DRIVING FORCES OF TODAY’S MANUFACTURING TECHNOLOGY

T. Cselle, CEO, Platit AG, Grenchen, Switzerland

Industrial Tooling’2003, Southampton Engineering Faculty, UK CONTENT: Manufacturing technologies are parts of the development process from an indus-trial society to a knowledge society. The important means of today’s production are knowledge, know-how, and innovation. They determine the value of the company much more than real es-tate, working capacity and capital. Due to states´ deregulation, privatization and globalization the national states lose, the national cultures and the companies gain importance. Innovative Knowledge Based Small and Medium sized Enterprises (KB-SME) generate over 80% of the new innovations; they are the driving forces of the manufacturing technologies in Europe. This paper reports on 3 important innovation fields, which originate from SME’s and will probably de-termine the development of the cutting technology within the next years: - The integration of different cutting technologies (like turning, drilling, milling, grinding, lasering, welding, hardening etc.) into multi-functional machine centers enables high precision machining in one set-up even in small series production. - Intelligent tools carry out the know-how very near to the cutting edge. They measure process parameters, move own axes and react to process changes through wireless communication with the CNC. - Nanostructured coatings break through the physical limits of today’s state-of-the-art coatings, keep high hardness even at high temperatures and can be deposited even on the normal manu-facturing shop floor. KEYWORDS: Knowledge based small and medium size enterprises, multi-functional machin-ing center, dry high performance machining, high and ultra precision machining, hexapods, parallel kinematics (PKM), intelligent tool, piezo sensor and actor, nanostructured coating, LARC-technology, virtual shutter, nanogradient, nanolayer, nanocomposite.

Company

Know ledge BasedSME

Vision

Mis

sionCulture

Vir

tua l

-> R

eal

Ad d

ed V

alue Innovation

Know

ledge - Know

How

High ProductivityHigh Tech Technology

Generating and Using of Innovative Manufacturing Technologiesin Knowledge Based Small/Medium Enterprises

branded product added v alueprofite, company image

nanostructuredcoatings

multi-functionalmachining centers

w ith intelligent tooling

2

1. Features of Knowledge Based Small and Medium Sized Enterprises (KB-SME) The main target of a company is the generating of added value. Added value will be generated not only by goods and materials (input and costs), but through branded products and hopes for more profit, better life and environment (virtual added value). The main characteristic of a KB-SME is generating added value through innovation: • The know-how of the knowledge workers is the main value of the company. • Their knowledge makes high-tech innovation with high productivity possible. This already

increases the added value in the first loop. • The (virtual) added value accumulates capital and increases liquidity without inflation. • This enables high-tech investments, which

o generate virtual and real added value of the company and of the customers and o increase the profit on both sides again.

Typical manufacturing example to generate added values in a KB-SME is the combination of dry high performance machining with integrated flexible coating: - Dry machining creates healthy working conditions and protects the environment. - High performance machining realizes effective machining with high productivity. - Integrated flexible coating brings the total tool production in one’s own hand

Company

KB-SME

Hum

an

Res

ourc

eM

anag

emen

t R&

D

Logistic

Production

Fina

nces

Management Marketing

1. The exchange of information and knowledge (not keeping it in one head)makes innovation possible.

2. The customer is well informed and more powerful. Marketing becomes not only mediation between production and customer but integration of customer processes.

3. Solving tasks should be done in projects, not in departments.

4. The special projects of the knowledge workers can be leaded by specializedexperts (Michael Jordan's).

5. Personal ego problems should be solved by rotation and changing project leadersand participants.

Flexible Flat Company Organization in the Knowledge Based SME

Company

Knowledge workers

employees

Relevantsociety

Suppliersservice

companies

Shareholdersinvestors Customers

Knoledge BasedSME

Vision

Mis

sion

Culture

1. The main value of a company is the know ledge of the "know ledge w orkers".

2. The cooperation of the stakeholders is focused according to bottlenecks.

3. The suppliers and customers are very strongly integrated in development and production processes.

4. The interest of the stakeholders must be balanced by the managementaccording to the vision andmission of the company.

Company Target: Increasing Stakeholder Value

The Stakeholders of a KB-SME

3

2. Integration of different cutting technologies into machine centers 2.1 Flexible multi-functional machining centers SME’s can not take the risk to invest into special machines for large scale series production. They need flexible machining centers to integrate different technological steps into one ma-chine. Flexible multi-functional machining centers integrate different cutting operations such as hard-turning, high frequency I.D. and O.D.-grinding, drilling and milling and use innovative techniques which are today’s driving forces to high performance production:

- complete machining in one loading to reduce form and position deviation of work piece, - vertical work piece clamping and spindle axis

o to reduce handling time for pick-up change o to optimize chip flow with the help of gravity o to minimize coolant demand for environment protection

- linear drive for high acceleration on hydrostatic guide ways for dynamical damping

suspended work piece

turning, dril l ing, and milling spindle

grinding wheel dressing spindle

HF spindle

inclined grinding spindle

Machining Center Integrates Different Cutting Technologieswith Optimum Chip Removal

Complete Machining w ith Different Cutting Technologiesof Hardened Steel in One Clamping

Source: Schaudt, Stuttgart, Germany

Turning Grinding

4

2.2 High Precision Machining Center for Micro Cutting with Solid and Laser Tooling The basic use of laser in machining centers is welding for rapid prototyping. Afterwards the sliced 3D model will be generated for the CNC program. With the help of powder nozzles and laser focusing heads the welded mold is generated with an oversize of 0.3 to 0.6 mm. After the changing in the cutting heads the mold can be machined by laser cutting and free form milling.

