Additive Manufacturing of a CNT/Al6Si Composite with the Nanolaminated Architecture via Cold Spray Deposition

Cold spraying (CS) is a solid-state layer-by-layer deposition technique allowing to fabricate complex-shaped metallic components, such as metal matrix composites (MMCs). It has been demonstrated that introduction of a nacre-like nanolaminated architecture in man-made MMCs can perfectly beat the conflict between strength and ductility (toughness). In this work, the fully dense carbon nanotubes (CNTs) reinforced Al6Si (hereafter called CNT/Al6Si) MMC with the nanolaminated architecture is successfully realized by flake powder metallurgy followed by CS. It is revealed that the nanolaminated architecture, containing nanosized grains, is properly created in the CNT/Al6Si flaky powder by ball milling, which is then conserved in the CS-processed component. The harmful excessive formation of Al4C3 due to interfacial reaction is limited and structural integrity of initially incorporated CNTs is well retained.