tribomechanical properties of dlc coatings metallic and ... › ... › 2016 › 09 ›...

T r i b o m e c h a n i c a l P r o p e r t i e s o f D L C C o a t i n g s D e p o s i t e d b y M a g n e t r o n S p u t t e r i n g o n

M e t a l l i c a n d I n s u l a t i n g S u b s t r a t e s

Indianapolis, May 10th, 2016

Dr. Iván Fernández Martínez

D i a m o n d L i k e C a r b o n ( D L C )

Diamond-like Carbon (DLC) is a metastable form of amorphous carbon with significant sp3 bonding. DLC coatings are of interest in a wide variety of applications to provide low friction and high hardness and wear resistance.

Applications - Glass: anti-scratch. - Molds: prevent plastic transfer - Engine parts: low friction (a-C). - Space parts: low friction (a-C:H). - Cutting tools: lubricated and dry

conditions. - Oil & gas: super lubricity in pipes. - ….

D L C : S t a t e o f t h e a r t

A. Voevodin, Surf. Coat. Technol. 82 (1996) 199–213. J. Robertson, Surf. Coat. Technol. 50 (1992) 185–203.

Ion assistance required ~ 100eV

Prof. Wolf-Dieter Munz “Industrial scale deposition of well adherent and low friction DLC coatings grown by HIPIMS and anode assisted unbalanced magnetron” – Private discussion

D L C h a r d c o a t i n g m a g n e t r o n d e p o s i t i o n

Anode to extend the plasma

Magnetically linked magnetrons

D L C h a r d c o a t i n g m a g n e t r o n d e p o s i t i o n

Prof. Wolf-Dieter Munz “Industrial scale deposition of well adherent and low friction DLC coatings grown by HIPIMS and anode assisted unbalanced magnetron” – Private discussion

Bias required Glass? Plastics?

55GPa Microhardess, comparable to filtered arc

I o n a s s i s t e d d e p o s i t i o n o n i n s u l a t o r s ? Magnetron magnetic design (electron filter) + modified asymmetric bipolar pulsed PS

Proprietary technology: Patent application number GB1605162.5 (March 2016)

2

V

4 3

5

8b

6

1b 10ab

9 2b 8c

- Positive ion bombardment - No electron bombardent :

Reduced thermal load?

Magnetron size 400x100mm2 (industrial relevant) – WC, Graphite targets HIPIMS Ti/Cr + WC improves coating adhesion Optimized magnetic field configuration to enhance ion assisted deposition

Proprietary technology: Patent application number GB1605162.5 (March 2016)

I o n a s s i s t e d d e p o s i t i o n o n i n s u l a t o r s ?

Magnetron size 400x100mm2 (industrial relevant) – WC, Graphite targets HIPIMS Ti/Cr + WC improves coating adhesion Optimized magnetic field configuration to enhance ion assisted deposition

Proprietary technology: Patent application number GB1605162.5 (March 2016)

I o n a s s i s t e d d e p o s i t i o n o n i n s u l a t o r s ?

Sample position

3 energy regimes are measured

I o n a s s i s t e d d e p o s i t i o n o n i n s u l a t o r s ?

Hardness value taken at around 10% total DLC thickness

Load partial unload curve

Hysitron TI950 Triboindenter Berkovich tip indenter BKL4

C o a t i n g H a r d n e s s : a b o v e 3 0 G P a o n f l o a t i n g s u b s t r a t e

Hardness = 32 Gpa Young modulus = 220 Gpa 500nm thick DLC

D L C h a r d c o a t i n g m a g n e t r o n d e p o s i t i o n

Prof. Wolf-Dieter Munz “Industrial scale deposition of well adherent and low friction DLC coatings grown by HIPIMS and anode assisted unbalanced magnetron” – Private discussion

Bias required

15GPa Microhardess with -75V Bias!

Proprietary technology: Patent application number GB1605162.5 (March 2016)

H a r d n e s s > 3 0 G P a H a r d n e s s < 1 2 G P a

I o n a s s i s t e d d e p o s i t i o n o n i n s u l a t o r s ?

