a case for more adaptions

A case for more adaptions

Expanding the coating spectrum with Oxinitrides and DLC

European Production Engineering

Gear Grinding TechnologyTwistControl Grinding

2009

>

y

> PREDICTION2009 will decide the fate ofthe Swiss machine toolindustry // Page 6

> INTEGRATIONUniversal grinding machinemounted into flow-oriented production // 1

> ADAPTATIONExpanding the coatingspectrum with oxidesand DLC // Page 29

Swiss Quality Production

© Carl Hanser Verlag, München. 2010. All rights including reprinting, photographic reproduction and

translation reserved by the publishers.

Special reprint from Swiss Quality Production 2009

PLATIT AGEichholz St. 9 - P.O.Box 151CH-2545 Selzach / SO, SwitzerlandPhone: +41 (32) 544 62 00Fax: +41 (32) 544 62 20eMail: [email protected]

© Carl Hanser Verlag, Munich

C U T T I N G TO O L S

2

> »When you take the catastrophe out ofa crisis it can be quite productive« [1.1].Companies do not need capacity increas-ing during a crisis. Innovative technolo-gies, however, can lead to a higher productquality and/or to branch out into new mar-kets and may even help to prevent or evenend the crisis.The In-House-Coating (IHC)is surly one of the most promising busi-ness models to realize this with the help ofcompact and flexible PVD units. Theseunits should be able to deposit any coat-ings from simple TiN through Nanocom-posites and oxides up to DLC. Since 2003Platit’s mainly SME (Small and MediumEnterprises) customers have worked world-wide with the ›π‹ coating systems with theirrotating cathodes. This article describesthe newest developments for this productfamily like: oxide and oxinitride coatingsas well as DLC coatings, preferably pro-duced as ›TripleCoatings‹ in combinationwith Nanocomposite coatings.

The user

needs dedicated coatings

»All tool manufacturers can master cut-ting materials and tool geometries. Thecompetitiveness will be decided by theused coatings« [1.2]. Standard coating of-fered by job coaters all over the world willnot help companies stay ahead of the com-petition. In order to be successful they needexclusive dedicated (tailor made) coatings

adapted to the specific application. Thisexclusivity is only possible if you make yourown coatings in your In-House-Coatingcentre. All major requirements of coatingusers [2] bear witness to the validity of thisstatement.The wide variety of applicationshas led to an increasing number of coat-ings. Today there are not less than 80 dif-ferent types in existence with all kinds ofchemical compositions. There are evenmore than 250 considering all the differ-ent stochiometries [3].

Flexible coating systems will only be in-tegrated into proprietary production pro-cesses when:■ Turnkey coating systems [4] are avail-

able. They should provide pre- and af-ter-treatment of cutting edges and sur-faces [5, 6, 7], stripping, cleaning andquality control systems.

■ The system can be operated even with-out high qualified personnel.

■ The system reaches cost-efficiency with-in two years.

■ The system enables the deposition ofconventional as well as high perform-ance coatings and dedicated coatingsfor specific applications.

Innovative units

for an wide range of coatings

»Innovation distinguishes between a leaderand a follower. Innovation is when the cus-tomer opens his valet« [1.3]. The cores ofthe π technology are the rotating cathodes([4], [6 ], [8]) with double shutters (Fig. 1,left). Before coating the targets are beingcleaned by means of the ›Virtual Shutter‹preventing contamination of substrates(tools):

Expanding the coating spectrum with Oxinitrides and DLC

A case for more adaptionsOxide and oxinitride coatings as well as DLC coatings, preferably produced as

›TripleCoatings‹ in combination with Nanocomposite coatings, are the latest coatings

of the ›π‹ coating system family of Platit.

