Coatings for Advanced Aero Engine Materials

Dr. Wilfried Smarsly

Materials Engineering

8 th HIPIMS Conference

1 - 2 July, 2009, University Sheffield, UK

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Anti-fretting coatingsCasing, blades, vanes, discs, shafts

Ti-fire protection coatingCompressor casing

Thermal barrier coatingTurbine blades, burner

Corrosion / oxidationprotection Coating

Turbine blades

AbradablesCasing, tip coating, seals

Erosion resistance coatingCompressor blades

Diameter adjustment coatingsgreat numbers of parts

Coatings required for aero engines

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resistance against fretting fatigue and wear

applications on casings, blade roots, discs and shafts

dense coatings with high bond strength

repairable by recoating

Chromium carbide

+ nickel – chromium coating

plasma sprayed

Coatings for fretting damage protection (1)

Turbine vane

nickel alloy cluster

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Coatings for fretting damage protection (2)

Cobalt-chromium oxide dispersion coating

seal ring

APS

Coating

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Titanium blades witherosion mulilayer coating

excellent bonding on base material

excellent bonding on thinblade leading edge

excellent erosion resistance againstparticle erosion

slight influence of coating on thebase material (LCF, HCF)

repairable by recoating

Coatings for erosion damage protection

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Coatings for blade abrasion damage protection

Cubic boronnitride

particlesattached

on blade tip

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applications on titanium compressor casings

low thermal conductivity

sufficient thicknessin order to protect the casingagainst Ti-fire

excellent erosion and bond strength

repairable by recoating

Coatings for titanium fire damage protection

Titanium casing withplasma sparyed TBC coating

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applications on casings,blade tip coating, sealsand rotary parts

abrasive in casing

harder coating on rotor

oxidation resistance athigher temperatures

erosion resistance

repairable

Coatings for rotor rub in damage protection

Casing

Rotor

Abradable Coating

Abradable Coating

Vane

Blade

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Coatings for rotor rub in damage protection

HPC clearance

control

by

abradable

plasma sprayed

coating

for rotor

rub in

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applications for turbine blades and vanes

coating includes protectiveelements (Al / Cr)

bonding to the base material throughdiffusion processes

dense passivation coating is built(rebuilding after coating loose)

smooth and aerodynamically surface

applicable at high temperatures

repairable by recoating

Coatings for oxidation and corrosion damage protection

Turbine vane

segments

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Oxidation and cracking of component surface

Oxidation

changed

near surface

chemical

composition

cracks

can formed

by

embritlement

Dechema e.V.

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Hot corrosion typ II 600 – 800 °C

Liquid

Alkali Sulfur

compounds

from

hot exhaust gas

reacts

with

component

surface

Dechema e.V.

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Hot corrosion typ I > 884 ° C

Gaseous

Sulfur Oxide

from

hot exhaust gas

reacts

with

component

surface

Dechema e.V.

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Stabilty of metal oxides

Dechema e.V.

Alpha aluminium

oxide

is the most stable

oxide

for protecting

component

surfaces

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Aluminium oxid forming coatings

Not + Al + PtAl

coated coating coating

Ox

ida

tio

nli

feh

NiAl

Diffusion

Zone

Ni alloy

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higher temperatures on the part surfaces comparedto the base material are possible

applications on blades, burner and casing

low thermal conductivity

elongation under thermal loading according tometal base material

applications at high temperature range(1150°C - 1200°C on the surface)

bonded to the base material through oxidation andcorrosions resistant interface layers

repairable by recoating

Coatings for heat damage protection

Highpressure

turbine

blade

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Plasma spray process for coatings

Gordon England

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Coating structure for heat damage protection (1)

ZrO2 plasma sprayed thermalbarrier coating- porous- micro cracks- poor bond strength

Al diffusion coating

NiCrAlY bond coatingatmospherically plasma sprayed

nickel-based superalloy

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EB PVD process for coatings

Thermal

protective

coating on

Vane Cluster

Penn State Univ.

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Coating structure for heat damage protection (2)

ZrO2 EB - PVD thermalbarrier coating

- columnar

- strong bond strength

- Y stabilized

NiCrAlY bond coating

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Thank You !

Horst Neubert

FOR YOUR INTEREST

AND ATTENTION !

Q U E S T I O N S ?