Laser Welding for Rapid Prototyping in Multi-Functional Machining Center

Source: Fraunhof er ILS, Germany

Sliced 3D-model Laser welded part f rom stellite Finished part by f ree f orm milling

Laser welding nozzle

Laser optic and cladding unit

3D-model of mold insert

The more exciting challenge for the integration of laser tooling into machining centers is the opportunity to cut shapes with very small dimensions and to produce contours which can not be produced or very difficult to be machined with solid tools, like drills, end mills etc.

Laser Drilled and Cut Parts Produced in Multi-Functional Machining Centers

Sources: Microcut, Switzerland, Kugler, Trumpf , Fraunhof er, wbk, Germany

5

The actual developments move the laser assisted HP-(High Precision)-Machines in the direc-tion of UP-(Ultra Precision)-machining.

Feature's Comparison: High Precision <-> Ultra Precision Machining

Workpiece High Precision Ultra PrecisionAccuracy < 1 µm Submicron rangeRoughness Ra ~ 10 nm Nanometer rangexD machining typically 2 1/2 - 3D typically 2DSeries even large series small serial, typically 1-5

Materials all, even steel nonf errous, crystals, semiconductor,

Env ironment normal work shop special labs

Machining tasks: Mechanics 5µm: watches, ball screws, compressors

0.05µm: sealing surf aces, diamond tips

0.5µm: ball bearings, valves, aerostatic bearings, inkjets

0.005µm: ultraprecision end mills, x-y guides

Machining tasks: Electronics 5µm: relays, resistant, silicon waf ers, TV-masks

0.05µm: IC storage, v ideo discs

0.5µm: CCD, Quarz-Osci, storage, thin coating parts 0.005µm: VLSI, thin f ilms

Machining tasks: Optics 5µm: optic holders, prisms 0.05µm: precision f lat glasses, optical lattices

0.5µm: optical scales, precision lens, X-ray mirrors

0.005µm: IR optics, v ideo discs

Because of the typical applications for 3D-machining and rapid prototyping, laser tooling is predestined for hexapods. In spite of this, the real breakthrough of the hexapods is not yet re-alized because of their limitations.

- Telescopic legs- Reliable joints missing- Ball screw not rigidly fixed- Heavy moving bodies: - ball screws, motors, sensors, cables- 6 motors for 5 axis (in machining)- Poor workspace wize / footprint ratio- Not compatible with linear drives- Thermal energy is produced in moving bodies- Non direct position measurement at reasonable costs

Hexapod's Limitations:

Laser Tooling is Predestined for Hexapods3D-Lasering 3D-Milling

6

2.3 From Hexapod to 3-axis Parallel Kinematics

1994: IMTS, Chicago"THE" solution for the future

1997: EMO, HanoverHexapods everywhere!To do what?

2000: IMTS, ChicagoSo,... is it really working?But: Urane (PKM) introduced!

2003: EMO, Milan?3 axis PKM -> breaktrough?

Dreams and Reality of Hexapod Machines

3-axis Hexapod with Linear Drive in Z: Urane

Source: Renault-Comau, Torino, ILIRMM, Montpellier, F

x/y/z: 500/500/200 mm- vf= 120 m/min- a=3.5 g- n= 40.000 RPM

Parallel kinematics machining centers (PKM) can probably solve the dilemma of the hexapods, because of the advantages which are important for the industrial practice: • PKM machines do not need difficult interpolation for simple 1 or 2 axes operations (e.g.

drilling or linear milling). • They are compact, can be integrated into production lines with a minimum of footprint. • They can use linear drives and achieve high acceleration and feed values. • They can carry out 5D-operations (especially inclined drilling) without rotary tables and

swivel fixtures.

7

3. Intelligent Tooling The development of intelligent tools is a subject that is hotly debated und promoted by the metal cutting industry. In this matter, two fundamental questions immediately arise: - What do we really mean by intelligence? - Can a tool show intelligence? As engineers, we have to cut through the philosophical verbiage and define intelligence as fol-lows: Intelligence is the ability to recognize new situations and to deal with them (possible real-time) on the basis of previously acquired knowledge. The days when higher or lower intelligence was ascribed only to human beings and animals are long past. The artificial intelligence of computers and expert systems has already been used in metal cutting technology for some considerable time. 3.1 Measuring of Machining Parameters during Cutting Prime examples of artificial intelligence uses are machine tool monitoring systems. The sen-sors measure specific parameters of the machining process (position, drive power, torque, forces, acoustic emission etc.) and evaluate them by the CNC. Manufacturing engineers have always wanted to measure the cutting forces directly at the cutting edge, at the point where the machining operation takes place. With the aid of the thin-film technology, with masked coat-ings it is possible in the lab today [15]. However, the inserts with measuring coating are not yet able to gauge the cutting forces dynamical enough (with high frequency) at rotating cutters. This type of task has to be solved by piezo-sensors and their preamplifiers integrated into the tool holder [26]. For controlling of the process stability the piezo acceleration sensors are often used because the can be built in not into the flux of force only.

Milling Cutter with Integrated 3-axes Piezo Vibration Sensor

Source: GFE, Schmalkalden, Germany While the actors can be piezo, inductive or capacitive elements, the transmission of power and signals has to be wireless in any cases. Only this makes it possible, to change the intelligent tools into the spindle from the tool magazine automatically without connecting cables by hand.

8

3.2 High Precision Adjustment during Cutting In the case of difficult internal contours the work piece can not be produced by the CNC pro-grammed axes of the machine. Either you use expensive special tools (which can only be ac-cepted for large series production), or you are able to build in programmable axes into intelli-gent tools.

