Engineering Strong Intergraphene Shear Resistance in Multi‐walled Carbon Nanotubes and Dramatic Tensile Improvements

Abstract

Strong intergraphene shear resistance is engineered in multi‐walled carbon nanotubes (MWCNTs) by embedding the nanotubes into a compressive‐stressing ceramic environment to exploit the exceptional strength of its inner graphene walls during tensile loading. A dramatic enhancement in the tensile failure load of MWCNT is achieved in the ceramic environment and a new “multi‐wall” failure mechanism is discovered.

Multi-Walled Carbon Nanotube-Aluminum Matrix Composites Prepared by Combination of Hetero-Agglomeration Method, Spark Plasma Sintering and Hot Extrusion

“…Thus, it is highly possible for the well-dispersed Al particles to be decorated with the oppositely charged, long and straight individual MWCNTs during mixing in ethanol. Although the heteroagglomeration method was mainly used for preparation of MWCNT-ceramic matrix composite powders, [15][16][17][18] our study confirms the effectiveness of this method in ethanol media for preparation of homogeneous MWCNT-Al metal matrix composite powders, though some MWCNT agglomerates were observed in higher MWCNT concentrations (e.g., 5.0 vol%). In this method, undesirable issues of MWCNT damage, work hardening and grain refinement of Al powders occurred in ball milling-assisted preparation method, [5][6][7][8] and formation of impurities during binder removal of composite powders happened in nanoscale dispersion method 12) are successfully resolved.…”

“…Here, we prepared the composite powders with uniform MWCNT dispersion by mixing the highly crystalline, surface-functionalized MWCNTs and the Al powders using hetero-agglomeration principle, [15][16][17][18] and fabricated fully dense MWCNT-Al matrix composite bulks by using the SPS and a subsequent hot extrusion process.…”

Sintering in a graphite powder bed of alumina-toughened zirconia/carbon nanotube composites: a novel way to delay hydrothermal degradation

“…The slight deviation of the G and 2D bands of the composites toward higher wavenumbers may be attributed to compressive residual stresses, which is consistent with the measured residual compressive stresses on the surface of the ATZ/G (-12378. [29] and Estili and Kawasaki [30] for the CNT-alumina system. The presence of surface compressive stresses has a beneficial effect on the tribological properties of alumina and alumina/zirconia ceramic prostheses [31,32] because they should impart LTD resistance (in addition to the alumina layer).…”

Multiwalled carbon nanotube-reinforced ceramic matrix composites as a promising structural material

“…The most important objective of this letter is introducing the recently processed, fully dense MWCNT-reinforced ceramic matrix composites to be considered as a promising potential structural material for employment in the severe working conditions, according to the previous achievements [1][2][3][4][5]. Next, as the working condition may affect the mechanical property of MWCNTs in the matrix, which mostly determines the mechanical performance of the composite, a strategy will be briefly introduced to be employed prior to the material selection step to directly investigate the changes in the mechanical response of MWCNTs (embedded in the ceramic matrix) after the composite experiences a specific working condition.…”

“…Multiwalled carbon nanotubes (MWCNTs) with their exceptional characteristics, and considered as a unique toughening-strengthening agent for conventional materials can be employed to reinforce the ceramics to obtain tough and strong structural materials resistant to the strong mechanical impacts and corrosive environments [1][2][3]. Theoretically, these expectations can be achieved if the individually dispersed MWCNTs can be entirely wetted by the ceramic phase, which results in the full density of the processed composite.…”