Thermal Conductivity and Sound Absorption Properties of Carbon Nanotube / Foam Aluminum Composites

Abstract

This article uses powder metallurgy technology to prepare foamed aluminum and carbon nanotubes (CNTs) / foamed aluminum composites. The laser thermal diffusion analyzer, thermal analyzer, and transfer function sound absorption coefficient test system were used to study the thermal conductivity and sound absorption properties of aluminum foam and its composites, respectively. The results show that the thermal conductivity of aluminum foam with 79% porosity is only 5W · m−1·K−1, which is much smaller than the thermal conductivity of aluminum. So it can be used as an ideal thermal insulation material; The thermal conductivity of carbon nanotubes (CNTs) / foamed aluminum-based composites increases first and then decreases with the increase in the mass fraction of CNTs. As the test temperature increases, the thermal conductivity of the material gradually increases. When the mass fraction of CNTs is 0.75%, the thermal conductivity of foamed aluminum-based composites reaches the maximum. As the test frequency increases, the sound absorption performance of foamed aluminum first increases, then decreases, and then gradually increases, reaching a maximum value around 1000 Hz. The sound absorption performance of CNTs / foam aluminum matrix composites decreases at lower test frequencies as the mass fraction of CNTs increases. At higher frequencies, as the mass fraction of CNTs increases, the sound absorption coefficient of foamed aluminum decreases first and then increases.

Carbon Nanotubes/Polyurethane Foam for Noise Passivation at 4000 Hz

“…An increased weight percentage of CNTs had shown diminished property even poorer than neat PU. Foamed aluminum with CNTs is another class of composite widely studied for sound absorption, where an increase in the CNT concentration increased thermal conductivity up to 0.7%, which further decreased with increasing concentration along with maximum sound absorption at 1000 Hz . 3D graphene-CNT composite foam with polydimethyl siloxane is used as a sound-absorbing material showing excellent attenuation in lower frequencies, which get shifted to higher frequencies with an increase of the CNT concentration .…”