Abstract Uniform dispersion and suitable interface are two critical issues to realize the high strengthening potential of carbon nanotubes (CNTs) in metal based composites. In this work, surface modification of CNTs was applied to simultaneously overcome these two challenges in Al matrix composites by a chemical oxidization method. It was found that the functional groups, such as hydroxyl and carboxyl groups, can be successfully decorated on the surface of CNTs by chemical oxidization, thus improving the dispersion of CNTs in ethanol. Concurrently, the morphology of oxidized CNTs and the Al-CNTs interface depend strongly on the activity of the applied oxidants. The mixture of sulphuric acid and hydrogen peroxide can slightly etch the outer walls of CNTs, which benefits the anchoring bonding between the CNTs inner walls and Al matrix, and improves the interface stability, hence exploits the load bearing capacity of the CNTs inner walls and eventually leads to the effective load transfer between Al and CNTs. The outstanding reinforcing effect of surface-modified CNTs was investigated and discussed by the strengthening models. This work provides a new approach to uniformly disperse CNTs and improve interfacial bonding for CNTs reinforced composites simultaneously.

中文翻译：

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化学氧化碳纳米管增强铝基复合材料的机械性能

摘要 均匀分散和合适的界面是实现碳纳米管（CNTs）在金属基复合材料中的高强化潜力的两个关键问题。在这项工作中，碳纳米管的表面改性被应用于通过化学氧化方法同时克服铝基复合材料中的这两个挑战。发现羟基和羧基等官能团可以通过化学氧化成功地修饰在碳纳米管表面，从而提高碳纳米管在乙醇中的分散性。同时，氧化碳纳米管和铝碳纳米管界面的形态在很大程度上取决于所用氧化剂的活性。硫酸和过氧化氢的混合物可以轻微蚀刻碳纳米管的外壁，有利于碳纳米管内壁与铝基体之间的锚固结合，并提高了界面稳定性，从而利用了碳纳米管内壁的承载能力，最终导致铝和碳纳米管之间的有效载荷转移。通过增强模型研究和讨论了表面改性碳纳米管的突出增强效果。这项工作提供了一种新的方法来均匀分散碳纳米管并同时改善碳纳米管增强复合材料的界面结合。