Difficult Work Piece Contour Machined by the Axes of the Intelligent Turning/Milling Head

working direction; axial feed

valve seat alignment seat with inlet radius die

bearing seat track rod seat Coolant channel with recesses

Intelligent Turning/Milling Head with Programmable Radial Axis

slide

facing head

Rotor (Energy+Data) Stator (Energy+Data)

coupling HSK 100

motor resolver spindle / drawbar

Source:Komet,

Besigheim ,Germany

9

Machining Internal Ball Contour with the Help of the Programmable Axial Axis of the Intelligent Tool

Source: Komet, Besigheim, D

Intelligent Tool P70-PTP can be set and moved programmable in the z axis during cutting!

Machining Internal Contour with the Help of the Programmable Axial and Radial Axis of the Intelligent Tool

Source: Komet, Besigheim, D

Intelligent Tool P70-U can be set and moved on a programmable contour, in z and y axis during cutting!

Adjustments of cutting edges (or even machine axes) can be carried out not only by mechani-cal elements but by piezo-actuators as well, within 1 µm accuracy.

clampingpiezo

flexiblejoint

inserts

settingpiezo

preload the

piezo

Source: [33], Gühring oHG, Albstadt, Germany

Fine Boring ToolAdjusted By Piezo Actuator

10

3.3 High Precision Feed during Cutting by Intelligent Tool The controlled movement of the intelligent tools’ axes can not be used for adjustment only. Be-cause of stability, reliability and accuracy the realization of feed movement by the tools can be the better solution than the feeding of the tool by the normal CNC machine axis.

Intelligent Tool for High Precision Boringmachinespindle

machinehousing

stator rotor

motor

tool

starting tool positionbefore machining

final tool positionafter machining

Axial Setting During Machining with Integrated MotorWireless Energy Transmission

An Additional NC-axis for the Machine

Source: Tooltronic (R), Mapal, Aalen, D

Optimum guidance (with short overhang) during whole drilling process

tool

motor

Tools for High Precision Hole Making with High l/d Ratio

Source: Tooltronic (R), Mapal, Aalen, D

Solid carbide drill:- cheaper tool. no setting necessary and possible- high deflection because high l/d ratio- high position accuracy with bushing/guide only or tool has to make its own pilot hole- lower feed rate at starting- high risk for breakage- special carbide grade necessary

Intelligent tool with own z axis:- optimum guiding (with short overhang) during whole drilling process-> maximum position and form accuracy- high feed rate for the total depth- reliable production- inserts are applicable

11

4. Nanostructured Coatings No doubt (Ti, Al)-based PVD coatings have conquered the market of high performance cutting tools in the last years. Depending on which statistics you believe, the market shares of the (Ti, Al)-based PVD-coatings for coated high performance cutting tools amount to 25-55%.

Marketshares of Coatings on Carbide Cutting Tools

1997 1998 1999 2000 2001 2002

y ears

0

20

40

60

80

100

[%]

TiNTiCNTiAlNothers

Source: VDMA, Frankf urt, Germany

The reasons for that are the outstanding features of the (Ti, Al)-based coatings: • High hardness (~25-38 GPa) at relatively low residual stress ~ (-3-5 GPa). • High hot hardness, resulting in low hardness lost (~ 30-40%) up to temperatures of 800°C. • High oxidation resistance (same rate at 800°C as for TiCN at 400°C and for TiN at 550°C) • Low heat conductivity (up to 30% lower relative heat indention coefficient than for TiN) The coating industry is enormously innovative. There are huge numbers of tests and solutions even to improve these outstanding features of the (Ti, Al)-coatings. E.g.: o Combination of ARC and sputtering o Filtering of ARC-droplets o Optimization of process parameters like ARC-current, BIAS-voltage, N2-pressure etc. o Optimization of the crystalline structure to avoid the columnar structure and corrosion o Deposition of multilayers to increase coating toughness and thickness o Addition of alloying components, such as

chromium and yttrium to increase oxidation resistance zirconium, vanadium, boron and hafnium to improve wear resistance, or silicon to increase hardness and resistance against chemical reactions.

Beside of the standard coatings the requirement is very high for special ones tailored to the special applications. The simple reason is the possible performance increase.

Application Field and Performance of Universal and Dedicated Coatings

application range

performance

universal dedicated

12

The conventional coatings are deposited as monolayers, monolayers with adhesion layer, gradients and multilayers.

Conventional Coating Structures

Monolayer Monolayerw ith

adhesion layer Multilayer

Gradient

Thickness: 2.5µm

Sublayer thicknesses:

1: 0.89 µm2: 0.22 µm3: 0.17 µm4: 0.23 µm5: 0.18 µm6: 0.25 µm7: 0.23 µm8: 0.35 µm

Gradientw ith

adhesion layer

Multilayer

There is no general accepted definition for nanostructured coatings. According to the own pri-vate definition, nanostructured coatings show structural changes in the range of 10 nm. The three most important structures are deposited as o nanogradients (with continuous changing of the composition from the substrate to the top), o nanolayers (with typical sublayer’s thicknesses of 3 – 10 nm), o nanocomposites (nanocrystalline grains are embedded into an amorphous matrix). Of course the different structures can be mixed in one single coating as well.

NanocompositeNanolayerNanogradient

100 nm

Show structural changes in the range of 10 nm (personal def inition)

Nanostructured Coatings

13

4.1 Nanogradients The gradient coatings usually start with an adhesion layer (mostly TiN) and continually change their structure to compositions with higher hardness and wear resistance.

