1. • By: Malik Tayyab
with co-member Muhammad Mutahir.
This work was conducted as a part of my final year project at NED
University of Engineering & Technology during the year 2011 in
Karachi, Pakistan.
This is a pdf file; since i created the presentation in ppt format(which is
obiviously animated) therefore some things you might consider
unclear. If you would like to have the ppt file or any other suggestion
regarding this topic you can reach me through my email address:
mallick_tayyab@hotmail.com

2. Group 2
MM 07009 Muhammad Mutahir
MM07026 Malik Tayyab
Project Advisor Prof. Dr. Ashraf Ali
Co-Project Advisor Asst. Prof. M. Sajid Ali Asghar
Department of Materials Engineering,
NED University of Engineering & Technology.

3. A nanometer is one billionth of a meter.
Nanotechnology is the study of manipulating matter on
an atomic and molecular scale.
Materials or structures possessing at least one dimension
sized from 1 to 100 nanometers.
Currently undergoing extensive development.
It has not yet yielded significantly useful commercial
products.
Malik Tayyab
Material Engineer

4. 1. Data Storage Devices.
2. Sensor units.
3. Optical devices.
4. Biomedical products.
5. Computing and information
storage devices.
6. Smart materials using Nano-
scale devices.
Malik Tayyab
Material Engineer

5.  Smallest synthetic motor that's ever been made.
 A gold rotor, nanotube anchors and opposing stators are
simultaneously patterned around the nanotubes using
electron beam lithography.
Malik Tayyab
Material Engineer

6. Bottom-up: Top-down:
Products are manufactured one Every product begins with a
atomic particle at a time. bulk material process and is
subsequently refined down.
Seek to have smaller (usually Top-down approaches seek to
molecular) components built up create Nano scale devices by
into more complex assemblies. using larger, externally
controlled ones to direct their
assembly.
Malik Tayyab
Material Engineer

7. Bottom Up Approach refers to the build up of a
material from the bottom: Atom by Atom, Molecule by
Molecule, or cluster –by-cluster
e.g. Polymer Synthesis
Malik Tayyab
Material Engineer

8. i. Zero-Dimensional Nanostructures: Nanoparticles
ii. One-Dimensional Nanostructures: Nanowires and Nano rods
iii. Two-Dimensional Nanostructures: Thin Films
iv. Three-Dimensional Nanostructures: Special Hybrid Structures
• Nano Buds
• Nano Torus
Malik Tayyab Malik Tayyab
Material Engineer

9. • Structural components with high
strength to weight ratios
• Batteries with better power output
• Abrasion resistant coatings
• Automotive Parts Ball bearings made of CNT-Cu
Nano composite.
Bicycle Crank set made of
CNT-Al Nano composite.
Malik Tayyab
Material Engineer

10. • Nano composites differ from conventional composite
materials due to the exceptionally high surface to volume
ratio of the reinforcing phase.
• Nano materials may have a significantly lower melting
point or phase transition temperature.
• Gravity plays no role whatsoever and inertial effects are
basically nonexistent because things are just so small.
All these and other similar factors give nanomaterials unique
properties like:
Copper turns transparent from opaque.
Gold becomes catalytic.
Aluminium becomes combustible.
Malik Tayyab
Material Engineer

11. There are two main types of carbon nanotubes that
can have high structural perfection.
• Single-walled nanotubes (SWNTs) consist of a
single graphite sheet seamlessly wrapped into a
cylindrical tube.
• Multi-walled nanotubes (MWNTs) comprise an
array of such nanotubes that are concentrically
nested like rings of a tree trunk.
Arm chair or Metallic
Zig Zag
Chiral
Malik Tayyab
Material Engineer

12. Two techniques selected for production of
Nano tubes:
• Arc Discharge Process
• Flame Synthesis
Can be used for the production
of both SWNTs and MWNTs.
Malik Tayyab
Material Engineer

13. The most common and perhaps easiest way to produce CNTs.
A technique that produces a complex mixture of components, and
requires further purification - to separate the CNTs from the soot and
the residual catalytic metals present in the crude product.
Applicable for production of both SWCNTs and MWCNTs.
Pressure gauge
Gas out
Gas in
Feed stock
cathode
Water in Water out
Malik Tayyab
Material Engineer Anode

