High Power Impulse Magnetron Sputtering -HIPIMS

Nanoscale Multilayer PVD Coatings to Serve in Demanding Environments. P. Eh. Hovsepian and A. P. Ehiasarian. National HIPIMS Technology Centre - UK, Materials and Engineering Research Institute, Howard Street, Sheffield Hallam University, Sheffield, S1 1WB, UK.

National HIPIMS Technology Centre - UK

• Definition of "Superlattice" : A superlattice is a periodic structure of layers of two (or more) materials. Typically, the thickness of one layer is several nanometers.

• Discovery: Superlattices were discovered early in 1925 by Johansson and Linde, [1] after the studies on gold-copper and palladium-copper systems through their special X-ray diffraction patterns. • First industrial application: AlN/TiN on cutting tools by Sumitomo of Japan, [2]. 1. Johansson; Linde (1925). Annalen der Physik. 78: 439. doi:10. 1002/andp.19253832104.

2. M. Setoyama, A. Nakayama, M. Tanaka, N. Kitagawa, T. Nomura, Surf. and Coat. Technol. 86-87, (1996). 225-230.

National HIPIMS Technology Centre, UK

Mechanical properties J.S. Koehler University of Illinois in 1970 theoretically predicted that by using alternate (nano-)layers of materials with high and low elastic constants, shearing resistance is improved by up to 100 times as the FrankRead source of dislocations cannot operate in the nanolayers, [1]. The concept of "superhardening" introduced by James Koehler : Q=GA-GB / GA+GB Q- critical stress to move a dislocation across the interface GA, GB, shear modulus of material A and B For Superhard material: Hv > 40 GPa 1. J. S. Koehler, Phys. Rev. B 2, 547 (1970).


Theories explaining the Superhardening effect - The Hall-Petch strengthening, (originally developed for bulk materials). N. J. Petch, J. Iron Steel Inst. 174, 25 (1953).

- The "Super modulus effect": Substantial, (150%-500%) Elastic moduli enhancement, (Cu-Ni). R. C. Cammarata, T.E. Schlesinger, C. Kim, S.B. Quadri, A.S. Edelstein, Appl Phys Let 1990, 56, 1862.

- "Coherency stress effect": Coherency stress develops due to the difference in the lattice constants that hinders dislocation motion, (Fe-Pt). B. M. Clemens, H. Kung, and S. A. Barnett, Mater. Res. Soc. Bull. 24, 20 ,1999.

- Dislocation blocking by layer interfaces, Xi Chu and Scott Barnett's model describing hardness- superlattice period relation. Xi Chu and Scott Barnett, J.of Appl. Physics 77, 4403, 1995.


Hardness enhancement of various superlattice structured coatings deposited by different PVD techniques TiN/VN by MS Linkoping University

U. Helmersson, S. Todorova, S.A. Barnett, J.-E. Sundgren, L.C. Markert. J. E.Greene, J. Appl. Phys. 62 (1987) 481.

TiN/AlN by Arc Sumitomo Electric Industries Ltd.

M. Setoyama, A. Nakayama, M. Tanaka, N. Kitagawa, T. Nomura. Surf. Coat. Technol. 86-87 (1996),

TiAlN/CrN by ABS Sheffield Hallam University

P. Eh. Hovsepian, W.-D. Münz, Nanostructured Coatings, Edited by A. Cavaleiro and J. Th. M. De Hosson, Springer/Kluwer, 2005, 555-644.


Monolithic vs Superlattice structures Monolithic Columnar Structure, BF TEM image

Nanoscale Multilayer Structure, BF TEM image


Industrial Scale Hauzer HTC 1000/4 PVD Coater at SHU

a) XSEM of CrN/NbN Coated knife blade b) BF XTEM showing the nanoscale multilayer structure on the tip of the blade, P.Eh. Hovsepian et al, Surf. and Coat. Technol. 133, (2000).


Wear mechanism of single and nanoscale multilayer coatings

wear track morphology, single layer coating

wear track morphology, nanoscale multilayer coating

P. Eh. Hovsepian, W.-D. Münz, Nanostructured Coatings, Edited by A. Cavaleiro and J. Th. M. De Hosson, Springer/Kluwer, 2005, 555-644.


