Effects of single-walled carbon nanotubes (SWNTs) on strengthening and toughening behaviors of aluminum-based composites with grain sizes ranging from nano- to micrometer have been investigated. The strength of composites is enhanced as an increase in SWNT volume and a decrease in grain size. Nanocrystalline composite containing 3.5vol.% SWNTs exhibits good ductility of ∼5% tensile elongation to failure as well as superior yield stress of ∼600MPa. However, the strengthening efficiency of SWNTs becomes half of the theoretical prediction for nanocrystalline composites due to the recovery process around the interface. Nanocrystalline composite containing 2.0vol.% SWNTs shows the fracture toughness of ∼57MPamm1/2, which is five times higher than that of starting aluminum. SWNTs may effectively block the propagation of necks and cracks, providing much improved ductility and toughness.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering