Compression, Energy Absorption, and Electromagnetic Shielding Properties of Carbon Nanotubes/Al Composite Foams

Abstract

Herein, pre-dispersed ball-milling and space-holder methods are used to prepare carbon nanotubes (CNTs) reinforced aluminum (Al) matrix composite foams (C-AMCFs). Systematic research is conducted on the mechanical and electromagnetic shielding properties of C-AMCFs as well as the optimal ball-milling time. The results demonstrate a quasi-linear relationship between CNTs contents and optimal ball-milling time. With the addition of CNTs, the compressive performances of C-AMCFs first increase and subsequently decrease. The 2.5 wt% C-AMCFs have the best mechanical performance, whose yield strength (19.25 MPa), plateau stress (20.87 MPa), and energy absorption capacity (8.874 MJ m⁻³), are both 1.72, 1.72, and 1.79 times than those of AFs, respectively. In the X-band (8.2–12.4 GHz), the addition of CNTs in C-AMCFs can increase their electromagnetic shielding effectiveness. The greatest electromagnetic shielding effectiveness of the 2.0 wt% C-AMCFs is 30–40 dB. By enhancing the reflection loss at the first interface as well as the absorption and reflection loss inside the cell walls, CNTs play an important role in improving the electromagnetic shielding performance of C-AMCFs.