This work provides an insight into the development of environmentally friendly alternatives to chromium-based coatings for the protection of aluminum against corrosion. Sodium silicate, zirconium silicate, and zirconium-stearate thin films were fabricated on AA6061 aluminum alloy substrates. On the other hand, sodium silicate, manganese sulfate monohydrate, and ammonium metavanadate were studied as corrosion inhibitors for AA6061 aluminum alloy.

1. Development of mechanically durable ecologic and
corrosion resistant non-chromate coatings for
aluminum
Ph.D. Candidate: Redouane FARID
Permanent Code: FARR18039004
Director: Prof. D.K.Sarkar

2. 2
Outline
Introduction
Objectives and methodology
Enhanced corrosion protection
of aluminum by ultrasonically dip coated
sodium silicate thin films
Literature review
Conclusion
Facile electrodeposition process of
zirconium-based superhydrophobic
thin films on aluminum
Zirconium silicate thin films by sol-gel process for
corrosion protection of aluminum
Evaluation of the corrosion
inhibition performance of non-
chromate corrosion inhibitors
for aluminum

3.  Global cost of corrosion by country
2,7 %
United states
India
4.2 %
4 %
6M
Japan
Russia
1 %
3
4.2 %
International measures of prevention, application, and economics of corrosion technologies study. NACE 2016.
https://www.guinnessworldrecords.com/world-records/most-expensive-man-made-object/
China
US $ 2 505 billion
3.4 % of GDP
2013
Introduction
X
© Konstantin Shaklein | Dreamstime

4. 4
Flixborough disaster. UK. 1974
Guadalajara explosions. Mexico. 1992 Prudhoe bay oil spill. Alaska. 2006
Bhopal Gas Tragedy. India. 1984
Introduction
Case study on some of the major corrosion catastrophes in the history. 2013.
 Major corrosion catastrophes in history

5. 5
Corrosion is defined as the degradation of a material caused
by its environment.
Introduction
Michael et al. Corrosion resistance of aluminum and aluminum alloys. 2010
 Mechanism of corrosion on metals

6. 6
Packaging
Construction
Transportation
Introduction
Statista.com/statistics/280983/share-of-aluminum-consumption-by-sector
 The importance of aluminum

7. 7
Introduction
• Low density
• Excellent conductivity of heat and electricity
• Good mechanical strength
• Highly reflective
Low corrosion resistance in aqueous environments
Alloying: Understanding the Basics, p351-416
 The aluminum properties

8. 8
Introduction
Fish Species [Cr] Acute Effects
Salmo gairdneri 0.005 mg L−1 Effect on fertilization
Tilapia
sparrmanii
0.098 mg L−1 Decrease in blood clotting time
Tilapia
sparrmanii
0.098 mg L−1 at pH
7.4-9.0
Decrease in WBC, RBC counts, and Hb concentration. Increase in
ALA-D activity.
Sccobranchus
fossilis
0.1-3.2 mg L−1 Increases in spleen to body ratio, WBC, RBC, Hb, MCV, PVC, and
splenocytes. Decreased antibody production and increased
susceptibility to bacteria
Periophthalmus
dipes
5-15 mg L−1 Decrease in ion-dependent ATPase activity
Labeo rohita 39.40 mg L−1 96 h-
LC50
Decrease in glycogen content, total lipid content and total
protein content of liver, muscle and gill.
Colisa fasciatus 60 mg L−1 Reduction in liver glycogen content. Hyperglycemic response
Carassium
auratus
250 μM Decrease in cell viability. Increase in ROS
Acute effects of chromium to freshwater fish
echa.europa.eu
Rev Environ Health. 2009 ; 24(2): 129–145
September 2017: Banned by Europe’s Registration,
Evaluation, Authorization and Restriction of
Chemicals (REACH)
 Chromium conversion coatings for corrosion protection of aluminum!

