Fabrication and characterization of AA6061/CNTs surface nanocomposite by friction stir processing

Abstract

Aluminum matrix composites (AMCs) are among the advanced materials that are employed in numerous industrial applications. AMCs have good stiffness and strength. They have low weight that makes them valuably handy for improving fuel efficiency and economy in the structures made from them. The friction stir processing (FSP) is a novel technique which is highly advantageous for producing composites, which are reinforced with particles that are sub-micron in size particularly in light weight metal matrix composites (MMCs). Current study is done to examine the potential of AA6061-based surface nanocomposites by reinforcing it with carbon nanotubes (CNTs) (as-received and purified) employing FSP. Fabrication of the composites is carried out by filling CNTs into the grooves of different sizes and friction stir processed (FSPd). Various parameters are investigated to attain best mechanical properties and dispersion of CNTs in the matrix. Metallography is used to reveal the material flow and grain size variation in the zones formed by the FSP. Micro hardness and tensile tests are conducted to evaluate the mechanical properties and an increase of 47.3% hardness and an increase of 32.4% ultimate tensile strength (UTS) are observed from the base FSPd material. Electron microscopic techniques are also employed to reveal the microstructural details.