Overcoming strength-ductility trade-off by building a micro-nano laminated structure based on an ultralow amount of single-dispersed carbon nanotubes
Overcoming strength-ductility trade-off by building a micro-nano laminated structure based on an ultralow amount of single-dispersed carbon nanotubes
复制标题
DOI：
10.1016/j.ijplas.2023.103805
复制
发表时间：
2023-11
影响因子：
9.8
通讯作者：
Hao Ding;X. Cui;Yuanyuan Zhang;Zhiqi Wang;Naonao Gao;Taiquan Zhang;Jiawei Luo;Xiangxin Zhai-Xiangxin
中科院分区：
文献类型：
--
作者：
Hao Ding;X. Cui;Yuanyuan Zhang;Zhiqi Wang;Naonao Gao;Taiquan Zhang;Jiawei Luo;Xiangxin Zhai-Xiangxin
采用电泳沉积结合放电等离子烧结和控温轧制的方法，成功制备了由CNT纳米层和Ti微层交替组成的新型微纳层状结构的CNT/Ti复合材料（碳纳米管增强钛基复合材料）。尽管CNT的添加量为超低的0.02重量百分比(wt.%)，但与通过相同方法制造的纯Ti相比，CNT/Ti复合材料表现出强度和延展性的同时增强。强度的提高归因于（i）单独分散、结构完整的碳纳米管的高强化效率和（ii）软钛微层和硬碳纳米管纳米层之间的不均匀变形导致的不均匀变形诱导（HDI）强化。此外，微纳层状结构引起的HDI硬化导致额外的加工硬化，增强了CNT/Ti复合材料的均匀变形能力。因此，如原位拉伸实验所观察到的，应变局部化被抑制，从而防止了界面的引发。此外，由于碳纳米管桥接和延性钛微层钝化裂纹尖端，界面裂纹扩展被显着延迟，从而促进了总断裂伸长率。此外，基于裂纹体积的三维可视化和定量分析，提出了由三个阶段组成的渐进断裂过程。这为通过合理设计基于超低用量的高质量纳米级增强体的分层结构，克服传统金属（Ti、Al、Fe、Ni等）基复合材料的强度-延展性权衡提供了新策略。
CNTs/Ti composites (Carbon nanotube reinforced titanium matrix composites) with a novel micro-nano laminated structure consisting of alternating CNTs nanolayers and Ti microlayers were successfully prepared by electrophoretic deposition combined with spark plasma sintering and temperature-controlled rolling. The CNTs/Ti composites exhibited a simultaneous enhancement in both strength and ductility compared to pure Ti fabricated by the same methods, despite the addition of CNTs being an ultra-low 0.02 weight percent (wt.%). The improvement in strength was attributed to (i) the high strengthening efficiency of individually dispersed, structurally intact CNTs and (ii) Heterogeneous deformation-induced (HDI) strengthening resulting from the heterogeneous deformation between soft Ti microlayers and hard CNTs nanolayers. Furthermore, the HDI hardening induced by the micro-nano laminated structure led to extra work hardening, enhancing the uniform deformability of CNTs/Ti composites. Consequently, strain localization was suppressed, as observed by in-situ tensile experiments, thereby preventing the initiation of interfacial. Additionally, interfacial crack propagation was significantly delayed due to CNTs bridging and crack tip blunting by ductile Ti microlayers, thereby promoting the total elongation to failure. Moreover, a progressive fracture process consisting of three stages was proposed, based on three-dimensional visualization and quantitative analysis of crack volumes. This provided a new strategy for overcoming the strength-ductility trade-off of traditional metal (Ti, Al, Fe, Ni, etc.) matrix composites through the reasonable design of a hierarchical architecture based on an ultra-low amount of high-quality nanoscaled reinforcements.