论文标题
研究金属基质复合材料中的碳纳米管上的结构缺陷，并通过严重的塑性变形处理
Study of the structural defects on carbon nanotubes in metal matrix composites processed by severe plastic deformation
论文作者
论文摘要
最近已经提出，碳纳米管（CNT）是针对谷物生长的稳定剂，即使在通过严重的塑性变形的纳米晶体和超晶粒材料的低温输入下也可能发生。在这项研究中，我们分析了CNT增强镍基质复合材料中具有不同增强重量分数的纳米管上的结构缺陷的演变。复合材料是通过高压扭转处理的，我们使用拉曼光谱作为主要特征技术。结果表明，对于经过高能加工的CNT，仅分析ID/Ig比（如可用文献中提出的）不足以进行评估G频段的转移，从而追踪无形化轨迹由CNT进行。此外，我们观察到，CNT遭受的变形与累积的应变有关，并且与这些复合材料的部分CNT级分有所不同。这与它们承受变形过程中发生的塑性应变的能力有关。另外，有缺陷的状态在实现微观结构改进的饱和度之前达到饱和度。这些结果将有助于有效地优化此类工程复合材料的处理。
Carbon nanotubes (CNT) have been recently proposed as stabilizers against grain growth that can happen even at low temperature inputs in nano-crystalline and ultrafine-grained materials obtained by severe plastic deformation. In this study, we analyzed the evolution of the structural defects on the nanotubes in CNT-reinforced nickel matrix composites with different reinforcement weight fractions. The composites were processed by high pressure torsion, and we used Raman spectroscopy as the main characterization technique. The results indicate that for CNT subjected to highly energetic processing, it is not sufficient to analyze only the ID/IG ratio (as proposed in the available literature), but it is also necessary to evaluate the shifting of the G band, which traces the amorphization trajectory undergone by the CNT. Furthermore, we observed that the deformation suffered by the CNT is related to the accumulated strain and varies with the partial CNT fractions of these composites. This is related to their capacity to withstand the plastic strain that occurs during deformation. In addition, the defective state reaches a saturation before achieving the saturation in the microstructural refinement. These results will help to efficiently optimize the processing of this type of engineering composites.