9. 9
Literature review
Coating Ref. Substrate Characteristics Comments
Rare-earth based Haque et al.
Resources 2014, 3,
614-635.
Aluminum, Steel Mainly works as cathodic
inhibitors, precipitation of Ce-
oxide on cathodic sites, induced
by the local pH increase
Minor improvement in pitting
potential and corrosion current
was noted
Silicate-based Garrity et al.
Electrochem. Acta
2014, 130, 9-21.
Aluminum The addition of sodium silicate
in 0.1 M NaCl inhibits the
corrosion of aluminum.
The corrosion protection
mechanism is found to be due to
the formation of aluminosilicate
on aluminum.
Lithium-based Visser et al.
Faraday Discuss.
2015, 180, 511-526.
Aluminum Barrier and self-healing
properties noted in the Li
containing primer
Lithium-based coatings; the
cost towards implementation
could be too important
Organic-based
(including epoxy, sol–
gel, polyurethane,
silane and
nanocomposites)
Wolf et al.
Springer Briefs in
materials 2014, 19-
39.
Aluminum, Steel Good barrier properties Nanocomposite: cost
towards implementation
could be too important
Phosphate-based Thomas et al.
Corros. Sci 2013, 69,
11-22.
Aluminum, Steel,
Carbon
Good barrier properties
provided by the precipitation of
metal-phosphate compounds
pH stability of phosphate-based
coatings inferior to chromium
oxide

10. 10
Novelty of the work
The objective of this work was to investigate how selected chromium–free thin films and
inhibitors impact the corrosion resistance of aluminum.
1. Fabrication of sodium silicate thin films on aluminum by a ultrasonic dip-coating process
and study their corrosion properties.
2. Fabricate zirconium silicate thin films on aluminum and investigate their corrosion
behaviors.
3. Fabricate zirconium-stearate superhydrophobic thin films on aluminum and study their
corrosion performance.
4. Study the corrosion inhibition properties of Na2SiO3, MnSO4.H2O, NH4VO3 and their
mixture for aluminum.

11. 11
Methodology of the work
1. Fabrication of sodium silicate thin films on aluminum by a simple ultrasonic dip-
coating process and study their corrosion protection properties in 0.6 M (3.5 wt.%)
NaCl aqueous solution.
2. Corrosion properties of zirconium silicate thin films on aluminum were investigated by
sol-gel process at different sol aging times in 0.6 M (3.5 wt.%) NaCl aqueous solution.
3. Nanostructured zirconium-stearate superhydrophobic thin films on aluminum were
fabricated using electrodeposition process at different molar ratios of zirconium source
(Zr) to stearic acid (SA) in 0.6 M (3.5 wt.%) NaCl aqueous solution.
4. The corrosion inhibition properties of Na2SiO, MnSO4.H2O, and NH4VO3 and their
mixture for aluminum were studied in 0.1 M NaCl aqueous solution.

12. 12
Characterization tools
12
Scanning electron microscopy
(SEM, JEOL JSM-6480LV)
First Ten Angstrom contact
angle goniometer
Fourrier transform
infrared
spectroscopy (ATR-
FTIR, Agilent
Technologies Cary
630)
PGZ100 potentiostat and 300
cm3 –EG&G PAR flat cell

13. 13
Electrochemical methods for corrosion characterization
Rp =
β𝑎βc
2.3icorr(β𝑎+β𝑐)
icorr: corrosion current density
Rp : Polarization resistance
β𝑎, βc : anodic and cathodic Tafel constants
Stern and Geary equation:
M. Stern, A.L. Geary, J. Electrochem. Soc. 104 (1957)
Rs : Solution resistance
Rct : Charge transfer resistance
Cdl : Double layer capacitance
Potentiodynamic
polarization test (Tafel)
 Electrochemical impedance
spectroscopy test (EIS)

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Enhanced corrosion protection of
aluminum by ultrasonically dip coated
sodium silicate thin films

15. 15
Enhanced corrosion protection of aluminum by ultrasonically dip coated sodium
silicate thin films
 Pretreatment of aluminum substrates
1 M NaOH 55o C on hot plate Immersion for 3 min Dried at 70o C on hot plate

16. 16
Enhanced corrosion protection of aluminum by ultrasonically dip coated sodium
silicate thin films
wt. Ratio
SiO2:Na2O
wt.% Na2O wt.% SiO2
3.22 8.9 28.7
Industrial sodium silicate composition
 Immersion time in the ultrasonic bath: 10 min
 Four different concentrations of sodium
silicate were used: 0.1, 0.5, 0.75 and 1 M.
 Heated at 100˚C for 2 h
 Preparation of sodium silicate thin films on aluminum
Clean Al Etched Al

