Evolution of the lattice defects and crystalline domain size in carbon nanotube metal matrix composites processed by severe plastic deformation
Evolution of the lattice defects and crystalline domain size in carbon nanotube metal matrix composites processed by severe plastic deformation
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DOI：
10.1016/j.matchar.2019.06.019
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发表时间：
2019-08
影响因子：
4.7
通讯作者：
K. Aristizabal;A. Katzensteiner;M. Leoni;F. Mücklich;S. Suárez
中科院分区：
文献类型：
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作者：
K. Aristizabal;A. Katzensteiner;M. Leoni;F. Mücklich;S. Suárez
通过高压扭转（HPT）加工镍（Ni）和碳纳米管（CNT）增强镍基复合材料。使用全粉末图案模型 (WPPM) 通过 X 射线衍射 (XRD) 分析位错密度和晶域尺寸的演变。随着施加应变的增加，复合材料在微观结构细化和硬度方面表现出明显的梯度。人们发现，当碳纳米管含量较高时，这种效应更加明显。特别是，HPT 后通过 WPPM 测量到了更高量的螺旋位错。结论是，HPT 处理的 CNT-MMC 的强化主要是由于加工硬化和晶粒细化，这两种机制都受到 CNT 存在的辅助，颗粒强化的贡献很小。
Nickel (Ni) and carbon nanotube (CNT)-reinforced Ni-matrix composites were processed by high-pressure torsion (HPT). The evolution of dislocation densities and crystalline domain sizes were analyzed by means of X-ray diffraction (XRD) using Whole Powder Pattern Modelling (WPPM). The composites showed an evident gradient in the microstructural refinement and in hardness with increasing applied strain. This effect was found to be more pronounced in the presence of higher amounts of CNT. In particular, a higher amount of screw dislocations was measured by WPPM after HPT. It was concluded that the strengthening of CNT-MMC processed by HPT is mainly due to work hardening and grain refinement, both mechanisms being assisted by the presence of CNT, with marginal contribution of particle strengthening.