Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt- Universität zu Berlin, Dental Materials and Biomaterial Research, Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Aßmannshauser Str. 4-6, 14197, Berlin, Germany; Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, 510056, China.
Bundesanstalt für Materialforschung und -prüfung, Berlin, 12205, Germany.
J Mech Behav Biomed Mater. 2023 Oct;146:106085. doi: 10.1016/j.jmbbm.2023.106085. Epub 2023 Aug 22.
Material extrusion of thermoplastic polymers enables the realization of complex specific designs with high performance composites. The present study aims at evaluating the mechanical properties of carbon fiber-reinforced semi-crystalline thermoplastic polymer polyether ether ketone (CFR-PEEK) manufactured by material extrusion and correlating them with results obtained by micro-CT. Samples in the shape of small bars were provided by Kumovis (Munich, Germany). The determination of surface roughness and density was followed by three-point bending tests. To reveal the pore distribution as well as the fusion quality of CFR PEEK when applied with external forces, micro-CT scans were performed with an X-ray microscope before and after the mechanical test to localize the sites where the fracture is generated. The density of CFR-PEEK bars indicated that they had superior mechanical properties compared with our previous study on unfilled 3D printed PEEK (bending modulus: (5.4 ± 0.5) GPa vs. (1.05 ± 0.05) GPa to (1.48 ± 0.10) GPa; bending strength: (167 ± 11) MPa vs. (51 ± 15) to (193 ± 7) MPa). Micro-CT analyses revealed the local 3D-distribution of voids. Voids of 30 μm diameter are nearly spherical and make up the main part of the total porosity. The larger the voids, the more they deviate from a spherical shape. Significant lack-of-fusion voids are located between the deposited filaments. By growing and merging, they act as seeds for the forming fracture line in the region of the flexural specimens where the maximum local tensile stresses occurred under bending load. Our work provides a detailed analysis of printed PEEK with fiber additive and relates this with mechanical properties.
热塑性聚合物的挤出成型使得具有高性能复合材料的复杂特定设计得以实现。本研究旨在评估由材料挤出制造的碳纤维增强半结晶热塑性聚合物聚醚醚酮（CFR-PEEK）的力学性能，并将其与微 CT 获得的结果相关联。由 Kumovis（德国慕尼黑）提供小棒形状的样品。随后进行表面粗糙度和密度的测定，以及三点弯曲试验。为了揭示 CFR PEEK 在受到外力时的孔隙分布和融合质量，在机械试验前后使用 X 射线显微镜对微 CT 扫描，以定位发生断裂的部位。CFR-PEEK 棒的密度表明，它们具有优于我们之前对未填充 3D 打印 PEEK 的研究的机械性能（弯曲模量：（5.4±0.5）GPa 比（1.05±0.05）GPa 至（1.48±0.10）GPa；弯曲强度：（167±11）MPa 比（51±15）至（193±7）MPa）。微 CT 分析揭示了空隙的局部 3D 分布。直径为 30μm 的空隙几乎呈球形，构成总孔隙率的主要部分。空隙越大，它们偏离球形的程度就越大。在沉积丝之间存在明显的未熔合空隙。它们通过生长和合并，在弯曲载荷下，在弯曲试样的最大局部拉伸应力区域中，充当形成断裂线的种子。我们的工作对具有纤维添加剂的打印 PEEK 进行了详细分析，并将其与机械性能相关联。