GDEOS of (nc-Ti1-xAlxN) / (a-Si3N4) Nanocomposite Coatingwith Gradient Structure Deposited from Pure Ti and AlSi Targets

For the not interrupted milling of the abrasive cast iron the gradient coating achieved the best results because of the highest hardness and wear resistance.

Milling Cast Iron with Gradient Nanocomposite Coatings

Mat.: GGG70 - Tools: solid carbide ball nose end mills- d=16mmvc=250/min – fz=0.02mm/z- ap=8mm - ae=0.5mm - up/down milling

NC: Nanocomposite coating: (nc-TiAlN)/(a-Si3N4) - Measured at VUT, Brno

40.5 40

75

95

120

5242

75

91

122

TiAlCrYNnanolayer

nc-multilayer-1 nc-multilayer-2 nc-monolayer nc-gradient0

20

40

60

80

100

120

140tool l i fe; T [min]

tool-1 tool-2

14

4.2 Nanolayers They emerge from the refinement of the multilayer technique. At certain periods, i.e. at certain thicknesses of nanolayers significant, hardness increases can be achieved.

Increasing hardness by controlled layer's period.Superlattice Nanolayers

TiN-CrN

AlN

TiN-CrN

7 nm

Source:Nortwestern University, IL, USA

& &

&

&

&

&&

&&

1 10 100 1000nanolayer period [nm]

0

10

20

30

40

50nanohardness; [GPa]

- The high hardness is realized through the strongly different Young modulus of the sublayer

materials. In the case of the figure above it can probably be explained by the cubic crystal structure of AlN, which will be hexagonal over ~10 nm.

- The hardness decrease at smaller periods below 6-7 nm is caused by the “rough” interface boundaries between the sublayers. If the interface between the components can be kept sharp no hardness decrease can be observed.

To produce nanolayers, it is essential to synchronize cathode control and rotation of the sub-strates. A constant nanolayer period for job coating is practically impossible when you have small and big cutting tools, inserts, mold and dies or even machine parts in the batch. For tools coated in large series the nanolayers can achieve enormous performance improve-ments. See the following example of a dedicated nanolayer coating for HSS reamers:

"Dedication" of Coatings and Cutting Parameters for HSS Reamers

Dedicated Thin Coatingfor Reaming

Thickness: 0.7 - 1 µmNanolayer period: 9nm

Sa: Average roughness over the whole surface measured by AFM

µAlTiN" dedicated" for reaming

Sa= 0.05 µm Sa= 0.02 µm

AlTiN High Performance

ARC-Coating

TiNStandard ARC-coating

Sa= 0.12 µm

15

(

(

(( (

(

'

'

' ''

'&

&

& &

&

&

0 5 10 15 20 25 30 35cutting speed; vc [m/min]

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35roughness; Ra [µm]

TiNTiAlNµAlTiN®

&

'

(

vc-TiN-opt= 13 m/min

vc-TiAlN-opt= 17 m/min

vc-µAlTiN®-opt= 23 m/min

Optimization of Coatings and Cutting Parameters for HSS ReamersCutting Speed Optimization

Feed Optimization

(

(( ( (

(

'

'

'' ' '

&

&

&

&

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35feed; f [mm/rev]

0

0.2

0.4

0.6

0.8

1

1.2roughness; Ra [µm]

TiNvc=13m/minTiAlNvc=17 m/minµAlTiN®vc-opt=23m/min

&

'

(

f-TiN-opt=0.128 mm/r

f-TiAlN-opt=0.14 mm/r

f-µAlTiN®-opt=0.2 mm/r

Tool Life Comparison

(

(

(

((

(

(

(

( (

( ( (

'

'

'

'

'

'

'

'

&

&&

&&

0 50 100 150 200 250 300 350number of holes; Lm

0

0.1

0.2

0.3

0.4roughness; Ra [µm]

TiNvc=13m/minf=0.128mm/rTiAlNvc=17m/minf=0.14mm/rµAlTiN®vc=23m/minf=0.2mm/r

&

'

(

Ra_TiN_ave=0.254um

Ra_TiAlN_ave=0.237um

Ra_µAlTiN®_ave=0.135um

Mat.: X155 CrVMo 12-1High alloyed cold working steel

DIN1.2379Tools: d=6.2 mm

reaming oversize=0.2 mmap= 12 mm - emulsion 7%

16

If we consider all parameters deciding for the productivity and quality of the reaming operation; - cutting speed, - feed, - tool life and - surface roughness of the reamed holes,

the dedicated nanolayer coating can realize an improvement by the factor 15.

100260

1511

vc*f*Lm/Ra0

200

400

600

800

1000

1200

1400

1600

1800performance; vc_opt * f_opt * Lm / Ra_ave [%]

TiN TiAlN µAlTiN

Performance Comparison

13 * 0.128 * 105 / 0.25417 * 0.14 * 178 / 0.237

23 * 0.2 * 305 / 0.135

Optimization of Coatings and Cutting Parameters for HSS Reamers

Mat.: X155 CrVMo 12-1- High alloyed cold working steel - DIN1.2379Tools: d=6.2 mm - reaming oversize=0.2 mm - ap= 12 mm - emulsion 7%

The leading equipment manufacturers are increasing the aluminium content step by step in their latest industrial (Ti, Al)-based coatings to improve hardness, wear and heat (oxidation) resistance. For differentiation beyond 50% aluminium content these coatings are referred as AlTiN-coatings.

