In this project, we demonstrated the development and Nano-mechanical study of Aluminum-cBN metal matrix composite (MMC) through the spark plasma sintering process. Aluminum is highly used in the automobile and aerospace industry. In this project, our objective was to increase the hardness and wear resistance properties of aluminum so we can increase the effective use in the field. To achieve that we used the cBN particles of different particle sizes in aluminum and observe their effects on hardness and wear resistance properties. We mixed the powders by the ultra-sonication process then used the Spark Plasma Sintering process for compaction of powders, which is an effective way to decrease the porosity of our solid. Parameters for the spark plasma sintering were 550°∁ temperature, 50 MPa pressure with a dwell time of 5 minutes. There were many practical reasons for using spark plasma sintering, it can prepare fully dense materials, requires less time for sample preparation at temperatures lower than melting points. It prevents grain coarsening, with regards to severe plastic deformation; spark plasma sintering can fully release residual stresses and as a result, produces fewer cracks and segregation along with uniform microstructure. We used different characterization techniques to test and analyze various properties of the samples. A high-level homogeneity was observed inside the MMC, by studying different SEM results, any phase changes after the sintering process was observed by XRD. We used the Archimedes principle to achieve the density of our sample. Then Vickers Hardness proved that the addition of cBN aided in increasing the hardness up to our predicted results. Several corrosion tests were performed to create a precise electrochemical study which consists of EIS(Electrochemical Impedance Spectroscopy) and PD (Potentio-dynamic) of the samples of the composite. Also, we determined the Poison’s ratio for the Nano-indentation study. Our aim is also to analyze and study the thermal expansion coefficient, thermal conductivity, and coefficient of wear resistance of our samples.

1. Development and Nanomechanical study of
the Aluminium-cBN Metal Matrix
Composite prepared by SPS.
Group Members:
Afifa Maryam (2017033)
Muhammad Ali Arif (2017236)
Shahood Iqbal (2017425)
Advisor:
Engr. Muzammil Irshad
Co-Advisor:
Dr Fahad Nawaz Khan

2. Objectives
2. Study the effect of
particle size on nano-
mechanical properties
and electrochemical
properties.
1. Development of
Aluminium-cBN
MMC for wear
resistant applications
and to optimize their
properties.
2

3. Process:
3
Procurement and
mixing of Aluminum
and cBN powders
Development of
sample through
Spark Plasma
Sintering
Characterization
and Result
Compilation
Analysis of Nano-
mechanical and
electrochemical
Properties.

4. Development
➔ Procurement of Aluminium and
cBN powder .
➔ Weighing of powders.
➔ Mixing (Ultrasonication)
➔ Sintering (SPS)
➔ Characterization
4

5. 5

6. Spark Plasma Sintering
6
Figure 1 shows schematic of the SPS process.
Sintering Parameters:
• Sintering Temperature 550℃
• Pressure 50 MPa
• Holding Time 10 min
• Heating/Cooling Rate 100 °C/min
Why Spark Plasma Sintering?
• Can prepare fully dense metals.
• Requires less time for sample
preparation at temperatures lower
than the melting point.
• Prevention of grain coarsening.
• As compared to SPD(Severe Plastic
Deformation),SPS can fully release
the metal’s inner stress.
• Less chances of cracks and
segregation.
• Obtain uniform microstructures.

7. Characterization
Done
 SEM
 XRD
 VICKER’S HARNDNESS
 NANO-INDENTATION
 DENSIFICATION
 FRACTURE TOUGHNESS
 Corrosion testing(EIS
and PD)
 Thermal Expansion
 Coefficient of wear
resistance
7
Characterzation
Left

8. SEM
● In order to observe the
microstructures of the samples
clearly, we used scanning electron
microscopy technique. The
magnification set up for the
experiment was x100 and x1000.
● Uniform homogeneity was
achieved after successful sintering
of the samples as the matrix and
reinforcement particles could be
clearly seen uniformly distributed
in the results.
● The sharp edged particles seen in
the images are of cubic boron
nitride. The matrix in the
backgroundis pure aluminum. The
differences can be clearly observed
by their respective contrasts.

9. Nano-Indentation
9

10. Hardness (Vickers)
10

11. DENSIFICATION
11
Sample Density
Pure Al 2.66
Al–cBN 20 micron 3.38398
Al-cBN 40 micron 2.59
Al-cBN 60 micron 2.63

12. XRD

13. EDX Analysis:
● Energy dispersive X-ray analysis was done to determine the
elements present inside the sample. It was done to ensure that no
other elements were to be found except Aluminum(Al),Boron(B)
and Nitrogen(N).
● Some traces of carbon and silicon were found. They may have
formed due to burning of the surface upon striking of x rays upon
the sample. The X-ray analysis graph is attached on next slide
along with the location of all elements.
13

14. 14
Aluminum being the
greatest in weight
percentage shows the
greatest and most
prominent peak on the
graph. While, peaks of
other elements are less
intense as weight
composition of added
cBN was also low.

15. Milestones
2020 2021
October and
November
Finalize the topic and start
literature review
December
Able to achieve our first
objective, Continue
Literature Review, Start
Material Characterization
January
Continue the
Characterization Procedure
and Literature Review
February
Finalize the Results and
Analysis and work on
Report Development
15
Final
Report
April

16. References:
16
I. Saheb, N., Iqbal, Z., Khalil, A., Hakeem, A. S., Aqeeli, N. Al, Laoui, T., & Al-qutub, A. (2012). Spark Plasma
Sintering of Metals and Metal Matrix Nanocomposites : A Review. 2012. https://doi.org/10.1155/2012/983470
II. Zeng, W., Qin, W., Gu, C., Sun, H., Ma, Y., & Cao, X. (2019). Microstructure and properties of pure aluminum
prepared by spark plasma sintering. Metallurgical Research and Technology, 116(3).
https://doi.org/10.1051/metal/2018105
III. Tian, W., Chen, F., Cheng, F., Li, Z., & Pang, G. (2020). Corrosion properties of pure aluminum prepared by
spark plasma sintering (SPS) using different grain size of aluminium powders as raw material. International
Journal of Electrochemical Science, 15(9), 9120–9134. https://doi.org/10.20964/2020.09.02
IV. Irshad, H. M., Ahmed, B. A., Ehsan, M. A., Khan, T. I., Laoui, T., Yousaf, M. R., Ibrahim, A., & Hakeem, A. S.
(2017). Investigation of the structural and mechanical properties of micro-/nano-sized Al2O3 and cBN
composites prepared by spark plasma sintering. Ceramics International, 43(14), 10645–10653.
https://doi.org/10.1016/j.ceramint.2017.05.325
V. Irshad, H. M., Hakeem, A. S., Ahmed, B. A., Ali, S., Ali, S., Ali, S., Ehsan, M. A., & Laoui, T. (2018). Effect of Ni
content and Al2O3 particle size on the thermal and mechanical properties of Al2O3/Ni composites prepared by
spark plasma sintering. International Journal of Refractory Metals and Hard Materials, 76(March), 25–32.
https://doi.org/10.1016/j.ijrmhm.2018.05.010

17. THANK YOU!
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