14. Sonication is the act of applying sound energy to
agitate particles in a sample.
• Temperature
• Solvent(normally ethanol)
• Vibrations
• Operating time
Malik Tayyab
Material Engineer

15. CNTs produced by arc discharge at
magnification 6000X.
Malik Tayyab
CNTs produced by arc discharge at
Material Engineer
magnification 24000X

16. Flame Synthesis
A wall-stagnation flow burner and its wall was made of catalyst
material.
The reactant gas used for the formation of the flame and the
synthesis of CNTs was ethylene/air premixed gas.
Malik Tayyab
Malik Tayyab Material Engineer

17. Source Material Purity Level Mean Diameter
F.S. Corp. Aluminum Powder 99.9% 2.7 30 µm
Arc Discharge CNT >50-70% 1.95 N/A
Shenzhen Nanotech CNT >97% 2.1 30 - 40 nm
MWNTs were used in this study with diameter 30 nm-40 nm.
Malik Tayyab
Material Engineer

18. SEM images of CVD synthesized CNTs
(source: (a) Shenzhen Nanotech )
(b) MMD SEM Analysis
Malik Tayyab
Material Engineer

19. SEM images of Aluminium powder at
different magnifications.
Malik Tayyab
Material Engineer

20. µm
Histogram showing the particle size distribution of Aluminium
powder. Malik Tayyab
Material Engineer

21. • Laser Particle Size Analysis depends upon analysis of the
"halo" of diffracted light produced when a laser beam passes
through a dispersion of particles in air or in a liquid.
• The angle of diffraction increases as particle size decreases,
so that this method is particularly good for measuring sizes
between 0.1 and 3,000 μm.
Analysis indicated that Aluminium powder has a wide
particle size distribution ranging from 10 μm– 200 μm,
with average particle size around 30 μm. Malik Tayyab
Material Engineer

22. The following challenges must be met:
1. Overcome the huge surface energy, enormous surface area or large
surface to volume ratio.
2. Ensure all Nano materials with desired size, and provide uniform
distribution.
3. Interfacial bond strength between CNT and metal matrix.
4. Chemical and structural stability of CNTs.
Malik Tayyab
Material Engineer

23. Malik Tayyab
Material Engineer
This is my own
interpretation; I
haven’t found
this in any
resource.
Illustration of dislocation interaction in a particulate composite (or age
hardened alloy) and carbon nanotube reinforced metal matrix composite.

24. Malik Tayyab
Material Engineer
Processing routes for CNT-MM Nano composites.

25. • Powder Metallurgy is the most popular & widely applied
technique.
• Electro deposition & Electro less deposition are the second
most important technique for deposition of thin coatings.
Malik Tayyab
Material Engineer

26. Basic process steps consist of mixing CNTs with metal
powder by grinding or mechanical alloying, Followed by
consolidation by compaction and sintering.
Malik Tayyab
Material Engineer

27. Malik Tayyab
Material Engineer
CNTs
Ultra sonication of CNTs in
ethanol for 1 hour.
Disentangled CNTs
CNT-Al Powder Aluminium
Ball Milling Powder Compaction Sintering
CNT-Al Nano composite
Process flow diagram for CNT-Al Nano composite.

28. Plastic Coupling Agent (PCA, an organic solvent: e.g. ethanol) is
added to vial to avoid excessive welding and straining of the
particles. Malik Tayyab
Material Engineer

29. Ball Mill Vial with Steel Balls
(a) Schematic representation of ball mill vial
showing the impact of milling media on powder
particles (b) Ball-powder-ball impact. Malik Tayyab
Material Engineer

30. During milling Al-CNT powder, following set of events occur :-
• Particle Deformation or Flattening,
• Sandwiching
• Particle Welding,
• Fracturing causing grain size reduction.
Malik Tayyab Malik Tayyab
Material Engineer

31. 1 % CNT, 200 RPM, 3 hours
2% CNT, 200 RPM, 3 hours
5% CNT, 200 RPM, 3 hours
Sample # % Composition Weight of CNT/g Weight of Al/g
1 Pure Al - 5
2 1%CNT-Al 0.05 4.95
3 2%CNT-Al 0.10 4.90
4 5%CNT-Al 0.25 4.75
Malik Tayyab
Material Engineer

