抄録
Metal composite powder coated with un-bundled carbon nanotubes (CNTs) were prepared by using the surfactant (surface active agent), having both hydrophobic and hydrophilic groups, via the wet process and consolidated by spark plasma sintering (SPS) and hot extrusion. Each CNT was independently dispersed in the surfactant water, because the electric affinity between the positive and negative charges due to hydrophobic and hydrophilic groups became larger than van der Waals forces between CNTs. After dipping the metal powder in this water and drying them out at 80C, the isolated CNTs existed on the powder surface. The sublimation point of the surfactant films on the powder surface was determined by differential thermal analysis (DTA). The thermal damage of CNTs during heating to remove the films was evaluated by Raman Spectroscopy and Transmission Electron Microscope (TEM) observation. Optical microscope and Field Emission Scanning Electron Microscope (FE-SEM) observation with Energy Dispersed X-ray Spectrometer (EDS) analysis were carried out on the above composite alloys with CNTs. Microstructures and mechanical properties of powder metallurgy (P/M) extruded pure magnesium and titanium composites with CNTs were examined, and the strengthening mechanism was discussed.