17. Immersion
Withdraw from
the sol
Deposition
17
Enhanced corrosion protection of aluminum by ultrasonically dip coated sodium
silicate thin films
Heat
treatment
 Ultrasonic dip-coating of aluminum substrates in sodium
silicate solution

18. 18
Enhanced corrosion protection of aluminum by ultrasonically dip coated sodium
silicate thin films
0.1 M
0.5 M
0.75 M
1 M
 ATR-FTIR analysis of sodium silicate thin films
Peak (cm-1) Assignments
1207 Si-O-Si (Stretching)
943 Si-O-Na
800 Si-O-Si (Bending)
501 Si-O-Si (Rocking)

19. 19
Enhanced corrosion protection of aluminum by ultrasonically dip coated sodium
silicate thin films
 SEM and EDS analysis of sodium silicate thin films
SEM images of (a) as-received aluminum substrate,
and sodium silicate thin films on aluminum
substrates formed using (b) 0.1, (c) 0.5, and (d) 1 M
of sodium silicate solution.
Al 0.1 M
0.5 M 1 M EDS spectrum of the sodium silicate thin film on
aluminum substrate formed using 1 M of sodium
silicate solution for the global region of SEM image.
1 M

20. 20
Enhanced corrosion protection of aluminum by ultrasonically dip coated sodium
silicate thin films
 Corrosion properties of sodium silicate thin films
Potentiodynamic polarization curves of as-received aluminum
substrate, sodium silicate thin films on aluminum substrates
formed using 0.1, 0.5, and 1 M of sodium silicate solution.
Polarization resistance and corrosion current density
variation of sodium silicate thin films on the aluminum
substrates as a function of normalized Si-O-Si peak area.
Substrate Corrosion
potential
Ecorr (mV)
Corrosion current density
icorr (µA/cm2)
Polarization
resistance
Rp (kΩ.cm2)
Corrosion
inhibition
efficiency η (%)
As-received aluminium -650 ± 22 10.600 ± 3.30 010.0 ± 02.0 -
0.1 M Sodium silicate -680 ± 47 01.100 ± 0.03 027.5 ± 00.5 89.62
0.5 M Sodium silicate -707 ± 45 00.085 ± 0.01 259.0 ± 40.0 99.19
1 M Sodium silicate -999 ± 33 00.050 ± 0.01 593.0 ± 32.0 99.52

21. 21
Enhanced corrosion protection of aluminum by ultrasonically dip coated sodium
silicate thin films
 Effect of chemical etching and ultrasonication on the corrosion properties of sodium silicate
thin films
Sodium silicate thin films on clean and etched
aluminum substrates
Sodium silicate thin films on by ultrasonication
process and simple dip-coating process
Preparation process Rp (kΩ.cm2) Icorr (µA/cm2)
Dip-coating 064.5 0.40
Ultrasonication With etching 157.0 0.19
Without etching 227.0 0.10
When ultrasound is introduced during the
deposition process, its cavitation effect
can effectively prevent the agglomeration
of particles and induce uniform dispersion
and continuous suspension [7].

22. 22
Enhanced corrosion protection of aluminum by ultrasonically dip coated sodium
silicate thin films
 Effect of chemical etching and ultrasonication on the corrosion properties of sodium silicate
thin films
Adhesion test on aluminum
substrate coated with
sodium silicate thin film
formed using 0.5 M sodium
silicate solution.
Adhesion scale according to standard ASTM D3359

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Zirconium silicate thin films by sol-gel
process for corrosion protection of
aluminum

24. 24
Zirconium silicate thin films by sol-gel process for corrosion protection of aluminum
 Good chemical stability
 High hardnessFire retardant
Biomedicals
Radioactif
container
Good candidate
for corrosion
protection of
aluminum

25. 25
Zirconium silicate thin films by sol-gel process for corrosion protection of aluminum
Preparation of zirconium silicate thin films with different aging times of the sol

