PVD Coating Technology

Bohler-Uddeholm India Value Added Services

Introduction

Bohler Uddeholm is the market leader in India for supplying tool steel & high speed steel of premium qualityand providing value added services to automotive, electronics, home appliance, packaging and constructionindustry sector

To meet the demand of tooling performance, we have a wide range of special steel in our product portfolio whichcovers cold work, plastic mould, hot work and cutting tool applications.

To achieve best performance, it is cretical to select a sutaible tool steel that is compitant in meeting the basicwork requirment. This means that the tool steel itself must have an optional combination of properties likehardness, strength and toughness and consequantly enough ressistance to different premature and permanantfailures like chipping, plastic deformation and cracking. etc.

There are, however, some normal & acceptable failures like wear that will happen sooner or later depending onthe properties of the working die surface. Therefore, one may decide to choose tool steel which has a higherhardness in order to resist wear. But this results in lower toughness and therefore is not recommanded.

surface treatment, like surface hardning, nitridng, hard coating can improve the sarface hardness withoutlosing the properties of the substrate, As a result, these types of surface treatment are widely used in advancedtooling technology.

Among these surface treatment, PVD coating is one of the best and most popular technologies to improveSurface properties. With tailored coatings, the hardness, corrosion resistance, high temrature resiustance and tribological properties can be modified to resist different surface failures.

Alpha Arc Coating System 900PMaximum capacity : Ø 750 X 800Mximum load : 850 Kg

Alpha Arc Coating System 400PMaximum capacity : Ø 450 X 485Mximum load : 300 Kg

BOHLER UDDEHOLM ADVANCED COATING

Bohler Uddeholm Advanced Coating is widely used in tooling applications with the following unique characteristics:• Thin (2-10 pm) • Low friction against steel• Hard ( 2000 - 4000 HV) • Low tendency for cold welding• Prserving the surface structure • Corrosion resistant• Superb adhesion to sibstarte • High Oxidation resistant

TABLE 1. THE HARDNESS SCALE OF HARD COATING

HV / Vickers 240 300 400 500 600 700 800 940700 to

1200

1400 to 1800

2000 to 8000 10000

HRC / Rockwell 20 29.8 40.8 49.1 55.2 60.1 64 68 - - - -

Type of steel or process N

itide

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Sol

id C

arbi

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PVD & CVD

coating Dia

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Bohler Uddeholm offers customers a wide range of PVD coatings for different types of applications. Forinstance, high hardness and abrasion resistance with low corfficiant of friction for cold work, thermal andabrasion resistance for hot work, and corrosion and abrasion resistance for plastic moulding.in order toachieve the combined properities, coating are designed to be in variable layer structures - monolayer,multilayer or nanostructured coatings.

BOHLER - UDDEHOLM DUPLEX COATINGThe combonation of a plasma nitriding and a subsequent deposition of PVD coating in a non-intrruptedarc process is called Bohler - Uddeholm Duplex Coating.

With plasma nitriding , the surface hardness of the steel substrate is increased, thus considerably improving the performance of a PVD coating. Bohler - Uddeholm Duplex Coating has the following advantages:

• No compound layer in steel• Increased surface hardness• Polished surface is preserved• Excellent adhesive strength• No change in dimension• Increased load capacity• Low plasma nitriding temprature (< 480°C)

Duplex Coating

Soft Steels Quenched Steels Hardend Steels

SPCS ARC TECHNOLOGY - ULTRAFINE COATING

Filtered arc technology is a method to provide precosion tools, components in the aircraft industry andincreasingly medical devices and implants with coatings that are extremely high in smothness and density.itwas devloped shortly after the introduction of the arc technology for industrial coatings.However, significantcosts and long delivery times made it barely economically viable for many coaters and users.

with the SPCS arc technology devloped at Eifeler. Layers can be deposited with surface quality and densitycomparable to those to the filtered arcbut without its drawbacks. Coating deposited by using SPCS arctechnology are labeled as ultrafine coating,eg. TIN-ultrafine,TiCN-ultrafine,etc. Plastic application with criticalrequirement on the surface finishing will benefit from ultrafine coating with its unrivaled properties against standard arc coating process.In application eg.cutting, micro-cutting, surgical instrument, ultrafine coatingalso shown to provide significant improvement