Oxidation Rate of Important PVD Coatings

Source: Richmond Research Center, VA, USA

)

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)

(

(

( ( ( (( ( ( (

(

$

$

$ $ $ $$$$

#

#

# # #

#

0 200 400 600 800 1000 1200

temperature; [°C]

0

20

40

60

80

100

120oxidation rate; [µg/cm²]

TiCN TiN TiAlN AlTiN# $ ( )

17

The increase of the hardness and the oxidation resistance can bring important performance improvements and this not only for dry high speed machining.

Tool Life Comparison at Drillingfor Coatings with Different Aluminium Content

Work piece material: 42CrMo4V - Rm=1000 N/mm2 - Tools: solid carbide drills - d=6.8 mmvc=110 m/min - f=0.174 mm/rev - ap=34 mm - emulsion-IC p=38 bar Q=8l/min

67.15

125

TiN/TiAlN(~50/50 %)

AlTiN(~67/~33%)

0

20

40

60

80

100

120

140

tool lif e; Lf [m]

Still, at some point, there is a limit: beyond 67%, 75% or even at 80% Al, further increases are neither useful nor meaningful.

Features of (Ti,Al)-based Coatings Depending on Al-Contents

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$

$

$ $ $

$

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0 0.2 0.4 0.6 0.8 1

Al content [at%] = (Al) / (Al+Ti)

0

10

20

30

40

50

0

0.0025

0.005

0.0075

0.01

0.0125

adhesioncritical load [N] x 2!

hardness [GPa] w ear resistanceabrasive volume [mm³]

$ ' )

These limits:

the period of nanolayers, which practically can’t be held constant for job coating and the maximal meaningful aluminium content of AlTiN-coatings

can only be broken by physically new solutions like the nanocomposites.

18

4.3 Nanocomposites In nanocomposite coatings different materials (e.g. Ti, Al, and Si) are deposited. They cannot be mixed. For example two different phases are emerged in the plasma, the nanocrystalline TiAlN will be embedded into the amorphous Si3N4-matrix.

Nanocomposite Structure; (nc-Ti 1-xAl xN)/(a-Si 3N 4)

Source: S. Veprek, TU München

TEM picture of a monolayer

coating

Model

Binary (ternary,...) system with a strong thermodynamical ly driven, spinodal segregationAll phases strong materials, Si is not in the metall ic phase.Nanocristall ine grains (nc-AlT iN) are embedded into the amorphous matrix (a-Si3N4)Spontaneous formation of a self-organized nanostructure with a strong interface which hinders grain boundary sl iding at crystall i te size < 10 nm

)

)

)

)

Generic Concept for the Design of Superhard Nanocomposites

This structure enables extremely high hardness (40-50 GPa) even at a lower Al content (e.g. 50%).

Hardness Increasing by Nanocomposite (nc-Ti 1-xAlxN)/(a-Si3N4) Structure

21

30

38

50

14

24

30

40

uncoated carbideK-grades

TiN TiAlN-AlTiN nanocomposite(nc-TiAlN)/(a-Si3N4)

0

10

20

30

40

50

60hardness; [GPa]

- nc segregation completed- Si is not in the metal lic phase, only Si3N4- high hardness- high stabil i ty upto high temperatures

19

The high hardness (40-50 GPa) can be maintained at high temperatures (up to ~1100 °C).

$

$

$

$

$

+

+

++ +

0 200 400 600 800 1000 1200 1400annealing temperature [°C]

0

10

20

30

40

50hardness [GPa]

0

2

4

6

8

10crysstaline grain size [µm]

Heat Resistance of Nanocomposite Coating (nc-Ti 1-xAlxN)/(a-Si3N4)

Measured at the Technical University Munich - S. Veprek, NACODRY project

TiAlNSi3N4

The enormous warm hardness will be extremely important for production without coolant, it means for dry cutting and for machining with minimum quantity lubrication.

Tool Life Comparison at End Milling with Minimum Jet Lubrication

Work piece material: HSS AlSi M2 - Tools: solid carbide end mills K20UF - d=12 mm - z=4vc= 150 m/min - fz=0.05 mm - ap=10 mm - ae=0.5 mm - Source: NACODRY -EU-Project

$

$

$

$$

$

$

$

$

$$ $

%

%

%%%%%%%%

%

%

%

)

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)

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))) )

'

'

'

'

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'

0 50 100 150 200 250 300

cutting time; T [min]

0

50

100

150

200

250wear; VBE; [µm]

TiN TiAlCN AlTiN (nc-TiAlN) / (a-Si3N4)' ) % $

20

Further improvement is possible if the nanocomposite coating is deposited with a nanolayer basic structure. The nanolayer period of attached figure was calculated by FFT to 35Å.

Depositon of Nanocomposites on the Basis of Nanolayerswith Cathode's Pair

4.4 LARC®-Technology To deposit nanocomposites based on nanolayers on an industrial and economic scale, the coating equipment have to fulfil the following basic requirements:

o The cathodes must be built in very close to each other. o A highly ionized plasma, o supported by a strong magnetic field is necessary. o This requires a very fast motion of the ARC track.

The new LARC-technology (LAteral Rotating ARC-Cathodes) fulfils these requirements. Both water-cooled cathodes are in permanent rotation. The magnetic field is generated by coils and permanent magnets controlled both, vertically and radially.

PVD-Coating of Nanocomposites with Dynamic Rotating ARC-Cathodes

substrates

door or backside shield

cathode_2

cathode_1

magnetic confinementsystem_1 magnetic

confinement system_2

rotary table

LARC®: LAteral Rotating ARC-Cathodes

21

The most important advantages of the LARC-technology come from the rotating cathodes and their lateral position. Therefore they are called π-advantages (features).

