament form are liquefied in the liquefier section and are consequently extruded and deposited onto the bed platform. The designed parts are manufactured layer by layer. Therefore, there is a gradient of temperature due to the existence of the cyclic reheating related to each deposited layer by the newer deposited ones. Thus, the stated temperature evolution will have a significant role on the rheological behavior of the materials during this manufacturing process. Furthermore, each processing parameter can affect this cyclic temperature profile. In this study, different processing parameters concerning the manufacturing process of polymer and polymer composite samples have been evaluated according to their cyclic temperature profiles. In addition, the manufactured parts by the additive manufacturing process (the extrusion method) can behave differences compared to the manufactured parts by conventional methods. Accordingly, we attempted to experimentally investigate the rheological behavior of the manufactured parts after the manufacturing process. Thus the three-point bending fatigue and the tensile behavior of the manufactured samples were studied. Accordingly, the effect of the reinforcement existence and its direction and density on the tensile behavior of the manufactured samples were studied. Therefore, this study is helpful for manufacturers and designers to understand the behaviors of the materials during the FFF process and subsequently the behaviors of the manufactured parts as a function of the different processing parameters. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]