The document discusses using nanoparticles as additives in galvanic zinc coatings to improve mechanical properties. It summarizes previous research showing that yttrium stabilized zirconia (YSZ) and titanium dioxide (TiO2) nanoparticles increase corrosion resistance and hardness. The document then describes experiments by Tec Star testing different nanoparticles, concentrations, and current densities. It finds that YSZ nanoparticles provide the best mechanical and morphological properties at medium and high current densities. TiO2 improves properties at low densities but harms surface finish. Both YSZ and TiO2 increase corrosion resistance in salt fog tests compared to standard zinc coatings.

1. TEC STAR S.r.l.
Viale Europa, 40 – 41011 Campogalliano (Italy)
Tel. (+39)059 527775 – Fax (+39)059 527773
C.F./P. IVA 03209920366
Nanoparticles in galvanic Zinc coating:
Mechanical properties improvement
Dr. Alberto Borghi
Tec Star Srl - President | CEO

2. TEC STAR S.r.l.
Viale Europa, 40 – 41011 Campogalliano (Italy)
Tel. (+39)059 527775 – Fax (+39)059 527773
C.F./P. IVA 03209920366
[Xia et al., 2009, Journal of Materials Processing Technology, 209: 2632–2640]
Introduction
Nanoparticles of Yttrium Stabilized Zirconia (YSZ) are good additive for galvanic Zinc
coating. They increase corrosion resistance and hardness of galvanic coating.

3. TEC STAR S.r.l.
Viale Europa, 40 – 41011 Campogalliano (Italy)
Tel. (+39)059 527775 – Fax (+39)059 527773
C.F./P. IVA 03209920366
[Fustes et al., 2009, Journal of Solid State Electrochemistry, 12:1435–1443]
Introduction
TiO2 nanoparticles, as additive for galvanic Zinc coatings, may decrease grain size
improving the hardness of the coating.
Other studies related to different galvanic
coatings, i.e. Nickel, give improvement of
chemical and mechanical properties using
differents nanoparticles additive. For
example: SiO2, TiO2, Al2O3, ZrO2, SiC, Cr2O3.

4. TEC STAR S.r.l.
Viale Europa, 40 – 41011 Campogalliano (Italy)
Tel. (+39)059 527775 – Fax (+39)059 527773
C.F./P. IVA 03209920366
YSZ Cr2O3
TiO2SiC
Experimentation parameters and
typology of nanoparticles (NP) used
as additive for galvanic Zinc coating.
Tec Star experimentation
Parameters Values
Type of Nanoparticle Cr2O3 YSZ SiC TiO2
Current Density Low Medium High
Concentration Low High

5. TEC STAR S.r.l.
Viale Europa, 40 – 41011 Campogalliano (Italy)
Tel. (+39)059 527775 – Fax (+39)059 527773
C.F./P. IVA 03209920366
Nanoparticles Stabilizer Dimension [nm] Zeta Potential [mV]
Cr2O3
- 838 +1.9
A 925 -6.2
B 857 +5.4
YSZ
- 728 -2.1
A 849 -3.7
B 879 +4.7
SiC
- 2292 +10.5
A 2371 -5.17
B 1474 +16.7
TiO2
- 1474 -0.8
A 1527 +6.0
B 1320 +4.2
Nanoparticles stabilizer: we measure the Zeta potential of NP in water dispersion.
The best solution for galvanic Zinc bath is with high positive Zeta potential.
Tec Star experimentation

6. TEC STAR S.r.l.
Viale Europa, 40 – 41011 Campogalliano (Italy)
Tel. (+39)059 527775 – Fax (+39)059 527773
C.F./P. IVA 03209920366
Tec Star experimentation
Current Density: Low Medium High
Current Density: Low Medium High

7. TEC STAR S.r.l.
Viale Europa, 40 – 41011 Campogalliano (Italy)
Tel. (+39)059 527775 – Fax (+39)059 527773
C.F./P. IVA 03209920366
Nanoparticles additives: Cr2O3 and TiO2, mechanical and morphological properties
TiO2 nanoparticles increase mechanical properties using low current density during
deposition process. At the same time give bad resutls in surface finishing of Zinc
coating.
Morphology and mechanical properties

8. TEC STAR S.r.l.
Viale Europa, 40 – 41011 Campogalliano (Italy)
Tel. (+39)059 527775 – Fax (+39)059 527773
C.F./P. IVA 03209920366
Nanoparticles additive: YSZ and SiC, mechanical and morphological properties
YSZ nanoparticles show, at high and medium current density deposition, the best
mechanical and morhological properties.
Morphology and mechanical properties

9. TEC STAR S.r.l.
Viale Europa, 40 – 41011 Campogalliano (Italy)
Tel. (+39)059 527775 – Fax (+39)059 527773
C.F./P. IVA 03209920366
Standard TiO2 low concentration
Neutral Salt Fog test results
72 hours
Corrosion resistance test

10. TEC STAR S.r.l.
Viale Europa, 40 – 41011 Campogalliano (Italy)
Tel. (+39)059 527775 – Fax (+39)059 527773
C.F./P. IVA 03209920366
Nanoparticles do not avoid white Zinc oxidation but
increase protection to red corrosion from the iron
substrate.
Best nanoparticles for corrosion resistance are TiO2 e
YSZ.
Corrosion resistance test

11. TEC STAR S.r.l.
Viale Europa, 40 – 41011 Campogalliano (Italy)
Tel. (+39)059 527775 – Fax (+39)059 527773
C.F./P. IVA 03209920366
TiO2 high concentration
144 hours
Experimentation on real samples using nanoparticle additives: TiO2 and YSZ.
Pictures show samples before and after Neutral Salt Fog test.
YSZ high concentration
Real Samples
After deposition

12. TEC STAR S.r.l.
Viale Europa, 40 – 41011 Campogalliano (Italy)
Tel. (+39)059 527775 – Fax (+39)059 527773
C.F./P. IVA 03209920366
Contacts
Dr. Alberto Borghi
borghi@tec-star.it
TEC STAR Srl
Viale Europa, 40
41011 Campogalliano (MO) - Italy
Tel (+39)059.526845
Fax (+39)059.527000