Fabrication of Al6061-CNT Composite by Mechanical Alloying Followed by Semi-Solid Powder Processing

Abstract

Carbon nanotubes (CNTs) have been widely investigated as a reinforcement material to improve the mechanical, electrical and thermal properties of composite materials. Various routes have been employed to fabricate aluminum-carbon nanotube (Al-CNT) composites in the past few years. However, uniform distribution of CNTs in the metal matrix is still challenging. In this paper, a novel semi-solid powder processing (SPP) was used to incorporate CNT uniformly into the Al6061-CNT composite. Al6061-CNT powders mechanically alloyed for different durations were also examined to understand how the CNTs were dispersed in the Al6061 powders. As-received CNT cluster balls were crushed into dense thin CNT layers during mechanical alloying. As mechanical alloying time increased, CNTs were dispersed in the Al6061 particles. Well-densified microstructures with severely deformed grains were observed in the Al6061-CNT composite.