Tensile and Wear Property of Various Diameter Carbon Nanotubes Reinforced Aluminum Composites
Date Issued
2004
Date
2004
Author(s)
Chuang, Jia-Lang
DOI
zh-TW
Abstract
The essential purpose of this research is to investigate the effects of diameters of carbon nanotubes on the mechanical and the wear properties of Metal Matrix Composites (MMCs). 6061 Al alloy powder (74μm) is used as metal matrix, and 1 wt% of carbon nanotubes with various diameters are added as strengthen phase. All MMC samples are prepared by powder metallurgy.
The hydrocarbon content in the Al alloy is decreased from 1.1 wt% to 0.045 wt% through de-waxing. After 48 hours of planetary ball milling, the length of carbon nanotubes is cut down to less than 5 μm, and the particle size of Al alloy powder decreased from 74μm to 29μm, respectively.
Wet mixing of the Al alloy powder and carbon nanotubes is adopted to avoid agglomeration of carbon nanotubes. After cold isotropic pressing, sintering and hot extrusion, composites with a density close to 100% of the theoretical density is obtained.
MMCs with the addition of 1wt% ball-milled carbon nanotubes of diameters 10~20nm is observed to have the largest tensile strength due to good dispersion of carbon nanotubes in the metal matrix. Those contain carbon nanotubes without ball milling have lower tensile strength, the fracture surface is observed to take place around inclusions. Large amount of carbon nanotubes were found in the fracture surface, suggesting that the agglomeration of carbon nanotubes provided sites for crack initiation.
The addition of 1wt% ball-milled carbon nanotubes of diameters 10~20nm gives MMCs the lowest wear rate. The wear rate is influenced by the aging condition. Lowest wear rate is obtained at the peak aged condition. This is in relation to the size of the precipitates during aging as well as the morphology of the interface between the precipitates and the Al alloy. As the diameter of carbon nanotubes increases, wear rates also increases, even higher than the Al alloy. This is related to the structures of the carbon nanotubes. Non-uniform axial deformations inside the multiwalled nanotubes may exist.
Subjects
奈米碳管
磨耗性質
鋁基複合材料
carbon nanotubes
aluminum matrix composite
wear property
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-93-R91527042-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):195822aa0e8c53755360eb1134c608e7