Lifetime in Dry High-Speed Machining Versus Critical Load Values in Scratch Adhesion Test


Introduction to HIPIMS Technology

6 MW (3000 Wcm-2)

Industrial Scale HIPIMS using Huettinger power supplies

Conventional DC Sputtering

power

Target area = 1200 cm2

time A.P. Ehiasarian, book chapter: Fundamentals and Applications of High Power Impulse Magnetron Sputtering, in ed. R. Wei, Plasma Surface Engineering Research and its Practical Applications, Research Signpost, Trivandrum, India ISBN 978-81-308-0257-2


Energy Dispersion Functions of Metal Ions Produced in the HIPIMS Plasma as well as Plasma Composition During Pretreatment Stage. 6

6

10

Ar 5

Cr (1+) 60%

Ar (2+) 2% 5

1+

Cr

Cr (2+) 14%

-1

Ion Flux /(counts s )

10

10

1+

Ar (1+) 23%

4

10

2+

Cr

Ar

3

10

Cr (3+) 0.4%

10

4

10

2+ 3

10

3+

Cr 2

2

10

10

1

10

0

a)

20

40

Energy /(eV)

60

A.P. Ehiasarian, P. Eh. Hovsepian, W.-D. Münz, EP 02 011 1 204.1 (2001). 10 0

b)

20

40

60

Energy /(eV)


Interface Chemistry - STEM-EDS and Coating Adhesion HIPIMS

100 nm Scratch Test Critical Load on HSS = 85 N National HIPIMS Technology Centre, UK

HRTEM of Interfaces Produced by DC-Argon and HIPIMS Etching

Ar-Etching Courtesy of Jeff Th.M. De Hosson, Dept. Appl. Phys. Mater. Sci. Centre, University of Groningen, The Netherlands.

HIPIMS-Etching National HIPIMS Technology Centre, UK

Local epitaxial growth on large areas due to HIPIMS pre treatment of the substrate

Homogeneous contrast along interface signifies local epitaxial growth on substrate (steel) grain P.Eh. Hovsepian, C. Reinhard, A.P. Ehiasarian, CrAlYN/CrN superlattice coatings deposited by the combined high power impulse magnetron sputtering technique.

Surf. and Coat. Technol. 201(2006)4105-4110.A.

Critical Load L c [N]

Growth defects originating from droplets during arc etching, ABS technology

80 70 60 50 40 30 20 10 0

65 56

CrAlYN/CrN arc etch

CrAlYN/CrN HIPIMS etch

XTEM images of CrN/NbN deposited by various techniques

CrAlYN/CrN nanoscale multilayer

CrAlN base layer

substrate

UBM coating

Arc coating

HIPIMS coating

P. Eh. Hovsepian, A. P. Ehiassarian, Y. P. Purandare, R. Braun, IM Ross, Plasma Processes and Polymers, Vol. 6, issue S1, 2009, pp. S118 – S123. P.Eh. Hovsepian , Q.Luo , D. B. Lewis, A. Farinotti, Thin Solid Films. 488 (2005)1-8.


Coating densification by High Power Impulse Magnetron Sputtering, HIPIMS

XTEM of TiAlN deposited by "standard" magnetron sputtering

High purity intercolumnar boundaries in TiN films deposited by HIPIMS. a) AR-cross sectional view, b) AR-plan view National HIPIMS Technology Centre, UK

SHU Nanoscale Multilayer Coating Family CrAlYN/CrN

TiAlCN/VCN

CrN / NbN

Me / C

CrAlN

TiAlN

CrN

MeN

D

interface

interface

interface

interface

SUBSTRATE

SUBSTRATE

SUBSTRATE

SUBSTRATE

D = 3.2 nm D = 4.0 nm High temperature oxidation High hardness low friction resistant Dry machining, automotive and Al and Ti cutting

D = 3.4 nm Corrosion and Wear resistant

aero engines.


D = 2 nm Low friction tribological

STRATEGY 1: Combining elements producing dense oxide scales with rare earth element(s), (Y). Application: protection against environmental attack at high temperatures P. Hovsepian, A. P. Ehiasarian, R. Tietema, C. Strondel, UK Patent GB 2450950, 19.05. 2010, priority date 02. 01. 2008.


