Fabrication of Carbon Nanotube Reinforced Al2O3/Cr2O3
Nanocomposites by Coprecipitation Process |
In
this research the effect of multi-walled carbon nanotubes
(MWCNTs) on the alumina/chromia (Al2O3/Cr2O3) nanocomposites has
been investigated. Al2O3/Cr2O3-MWCNTs nanocomposites with
variable contents of Cr2O3 and MWCNTs were fabricated using
coprecipitation process and followed by spark plasma sintering.
XRD analysis revealed a good crystallinity of sintered
nanocomposites samples and there is only one phase presence of
Al2O3-Cr2O3 solid solution. Density, Vickers microhardness,
fracture toughness and fracture strength have been measured in
the sintered samples. The results show that the relative
density, microhardness and fracture strength of nanocomposites
are significantly improved at low contents of Cr2O3 and MWCNTs.
The increase of MWCNTs content in the nanocomposites has
adversely affected due to increasing the tangle and interaction
of MWCNTs with each other, which leads to agglomeration in the
nanocomposites. While the increasing of Cr2O3 content in
nanocomposites increases formation of Al2O3-Cr2O3 solid solution
that actually requires the high sintering temperature to achieve
good densification. The fracture toughness of Al2O3/Cr2O3-MWCNTs
nanocomposites was enhanced by increasing the carbon nanotube
content. |
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