Ex Situ Fabrication of Multiwalled Carbon Nanotube-Reinforced Aluminum Nanocomposite via Conventional Sintering and SPS Techniques

The present study is based on the fabrication of multiwalled carbon nanotube (MWCNT)-reinforced Al-based metal matrix nanocomposite (AMnC) by conventional and spark plasma sintering (SPS) techniques. Acomparative analysis is done between the Al-MWCNT nanocomposites fabricated by these sintering techniques. Analytical characterization like SEM, HRTEM XRD, Raman spectroscopy, and FTIR was performed to determine the microstructure, strengthening mechanism, chemical bonding, and densification process in the nanocomposites. 1, 2, and 3 wt.% MWCNT-reinforced AMnCs have been fabricated following the ex situ powder metallurgy (PM) technique. The result indicates a significant increase in the mechanical properties up to 1 wt.% MWCNT addition to the Al matrix for conventionally sintered nanocomposites as that beyond 1 wt.% nanofiller addition, MWCNT starts to agglomerate resulting to be detrimental to the performance of the AMnCs. The 1 wt.% SPSed AMnC showed similar to 200%, similar to 50%, similar to 10%, similar to 34%, and similar to 77.4% increase in the values of modulus, compression strength, density, hardness, and wear rate with respect to conventionally sintered 1 wt.% reinforced AMnC. However, SPSed nanocomposites exhibit superior mechanical properties in contrast to the conventionally sintered nanocomposites which is attributed to the improvement in the densification, grain size, and uniform MWCNT distribution.