Li Qiushi, Zhao Wei, Li Yongxiang, Yang Weiwei, Wang Gong
CAS Key Laboratory of Space Manufacturing Technology, Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences, Beijing 100094, China.
University of Chinese Academy of Science, Beijing 100049, China.
Polymers (Basel). 2019 Apr 10;11(4):656. doi: 10.3390/polym11040656.
Fused deposition modeling possesses great advantages in fabricating high performance composites with controllable structural designs. As such, it has attracted attention from medical, automatic, and aerospace fields. In this paper, the influence of short carbon fibers (SCFs) and the orthogonal building orientation on the flexural properties of printed polyether ether ketone (PEEK) composites are systematically studied. The results show that the addition of SCFs raises the uniform nucleation process of PEEK during 3D printing, decreases the layer-to-layer bonding strength, and greatly changes the fracture mode. The flexural strength of vertically printed PEEK and its CF-reinforced composites show strengths that are as high as molded composites. X-ray micro-computed tomography reveals the microstructure of the printed composites and the transformation of pores during bending tests, which provides evidence for the good mechanical properties of the vertically printed composites. The effect of multi-scale factors on the mechanical properties of the composites, such as crystallization in different positions, layer-by-layer bonding, and porosity, provide a successful interpretation of their fracture modes. This work provides a promising and cost-effective method to fabricate 3D printed composites with tailored, orientation-dependent properties.
熔融沉积成型在制造具有可控结构设计的高性能复合材料方面具有巨大优势。因此，它已引起医学、自动化和航空航天领域的关注。本文系统研究了短碳纤维（SCF）和正交构建方向对打印聚醚醚酮（PEEK）复合材料弯曲性能的影响。结果表明，添加SCF会提高3D打印过程中PEEK的均匀成核过程，降低层间结合强度，并极大地改变断裂模式。垂直打印的PEEK及其CF增强复合材料的弯曲强度显示出与模塑复合材料一样高的强度。X射线微计算机断层扫描揭示了打印复合材料的微观结构以及弯曲试验过程中孔隙的变化，这为垂直打印复合材料良好的力学性能提供了证据。多尺度因素对复合材料力学性能的影响（如不同位置的结晶、逐层结合和孔隙率）成功解释了它们的断裂模式。这项工作提供了一种有前景且经济高效的方法来制造具有定制的、与取向相关性能的3D打印复合材料。