BY TIBOR CSELLE, MARCUS

MORSTEIN, ANDRES LÜMKEMANN,

OLIVIER CODDET UND

JAN PROCHAZKA

Figu

res:

Pla

titLateral and central rotating cathodes1

The rotating cathodes with double shutters, which allowing a flexible configura-tion, are the core of the ›π‹ technology

TiAlCr

Closed Opened

The target is cleaned to the back side before deposition

SWISS QUALITY PRODUCTION 2009 3

■ The ›Tube Shutter‹ is closed to preventthe tools from being contaminated byprevious processes.

■ The ARC ignites toward the back; theVirtual Shutter is activated.

Deposition (coating) begins with clean tar-gets:■ The Virtual Shutter is deactivated.■ The Tube Shutters are open.■ The ARC ignites toward the tools.This double shutter technique gives a verygood adhesion (without prolonged etch-ing) as well as smooth, droplet-arm sur-faces.

The smooth change-over from one pro-duction setup to the next enables the ma-

nufacturing of a wide variety of coatingsas well as short processing times.

Thanks to its cathodes sitting right nextto each other the ›LARC‹ (LAteral RotatingCathodes) technology enables the use ofcost effective non alloyed targets as well asthe deposition of a great number of coa-tings with the same cathodes. Composi-tion and stochiometry can be further de-fined through the use of software.Thus thecathode configuration (Cr-Al-Ti) shownin Fig. 1 (right) allows the production ofpractically all popular PVD coatings fromthe market:■ TiN, TiCN, TiCN-MP, Ti2N, SuperTiN,■ TiAlCN (75/25, 80/20 per cent),

■ TiAlN (50/50 per cent), AlTiN(60/40, 67/33 per cent),

■ CrN, CrTiN, AlCrN (70/30, 80/20 per cent),

■ TiAlCrN = All-in-One,■ all coatings also with DLC top

coating.For the deposition of Nanocompos-ite coatings the Al cathode (Fig. 1,right) is replaced with an AlSi cath-ode. The spinodal segregation [9]needed for this process is achievedthanks to the closeness of the Ti-AlSi and/ or Cr-AlSi cathodes. Thenanocrystalline TiAlN or AlCrNgrains are embedded in the amor-phous SiN matrix thus enabling thebuild-up of Nanocomposite struc-ture and coatings [8]:

■ ›nACo‹: TiAlN/SiN,■ ›nACRo‹: CrAlN/SiN,■ ›nATCRo‹: AlTiCrN/SiN.The SiN matrix encases the grains, impedestheir growth and this structure makes theincreasing of the hardness possible (Fig. 2.

TripleCoatings [3], [8], [10] consist ofconventional and Nanocomposite coatings:■ ›nACo3‹: TiN + AlTiN + nACo,■ ›nACRo3‹: CrN + AlTiCrN A nACRo,■ ›nATCRo3‹: CrTiN/+ AlTiN + nACTRo.They are deposited in three phases (Fig. 2).The best adhesion is achieved by using ti-tanium and/or chrome without using of al-loyed targets.Thanks to the similar Young’smoduli the adhesive layer allows a smooth

Deposition of ›TripleCoatings3‹2

Deposited in three phases, ›TripleCoatings3‹ consist of conventional and Nanocompositecoatings

Cr TiAlSi

Al(Ti)

1st step:Adhesionlayer CrTiN

2nd step:Core layer AlTiN

3rd step:Top layer nATCRo®

nATCRo3®

1. CrTiN 2. AlTiN 3. AlTiCrN/SiN

Cutting speed versus tool life3

Verified: A TripleCoating and an oxinitride coating achieve high cutting speed in dry cutting processes

SECO Pramet CNMG 120408-PM

Cutting speed; vc [m/min]

Tool

life

; Tc

[min

]

0

5

10

15

20

25

30

35

40

45

50

200 250 300 315 330 350

nACoX

nACo3

Standard-Schichtdes WSP-Herstellers

vc = 250…350 m/min, f = 0.25mm/rev, a = 1.5 mm –Material: C60 (1.1221), HB225 tool life end criterium: VBmax ≤ 200 μm

Measured atTH Budapest

Standard coatingof the insert manufacturer

SWISS QUALITY PRODUCTION 2009 4

transition between substrate and coating.Because of its low internal stress the mid-dle layer provides a robust core with a goodresistance to wear as well as superior hard-ness. The central cathode (›CERC‹: CEn-tral Rotating Cathode [4]) ensures a highdeposition rate it means high productivi-ty. The Nanocomposite top layer shows anextremely high hardness and an excellentthermal isolation (silicon) as well as a highresistance against abrasive wear. Due totheir different structures the TripleCoat-ings lend themselves for all kinds of ap-plications as shown under ([3], [8], [10]).See figure 3.