COMPARISION BETWEEN STANDARD ARC COATING AND SPCS ULTRAFINE COATING

STANDARD ARC COATING SPCS ULTRAFINE COATINGsome dropletes smoother & denser coating

Sutaible for most applications Enhanced adhension But may require post- polishing Advantageous for slected applications

COLD WORK APPLICATION

For cold work applications like forming,fine blanking and powder compacting,etc.,thetypical failures on the surface are abrasive wear,adhesive wear,galling and friction.

Forming tools with better galling wear resistance will be needed more in the furture as the trend is towrds anincreased use of high strength sheet materials,higher process speeds,the use of progressive dies with fewer stwpsand the use of more enviornmental friendly but normally less effictive lubricants.

As mentioned before, Duplex coating with a plasma nitriding layer beneath the hard coating has a better supportfor the coating layer and therefore further increase the performance and tool life. As such, Duplex coating is strongly recommended for forming of high strength applications.

In blanking and cutting. It depends on the work material and the design of the die (tight die clearance in fineblanking for example), the tool failure can be plastic deformation,chipping,abrasive or adhessive wear

Abrasive Wear Galling Adhesive Wear

HardnessAmount of carbides Carbide sizeCarbide Hardness

Surface hardnessSurface roughnessCoeff. of friction

Surface hardnessDuctilityCoeff. of friction

HOT WORK APPLICATION

In hot work applications like die-casting, typical surface failures are erosion,soldering, corrosionand thermal fatigue.it is proven that with a suitable coating which acts as a buffer layer,this can minimise dies from soldering.corrosion and errosion, where the failure mechanism is due to, orpartly due to the reaction of the melt, lubricant and tool steel. Surface coating of die casting dies.can also help eliminate cracking and chipping if these failures originate from the surface attack.

In hot forging and extrusion applications, the mail surface failure is hot wear. This is a result of hardness decrease under elevated temperatures

Soldering

In die-casting dies, in which cores surrounded by high temprature melt. Soldering is always themain problem that causes a lot of failures, for instance cracking due to high ejection force. PVDcoating can act as an insulation layer to prevent reaction between the die steel and the castingmelt, hence minimising soldering. For some special cases where cooling is not sufficient or the melt velocity too high due to design restriction in geometry, erosion and soldering can be a critical problem. In this case, hard and high tempreature resistant PVD Coatings like in duplexprocess can help.

Erosion

PLASTIC MOULDING APPLICATION

Typical failures on the surface of plastic moulds are abrasive wear, scratch and corrosiondepending on the type of plastic and the additive. Surface failures in plastic moulding can be costly, as the user has to re-polish the moulds regularly to restore the glossy cavity surface.

Plastic moulds, hot channel injector and valve pins can be coated by PVD. In most cases the tools for plastic moulding need a very smooth coating. This can be achived with SPCS TIN-ultrafine coating.

Coating in plastic applications are mainly for increasing the cavity surface hardness, henceminimising scratches and protecting the polished surface against wear. Moreover, demouldingcan also be improved because of reduced adhesion between the steel and the plastic.multilayered CrN coating is proven to have very good corrosion resistance when the plastic iscorrosive.

Sometime post polishing is necessary if there is an extremely high requirment on the surface of the cavity.

Benefits from SPCS TIN - ultrafine coating• Defect free chromium plating of plastic part• Best surface quality of plastic part• Improved mould release• Preserved mirror polished mould surface

StandardUltrafine

CUTTING TOOL APPLICATION

Bohler Uddeholm india offeres a variety of PVD coatings for the cutting tool industry. From the listof product portfolio, Bohler Uddeholm's Standard and Advanced coating fulfills the marketdemand to increase the productivity by working under higher cutting parameters, long lastingtool life, hard machining, dry cutting etc.

Bohler Uddeholm Ultrafine PVD coating will stand unique in the market that offers very highdense and smooth finish coating with the latest SPCS technology which are most recommendedfor all types of cutting tools.

