Dispersion mechanism-induced variations in microstructural and mechanical behavior of CNT-reinforced aluminum nanocomposites

Abstract The combination of powder metallurgy and ball milling method has been widely regarded as the most beneficial route for producing multi-walled carbon nanotubes (MWCNTs)-reinforced aluminum matrix composites. In this study, effects different times (1, 2, 4, 8 h) on structural, morphological, crystallographic properties MWCNTs-reinforced Al7075 composite powders were characterized by particle size analyzer, Raman spectroscopy, scanning electron microscopy (SEM), high-resolution transmission (HR-TEM), X-ray diffraction (XRD). After morphological structural characterization milled powders, microstructural mechanical hot-pressed composites evaluated using an optical microscope, SEM, density, Brinell hardness measurements. Considering characterization, MWCNTs gradually distributed embedded within time increased. Milling h resulted in a minimum level (11 µm) with shortened uniformly dispersed CNTs. increased from 91 to 237 HB -a ?%160 after milling. Such remarkable increment could be attributed several concurrent strengthening related dispersion, solution, grain refinement, Orowan looping mechanisms. However, relative density results revealed that produced 2 exhibited highest (%99.96). observed differences between ascribed powders’ deteriorated packing sintering behavior due particles variation range morphology, which following protocols.