Enhancement of thermal–mechanical performances via a selective CNTs configuration in laminated CNTs/AZ31B composite

Abstract

Magnesium alloy is an excellent lightweight material. While the alloying process improves mechanical properties, it often reduces material thermal conductivity. An effective way to balance these two properties is to add CNTs. In this paper, a novel laminated CNTs/AZ31B composite was fabricated by introducing CNTs with selective configuration. First, the specific configuration of CNTs was built onto AZ31B sheets with a reticle mask using the electrophoretic deposition process. Then, the CNTs/AZ31B composite was obtained by the hot-pressing process. The effect of deposition factors on composite forming quality was studied to seek a satisfactory interlayer binding. Finally, the mechanical and thermal properties of CNTs/AZ31B composites with different CNTs content and deposition orientations were tested. The results show that the mechanical and thermal properties of CNTs/AZ31B composites were noticeably anisotropic. By adding 0.5 wt% CNTs, the tensile strength and Young’s modulus of the CNTs/AZ31B composite were effectively enhanced by 30.3 % and 10.5 %, respectively. Meanwhile, the thermal conductivity of the composites increased to 84.2 W/ (m·K) when adding 0.25 wt% CNTs, with heat conduction and dissipation performance enhanced. The studies of tensile fracture and CNT-Mg interfaces of CNTs/AZ31B composite show that CNTs can act as a shortcut of heat flow and load transfer.