Nanocomposite Zinc Coating

TEC STAR S.r.l.Viale Europa, 40 – 41011 Campogalliano (Italy)Tel. (+39)059 527775 – Fax (+39)059 527773

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Nanoparticles in galvanic Zinc coating: Mechanical properties improvement

Dr. Alberto Borghi

Tec Star Srl - President | CEO


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 Zinccoating. They increase corrosion resistance and hardness of galvanic coating.


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 sizeimproving the hardness of the coating.

Other studies related to different galvaniccoatings, i.e. Nickel, give improvement ofchemical and mechanical properties usingdifferents nanoparticles additive. Forexample: SiO2, TiO2, Al2O3, ZrO2, SiC, Cr2O3.


C.F./P. IVA 03209920366

YSZ Cr2O3

TiO2SiC

Experimentation parameters andtypology of nanoparticles (NP) usedas 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


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.



C.F./P. IVA 03209920366


Current Density: Low Medium High

Current Density: Low Medium High


C.F./P. IVA 03209920366

Nanoparticles additives: Cr2O3 and TiO2, mechanical and morphological properties

TiO2 nanoparticles increase mechanical properties using low current density duringdeposition process. At the same time give bad resutls in surface finishing of Zinccoating.

Morphology and mechanical properties


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 bestmechanical and morhological properties.

Morphology and mechanical properties


C.F./P. IVA 03209920366

Standard TiO2 low concentration

Neutral Salt Fog test results

72 hours

Corrosion resistance test


C.F./P. IVA 03209920366

Nanoparticles do not avoid white Zinc oxidation butincrease protection to red corrosion from the ironsubstrate.

Best nanoparticles for corrosion resistance are TiO2 eYSZ.

Corrosion resistance test


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


C.F./P. IVA 03209920366

Contacts

Dr. Alberto [email protected]

TEC STAR SrlViale Europa, 40

41011 Campogalliano (MO) - ItalyTel (+39)059.526845 Fax (+39)059.527000

Nanocomposite Zinc Coating

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