The inevitable native oxide layer is a critical issue to achieve high mechanical performance of CNT/Al-alloy composites, especially prepared by powder metallurgy. Here, an easy strategy was proposed to avoid and eliminate the negative effect of native oxide (Al₂O₃) layer by Mg addition, and significant improvement of ductility was achieved in the CNT/Al-Cu composite. Native Al₂O₃ remained as continuous layers around CNTs or clusters of fragments in the CNT/Al-Cu without Mg addition. Mg addition transformed the native Al₂O₃ layer into spinel MgAl₂O₄ nano-phases dispersed both inside grains and on the interfaces. It is supposed that this transformation of oxide layer could improve the interfacial bonding due to Al-Al and Al-CNT direct interfacial contact. As a result, compared with CNT/Al-Cu composites, the tensile strength only changed a little, however, almost two times of fracture ductility was achieved by Mg addition in the final composites.

不可避免的天然氧化物层是获得CNT /铝合金复合材料高机械性能的关键问题，尤其是通过粉末冶金制备的复合材料。在此，提出了一种简单的策略来避免和消除通过添加Mg引起的自然氧化物（Al ₂ O ₃）层的负面影响，并且在CNT / Al-Cu复合材料中实现了延展性的显着改善。天然Al ₂ O ₃保留为连续的碳纳米管周围的连续层或碳纳米管/铝铜中的片段簇，而没有添加镁。镁的添加将天然Al ₂ O ₃层转化为尖晶石MgAl ₂ O ₄纳米相分散在晶粒内部和界面上。据推测，由于Al-Al和Al-CNT直接界面接触，氧化物层的这种转变可以改善界面结合。结果，与CNT / Al-Cu复合材料相比，拉伸强度仅改变了一点，但是，通过在最终复合材料中添加Mg，断裂韧性几乎达到了两倍。