Nanoscale Multilayer CrAlYN/CrN Deposited by HIPIMS/UBM •Ti- free formula, •Y- stabilised interface by Y+ and Cr+ ion etching using HIPIMS

CrAlN

interface

•CrAlYN/CrN nanoscale multilayer, (Δ = 4.7 nm) deposited by HIPIMS or UBM or combined HIPIMS/UBM technique.

SUBSTRATE P. Hovsepian, A. P. Ehiasarian, R. Tietema, C. Strondel, UK Patent GB 2450950, 19.05. 2010, priority date 02. 01. 2008.


CrAlYN/CrN Coating-Substrate Interface Microstructure STEM Bright Field

STEM Z-Contrast

CrAlYN/CrN CrAlN g-TiAl High density Y and Cr implanted zone 5nm P.Eh. Hovsepian, C. Reinhard, A.P. Ehiasarian, Surf. and Coat. Technol 201(2006)4105-4110.


High Temperature Phase and Hardness Stability of CrAlYN/CrN

P. Eh. Hovsepian, A.P. Ehiasarian, R. Braun, J. Walker, H. Du, Surf and Coat. Technol. 204 (2010) 2702-2708.


High Temperature Tribological Behaviour of CrAlYN/CrN

P. Eh. Hovsepian, A.P. Ehiasarian, Y. Purandare, R. Braun, I.M. Ross, Plasma Process. Polym. 2009, 6, 51185123. J.C. Walker, I.M. Ross, C. Reinhard, W.M. Rainforth, P.Eh. Hovsepian, Wear 257 965-975


Mass change vs. number of cycles of γ-TiAl specimens bare and coated with CrAlYN/CrN + CrAlYON, thermally cycled at 850°C in air.

R. Braun, W. Braue, M. Fröhlich, C.Leyens, P. Eh. Hovsepian, Materials at High Temperatures, (2009), 26(3) 305-316


Maximum stress vs. number of cycles to failure of γ-TiAl specimens bare and coated with CrAlYN/CrN using different magnetron sputtering technologies.

R. Braun, U.Schulz, C. Leyens, P. E. Hovsepian, and A. P.Ehiasarian, Int. J. Mat. Res. 101 (2010) 5, 648-656.


NP gas turbine buckets and OSVAT engine valves coated with CrAlYN/CrN nanoscale multilayer coating at SHU.

European Integrated Project "INNOVATIAL" FP6-2003-NMP-NI-3.


Wear and fretting resistance of TiAl turbine blades with best available coatings in simulated aero engine environment Low Pressure Turbine Blade required in Gamma TiAl

New Aero Engine Concept: Geared Turbo Fan

Oxidation and Corrosion Resistant Coatings max. 800 °C 35.000 hours

Up to 30% less CO2 Perceived aircraft noise is halved

Wear Resistant Coatings • max . 800 °C 25.000 Cycles

50 % weight reduction per blade compared to current nickel alloy

Fretting wear tests with contact pressures relevant to blade shroud contact area

European Integrated Project "INNOVATIAL" FP6-2003-NMP-NI-3.

CrAlYN/ CrN + Al2O3

STRATEGY 2: Utilisation of Magnéli phases formed in-situ at the asperity contacts during sliding High hardness, low friction V-based nanoscale multilayers, TiAlN/VN. In- situ formation of V2O5, a highly lubricious, low melting point, (Tm= 681Co) tribo-film.

Schematic crystal structure of V2O5


High magnification XTEM image showing the nanoscale multilayer structure of TiAlN/VN coating and V2O5 tribo-film.

P. Eh. Hovsepian, D. B. Lewis, W.-D. Münz, Surface and Coatings Technology, 133-134 (2000), p. 166-175. Q. Luo, Z.Zhuo, W.M. Rainforth and P. Eh. Hovsepian. Tribology letters, Vol. 24, No.2 November 2006, 171-178.


SEM image of the wear track of TiAlN/VN in dry sliding pin-on-disc test at 7000C.