PVD Coating Benefits on Cutting Tools

• Excellent Wear Resistant• Advanced Oxidation Resistant• Low thermal Conductivity• Low Coefficient of Friction• Increased cutting speed & feed rate

CROSAL® for Gear Cutting Tools

Parameters

• PM-hob, Bohler S3902- Cutting technique, Felsomat

• 5. gear, 16MnCr5

• Dry cutting:roughning with 180 m/min.refining with 360 m/min.

SURFACE QUALITY OF THE TOOL

Appropriate preparation on the surface prior to coating is one of the most important factor for a successful coating. A surface is considered good for coating when it is

• Fine ground• Polished and metallically-celaned• Sufficient in substrate hardness• Low in roughness (Rz < 1µm)• Properly heat-treated• Protected against corrosion

Some kind of surfaces are not suitable for depositiion of coatings, for example, EDM erodedsurfaces, hard turned surfaces, nitrided surfaces, which are unfortunately frequently found in toolshops. Such kind of surfaces lead to bad or even no adhesion for coating, therefore specialpreparation shall be carried out to remove such defected layer.

EDM ERODED SURFACE HARD TURNED SURFACE No caoating adhesion Bad adhesionof PVD

POLISHING

Highly polished surface are the most advantageous. The surface roughness shall be as low aspossible. Polishing shall be done in a way not destroying the surface properties of the steel;otherwise it will result in delamination of the coating.

SURFACE CLEANLINESS

Although there is always a cleaning process before coating, it is highly recommended to keep the substrate as clean as possible before sending it for coating. Debris, residual working material aswell as rusty scale shalle be properly removed, especially from water channels, holes or areaswhere cleaning by ultrasonic cleaning machine is difficult. It is important that the substrate hasgood protection against corrosion. So, during transporting the substrate to the coating divisio,apply corrosion protecting oil on the substrate.

Coating recommendation stamping/forming

< 3mm > 3mm < 3mm > 3mm < 3mm > 3mm

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Coating recommendation - plastic injection moulding

legend : XXX -Strongly Recommended XX - Recommended X- Can be used

PVD

Duplex PVD

DUMATICDuplex-VARIANTIC®

Duplex- CrCNDuplex- TOPMATIC

Duplex-CROSAL®

CROSAL®EXXTRAL®TIGRAL®SISTRAL®

TOPMATIC

TiNTiCNCrN

High Strength

ZN -plated

Aluminium Standard

CrCNVARIANTIC®

StainlessCoatings Non-ferrous

xxxxxx

TiAlNCrNTiCNTiNThermoplast

Fluorhaltigs Polymerisate PTFE, PVDFAcetalherze POMPolyamide PA

Polyolefine PE, PP, PBStyrol polymerisate PS, SB , SAN, ABS, ASA

Chlorhaltinge Polymerisate PVC

Polyurethane PUR

Elastomer

filling behaviour

Polyurethane PUR

Duroplast

corrosioncovering of mouldsdemoulding

X XXxxx XX

Aminoplaste MF, UF, MP

abrasionadhesion

Celluleoseester CA, CP, CAPPolyacrylate PMMA

Polyurethane TPU

Lineare Polyster PC, PBT(B),PET(P)

Polyarylenthene PEEK, PPS,PSU,PES,PPE,PPO

Polyamide PI

XX XXxxx XXX XX

XXXX

xxxxxx

xxx XXX

X XX XXX XXX

Wear mechanism

xxxXXX

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x xxx x xxTiN TiCN CrN TiAlN

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TiN TiCN CrN TiAlN

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xxx xxx

Flurierte Elastromere Multipolymer - TPE,FPM xxSynthetisher Kautschunk NBR, EPDM, Si xx

Name of Coating

MaterialMicro hardness

HV 0.05

Coeff.of friction

against steel

Coating thickness (µm)

TiN TiN 2300±200 0.6 2 ~ 4

TiCNTiCN

( multilayer )3500±500 0.2 2 ~ 4

EXXTRAL ® AlTiN 3300±300 0.7 2 ~ 5

SISTRAL ®AlTiN ( nano-structured )