New coatings enlarge

the spectrum of applications

»Creativity is the combination of ideas«[1.4].A successful PVD deposition and/orapplication of oxide and oxinitride is on-ly possible in conjunction with other coat-ings. Otherwise, the end result lacks thedesired adhesion, cohesion, and hardness.When combined with conventional nitridesand especially Nanocomposite coatingsthe range of applications is pretty wide.Oxide and oxinitride coatings serve to sep-arate tool/component and workpiece andachieve a low affinity between the two, es-pecially in dry cutting processes (Fig 3)where high temperatures are reached [11].They offer the following advantages:■ high resistance against adhesive wear,

abrasive wear, oxidation, oxygen diffu-sion (the layer already is as an oxide),

■ chemical and thermal isolation andchemical indifference,

■ reduced friction even at temperaturesof more than 1000 °C,

■ fewer built-up edges and less materialinterdiffusion in the tribo contact zone.As a metal nitride basis is needed to pre-

vent cracking and plastic deformation thecoatings are (like with CVD) being builtinto a multi-layer structure (Fig. 4). Ourcurrent oxide coatings are based on an evo-lution of the TripleCoatings principle:■ ›AlCrNoX‹: CrN + AlCrN + AlCrON

(optional + AlCrN)■ ›nACoX‹: TiN + nACo + AlCrN + Al-

CrON (optional + AlCrN)ARC processes with oxygenic gaseous mix-tures are particularly stable thanks to therotating LARC cathodes. No increase inARC voltage during the process. Possibil-

ity of using high ionic currents and there-fore high deposition rates. Possibility ofusing DC BIAS amplifiers with low O2

contents where charges can be avoided bymeans of an medium-frequency pulsedBIAS (up to 350 kHz). The preferred ni-trogen/oxygen (N/O) rate is 50/50 to 80/20per cent. Typical coating thickness is 7 to18 µm. Typical overall hardness is 30 GPaand typical Young’s modulus around400 GPa.

Diamond-Like Coating (DLC) is a meta-stable form of amorphous carbon with ahigh percentage of cubic sp3 elements. Themetal-doped first generation of Platit DLCcoatings (CBC; Me-C:H) is deposited in apure PVD process. In order to achieve goodadhesion it is being manufactured in abatch in combination with hard coatings.Hence their names ›CROMVIc‹: CrN +CBC, ›cVIc‹: TiCN + CBC, ›nACVIc‹: nA-CRo + CBC et cetera.

CBC coatings improve the running-incharacteristics of chip removal and for-ming tools and play an important role inthe treatment of soft and adhesive mate-rials which cause built-up edges. The me-

tal-free second generation of Platit DLCcoatings (CBC2: a-C:H:Si) is deposited ina combined PVC/PECVD process [4]. He-re specific siliceous gases help improve thefollowing characteristics:■ chemical stability,■ optical transparency,■ extremely good adhesion (DLC coat-

ings) (Lc1 > 55 N,Lc2 > 75 N,Lc3 > 100 N),■ high mechanical hardness (> 25 GPa),■ smooth surfaces (Sa < 0.03 µm)■ low friction coefficient (µ < 0.1 for good

durability without break-through).Today, DLC coatings are mainly used incomponent mass production to protectagainst wear and tear through less friction.This is, however, not a field of businessPlatit will participate in. As opposed tostandard equipments the new machines(›π111+DLC‹,›π300+DLC‹,›PL1001+DlC‹,Fig. 5) feature the following additionalcharacteristics [4]:■ Virtual Shutter in combination with

