1. 101
Abstract
In the present study, aluminum-matrix composites reinforced by CNTs are
produced by powder metallurgy. The first step is to mill the powder aluminum
alloy 6061 with different fractions and two different types of CNTs (single-wall
and multi-wall) in dry and neutral environment, using a high energy planetary
ball mill. 1.3 and 5% Multi-wall CNT or 1 and 3% Single-wall CNT were added
to aluminum alloy 6061 and Milling to 20 hours. Mechanically milled powders
undergone SPS process with the pressure of 37MPa at 340◦
C in graphite molds.
Once again, powder mixtures at compacted by uniaxial compression at 700MPa
and sintered at 580◦
C. The samples were study by SEM and EDS. The phase
analysis was performed using X-ray diffraction (XRD). Porosity, density and
hardness of the samples also were examined
The results showed that products undergone spark plasma sintering process
(SPS) have lower porosity, higher hardness and density than the ones resulted
from vacume sintering process in furnace. Furthermore, the type of CNT
influences hardness and density of the samples. Basicallyl, increasing of
percentage of CNT resulted in increase of porosity and reduction density.
Samples containing 5% of multi-wall CNT and processed by SPS and vacume
sintered in a furnace exhibited 39 and 37 percent increase of hardness,
respectively.
Keywords: CNT, aluminum alloy 6061, High energy planetary ball mill, SPS,
sintering.

2. 102
Islamic Azad University
Science and Research Branch
Faculty of Materials Engineering
A Thesis Submitted to the Faculty of Materials Engineering in Partial
Fulfillment of the Requirements for the Degree of Master of Engineering
The effect of sintering and powder conditions on the properties
Al alloy-CNT nanocomposite
Thesis Supervisor:
Ali Reza Khodabande, Ph.D
Thesis Advisor:
Mohammad Ardestani, Ph.D
By:
Asma Bokaiyan
September 2015