Abstract Increasing interest in 3D-printed high-performance polymers is observed due to their excellent mechanical properties and high resistance to chemical and thermal degradation. One of the ongoing challenges is to achieve sufficient joint strength because of the inertness of thermoplastics. In the current work, effects of surface treatment on shear bond strength of 3D-printed samples were focused and assessed. First, polyetherimide (PEI), polyether ether ketone (PEEK) and PEEK/CF(carbon fiber) as adherend were produced via FDM 3D printing. Then, sanding or atmospheric plasma treatments were carried out to improve the surface wettability of the 3D-printed specimens. Significantly, reduction in surface roughness was observed in sanding treated specimens, while nearly no change occurred in plasma-treated counterparts. However, surface free energy and wettability were greatly improved after plasma treatment. Single lap-shear tests and failure mode for PEI, PEEK and PEEK/CF using two different adhesives (film and liquid) were investigated, and the effect of surface treatment on bond strength was further compared. Results suggested that liquid adhesive contributed higher joint strength for surface-treated specimens in comparison to film adhesive. Besides, atmospheric plasma treatment is more efficient and safer method for 3D-printed PEEK and PEEK/CF, achieving a higher joining strength.

中文翻译：

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打磨和等离子处理对 3D 打印 PEI、PEEK 和 PEEK/CF 剪切粘合强度的影响

摘要 由于 3D 打印的高性能聚合物具有优异的机械性能以及对化学和热降解的高抵抗力，因此它们越来越受到关注。由于热塑性塑料的惰性，目前面临的挑战之一是获得足够的接合强度。在目前的工作中，表面处理对 3D 打印样品的剪切粘合强度的影响进行了重点和评估。首先，通过FDM 3D打印生产聚醚酰亚胺（PEI）、聚醚醚酮（PEEK）和PEEK/CF（碳纤维）作为被粘物。然后，进行打磨或大气等离子体处理以提高 3D 打印样品的表面润湿性。值得注意的是，在打磨处理的试样中观察到表面粗糙度降低，而在等离子处理的试样中几乎没有发生变化。然而，等离子处理后表面自由能和润湿性大大提高。研究了使用两种不同粘合剂（薄膜和液体）的 PEI、PEEK 和 PEEK/CF 的单次搭接剪切试验和失效模式，并进一步比较了表面处理对粘合强度的影响。结果表明，与薄膜粘合剂相比，液体粘合剂对经表面处理的试样具有更高的接合强度。此外，常压等离子体处理是 3D 打印 PEEK 和 PEEK/CF 更有效、更安全的方法，可实现更高的接合强度。结果表明，与薄膜粘合剂相比，液体粘合剂对经表面处理的试样具有更高的接合强度。此外，常压等离子体处理是 3D 打印 PEEK 和 PEEK/CF 更有效、更安全的方法，可实现更高的接合强度。结果表明，与薄膜粘合剂相比，液体粘合剂对经表面处理的试样具有更高的接合强度。此外，常压等离子体处理是 3D 打印 PEEK 和 PEEK/CF 更有效、更安全的方法，可实现更高的接合强度。