Formation and heat treatment of kinetic sprayed nanocrystalline Al coatings reinforced with multi-walled carbon nanotubes: The relationship between microstructural features and physical properties

Nanocrystalline (nc) Al matrix composites reinforced with multi-walled carbon nanotubes (MWCNTs) (1.0 and 3.0 vol.%) were fabricated by mechanical attrition and consolidated using a kinetic spraying process, followed by heat-treatment at a homologous temperature of 0.67 T/TM for 1-4 h. Microstructural features including thermal stability of the nc structures, the interface between MWCNTs and the Al matrix, and the MWCNT structures of as-sprayed and heat-treated MWCNT/nc Al composite coatings were characterized and related to their corresponding mechanical and physical properties. The relationship between microstructural features and properties of the composite coatings was investigated.