P. H. Mayrhofer, P.Eh. Hovsepian, W.-D. Münz, C. Mitterer , Surf, Coat and Technol.177, (2004), p. 341-347.


Mechanical and tribological properties of various PVD coatings Structure

Hardness Hk, 25gr

Adhesion on HSS Lc, N

Residual Stress, GPa

Coef. of Friction, Al2O3

Sliding Wear Coefficient m3 N-1m

TiAlCrYN

Monolithic

2800

50

- 3. 8

0.8

2.5 10-16

TiAlN/CrN

Superlattice D= 3.2 nm

3500

50

- 5.1

0.7

2.38 10-16

DLC Cr/WC/a-CH

Multilayer

2800

30

- 0.74

0.31

3.0 10-16

70

- 3. 3

0.4

1.26 10-17

Coating

TiAlN/VN

Superlattice D= 3 nm

3500

P. Eh. Hovsepian, D. B. Lewis, W.-D. Münz, Surf. and Coat. Technol. 133-134 (2000) 166-175.


STRATEGY 3: Utilisation of Low Shear Strength Interfaces produced by dynamic segregation of small atomic radius elements such as Carbon High hardness, low friction V-Carbon based nanoscale multilayers, TiAlCN/VCN.

Application: Machining of "sticky alloys" and MMC materials. P. Eh. Hovsepian, A. P. Ehiasarian, "PVD Coated Substrate" - GB0508485.0 filed 27 April 2005, EP 1874981, 14.01.2009.


BF XTEM Image of TiAlCN/VCN and TiAlN/VN Superlattice Structured Coatings D= 2.2 nm

Base Layer

TiAlCN/VCN

TiAlN/VN

P. Eh. Hovsepian, A.P. Ehiasarian, I.Petrov, C. Schimpf. Surface Engineering. DOI 10.1179/026708408X336337.


Flank Wear / No. of Passes in Al 7010-T 7651 Alloy 25 mm dia, HSS, 2- Flute End Mill, Vc:1884 m/min, Ap: 4 mm, Ae: 2 mm, Vf: 0.33 mm/rev. 0.3

Flank Wear (mm)

0.25 Uncoated 0.2

TiAlCrYN DLC

0.15

TiAlN/VN 0.1

TiAlCN/VCN

0.05

80 32 0 56 0 80 0 10 40 12 80 15 20 17 60 20 00 22 40 24 80 27 20 29 60 32 00 34 40 36 80 39 20 41 60 44 00 46 40 48 80 60 20 80 60

0

No. of Passes

Papken Eh. Hovsepian , Arutiun P. Ehiasarian , Anthony Deeming , Christian Schimpf, Plasma Process. Polym. 2007, 4, S897-S901.


10-20 nm

Wear Mechanisms of TiAlN/VN and TiAlCN/VCN Superlattice Coatings Low Shear Strength Interface

High Shear Strength Interface

BUILD UP LAYER TRIBOFILM DELAMINATION INTERFACE

BASE LAYER

SUBSTRATE

TiAlN/VN

D= 3- 4 nm

D= 3nm

DELAMINATION INTERFACE

BASE LAYER SUBSTRATE

CARBON ACCUMULATION AT THE INTERFACE

TiAlCN/VCN

P. Eh. Hovsepian, A.P. Ehiasarian, I.Petrov, C. Schimpf. Surface Engineering. DOI 10.1179/026708408X336337.


Demonstrator selection Alticut EC Project Automotive component Engine head – Fiat 1.9 JTD

Material: AlSi9Cu1 Machining operations to be considered for the component are: • Face milling • Drilling • Tapping • Thread milling and/or roll tapping CENTRO RICERCHE FIAT

Hauzer || Techno Coating PVD/ PACVD TECHNOLOGY

Demonstrator selection Alticut EC Project Aeronautic component 1 A wingbox rib of a typical Airbus wing •49 •48 •47 •46 •45 •44 •43 •42 •41 •40 •39 •38 •37 •36 •35 •34 •33 •32 •31 •30 •29 •28 •27 •26 •25 •24 •23 •22 •21 •20 •19 •18 •17 •16 •15 •14 •13 •12 •11 •10 •8•9 •7 •6 •5 •2•3•4