32. Powder handling was performed in Vacuum Glove Box, Argon
gas was supplied for inert atmosphere.
In order to avoid environmental effects like oxidation of
Aluminium powder, moisture adsorption.
Aluminium powder is highly reactive, Resources indicate that a
thin passivation layer of alumina (4 nm thickness) forms in about
100 picoseconds on any exposed aluminium surface(Aluminium
Nano clusters).
Malik Tayyab
Vacuum Glove Box. Material Engineer

33. Milled powder samples were compacted by a 100 Ton
Hydraulic press.
Compaction pressures were calculated and determined
by trail and error method.
In Accordance to ASTM Green density vs. Compaction
Pressure plot for 601AB Aluminium, 40 M Pa appeared
to be the optimum pressure.
Malik Tayyab
Material Engineer

34. • Process based on Atomic Diffusion.
• Driving force for densification is the change in free energy
from the decrease in surface area.
Solid state sintering
Liquid phase sintering
Temperature (°C)
540 °C
0.5 hour
Time (hours)
Malik Tayyab
Material Engineer

35. Characterisation Technique
• Scanning Electron Microscopy
• X Ray Diffraction
The dispersion of CNTs in Aluminium matrix was investigated.
CNTs were observed at the weld interfaces between Aluminium
particles.
Malik Tayyab
Material Engineer

36. 2% CNT-Al Nano composite showing weld
splats of fine Al particles on coarse ones.
Malik Tayyab Uniform distribution of CNTs found in the Al
Material Engineer matrix.

37. Figure showing 2% CNT-Al Nano composite
showing CNT reinforcement in Al matrix.
Malik Tayyab
Material Engineer

38. A perfect view of CNT at the weld interface
in 2% CNT-Al Nano composite.
Malik Tayyab Agglomerates of CNTs in 5% CNT-Al Nano
Material Engineer composite.

39. CNTs Aluminium
Individual X-Ray diffratograms of CNTs (100% intensity at 26°) and Aluminium
Malik Tayyab
overlapped.
Material Engineer

40. Malik Tayyab
Material Engineer

41. X-Ray diffraction pattern of 2% CNT-Al Nano composite, no carbon peak observed.
Malik Tayyab
Material Engineer

42. • Improper powder handling.
• Oxygen pick up by Aluminium
powder during processing.
• Improper calculation of the plastic
coupling agent (PCA). One of the failed sintered compacts.
Fractured surface of failed Nano CNTs observed at the fractured surface.
composite compact.

43. Elements Weight % Atomic %
CK 13.12 25.33
Al K 86.88 74.67
Totals 100.0
Energy Dispersive Spectroscopy confirming the presence of CNTs in
Malik Tayyab
the 2% CNT-Al Nano composite (Elemental Detection). Material Engineer

44. Malik Tayyab
Material Engineer
Elements Weight % Atomic %
OK 5.67 9.21
Al K 94.33 90.79
Totals 100.00
EDS pattern showing no carbon peaks, Oxides were observed in the matrix.

45. Malik Tayyab
Material Engineer
SEM SecondaryMapping Image
SEM X Ray Electron
Time provided was not sufficient due to some constraints else
the nanofiber like image had appeared in the C x-ray map.
X-Ray Mapping Images showing the distribution of
CNTs in aluminium matrix of 2% CNT-Al Nano
composite along with oxide dispersions.

46. • Ball milling has been proven to be a very promising technique for the
dispersion of CNTs in Al matrix. It has also been noticed that this technique
excessively strain hardens the matrix as the milling time increases.
• CNTs were found to be embedded in the matrix as an interphase at the
Aluminium powder particle weld interfaces.
• The fractured green compact also revealed CNTs in between the Aluminium
crystallites.
Future Work and Recommendations
• CNT-Al can also be prepared via Electrodeposition; this process gives added
benefit for coating surfaces requiring wear resistance.
• Pure Al and Aluminium alloys are known to generate hydrogen from alkaline
water for Polymer Electrolyte Membrane Fuel Cells. CNT-Al nanocomposites can
be used for hydrogen generation as a green renewable energy source.
• Hybrid Nano composite comprising of two different Nano reinforcements might
be another interesting approach to enhance the mechanical and other
physical characteristics of the nanocomposites (CNT/ Dispersed Oxides/ Al
Composite or using two different types of CNTs). Malik Tayyab
Material Engineer

47. Malik Tayyab
Material Engineer

48. http://berkeley.edu/news/media/releases/2003/07/23_motor.shtml

49. Malik Tayyab
Material Engineer