C o m m e r c i a l D C - P u l s e d P S M o d i f i e d D C - P u l s e d P S

S E M i m a g e : D e n s e D L C f i l m

SEM cross section of WC/DLC coating

Rockwell HRC tests - 150kg - Diamond indenter conical tip

A d h e s i o n o n m e t a l s : S t a n d a r d R o c k w e l l ( D a i m l e r o r M e r c e d e s ) t e s t s

HF1

DLC on HSS

HSS substrate surface

DLC coated surface DLC delaminated coating

Cr + WC + DLC on HSS

NO DLC coating delamination

Indentation HF5 HF1

675mN load 5um tip radius

Rockwell HRC tests, 150kg

Diamond indenter conical tip

HF1

A d h e s i o n o n m e t a l s : R o c k w e l l a n d n a n o - s c r a t c h t e s t s

HF1

F r i c t i o n a n d w e a r – A S T M G 9 9 S t a n d a r d t e s t

SS304 uncoated substrate DLC coated SS304

HF1

0 2000 4000 6000 80000.0

0.1

0.2

0.3

0.4

0.5 Frictioncoeff.

Frict

ion

coef

ficie

nt

t (s)

F r i c t i o n a n d w e a r – A S T M G 9 9 S t a n d a r d t e s t

Ongoing stress measurements in DLC coatings

L o w a c c u m u l a t e d s t r e s s @ h i g h h a r d n e s s

Biased process : high DLC coating stress N4E process : low DLC coating stress

D L C c o a t i n g o n G l a s s

Delamination problem: Need to reduced thicknesses and ion bombardment

Hardness in the range of 20GPa for 40nm thick DLC layer

DLC

Glass

D L C c o a t i n g o n G l a s s

Substrate can be pre-treated with reactive gases such as oxygen

+485V

Current to floating potential (10mV/A)

D L C c o a t i n g o n G l a s s

8006004002000

8

7

6

5

4

3

2

1

0

X[nm]

Z[nm

]

8006004002000

12

10

8

6

4

2

0

X[nm]

Z[nm

]

Untreated glass substrate

Oxygen treated glass substrate

RMS roughness : 2.6 nm

RMS roughness : 1.4 nm

D L C c o a t i n g o n G l a s s : n a n o - s c r a t c h t e s t s

500mN critical load – 5 micron tip radius

Characteristics - Acceleration of a test probe (diamond tip)

towards sample.

- Impact energy can be controlled and quantified.

- multiple impacts.

- Strain rate: 100-1000 (s-1).

* J.M. Wheeler et al., Surface & Coatings Technology 232 (2013) 264–268 “Analysis of failure modes under nano-impact fatigue of coatings via high-speed sampling“

N a n o - i m p a c t t e s t i n g o n D L C c o a t i n g s

Loads: 5, 10, 15mN

N a n o - i m p a c t t e s t i n g o n D L C c o a t i n g s

Advantages - Produce contact fatigue.

- Adhesion failure without substrate deformation

- Measure dynamic instead of static hardness

Simulate thin film in-situ service for machining operations

* J.M. Wheeler et al., Surface & Coatings Technology 232 (2013) 264–268 “Analysis of failure modes under nano-impact fatigue of coatings via high-speed sampling“

N a n o - i m p a c t t e s t i n g a - C : H o n S i

Test conditions - Conical tip. R= 5(µm) - Impact Height: 10 (µm) - Rest time: 500 (ms) - Specimens: a-C and a-C:H on Si

a - C o n M 2 s t e e l w i t h C r - H I P I M S i m p l a n t .

HF1 Rockwell DLC on M2 Steel Multiple Impact with Previous Conditions Multiple impacts: 30 mN during 1200s.

No delamination!

Loads: 5 to 30mN Load: 30mN

Guggenheim Museum, Bilbao

ecnf conference

www.ecnf2016.org

Submit your abstract in May!!! Main topics:

Characterisation techniques and Properties

Novel 2D materials

From molecules and nanoparticles to thin films

Tribological coatings

Energy conversion (solar, batteries) and catalysis

Nanostructured coatings

Thank you for your attention!