Peng Zizhao, Li Jiahui, Durandet Yvonne, Sola Antonella, Trinchi Adrian, Tran Phuong, Gao Wei, Liu Xuemei, Ruan Dong
Department of Mechanical and Product Design Engineering, School of Engineering, Swinburne University of Technology, Hawthorn, VIC 3122, Australia.
Victorian Hydrogen Hub (VH2), Swinburne University of Technology, Hawthorn, VIC 3122, Australia.
Polymers (Basel). 2025 Aug 27;17(17):2314. doi: 10.3390/polym17172314.
Additively manufactured continuous fibre-reinforced polymers (CFRPs) offer promising mechanical properties for engineering applications, including aerospace and automotive load-bearing structures. However, challenges such as weak interlayer bonding and low strength compared to traditional composites remain. This paper presents an experimental investigation into the effects of nitrogen (N) purging during printing and thermal annealing after printing on the tensile performance of additively manufactured CFRPs. Tensile tests were conducted on Onyx specimens produced by material extrusion and reinforced with continuous carbon fibre filaments (CFF), glass fibre filaments (GFF), or Kevlar fibre filaments (KFF). Results showed that N-purging and post-annealing had different effects on the tensile properties of various CFRPs. Particularly, N-purging, post-annealing, and their combination enhanced both the Young's modulus and ultimate tensile strength (UTS) of KFF/Onyx specimens. For GFF/Onyx specimens, both treatments had a minor effect on the Young's modulus but enhanced UTS. CFF/Onyx specimens exhibited improved Young's modulus with N-purging, while both treatments reduced UTS. The different response of the CFRPs was associated with diverse governing failure mechanisms, as proved by microstructural and fracture surface inspection. Additionally, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analyses also revealed the thermal behaviour and crystal structures that influence the mechanical properties of CFRPs.
增材制造的连续纤维增强聚合物（CFRP）为工程应用提供了有前景的机械性能，包括航空航天和汽车的承重结构。然而，与传统复合材料相比，仍存在诸如层间结合薄弱和强度低等挑战。本文对打印过程中的氮气（N）吹扫以及打印后的热退火对增材制造的CFRP拉伸性能的影响进行了实验研究。对通过材料挤出生产并用连续碳纤维长丝（CFF）、玻璃纤维长丝（GFF）或凯夫拉纤维长丝（KFF）增强的玛瑙石试样进行了拉伸试验。结果表明，N吹扫和退火后处理对各种CFRP的拉伸性能有不同影响。特别是，N吹扫、退火后处理及其组合提高了KFF/玛瑙石试样的杨氏模量和极限拉伸强度（UTS）。对于GFF/玛瑙石试样，两种处理对杨氏模量影响较小，但提高了UTS。CFF/玛瑙石试样在进行N吹扫后杨氏模量有所改善，而两种处理均降低了UTS。微观结构和断口表面检查证明，CFRP的不同响应与多种主导失效机制有关。此外，差示扫描量热法（DSC）和X射线衍射（XRD）分析还揭示了影响CFRP机械性能的热行为和晶体结构。