26. 26
ATR-FTIR analysis of zirconium silicate thin films
Zirconium silicate thin films by sol-gel process for corrosion protection of aluminum
Peak (cm-1) Assignments
1052 Si-O-Si (Stretching)
940 Si-O-Zr (Stretching)
811 Si-O-Si (Stretching)
501 Zr-O (Bending)
1 h
72 h
48 h
24 h

27. 27
Effect of the aging time of the sol on the morphology of zirconium silicate thin films
Zirconium silicate thin films by sol-gel process for corrosion protection of aluminum
24 h
72 h
Al
72 h

28. 28
Corrosion properties of zirconium silicate thin films
Substrate
Corrosion
potential
Ecorr (mV)
Corrosion
current
density
icorr (µA/cm2)
Polarization
resistance
Rp (kΩ.cm2)
As-received
aluminum
-650
10.60 010
1 h aging time -875 00.59 024
24 h aging time -656 00.30 234
48 h aging time -685 00.07 390
72 h aging time -584 00.04 446
Zirconium silicate thin films by sol-gel process for corrosion protection of aluminum

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Facile electrodeposition process of
zirconium-based superhydrophobic thin
films on aluminum

30. 30
Corrosion properties of zirconium-based superhydrophobic thin films
Facile electrodeposition process of zirconium-based superhydrophobic thin films on
aluminum
Water droplet behavior in Wenzel’s
and Cassie-Baxter’s state.
Superhydrophobic thin films
prepared at CURAL laboratory
Superhydrophobicity in nature

31. 31
Preparation of zirconium-based superhydrophobic thin films on aluminum
Facile electrodeposition process of zirconium-based superhydrophobic thin films on
aluminum
Zirconium n-propoxide
(C12H32O4Zr)
Stearic acid (C18H36O2)
Zirconium-stearate thin films with
Zr/SA molar ratio of 1, 2, 4, 8
10 V

32. 32
ATR-FTIR and thickness analysis of zirconium-based superhydrophobic thin films
Facile electrodeposition process of zirconium-based superhydrophobic thin films on
aluminum

33. 33
SEM images of zirconium-based superhydrophobic thin films
Facile electrodeposition process of zirconium-based superhydrophobic thin films on
aluminum
Al Zr/SA=0
Zr/SA=2 Zr/SA=4 Zr/SA=8
Zr/SA=1

34. 34
EDS images of zirconium-based superhydrophobic thin films
Facile electrodeposition process of zirconium-based superhydrophobic thin films on
aluminum
Al Zr/SA=0
Zr/SA=2 Zr/SA=4 Zr/SA=8
Zr/SA=1
Zr/SA molar
ratio
Thin films chemical composition (at. %)
C O Zr
0 85.75 14.24 00.00
1 87.53 11.58 00.88
2 78.07 18.71 03.21
4 64.99 27.87 07.15
8 53.36 32.13 14.51

35. 35
Corrosion properties of zirconium-based thin films
Facile electrodeposition process of zirconium-based superhydrophobic thin films on
aluminum
Sample Corrosion
potential
Ecorr (mV)
Corrosion current
density
icorr (µA/cm2)
Polarization
resistance
Rp (kΩ.cm2)
CA (˚)
As-received Al -610 ± 10 3.600 ± 1.00 022 ± 002 083 ± 2
Zr/SA=0(Only SA) -710 ± 41 7.200 ± 0.27 006 ± 022 100 ± 4
Zr/SA=1 -737 ± 14 4.460 ± 2.00 022 ± 009 107 ± 6
Zr/SA=2 -696 ± 34 0.410 ± 0.05 449 ± 036 114 ± 9
Zr/SA=4 -683 ± 34 0.028 ± 0.01 686 ± 178 165 ± 3
Zr/SA=8 -704 ± 31 0.020 ± 0.01 778 ± 102 151 ± 4

36. 36
EIS analysis of zirconium-based superhydrophobic thin films
Facile electrodeposition process of zirconium-based superhydrophobic thin films on
aluminum
Zr/SA=8 Zr/SA=8Zr/SA=8
Rs
(Ω·cm2)
CPEf Rf (kΩ·cm2) CPEdl Rct
(kΩ·cm2)Yf
(Ω−1·sn·cm−2)
nf Yf
(Ω−1·sn·cm−2)
nf
As-received Al 022 - - - 2.3 ×10-6 0.9 037
Superhydrophobic
thin film
597 1.6 ×10-8 0.8 1.6 ×102 8.6 ×10-8 0.6 552

