Nanocomposites and nanomaterials

Thermodynamic study
 of Al – 1.5 % MWCNTs nanocomposites
T. Dorbani1, M.C. Bouleklab1, S. Hamamda1, Y. Naoui1,                            S.G. Nedilko2, S. Revo2
1 Laboratory of Thermodynamics and Surface Treatment of Materials, University brothers Mentouri Constantine 1, Algeria. 

2 National Taras Shevchenko University of Kyiv, Ukraine. 
64/13, Volodymyrska str., Kyiv-01601, Ukraine. 
E-mail: SGNedilko@gmail.com

In this work, we cover the role of incorporating 1.5% MWCNTs into aluminum matrix. The samples were prepared using a powerful 50 g acceleration planetary ball mill to obtain a homogeneous dispersion of the MWCNTs.
The measurements of coefficient of thermal expansion (CTE) were proceed following the directions:
αx: parallel to the rolling direction X,
αy: perpendicular to the rolling direction Y,
αz: perpendicular to the rolling plane Z.

Dilatometry data has shown the behavior of the coefficient of thermal expansion is strongly anisotropic. In the base plane, α is isotropic. This implies that the effect of MWCNTs in the base plan is about the same. This can be attributed to the homogeneous distribution of MWCNTs. 
On the other hand, αz differs completely from αy and αx, hence the presence of a strong anisotropy. At high temperature range αz is linear and practically constant. It is the same order of magnitude as that of the nanotubes themselves.
The DSC signal of Al + 1.5% MWCNTs was weak compared to that of pure aluminum prepared following the same protocol.
The weight loss is negligible compared to that of pure aluminum.
Raman spectra shows that the ID/IG ratio low implying that the milling process did not deteriorate the MWCNTs.