6. Multi- and Nanolayers in ul tracompact units due to the - optimum space use - by cyl indrical,rotating cathodes on the side

3. Smooth coating surface - with minimazed droplets, due to the - VIRTUAL SHUTTER - fast ARC track motion - at consistent target erosion

5. Programmable Stochiometry depostion of - di fferent / gradient coatings - without changing the low cost targets from e.g. pure T i, Al, AlSi

4. Nanocomposite deposition due to the - fast ARC track motion with - high magnetic field intensity at - highly ionized plasma - with 2 phases: e.g. (nc-T iAlN) / (a-Si3N4)

1. Optimum Adhesion with VIRTUAL SHUTTER® due to the - turnable magnetic field without sensitive mechanical elements; - to the back for fast target cleaning - to the substrates for smooth depostion

2. Maximum effective target w idth: d*π due to the - cyl indrical - rotating cathodes

π - Features of the LARC® - Technology

4.4.1 VIRTUAL SHUTTER Optimal adhesion is the most important criterion for good coating. The lateral arrangement of the cylindrical cathodes makes VIRTUAL SHUTTER possible, working without sensitive me-chanical elements.

magnetic fields turned by 180°

target cleaning anddeposition of large particles against wall

substrates

rotary table

magnetic fields areturned back after cleaningat 0° for deposition

®)

ARC isburningto the

substrates;cathode isdepositing

ARC isburning

to theback;

cathode iscleaned

22

The magnetic field is turned by 180° and the ARC is ignited from the back. Due to this proce-dure it is possible to clean the targets before the coating process begins - and to deposit the initially large particles (droplets) against the wall. Meanwhile the substrates can be cleaned in intensive plasma. The ARC will be turned towards the tools without being distinguished. In ef-fect, it is possible to shorten the time of ion etching and to deposit the adhesive coating with metallic clean targets. The optimum adhesion directly improves the cutting performance.

®)Tool Life Comparison without and with

145208

672752

1374

1786

2728

TiN LARCTiN

ARCAlTiN

NC-gradientwithout VS

NC-gradientwith VS

LARC-AlTiNgradientwith VS

NC-Multilayerwith VS

0

500

1000

1500

2000

2500

3000tool life at 0.2mm average corner wear

Mat.: X155 CrVMo 12-1 - DIN 1.2379 - High alloyed cold work tools steelTools: solid carbide drills - d=5mm - ap=15 mm - vc=70 m/min - f=0.16 mm/rev -emulsion 7%

4.4.2 ”Wide” Targets The most trivial advantage of the rotating cylindrical cathodes is their width. With the same space requirement they are π-times wider than planar targets.

Rotating Target = Wide Target

Target width: d* πlonger target life

)5

d d d*πPlanartarget

Cylindricaltarget

23

4.4.3. Reduction of the ARC-droplets - With conventional ARC technology, most of the droplets are created at the beginning of the process. It starts during the ignition of the ARC, when the standing spot melts the largest baths.

Emergence of the Droplets

droplets

molten metal

plasma ARC

- The size and number of the droplets depend during the deposition among others on the speed of the ARC-spot movement. It is created, respectively guided only by magnetic control for the planar targets with steered ARC. The spot movement is considerably faster and more regular with rotating cathodes. It is a result of the target rotation together with the vertical oscillation of the wide magnetic field.

- fast ARC-spot- magnetic field with high intensity- regular, steady target erosion

ARC Spot and Target Erosionat Planar- and

Rotating Cathodes

With the help of the Virtual Shutter and the rapid ARC spot movement, the LARC-technology can produce layers with significantly lower roughness.

Coating's Surface Comparison: ARC <-> LARC

ARC LARC®

Ra=0.2 - 0.37 Ra=0.07 - 0.13

24

4.4.4. Crack Absorption by Nanocomposites Deposited from Pure Metallic Targets - Due to the fast ARC-Spot low-cost target materials can be used even with low melting points (e. g. Al or AlSi). They can replace the expensive alloyed targets (e. g. Al25%/Ti75%, Al50%/Ti50%, Al67%/Ti33% etc.). - A target consisting of pure silicon is not conceivable due to simple, mechanical reasons. The silicon is deposited from alloyed targets (AlSi, CrSi, TiSi etc.) After the deposition from the tar-get, Al and Si must be segregated. Silicon is not solved into the metallic phase, the nanocrys-talline grains (TiAlN) are embedded into an amorphous Si3N4-matrix. For this highly ionized plasma, a highly intensive magnetic field is necessary. A fast ARC-spot movement will permit a high intensive magnetic field without “cutting through” the targets (which is a real danger with planar targets). The emergence of the nanocomposite structure shows no “space” between the nanocrystalline grains, keeps the crystal sizes small and the interface boundaries sharp, there-fore giving a high hardness. An additional advantage is the stop of crack propagation at the grain boundaries. It is especially important at cutting sticky, hard to cut materials (like TiAl6V).

Nanoindentation of Nanocomposite (nc-Ti1-xAlxN) / (a-Si3N4)

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0 200 400 600 800 1000displacement; [nm]

0

10

20

30

40

50

60hardness H; [GPa] - E/H

0

100

200

300

400

500

600E-modulus; [GPa]

Hardness [GPa] E-Modulus [GPa]E/H"

Indent w ithout cracks!