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Evaluation of the corrosion inhibition
performance of non-chromate corrosion
inhibitors for aluminum alloy

38. 38
Evaluation of the corrosion inhibition performance of non-chromate corrosion
inhibitors for aluminum alloy
 Corrosion inhibitors
Inhibitors are substances or mixtures that in low
concentration and in aggressive environment
inhibit, prevent or minimize the corrosion.

39. 39
Evaluation of the corrosion inhibition performance of non-chromate corrosion
inhibitors for aluminum alloy
 The choice of inhibitors

40. 40
Evaluation of the corrosion inhibition performance of non-chromate corrosion
inhibitors for aluminum alloy
 Experimental
300 ml of 0.1 M NaCl corrosive
solution
Injection of inhibitors:
 10-2 M of Na2SiO3
 10-4 M of MnSO4.H2O
 10-4 M of NH4VO3
Aluminum substrate

41. 41
Evaluation of the corrosion inhibition performance of non-chromate corrosion
inhibitors for aluminum alloy
EIS analysis of inhibitors in corrosive solution of NaCl
Inhibitor
Rs
(Ω.cm2)
CPEf Rf
(Ω.cm2)
CPEdl Rct
(kΩ.cm2)Y1(Ω-1.Sn
.cm-2) nf Ydl(Ω-1.S-n
. cm-2) ndl
Na2SiO3
86 3.26 × 10-11 1.40 143 6.99 × 10-6 0.90 047
Na2SiO3/ MnSO4.H2O 99 1.40 × 10-10 1.29 183 4.38 × 10-6 0.95 169
Na2SiO3/ NH4VO3
92 1.18 × 10-10 1.31 171 4.02 × 10-6 0.86 753
Na2SiO3/ MnSO4.H2O/
NH4VO3
90 2.67 × 10-6 0.69 170 2.29 × 10-6 0.88 926

42. 42
Evaluation of the corrosion inhibition performance of non-chromate corrosion
inhibitors for aluminum alloy
Potentiodynamic polarization tests
OCP (mV)
Vs. Ag/AgCl
Corrosion
potential
Ecorr (mV) Vs.
Ag/AgCl
Corrosion current
density
icorr (µA/cm2)
Polarization
resistance
Rp (kΩ.cm2)
Corrosion
inhibition
efficiency
η (%)
NaCl -734 -741 2.000 013 -
Na2SiO3 -678 -680 0.250 100 87.50
Na2SiO3/ MnSO4.H2O -798 -775 0.160 133 92.00
Na2SiO3/ NH4VO3 -861 -843 0.003 679 99.50
Na2SiO3/ MnSO4.H2O/
NH4VO3
-838 -816 0.002 722 99.99

43. 43
Evaluation of the corrosion inhibition performance of non-chromate corrosion
inhibitors for aluminum alloy
SEM analysis
Al
MixtureNa2SiO3
/MnSO4.H2O
NaCl Na2SiO3
Na2SiO3
/NH4VO3

44. 44
Evaluation of the corrosion inhibition performance of non-chromate corrosion
inhibitors for aluminum alloy
Corrosion properties of sodium silicate thin films
Al
Mixture
Na2SiO3
/MnSO4.H2O
NaCl Na2SiO3
Na2SiO3
/NH4VO3

45. • Non-chromate thin films were successfully fabricated on aluminum
substrates for corrosion protection
• Sodium silicate thin films enhanced the corrosion resistance of
aluminum. The Rp of the thin films was 593 kΩ.cm2 compared to 10
kΩ.cm2 for aluminum.
• Zirconium silicate thin films shows improve the corrosion resistance of
aluminum substrates. The Rp of the thin films was 446 kΩ.cm2 compared
to 10 kΩ.cm2 for aluminum.
• Zirconium-stearate superhydrophobic thin films shows
excellent corrosion protection with Rp of 778 (kΩ.cm2)
compared to 10 (kΩ.cm2) as-received aluminum.
• Chromate-free corrosion inhibitors were tested. The best corrosion
protection results were obtained when the mixture of the inhibitors
were used.
Conclusion

