Abstract A novel carbon nanotubes (CNTs)-reinforced magnesium (Mg) matrix composite was successfully fabricated via an in situ synthesis of Mg on the surfaces of CNTs and a powder metallurgy (PM) process. The nanoscale Mg grains were first synthesized in situ on CNTs via the solid-state displacement reaction of lithium (Li) to Mg in anhydrous magnesium chloride (MgCl2) to obtain Mg-encapsulated CNTs (CNTs@Mg) composite powders. These were used to fabricate CNTs@Mg bulk composites via the PM method. In the CNTs@Mg in situ composite structure, the synthesized Mg grains were in contact with CNTs in a stacking manner, and nanoscale contact and diffusion bonding occurred at the CNTs–Mg interface, realizing not only strong interface bonding between CNTs and Mg but also the dispersion of CNTs in the Mg matrix. The CNTs@Mg composites exhibited improved mechanical properties. The microhardness, ultimate tensile strength (UTS), and breaking elongation of 4.0 wt% CNTs@Mg bulk composite were increased by approximately 43.5%, 33.4%, and 31.3% compared with pure Mg bulk, respectively. Furthermore, the mechanical properties of the CNTs@Mg bulk composites were superior to those of CNT/Mg composites fabricated via the traditional addition process. Therefore, the investigated CNTs@Mg composites are promising candidates for the field of lightweight structural materials.

中文翻译：

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新型原位合成工艺制备的碳纳米管增强镁基复合材料的微观结构和性能

摘要 通过在碳纳米管表面原位合成镁和粉末冶金（PM）工艺，成功制备了一种新型碳纳米管（CNTs）增强镁（Mg）基复合材料。首先通过锂（Li）与无水氯化镁（MgCl2）中的Mg的固态置换反应在CNT上原位合成纳米级Mg颗粒，以获得Mg包封的CNT（CNTs@Mg）复合粉末。这些用于通过 PM 方法制造 CNTs@Mg 块状复合材料。在 CNTs@Mg 原位复合结构中，合成的 Mg 颗粒以堆叠的方式与 CNTs 接触，在 CNTs-Mg 界面发生纳米级接触和扩散结合，不仅实现了 CNTs 和 Mg 之间的强界面结合，而且碳纳米管在镁基体中的分散。CNTs@Mg 复合材料表现出改善的机械性能。与纯 Mg 块体相比，4.0 wt% CNTs@Mg 块体复合材料的显微硬度、极限拉伸强度 (UTS) 和断裂伸长率分别提高了约 43.5%、33.4% 和 31.3%。此外，CNTs@Mg 块状复合材料的机械性能优于通过传统添加工艺制备的 CNT/Mg 复合材料。因此，所研究的 CNTs@Mg 复合材料是轻质结构材料领域的有希望的候选者。CNTs@Mg 块状复合材料的机械性能优于通过传统添加工艺制备的 CNT/Mg 复合材料。因此，所研究的 CNTs@Mg 复合材料是轻质结构材料领域的有希望的候选者。CNTs@Mg 块状复合材料的机械性能优于通过传统添加工艺制备的 CNT/Mg 复合材料。因此，所研究的 CNTs@Mg 复合材料是轻质结构材料领域的有希望的候选者。