The resistivity and thermal coefficient of\ud
resistivity (TCR), of metallic matrix composites, MMCs,\ud
aluminum–carbon nanotube, Al-CNT, were studied under\ud
high vacuum in the temperature interval from RT to 800 K.\ud
The samples shaped as small cylinders and containing\ud
single-walled CNTs or multi-walled CNTs were sintered at\ud
625 C. The resistivity of sintered samples of pure Al was\ud
found three orders of magnitude higher with respect to\ud
bulk, having the former a density value equal to 98.8 % of\ud
bulk Al. The explored range of the CNT concentration was\ud
within 5 wt%. At the highest CNT concentrations, the\ud
trend of resistivity against temperature was found negative\ud
being more pronounced for composites with MWCNTs.\ud
For Al-SWCNT composites, at around 3.3 wt%\ud
(4.2 vol%), TCR is practically independent from temperature;\ud
for Al-MWCNT, the TCR zero-crossing occurs at\ud
different compositions depending on temperature. Higher\ud
is the temperature, lower is the TCR zero-crossing composition.\ud
Resistivity data were discussed in the framework\ud
of the Matthiessen’s rule and sound evidences were shown\ud
that no Al4C3 formation was detected at working\ud
temperatures