Keronite® Surface Treatment for Light Alloys

ASETS2009 ConferenceDenver 2 Sep 2009

Steve Hutchins

Wear ResistantExtremely HardChemical ResistanceElectrical ResistanceThermal BarrierSuperb AdhesionClean Technology

What is Keronite?

An advanced surface treatment for aluminium, magnesium and other light alloys

A patented process based on a technology known as Plasma Electrolytic Oxidation (PEO)

Plasma process converts light alloy surface into a hard layer of protective ceramics

A family of coatings

Opens up new applications for light alloys

A clean technology

The Keronite Process

PowerSignal

PowerSupply

Keronite uses a plasma discharge to convert the substrate surface into complex ceramics

The part is introduced into the tank and connected to the power supply

A plasma discharge forms, creating very high energy conditions localised in a thin surface layer.

Key process characteristics Oxidation of the substrateElementary co-deposition from the

electrolyteFusing of the layer via plasma discharges

Air

HeatExchanger

Pump

RecirculatingElectrolyte

4

CleanTechnology

XADHESION

SUPERB

Keronite Properties

Up to 2,000 HV on aluminiumUp to 700 HV on magnesium

Comparative hardness (HV)

0 500 1000 1500 2000 2500

Aluminium

Mild Steel

304 Stainless Steel

Hard Anodized Aluminium

Hardened Tool Steel

Hard Chrome

KERONITE™ on Aluminium

Hardness

Hardness

Keronite coating on 7075 Hardcoat anodising on 7075

0

50

100

150

Nitridedsteel

Uncoated 2xxx alloy

Uncoated 5xxx alloy

Keronite coated

2xxx alloy

Keronite coated

5xxx alloy

Steady StateOver 1000 revs

Vol

umet

ric

wea

r ra

te (m

m3

/ km

)

Wear rates – ASTM G65

Source: ABB, Cambridge University and Southampton University, poster presented at Materials Congress 2006.

Ford Cyclic Corrosion Testing on Mg

Keronite meets or exceeds the requirements of AMS 2466 “Hard Anodic Coatings for Magnesium Alloys”

Keronite

Keronite + ecoat

Cr6 + powder

Diecast Mg AM60 test plates, 30 day cyclic testing

Galvanic corrosion protection

Mg plate + stainless

steel screw

Galvanic corrosion after just 7 hours in salt fog

Mg plate + Keronite on

Al screw

Mg plate + zinc plated steel screw

Mg plate + anodised Al

screw

Confidential

Flexibility

100µm detached Keronite film showing ability to be bent or flattened elastically

In more severe deformation, both plastic and elastic deformation occurs before failure

Flexibility gives the coating resilience against small impacts or deformation of the substrate. Avoids cracking and delamination in-service

Courtesy of Cambridge University

1cm

High Dielectric Strength CoatingsHigh Dielectric Strength Coatings

Breakdown voltage (max unsealed) Thickness

Alloy V um

6xxx 1500 50

5xxx 2500 80

LM24 540 8-20

99.9Al 560 15AA6xxx

Average voltage breakdown figures3000V has been achieved when sealed.Thin layers give low thermal barrier

Power electronics cooling devices.

Composite coatings

Polymers : Paints, lacquers, PTFE, E-coats, powder coats, organic-non organic polymersMetals : Ni, Cu (electroless), PVD, CVDCeramics: PVD, CVD

500 nm

Nanometre-scale porosity facilitates impregnation

Sharp edges and corners

Keronite on Ti-6-4

Courtesy: University of Bologna

Keronite on Ti - friction

Courtesy: University of Bologna

Cylinder-on-flat disc dry sliding wear

5-20N loadØ40mm steel

cylinder plasma sprayed with Al2O3 + TiO2 of 1180 HV

0.6m/sSliding

distance 5000m

Keronite on Ti - Wear

Courtesy: University of Bologna

>10x more wear resistant than Ti Type 2 anodising according to AMS2488Anti-fretting gimbal bearings on satellites

Applications

Marinized aluminium components

Keronite

Trilobit 2 seismic node, at 4000m deep seabed operated by ROVCourtesy: Carrack Measurement Technology and CGGVeritas

Aluminium sprockets

Harder than sandWeight savingRedesigned from Steel to AlImproved in service performanceClean Technology

Harder than sand, Keronite enables the replacement of steel with aluminium and 66% weight savings, with superior performance

Extract from distributor website: “these ceramic coated alloy rear sprockets will outlast ordinary alloy sprockets by 300%, AND increase the life of your chain too.”

Aluminium print rollers

Harder than sandWeight savingRedesigned from Steel to AlImproved in service performanceClean Technology

Hard chrome replacement

Faithfully follows gravure pattern on surface

Improved wear resistance and corrosion resistance

No galvanic action between coating and roller

Ball valves

Keronite gives the advantages of a ceramic finish for the cost of an aluminium component –fuel line ball valvesProvides excellent wear protection against PTFE seals, ingrained dirt etc

Black aluminium coating

Keronite Black Al coating demonstrates resistance to the extremes of temperature found in space

Thermal emissivity approx 0.84

Absorption coefficient approx 0.90-0.95 over optical and near IR range.

Corrosion resistance allows use of high-strength alloys

Fully UV stable

Thank you

For more information please contact:

Bill BuchmanKeronite Inc

Greenwood INbill.buchman@keronite.com

Tel 586 677 2443