Material: Aluminum 7010-T7651 CENTRO RICERCHE FIAT

Hauzer || Techno Coating PVD/ PACVD TECHNOLOGY

Life time of TiAlVCN/VCN coated turning inserts in machining of forged Ti acetabular cups (orthopaedic implants) at SYMMETRY Medical inc., UK

Number of Components turned per turning tip. Constant surface speed of 60 m/min, Feed of 0.15 mm/rev, water based coolant. Coated tip

70

106

71

90

120

91

Uncoated tip

19

56

24

36

34

34


STRATEGY 4: Utilisation of high ion irradiation to achieve phase separation and formation of self-organised nanostructures in Me- doped Carbon films. Application: Low friction high wear resistant tribological coatings.


XTEM images of the microstructure and friction curves of Cr/C films

Y.N. Kok, P.Eh. Hovsepian, Q. Luo, D.B. Lewis, I. Petrov, Thin Solid Films Volume 475(2005) 219-226.


Raman Spectra of C/Cr Coatings Deposited at Various Bias Voltages Downshifted Raman peak intensity, suggesting the replacement of C-C bonds with metal carbides as a consequence of the intensive ion irradiation Intensity G-band

D-band

Raman shift, cm-1

Y.N.Kok, P.Eh. Hovsepian, R.Haasch, I. Petrov. Surf, Coat and Technol.200, (2005) p. 1117-1122.


HRXTEM of Self-Organised Multilayer Structure of C/Cr Developed at Ub= - 350V.

~ 20 nm

pronounced self-organised multilayer structure (bi-layer thickness ~20 nm) white contrast: onion-like carbon in the matrix of metal carbides. P.Eh. Hovsepian, Y.N. Kok, A.P. Ehiasarian, R. Haasch, J.-G. Wen, I. Petrov. Surf, Coat and Technol, 200 (2005)1572-1579.


BF XTEM Images of C/Cr Films Deposited at Various Bias Voltages g

20 nm Ub = - 350V

25 nm

Ub = - 450V

Ub = -550V

P.Eh. Hovsepian, Y.N. Kok, A.P. Ehiasarian, R. Haasch, J.-G. Wen, I. Petrov, Surf, Coat and Technol, 200 (2005)1572-1579.


Microstructure of C/Cr with sequentially deposited low bias/ high bias voltage layers Ub = - 350 V Ub = - 75 V

Ub = - 350 V Ub = - 75 V Ub = - 350 V Ub = - 75V Ub = - 350 V

Ub = - 75V CrN Base Layer

Substrate

Me- doped carbon coating deposited on fine blades in conditions of high ion irradiation

The deposition of high aspect ratio, low friction coating creating sharp but robust cutting edge resulted in reduction of the cutting forces by factor of five and increased life-time by factor of three. National HIPIMS Technology Centre, UK

STRATEGY 5: Utilisation of tribo- chemical reactions to achieve insitu formation of lubricious phases in conditions of boundary lubrication in Me- doped Carbon films. Application: Low friction high wear resistant tribological coatings to operate in boundary lubricated conditions at elevated temperatures. P. Eh. Hovsepian, D. Doerwald, R. Tietema, A.P. Ehiasarian. European Patent 2 963 145. Priority claimed: EP/30.06.2014/EPA 14175063.


LAXRD, XSEM and TEM analyses of Mo-W doped Carbon films

P. Eh. Hovsepian, P. Mandal, A. P. Ehiasarian, G. Safran, R. Tietema, D. Doerwald. Applied Surface Science 366(2016) 260-274.


Coefficient of friction of various DLC coatings compared to the Mo-W-C, (CMW1R) coating Tests carried out with highly viscous Mobil1 Extended lifeTM 10W-60 multigrade synthetic engine oil free of friction modifiers

P. Eh. Hovsepian, P. Mandal, A. P. Ehiasarian, G. Safran, R. Tietema, D. Doerwald. Applied Surface Science 366(2016) 260-274. P. Mandal, A. P. Ehiasarian, P.Eh. Hovsepian Tribology International, 90(2015)135-147.


