Predicting the influence of material composition on the printability of highly filled metal powder-polymer systems present a significant challenge in metal fused filament fabrication (MF³). The current work presents an approach to evaluate new material compositions used to fabricate filaments for their printability. In this study, filaments with 59 vol.% (87 wt.%) of Ti-6Al-4V powder with two particle size distributions {fine (D₅₀ = 13 μm) and coarse (D₅₀ = 30 μm)} dispersed in a polymer matrix were examined. The respective forces to overcome the pressure drop, for successful printing, were found to increase with an increase in the feed rate, and were also dependent on the feedstock viscosity. In addition, shear forces estimated from the filament shear strength were found to be limiting conditions for successful printing. Based on these observations, a criterion has been proposed to evaluate filament printability from the predicted limiting force for filament failure and the required force to achieve continuous material flow for successful printing. Under present experimental conditions, successful printing was achieved up to 2 mm/s and 8 mm/s for fine and coarse powder filaments, in good agreement with the model predictions. The model was experimentally tested and found to be applicable for other compositions. The results demonstrate a new printability criterion to design novel materials for MF³.

预测材料组成对高度填充的金属粉末-聚合物体系可印刷性的影响，对金属熔丝制造（MF ³）提出了重大挑战。当前的工作提出了一种评估用于制造细丝的可印刷性的新材料成分的方法。在这项研究中，长丝具有59％（体积）（87％（重量））的Ti-6Al-4V粉末，具有两种粒径分布（细（D ₅₀  = 13μm）和粗（D _50） ＝30μm）}分散在聚合物基质中。发现为成功印刷而克服压降的相应力随着进料速率的增加而增加，并且还取决于原料粘度。另外，发现从长丝剪切强度估计的剪切力是成功印刷的限制条件。基于这些观察，已经提出了一种标准，用于根据预测的细丝故障极限力和为获得成功的印刷而获得连续的材料流动所需的力来评估细丝的可印刷性。在目前的实验条件下，细粉和粗粉丝的成功印刷速度分别达到2 mm / s和8 mm / s，与模型预测非常吻合。该模型经过实验测试，发现适用于其他组合物。结果表明，设计用于MF的新型材料的新可印刷性标准³。