Grain boundary stops crack propagation

(nc-Ti xAl1-xN)/(a-Si3N4) Nanocomposite at Millingin Aerospace Materials

Mat.: TiAl6V - VHM-Fräser d=25mmvc=250 m/min - fz=0.11 mm - z=12 - r=1.2-1.9 mm - ap=0.5 mm - ae=1.1 mm - x=0.5

44 44

53

44

80

TiAlCN+WC/C

TiAlCN AlTiN TiAlN+CBC

(nc-TiAlN) /(a-Si3N4)

0

20

40

60

80

100

tool life; T [min]

25

4.4.5 Programmable Stochiometry Due to the fast ARC-spot and the use of different “pure” targets (e. g. Ti, Al or AlSi) the coating stochiometry (composition) is freely programmable (continuously changeable = gradient) even during the processes.

Programmable Coating's StochiometryGDEOS of (nc-Ti 1-xAlxN)/(a-Si3N4) Nanocomposite with Multilayer Structure

- At the beginning of this LARC-coating, the aluminium will be deposited later to the titanium, so that an optimum adhesion coating can emerge. - Afterwards, during the deposition, the Al-content is continuously increased, so that the hard-ness, temperature stability and oxidation resistance of the coating improve. 4.4.6 Deposition Multi- respectively Nanolayers Multi- and nanolayers are gradients with periodical changes. Increasing hardness leads to higher internal (residual) stress. With the help of the multilayer structure, the internal (residual) stress can be kept at the excellent values of ~ (-3-4 GPa) which is extremely important for heavy machining, e.g. for interrupted cuts.

Face Milling in Interrupted Cut with Indexable InsertsIntermediate Multilayer of Nanocomposite (nc-Ti1-xAlxN) / (a-Si3N4)

Improves Coating Toughness

Mat.: C45 - 1043 - vc=177 m/min - f=0.244 mm/rev - ap=2mm - Mil l ing head

61

118

Monolayer (nc-TiAlN)/(a-Si3N4)with intermediate multilayer

0

20

40

60

80

100

120

140tool life: [min]

26

The requirement for steady improvement needs dedicated coatings for the special applications. The features of the LARC®-technology make the free tailoring of the coating architecture and structure possible and therefore the combination of the advantages of nanogradient, nanolayer and nanocomposite coatings is available.

Calo picture:Adhesion monolayer (TiN)

gradiently merged over to multilayerplus monoblock toplayer

(nc-AlTiN)/(a-Si3N4): Dedicated Coating for Hard Milling (nACo®-H)

TEM picture-1:Multilayer structure

TEM picture-2:Nanocomposite structure

based on nanolayerThickness: 2.2 ym

This structure was developed especially for 3D hard milling. The deposition was started with an adhesion layer with TiN as monolayer. A gradient structure leads over to a multilayer part which plays the rule of the damping spring in the coating. The multilayer is merged over gradiently into an Al rich monoblock top layer which has to be hard and extremely wear and heat resistant.

Hard Milling with AlTiN and Nanocomposite Coatings

Hard milling in 2D-spirale - 1.2343 - X38CrMoV5-1 - Hot work tool steels - 57 HRCTools: ball nose solid carbide end mills, d=10mmx57, hydrochuck

RPM=18500, fz=0.18mm, ap=0.25mm, ae=0.6mm, Outer Minimum Jet LubricationMeasured by iFT Grenchen, Switzerland

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0 200 400 600 800 1000 1200

mill ing distance; Lf [m]

0

50

100

150

200

250

300

350corner wear; VB [µm]

uncoated AlTiN-Y67%/33%

AlTiN-F75%/25%

AlTiN +TiSiN-H50%/50% nACo®" $ ' )

27

4.4.7 Size of the Coating Equipment Thee first LARC-coating units were designed to be compact – not of the size used by large tool manufacturers. Why? - Coating should not be a privilege of the large coating centres and tool manufacturers. Small and medium-size enterprises should be able to deposit the most modern layers in their own workshops. - The new coatings cannot detach TiAlN & Co. immediately. At the moment, the market does not yet require volume nanocomposite coating. The need of nanostructured coatings will in-crease continually within the next years, making utilization of larger coating units possible. - The lateral cylindrical targets on the side require minimum space. It is thus possible that sev-eral cathodes, requiring little space, deposit coatings with different metallic components even in small compact equipment. - After having mastered the technology and production of cathodes in a minimize space re-quirement, the up-scaling will be easier. It is important that the cathodes are installed by pairs with small intermediate distances. This ensures the deposition of nanocomposites with high productivity and without expensive alloyed targets (e.g. TiAl). - In small units it is not absolutely necessary to coat totally different substrates together for economical reasons. One can separate the substrates into groups according to the sizes or application and coat them in small dedicated batches. Therefore and because of the small dis-tance between the cathodes the optimum nanolayer period can be deposited much easier even below 10 nm. - Several small coating units are not less productive than a large one. In fact they are much more flexible and provide a reliability of service. - On a side note, making small coating units results in a smaller profit for the equipment manu-facturers than large ones. Seen in a long term, it has always been worthwhile. SUMMARY The knowledge based small and medium size enterprises (KB-SME) are the driving forces for the development of new innovative technologies for today’s manufacturing industry. There are a lot of innovative ideas, products and technologies, developed by KB-SME’s, they point the way ahead. This paper shows three of them with outstanding importance:

• Integration of conventional cutting technologies and lasering into multi-functional ma-chine centers for high performance and precision machining

• Intelligent tools measuring and reacting directly on the cutting edge • Compact coating machines depositing nanostructured coatings directly in the manufac-

turing work shop The innovative technologies of the KB-SME’s are extremely important for the manufacturing industry and for the whole society as well; Over 80% of the employees in the European manu-facturing industry are working in a company with less than 250 people.

In Which Companies are the People Employedin the Manufacturing Industry of European Countries?