Raman analyses of the wear track after lubricated sliding at 200oC

MoS2 powder used as a standard

Different positions in the wear track of Mo-W doped Carbon film

WS2 powder used as a standard



Coefficient of friction of Mo-W-Carbon and DLC films as a function of sliding distance in lubricated sliding at 200oC against a 100Cr6 counterpart



Static oxidation behaviour of Me-C and DLC coatings Me-C, 400oC

Me-C, 500oC

DLC, 400oC

DLC, 500oC

Substrate exposed

Coating


Typical application of the Mo-W-Carbon films

STRATEGY 6: Combining highly wear resistant with electrochemically stable elements to achieve corrosion and wear resistant coatings, CrN/NbN. Applications: • Corrosion and wear resistant coatings on steel to replace hard chrome. • Corrosion, wear and water droplet erosion resistant coatings on steel to protect components in steam turbines. • Protective coatings on medical implants. National HIPIMS Technology Centre, UK

Corrosion resistance of PVD coatings



Mass gain of various coatings exposed to pure steam at 650oC after 2000 h. Coated samples vs P92 24 22

P92 Substrate

m/So (mg/cm2)

20 18 16 14

MASS GAIN after 2000 hours

12 10

P92 >>> P92 + Al2O3 >P92 + Fe44Cr5Al > P92 + CrN/NbN

8 6

SHU Coatings: P92 + CrN/NbN

4

GTU Coatings: P92 + Fe44Cr5Al

BAM Coatings: P92 + Al2O3

2 0 0

200

400

600

800

1000

1200

1400

1600

Time (h)


1800

2000

Cross-sectional back scattered SEM analysis of CrN/NbN exposed to steam at 650oC after 2000 h: (a) Coating cross-section showing the coating and oxide layers on top (b) Elemental mapping conducted on the cross-section.

P. Eh. Hovsepian , A.P. Ehiasarian , Y.P. Purandare, B. Biswas, F.J. Perez, M.I. Lasanta, M.T. de Miguel, A. Illana, M. Juez-Lorenzo, R. Muelas, A. Agüero, Materials Chemistry and Physics 179 (2016) 110-119.


Hot Tensile Test Conditions, T= 650 °C, έ = 1 mm/ min

Strained up to elastic limit YS

Strained up to 20 % of absolute UTS

1: Passing Ultimate Tensile Strength, (UTS) with subsequent testing down to 20% UTS absolute value: pure plastic deformation 2: Up to Yield Strength (YS) value: pure elastic deformation


Strain controlled, (0.4% strain) Low Cycle Fatigue tests at 650oC

•

Both uncoated and coated specimens failed after similar number of cycles, Nf = 1700 and Nf= 1712 respectively

High temperature creep tests at 650oC, tensile stress of 120 MPa

•

HIPIMS coating improved the creep lifetime by almost factor of two from 564 hours to 908 hours.


Schematic of water droplet / solid surface interaction The pressure during the impact is given by the water hammer equation:

P   0c0V0 VDT

 K c  1.41  c d

2 ic R 2 2 w w w

13

  

Damage Threshold Velocity, VDT - the lowest velocity, which theoretically could cause surface damage.

VDT denotes the Damage Threshold Velocity ,DVT Kic2 the fracture toughness of the target material


Fracture Toughness, Indentation Hardness and Young's Modulus of CrN/TiN superlattice film as a function of the bilayer period.

R. Hann, M. Bartosik, R. Soler, C. Kirchlechner, G. Dehm, P. H. Mayerhofer. Scripta Materialia 124 (2016) 67-70


CrN/NbN on P92 steel. Water droplet erosion test results. Test conditions: water pressure: 9 bar; impact frequency: 480 m min-1 ;

total number of impacts: 2.4 million

Surface morphology, SEM as deposited CrN/NbN

Surface morphology, SEM after water droplet erosion

2D and 3D profilometry after the impact, showing 20 µm depression but no coating spallation. P. Eh. Hovsepian*, A. P. Ehiasarian, Y. Purandare, P. Mayr, K. G. Abstoss, M. Mosquera, W.Schulz, A. Kranzmann, M. I. Lasanta, J. Trulillo. Journal of Alloys and Compounds, 746 (2018) 583-593.


CrN/NbN – In vitro and In vivo Performance details

In vitro : Cobalt ion release 22 ppb uncoated