3400±500 0.7 2 ~ 4

CROSAL ® AlCrN based 3300±300 0.4 2 ~ 5

VARIANTIC ®TiAlCN

( multilayer )3500±500 0.2 2 ~ 4

CrN CrN 2000±200 0.2 ~ 0.3 2 ~ 6

CrCNCrCN

( multilayer )2300±200 0.2 ~ 0.3 2 ~ 6

ZrN ZrN 2800±200 0.5 2 ~ 4

ZrCNZrCN

( multilayer )3100±300 0.5 2 ~ 4

Varianta ® SUPRAL

AlTiCN 3500±300 < 0.5 2 ~ 4

TIGRAL ®AlCrTiN

(nanolayer)3300±300 0.6 3 ~ 5

TOPMATIC TiAlN 2800±200 0.4 5 ~ 9

DUMATICTiN / TiC (

Multilayer )3700±200 0.3 3 ~ 5

• Drawing and forming of high alloyed CrNi-steels • Punching of thick steel foils and massive

forming of steel

Very high hardness, very high adhesive force, low coeff.of

friction.Silver - Grey400°C

•machining of cast iron and high temp. alloys• excellent for

drilling operation for steel

High hardness,Low friction,high oxidation

resistanceAnthracite800°C

• All application in machining of steel,if temp.is high and

abrasive wear is dominand • PDC application

High oxidation resistance, high warm-hardness,high

wear resistanceGrey900°C

• For application of massive forming of steel • For higher

thickness

Very high toughness, good oxidation resistance,,high

wear resistanceAubergine800°C

• Plastic moulding (improve mold release)• Aluminum &

magnesium die casting

High hardness,Low Stress, high adhesive force, very high resistance agaainst corrosion

Silver - Grey600°C

600°C Light - YellowLow tendency for cold

welding, excellent corrosion resistance

• Cast Al. & non-ferrous material machining •machining of fiberglass,nylon & polymer

materials

• Cast Al. & non-ferrous material machining •machining of fiberglass,nylon & polymer

materials

Very hard, Low tendency for cold welding, excellent

corrosion resistanceBrown - Silver600°C

• Processing of steel at elevated temp.& strong

abrasive wear;dry cutting;fine blanking • PDC application

Extremely High oxidation resistance, high warm hardeness, high wear

resistance

Slate - Grey1100°C

• High performance universal coating;for drawing and

formingof high and low-alloyed steel

Low friction,high oxidation resistance

Old- Rose800°C

• Plastic moulding (improve mold release)• Aluminum &

magnesium die casting

Low Stress, high adhesive force, very high resistance

agaainst corrosionSilver - Grey600°C

Bohler-Uddeholm PVD Coating Portfolio

Recommended applicationsGeneral characteristicsColourMax. temp.of

operation

• Machining of hardened steel • For use on carbide endmill

and drills800°C Anthracite

High Hardness, high oxidation resistance, low coeff. friction available in

'ultrafine'

• High performance coating for high proecess temp.

•machining of hardened steel, Inconel

High oxidation resistance, high warm hardeness, high wear resistance available in

'ultrafine'

Anthracite900°C

• Metal Forming • Plastic molding • Machining of irion

based material

Allround coating, bio-compatible, Available in

UltrafineGold500°C

Blue - Grey400°C

High Hardness, excellent wear resistance, imped

toughness available in 'ultrafine'

• High performance cutting where moderate tempratures are generated at cutting edge

WORKS WORLDWIDE

www.bohler-uddeholm.in

Corporate Office

BöHLER-UDDEHOLM INDIA PVT LTDA-409, Skylark, Plot No.63, Sector 11, CBD Belapur,Navi Mumbai - 400 614, Maharashtra, India. Office: 022 27577441

Pune Works

BöHLER-UDDEHOLM INDIA PVT LTDPAP S-2, Phase -II, Chakan Industrial Area,Village Savaradari, Taluka -Khed, Dist. Pune - 41- 501 . Maharashtra, India. Cell: 9659677711