Interfacial in-situ Al2O3 nanoparticles enhance load transfer in carbon nanotube (CNT)-reinforced aluminum matrix composites.

Dissatisfactory load transfer has been a critical issue in carbon nanotube (CNT)- and graphene-reinforced metal matrix composites (MMCs) mainly because of the intrinsically unpleasant carbon-metal interfaces. Here we show by introducing in-situ Al 2 O 3 nanoparticles at aluminum (Al)-CNTs interface, the load transfer efficiency can be noticeably enhanced in powder metallurgy CNTs/Al composites. From in-situ tensile tests, the nanoparticle-modified Al-CNTs interfaces result in CNT fracture, a sign of high load transfer efficiency; while clean interfaces without nanoparticles lead to CNT pulling-out. The nanoparticle-induced enhancement of interface strength can be explained by the increased sliding resistance of CNTs in MMCs at the wake of cracks under tensile loading. Our study provides a new strategy for designing strong carbon-metal interfaces to fabricate high-performance nanocarbon-reinforced MMCs. Image 1 • A type of strong Al-CNT interface was studied by TEM and in-situ tensile tests. • Clean Al-CNT interfaces led to CNT pulling-out. • Al-CNT interfaces with in-situ alumina nanoparticles resulted in CNT fracture. • Alumina nanoparticles increased interfacial strength without damaging CNT structure. [ABSTRACT FROM AUTHOR]