Tube shutters,■ 350 kHz BIAS amplifier,■ pulsed ARC amplifier (optional),■ additional gas tanks and pipes with mass

flow controller,■ specific heaters with dust filter,■ optional upgrades at operator plant.The CBC2 coatings deposited with theseequipments are ideal for high-quality toolsand components as well as the requirementsof high tech installations for example die,stamp and forming tools, thread moulding,

MANUFACTURERiPLATIT AGCH-2545 SelzachPhone +41 32 6542600Fax +41 32 6542683> www.platit.com

Structures of oxide and oxinitride coatings4

Oxide and oxinitride coatings are being built into a multilayer structure

Carbide

Nanocomposite

Nitride

Oxide or OxinitrideTop nitride (optional)

AlCrON

AlCrN

nACo= TiAlN/SiN

TiN = adhesionlayer

AlCrN

AlCrON

AlCrN

CrN = adhesionlayer

Model

nACoX®

AlCrNoX

© Carl Hanser Verlag, Munich

C U T T I N G TO O L S

5

medical instruments and implants, heavy-duty components in motor sports like valverods and lever grips or general engineeringcomponents like turbine blades, sewing-machine spindles. The CBC2 coatings aremanufactured with at least one thin adhe-sive PVD layer,but also in combination withcomplete PVD coatings in one batch. Themost important types of structures andfields of applications are:■ ›cViC2‹: TiCN + CBC2; die and forming

tools, medical instruments and im-plants,

■ ›CROMVIc2‹: CrN +CBC2; componentswith low coating temperatures,

■ ›CROMTIVIc2‹: CrTiN + CBC2; com-ponents with corrosion protection, toolsfor aluminium chip removal,

■ ›nACVIc2‹: nACRo + CBC2; chip re-moval and forming tools for specificmaterials (Inconel or titanium alloys),

■ ›Fi-VIc2‹: nACo + CBC2; heavy-dutycomponents (for example valve rods).

Summary and outlook

From a high-quality coating plant manu-facturer SMEs expect not only regulartechnical support, but also a continuousproduct development e.g. for specific ap-plications [12]. This is the only way com-panies can stay ahead of the competition.This article describes the current devel-

opments of the π family of coating ma-chines from Platit. The existing equipmentcan be upgraded on-site by means of hard-ware and software in order to produce ox-ide, oxinitride and/or a new generation ofDLC coatings. These upgrades enable theproduction of coatings for cutting tools innew fields of applications and the breakinto new markets fields [13]. »Sustainablesuccess can only be achieved by develop-ing new and innovative markets and of-fering the customer a differentiated andrelevant value system« [1.5], [14]. ❚

REFERENCES

1.1 Max Frisch, 1.2 Michael Müller, Walter AG,

1.3, 1.4 Steve Jobs, Apple Inc., 1.5 Renée Mau-

borgne, W. Chan Kim, Insead

2 Thin-Film Coating Market, Study, LEK Consul-

ting GmbH, München 2007

3 Cselle, T. a. o.: TripleCoatings – eine neue Ge-

neration von PVD-Schichten für Zerspanwerk-

zeuge, Spanende Fertigung, Vulkan-Verlag, Essen

2008, p. 258-268

4 Compendium 2009, Platit AG, Grenchen 2009,

www.platit.com

5 Cselle, T.: Influence of Edge Preparation on the

Performance of Coated Cutting Tools, Invited talk

on the International Conference on Metallurgical

Coatings and Thin Films, San Diego, April/2007,

www.platit.com

6 Preiß, P. a. o.: Einfluss der Schneidkantenpräpa-

ration und Beschichtung auf das Leistungsvermö-

gen von Präzisionszerspanungswerkzeugen, 8.

