New Nanotechnology Developments

for Corrosion Protection

NanoEngeneering - Hannover Messe, 21.04.2010

Dr. Thomas John-Schillings

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Content

Tasks of metal pretreatment

Traditional metal pretreatment: Iron- and Zincphosphating

Question about Phosphating

Presentation of Nanoceramics Bonderite NT-1 & TecTalis

Process

Benefits

Corrosion protection in comparison with traditional processes

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Why metal pretreatment?

Prior to painting substrates are often:

Dusty

Oily (forming oils, temporary corrosion protection)

Corroded (rust, welding scale)

Pretreatment provides:

Cleaning

Paint Adhesion

Better Corrosion Protection

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Traditional Metal Pretreatments

Zincphosphating

best corrosion protection

excellent paint adhesion

process difficult to monitor

very cost intensive

Ironphosphating

simple, flexible process

moderate process costs

Low corrosion protection

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Why should Phosphatings being

replaced?

very high sludge formation

very narrow process operation window lot of parameter

difficult multi metal pretreatment

many process steps lot of active bathes

high amount of heavy metals (Zn, Mn, Ni)

environmental unfriendly process (energy, phosphate, COD,

heavy metals)

Question: Which aspects of Zinc-/Fe-Phosphating are mostly

unsatisfying?

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Iron-

phosphating

Bonderite NT-1

Zinc-

phosphating

TecTalis

Eisen-

phosphatierung

Nanoceramics replace phosphating

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Which benefits provide Nanoceramics with respect to

Nanoceramics replace phosphating

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What are Nanoceramics

phosphate free metal pretreatment process

provides excellent paint adhesion and corrosion protection

replacement of iron- or zincphosphating

multimetal pretreatment process (steel, zinc, aluminium)

forming a thin ceramic conversionlayer (Nanoceramics)

application in existing lines (dip or spray)

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pH = 3.8 5.0

T = 10 - 50 C

time= 30 - 180 s

ZnO

Zn

Steel

ZrOXFy

H2ZrF6 Zn+2

H2ZrF6 + M + 2H2O ZrO2 + M2+ + 4H+ + 6F- + H2

M = treated substrate; Fe, Zn, Al, Mg

Nanocearmic coatings

Chemical Reaction

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5

250

1000

5000

10000

Zincphosphate

Ironphosphate

Chromates

NanoceramicsNanoceramics

bigger Molecules

[nm]

100

50

AFM (Atomic Force Microscopy) AFM (Atomic Force Microscopy)

TecTalis TecTalis CoatingCoating

SEM (Scanning Electron Microscopy)SEM (Scanning Electron Microscopy)

Phosphate Phosphate CoatingCoating

Nanoceramic Coating

Dimensions

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Typical Bonderite NT-1 process

Alkaline cleaning the only heated step

DI-Rinse prior to Bonderite NT-1

Conversion coating with Bonderite NT-1

(20 sec. or more)

DI-Rinse after Bonderite NT-1

Optional: Dryer after Bonderite NT-1

Powder coat, wet paint, CED/AEDC

Cleaning RinseDI-

RinsePaintNT-1

DI-

Rinse

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TecTalis process layout

typical typical ZincphosphateZincphosphate lineline

Cleaning Rinse Activation Phosphate. PassivationRinse D-Rinse

typicaltypical TecTalis TecTalis processprocess

5555CC

Cleaning Rinse TecTalisTecTalis Rinse

230 m

180 m

DI-Rinse

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Corrosion protection and

paint adhesion

Corrosions tests

judgement of the area and the creep at the cut

Constant climate test DIN EN ISO 6270-2 Neutral Salt spary DIN EN ISO 9227 AASS Cycling climate test VDA 621 415 Outdoor exposure VDA 621 414

Adhesion-tests

judgement before and after corrosion test

cross hatch stone chip -test Erichsen-Tiefung

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Perfomance:

Bonderite NT-1 vs FePhos

Bonderite NT-1 Fe-Phosphate

Customer sampes

Creep after 500h NSS

Bonderite NT-1 (left)

2.2 mm creep

Ironphosphate (right)

6,5 mm creep

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0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,0

E-coat 1 E-coat 2 E-coat 3 E-coat 4 E-coat 5 E-coat 6

Creep at cut [U/2 in mm] Granodine 958

TecTalis

spec

Performance: Comparison

Tectalis vs ZnPhos

70 cycles VDA Steel + CDP

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Comparison of process costs

example:

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Performance comparison

ZnPhos vs TecTalis

performance, e.g.

corrosion protection

Proces-

parameter

area i.O. results ZnPhos

areaarea i.Oi.O. . resultsresults TecTalisTecTalis

TecTalisTecTalisZnPhos

Specification

ProcessProcess windowwindow TecTalisTecTalis

Process window ZnPhos

automatical processcontrole (Lineguard Supervisor) for critical parameter possible!!

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Benefits of Nanoceramics vs

Phosphating

A lot of savings, e.g.

Maintenance and Cleaning

Water consumption

Heating ( ambient temperature)

Sludge disposal

Result in: Process costs decrease

Efficiency Process

Environment Quality

conversion at ambient temperature

short contact time

simple bath monitoring (pH)

real multimetal process

low energy consumption

no toxic heavy metals

phosphate free conversion

no contribution to COD

less disposal (sludge)

no hazardous substances

enhancement of corrosion

protection vs FePhos

replacement of Zincphosphating in

often possible

Compatible with Al, Zn, steel and

most available paint systems

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Nanoceramics - References

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Thanks for your attention!