title: Thermal analysis of Al + 0.1% CNT ribbon.
abstract: The objective of this work is a dilatometric study of Al + 0.1% of multiwall carbon nanotubes nanocomposite material (NCM) in three directions: X - parallel to the rolling direction; Y - perpendicular to the rolling direction and (Z) perpendicular to the ribbon plane. NCM specimens were made in the form of a 0.1-mm-thick ribbon. The temperature range used for measurements was 20°C to 600°C. The obtained results show that presence of nanotubes affects the thermal expansion coefficient (TEC) measured in different directions. αx(T) and αy(T) - TEC plots as a function of temperature along X and Y directions, respectively - have substantially the same shape and overlap in the area of 400°C. The expansion along X-axis becomes greater than along Y-axis below this temperature value. It is clear that the coefficient αz(T) is lower than αx(T) and αy(T) over the entire temperature range. The expansion along Z-axis is smaller compared to that along X- and Y-axes. This behaviour suggests that there is a strong interatomic interaction along this direction (Z). αz(T) becomes monotonous and constant and is equal to 8 × 10(-6)°C(-1) at temperatures above 300°C. Such order of magnitude had not been obtained in earlier studies of aluminium alloys. The obtained TEC shows high anisotropy, which grows with the increase of temperature. The heat flow (differential scanning calorimetry, (DSC)) of Al + 0.1% carbon nanotubes (CNT) NCM is more intense compared to that of pure aluminium produced in similar conditions. The two representative curves have similar shape and are almost entirely overlapped. The thermogravimetry results confirm those of DSC. The Raman spectrum of this nanomaterial shows that intensity of G and D bonds is significantly increased compared to that of the pure material. The infrared diagram also confirms that in this case the mentioned bonds are more intensive NCM. The tensile strength measurements (σB) of the studied NCM also demonstrate that its value increases from 140 ± 10 MPa for Al without nanotubes to 200 ± 10 MPa for NCM.
authors.affiliation: Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, 01601 Kyiv, Ukraine.
authors.forename: Sergiy
authors.initials: S
authors.lastname: Revo
authors.affiliation: Laboratory of Thermodynamics and Surface Treatment of Materials, Constantine University 1, B.P. 325 Route Ain El Bey, Constantine, 25017 Algeria.
authors.forename: Smail
authors.initials: S
authors.lastname: Hamamda
authors.affiliation: Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, 01601 Kyiv, Ukraine.
authors.forename: Kateryna
authors.initials: K
authors.lastname: Ivanenko
authors.affiliation: Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, 01601 Kyiv, Ukraine.
authors.forename: Oleh
authors.initials: O
authors.lastname: Boshko
authors.affiliation: Laboratory of Thermodynamics and Surface Treatment of Materials, Constantine University 1, B.P. 325 Route Ain El Bey, Constantine, 25017 Algeria.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Djarri
authors.affiliation: Laboratory of Thermodynamics and Surface Treatment of Materials, Constantine University 1, B.P. 325 Route Ain El Bey, Constantine, 25017 Algeria.
authors.forename: Abdelhamid
authors.initials: A
authors.lastname: Boubertakh
keywords: Anisotropy; Carbon; Nanomaterial; Nanotube; Ribbon; Thermal expansion