46. This part summarizes the possible work that could be accomplished in
order to develop a deeper understanding on the different thin films and
inhibitors studied in this work.
• Study the porosity of sodium silicate thin films fabricated by ultrasonic
dip-coating process will help to develop better understanding on their
corrosion properties.
• The surface treatment effect on the adhesion of zirconium-stearate
superhydrophobic thin films to improve the adhesion on aluminum
surfaces
• To improve better understanding, the inhibitors could be tested in
different pH and temperature conditions. Furthermore, the aeration
during the inhibition experiments was also reported to be an important
factor that could influence the efficiency of the inhibitors.
Recommendations

47. Journal articles
 Redouane Farid, Karthikeyan Rajan, Dilip Kumar Sarkar, Enhanced corrosion protection of
aluminum by ultrasonically dip coated sodium silicate thin films, Surface and Coating
Technology, 374, (2019), 355-361.
 Redouane Farid, Dilip Kumar Sarkar, Debasis De, Facile electrodeposition process of
zirconium-based superhydrophobic thin films on aluminum, The International Journal of
Wettability Science & Technology (IJWST), 1, (2019), 121-136.
 Redouane Farid, Dilip Kumar Sarkar, Debasis De, Evaluation of the corrosion inhibition
performance of non-chromate corrosion inhibitors for aluminum alloy. In preparation.
 Redouane Farid, Dilip Kumar Sarkar, Zirconium silicate thin films by sol-gel process
for corrosion protection of aluminum, (2019), In preparation.

48. Proceedings and presentations
Redouane Farid and Dilip Sarkar Kumar(2018, May). Étude du comportement anticorrosion des
revêtements superhydrophobes sur les alliages de l’aluminium. Oral presentation at 87th ACFAS
Congress. Saguenay. QC
Redouane Farid, Dilip Sarkar Kumar, Sofiene Amira, David Levasseur. (2018, June). Development of
mechanically durable ecologic and corrosion resistance non-chromate coatings for aluminum. Poster
session presented at La Journée des étudiants du REGAL. Montreal QC
Redouane Farid, Dilip Sarkar Kumar, Sofiene Amira, David Levasseur. (2018, June). Zirconium-based
thin films for the corrosion protection of aluminum. Oral presentation at La Journée des étudiants
du REGAL. Montreal QC.
 Redouane Farid, Dilip Sarkar Kumar, Sofiene Amira, David Levasseur. (2018, August) Development of
Superhydrophobic thin films on aluminum as a corrosion barrier. Paper presented at the 6th International
Conference & Exhibition on Advanced & Nano Materials. Quebec QC.
Redouane Farid, Dilip Sarkar Kumar, (2019, August) ’Silicate-based thin films for corrosion protection of
aluminum alloy. Oral presentation presented at the 7th International Conference & Exhibition on
Advanced & Nano Materials. Quebec QC.
Redouane Farid, Dilip Sarkar Kumar, David Levasseur, (2019, October) ’Development of mechanically
durable ecologic and corrosion resistance non-chromate coatings for aluminum’ poster presentation at
journée international des étudiants du REGAL, Quebec QC.

49. Acknowledgement
• Natural Science and Engineering Research Council of Canada (NSERC)
• Fonds de recherche du Québec - Nature et technologies (FRQNT)
• Aluminum Research Centre – REGAL
• Jayant Barode, a previous PhD student at the University Research Centre on
Aluminum (CURAL), and Tristan Billet a bachelor visiting student at CURAL
centre for carrying out the experimental work in sodium silicate part.
• Sofiene Amira and David Levasseur for their collaboration.
• PQ National silicate company for providing liquid sodium silicate.

50. Jury members
Dr. Zhan Zhang
Dr. Debasis De
Colleagues
Technicians
Farah
Prof. Dilip Kumar Sarkar
Familly
Mustapha
Mahdiyeh Zahira
Jabril
Prof. Hassan Ezzaidi
Fouad