Source:VDI, Düsseldorf , Germany'

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0 200 400 600 800 1000number of employees in the company

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28

References [1] Barthelmä, F. a.o.: Intelligente Werkzeugkonzepte durch Sensor- und Aktorintegration Werkzeugtagung, Schmalkalden, Nov/2002 [2] Berndt, R. (editor): E-Business-Management, Springer, Berlin, New York, 2001 [3] Carter, C.: Machine Tool Market and Technical Trends, Gorham Conference, Atlanta, May/2001 [4] Derflinger, V., Schütze, A. o.a.: Mechanical, Structural and Performance Properties of Various Aluminium Containing Wear Protecting Films, PSE, Garmisch Partenkirchen, Sept/2002 [5] Durante, S.: Machine Tool Design, Tool Optimization, Advanced Materials a Global Approach Gorham, Atlanta, May/2001 [6] Erkens, G. o.a.: About the Performance of Crystalline PVD-Alumina Coatings in Cutting Applications, ICMCTF, San Diego, May/2001 [7] Heisel, U. a.o.: Werkzeugmaschinen mit Beinen – die Hexapod-Maschine, TU Stuttgart/2002 [8] Holubar, P., Jilek, M., Sima, M.: Present and Possible Future Applications of Superhard Nanocomposite Coatings, ICMCTF, San Diego, April/2000 [9] Jilek, M., Holubar, P., Sima, M.: Hard PVD Nanocomposite Coatings not only for Dry Machining Plansee Seminar, Reutte, June/2001 [10] Karimi, A., o.a.: Fracture Behaviour of Nanocomposite Thin Films by Nanoindentation ICMCTF, San Diego, May/2001 [11] Kress, J.: Präzisionsbearbeitung von Bohrungen, Micro Machining, TU Dresden, March/2003 [12] Krulis-Randa, J., Ergenzinger, R.: Management Model in the Time of New Economy MBA-Forum, GSBA Zurich, March/2001 [13] Kruszynski, J.: Nutzung der Innovationen in der Zerspanungstechnik, VDI, Stuttgart, Febr/2003 [14] Kugler, L.: Maschinenentwicklung für die Mikro- und Ultrapräzisionsbearbeitung Mikroproduktionstechnik, Hanser, Karlsruhe, März/2003 [15] Lüthje, H.: Intelligente WSP für die Zerspanung - Sensorintegrierte Hartstoffbeschichtung Intelligente Systeme und Prozesse in der Zerspanung, TU Dresden, June/2001 [16] Matthews, A.: Developments in PVD Coatings, Gorham Conference, Atlanta, Nov/2000 [17] Morstein, a.o.: Nanocomposite and Nanogradient Coatings, MRS Fall Meeting, Boston, Dec/2002 [18] Manger, P.: Komplettbearbeitung auf multifunktionellen Werkzeugmaschinen durch Verfahren- kombination, Seminar Micro Machining, TU Dresden, March/2001 [19] Musil, J. o.a.: Structure-Hardness Relations in Sputtered Ti-Al-V-N Films PSE, Garmisch Partenkirchen, Sept/2002 [20] Münz, W.D.: Super Lattice Structured Hard Coatings, VIDE, Nancy, March/2000 [21] Nowotny, St. o.a.: Integrated Laser Milling center for Complete Machining, ICALEO, Scottsdale, Oct/2002 [22] Schulz, H.: Coating Industry – Quo Vadis? - Gorham, Atlanta, Nov/2002 [23] Paldey, S., Deevi, S.: Single Layer and Multilayer Wear Resistant Coatings of (Ti,Al)N: a Review Materials Science and Engineering, Elsevier B.V., New York, NY, A342 (2003), p.58-79 [24] Pierrot, F.: Towards Non-Hexapod Mechanisms for High-Performance Parallel Machines CIRP Meeting, Paris, Jan/2001 [25] Probst, L.: Neues Maschienkonzept zur Trockenbearbeitung, Alzmetall, Altenmarkt, 2000 [26] Stirnimann, J. a.o. : Advances in Cutting Force Dynamometry Industrial Tooling, Southampton, Sept/2003 [27] Suzuki, T. a.o. : Microstructure and Secular Instability of the (Ti, Al) films Journal of Materials Science, 35/2000, p.4193-4199 [28] Veprek, S.: Ultra Hard Nanocomposite Coatings with Hardness of 80 to 105 GPa VIDE, Nancy, March/2000 [29] Veprek, S., Jilek, M.: Super- and Ultra Hard Nanocomposite Coatings: Generic Concept for their Preparation, Properties and Industrial Applications, Vacuum, 67 (2003) p. 443-449 [30] Vetter, J., o.a.: AlTiCrN Coatings for Dry Cutting, PSE, Garmisch Partenkirchen, Sept/2002 [31] Weinert, K. (editor): Cutting Manufacturing, Handbooks, Vulkan, Essen, 1994-2001 [32] Zimmermann, H.: Kommerzielle Entwicklung neuer Schichtwerkstoffe für besondere Zerspanungsaufgaben, Oberflächen – Polysurfaces, Bern, 4/2000, p. 14-19 [33] Cselle, T.: Fine Boring Tool with Piezo Actors Patent 19945455.8, European Patent Office, Munich, 14.04.99 [34] Cselle, T.: Know Important from Urgent, Industrial Tooling, Southampton, Sept/1999 [35] Cselle, T., o.a.: Nanostructured Coatings and Processes on an Industrial Scale Gorham, Atlanta, Nov/2002 [36] Cselle, T. a.o.: LARC®: New Industrial Coating Technology Werkstatt & Betrieb, Hanser, Munich, 3/2003