Schmalkaldener Werkzeugtagung, 05./06.11.2008

7 Lümkemann, A. a. o.: Nanocomposite Coatings

and Triple Coatings on High Performance Tools

with Dedicated Edge Preparation, ICTCMF, GP-1,

San Diego, April/2009

8 Morstein, M. a. o.: Rotating ARC PVD Catho-

des, Five Years of Dependable High Performance,

ICTCMF, G7-6, San Diego, April/2007

9 Veprek, S. a. o.: Different Approaches to Super-

hard Coatings and Nanocomposites, Thin Solid

Films, Elsevier, Amsterdam, 476 (2005), p. 1-29

10 Cselle, T. a. o.: TripleCoatings – New Genera-

tion of PVD-Coatings for Cutting Tools Machine

Manufacturing, Budapest, 1/2009, p. 19-25

11 Morstein, M. a. o.: Influence of the Chemical

Composition on the Tribological Properties of

Nitride-Based Nanocomposite Coatings,

ICTCMF, B6-3-3, San Diego, May/2009

12 Fette-IFT-Platit: LMT-Nanosphere: Maßge-

schneiderte Werkzeugbeschichtungen senken die

Lebensdauerkosten, LMT-Symposium, Oberko-

chen, March/2009

13 Cselle, T. a. o.: Flexible Beschichtung von TiN

über Nanocomposite und Oxide zu DLC – Indus-

trie-Workshop, Schmalkalden, 16.06.2009

14 Mauborgne, R.; Kim, C. W.: Blue Ocean Stra-

tegy: How to Create Uncontested Market Space

and Make Competition Irrelevant, Harvard, Bos-

ton 2005

Dr.-Ing. Tibor Cselle is CEO at Platit inSelzach / SO, Switzerland> [email protected]

Dr.-Chem. Marcus Morstein is head of thedepartment R&D at Platit

Dr.-Phys. Andreas Lümkemann is assistentin the department R&D at Platit

Dipl.-Phys. Olivier Coddet is assistant in thedepartment R&D at Platit

Dr. Jan Prochazka is assistant in the depart-ment R&D at Platit

New members of the coating system family of Platit5

Coating units ›Platit+‹ for deposition of OXI and DLC coatings

More than 1000 parts of sewing machinesin one batch of the π 300+DLCfor coating with CROMTIVIc 2®

Source: KPTU, Seoul, South Korea

®3TripleCoatingsDedicated for Applications and Users

Material: 1.2080 - X210Cr12 (Hardness = 60,5 HRC)

Tools: Solid carbide ball nose end mills - d=10 mm – z=2

n =10445 min-1, ap = 0.14mm, ae = 0.1mm, fz = 0.1mm, external cold air nozzle

Hard Milling with Dedicated Coatings

®3Micro Hobbing using Dedicated Coating AlXN

Dry micro hobbing – vc=200 m/min

Source: Tool Manufacturer Japan

Standard

coating

of the tool

manufacturer

3®AlX N1

AlX N2

3®

0 100 200 300 400 500

0.07

0.06

0.05

0.04

0.03

0.02

0.01

0

flank

wea

r[μ

m]

6000

5000

4000

tool

life;

Lf[m

]

3000

2000

1000

0

unco

ated

TiN

nAC

o

with

mon

oblo

ck

inte

rfac

e-1

® 3

3233 28833340

4955 5370

nAC

o

with

mul

tilay

er

inte

rfac

e-2

® 3

nAC

o

with

grad

ient

inte

rfac

e-3

® 3

®3Hard Turning using Coated CBN-Inserts with Special Adhesion Structure for nACo

Mat: 100Cr6 – 63 HRC – vc=140 m/min – f=0.12mm –

ap=0.2mm dry - Source: GFE, Schmalkalden, Germany

tool life Lf [m]

After milling Lf=444 m

After milling Lf=888 m

Adhesion layer with different interfacesMultilayer coating; AlTiN

Top layer; nACo

Adhesion layer 0 Adhesion layer 1Adhesion layer 2

Gradient adhesion layer

CBN CBN CBN

Special market coating-1for hard milling



3®nACo


nACo3®

a case for more adaptions

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