Effects of plasma treatment distance on the adhesion properties of carbon fiber composites were investigated, and the association between the distribution of surface physical characteristics on the composites and their bonding properties was discussed. After plasma treatment at different distances, surface morphology of the bonding area was obtained and the roughness distribution model was established. The change in surface physical characteristics directly influences the wettability of the bonding surface and the tensile shear strength (TSS) of the bonded components. When the TSS showed an increase by 19.47% at the treatment distance of 15 mm, metallographic images indicated that the bonding layer was integrated with the composites and the joint in the component was dominated by cohesive failure. When the TSS showed a decrease by 30.72% at the treatment distance of 5 mm, metallographic images indicated that voids and delamination were introduced in the bonding layer and fiber tearing failure mode appeared in the plasma etched area. Moisture‐heat resistance of the bonded components was also considered and a noticeable increase in water absorption was observed in the case of excessive treatment at the distance of 5 mm, which was also related to the distribution of physical characteristics induced by the plasma treatment.Highlights Surface characteristic distribution of plasma‐modified composites was analyzed. State of resin and fibers on composite surface varied with the treatment distance. Semi‐annular plasma treatment traces appeared in the roughness distribution. The high roughness in the distribution played a key role in bonding properties. Performance degradation due to close treatment was also distribution‐dependent.

中文翻译：

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碳纤维复合材料表面物理特性分布与粘结性能的关联分析

研究了等离子体处理距离对碳纤维复合材料粘合性能的影响，并讨论了复合材料表面物理特性的分布与其粘合性能之间的关系。经过不同距离的等离子处理后，获得了键合区的表面形貌，并建立了粗糙度分布模型。表面物理特性的变化直接影响粘合表面的润湿性和粘合部件的拉伸剪切强度（TSS）。当处理距离为 15 mm 时，TSS 增加 19.47%，金相图像表明粘结层与复合材料一体化，且组件中的接头以内聚破坏为主。当处理距离为5 mm时TSS下降30.72%时，金相图像表明粘合层中引入了空洞和分层，等离子蚀刻区域出现了纤维撕裂失效模式。还考虑了粘合部件的耐湿热性，在5毫米距离处过度处理的情况下，观察到吸水率明显增加，这也与等离子处理引起的物理特性的分布有关。 分析了等离子体改性复合材料的表面特征分布。 复合材料表面树脂和纤维的状态随处理距离的变化而变化。 粗糙度分布中出现半环形等离子体处理痕迹。 分布中的高粗糙度对粘合性能起着关键作用。 由于密切治疗而导致的性能下降也与分布有关。