Characterisation Programme 2006-2009Polymer Multi-scale Properties Industrial Advisory Group
28th June 2007
SE02: Improved Design and Manufacture of Polymeric Coatings Through the Provision of
Dynamic Nano-indentation Measurement Methods
Lead Scientist: Nigel Jennett
Project Manager: Rob Brooks
Wednesday, 12 September 2007
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Presentation outline
• Brief review of:– The project motivations– Instrumented indentation– SE02 Project outline
• Sensitivity study of parameters affecting dynamic indentation results
• Adaptation of NanoTest for variable rate, frequency and temperature dynamic indentation
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Nano-indentation applications
Ideal for measuring elastic and plastic properties of small volumes of materials, e.g. thin films and micro/nano-structures.• Coatings and Surface Engineering sectors / users, e.g.
Electronics, optics, automotive, aerospace, biomedical, pharmaceutical sectors..
• Local/surface properties of biological or polymeric materials (very soft, low force indentations)
• Micro-mouldings, nano-composites and ultra hard coatings where indentation depths are very small.
• Nano-mechanical testing of nano-engineered structures and materials
• Designers needing input data for models
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Instrumented Nanoindenter Schematic
StageLOAD FRAME
Magnet
Indenter
CapacitanceDisplacementGauge
Suspensionsprings
Sample
Coil
Current Source
Displacement sensor
Computer
Quasi-static
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0.73
loading unloading
samplesample
loading unloading
samplesample
loadingloading unloading
samplesample
loading unloading
samplesample
loading unloading
StageLOAD FRAME
Coil
Magnet
0.73
AreaForceHIT =
Cf
Frame
Compliance
SC CAE 11* ×∝
Contact
Area
Instrumented Indentation
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Schematic Indentation cycle
0.73
Cf
Creep / Viscosity
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Standard Polymers: quasi-static responseLoad Vs. Depth Curves
0
0.5
1
1.5
2
2.5
0 500 1000 1500 2000 2500 3000 3500
Depth (nm)
Load
(mN
)
PS - 1PS - 3PS - 4
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Motivation• Requirement for local polymer properties in part
design:-– bearings, gears, cams, press-fit parts, composites (matrix
and interfaces)• Requirement for properties of small volumes
– e.g. mico-mouldings, packaging, coatings.• Production control and QA via sensitivity of surface
to production parameters. – Thermal history affects surface properties and can be
detected by indentation.
Nanoindentation has the resolution but polymers have time/rate dependent properties.
⇒ Dynamic measurement methods are required!
Wednesday, 12 September 2007
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Instrumented (Nano)indenter Schematic
StageLOAD FRAME
Magnet
Indenter
CapacitanceDisplacementGauge
Suspensionsprings
Sample
Coil
Current Source
Displacement sensor
Computer
Quasi-static
Oscillator
Lock-in amplifier
/ Dynamic
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Scientific Objectives• Validate indentation protocols for measuring loss
and storage modulus and time constants of visco-elastic materials and feed into:
• ISO standardisation (new work item)• Development of 1GPa certified reference material
• Compare methods to measure polymer properties as a function of frequency and temperature.
• Develop ultra-rapid indentation and creep-relaxation measurement methods for characterisation of visco-elastic materials.
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Dynamic Calibration #1 Support spring stiffness (Ks) = 43.12 N/m Indenter mass (m) = 0.0073 KgDamping Coefficient (C ) = 3.73 Ns/m
1 10 100 1000
10-4
10-3
10-2
1/mw2
1/Ciw
Data: Final_BModel: user1Equation: y=1/((P1-P2*x^2)^2+(x*P3)^2)^0.5Weighting: y No weighting Chi^2/DoF = 3.3348E-9R^2 = 0.99995 P1 43.11764 ±0.10679P2 0.00728 ±0.00094P3 3.73455 ±0.0149D
ynam
ic C
ompl
ianc
e (h
0/F0)
Frequency, w (rad/sec)
Free Hanging Indenter
1/Ks
1/Diw
i
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Dynamic Calibration #2 Damping Coefficient vs. Position
Di = Do + D1x + D2x2 + D3x3 Ns/m
-3 -2 -1 0 1 2 33.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5Polynomial Regression for Data2_B:Y = A + B1*X + B2*X^2 + B3*X^3 + B4*X^4
Parameter Value Error t-Value Prob>|t|---------------------------------------------------------------------------A 3.76138 0.00617 609.99994 <0.0001B1 0.02458 0.0046 5.34438 <0.0001B2 0.28443 0.00404 70.36398 <0.0001B3 -0.00489 7.32653E-4 -6.67395 <0.0001B4 0.00736 4.72118E-4 15.59502 <0.0001---------------------------------------------------------------------------
R-Square(COD) Adj. R-Square Root-MSE(SD) N---------------------------------------------------------------------------0.99971 0.99967 0.01827 31---------------------------------------------------------------------------
Dam
ping
Coe
ffici
ent,
C1 (N
s/m
)
Indenter Position (V)
Di
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Spring and dashpot modelE′= Storage modulusE″= Loss modulusδ = Phase shiftTan δ = Damping coefficient
( ) ( )( )ωωωδ
EE
′′′
=tan
( )εσ EiE ′′+′=
( )2222
0
0 ωω mKDhF
si −+=
DiKs
m
S Ds
Kf
-4
-3
-2
-1
0
1
2
3
4
0 10 20 30 40 50 60 70 80 90 100
Time (milli-seconds)
Forc
e ( µ
N) /
Dis
plac
emen
t (nm
)
DisplacementLoad
Phase Shift
Amplitude
h(t)
F(t)
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Dynamic contact mechanics
δ )(2'
chASE π
=ωDs Storage Modulus
S
)(2''
c
s
hADE πω
= Loss Modulus
Results are available point wiseOr by plotting S or D vs.√A(hc)
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Storage modulus by graphical method
y = 4E-06x - 0.0003R2 = 0.9997
y = 3E-06x + 0.0001R2 = 0.9995
0.0E+00
5.0E-03
1.0E-02
1.5E-02
2.0E-02
2.5E-02
0 1000 2000 3000 4000 5000 6000 7000 8000
sqrt (Contact Area)
Con
tact
Stif
fnes
s (m
N/n
m)
PS - 1 E = 2.5 GPaPS - 3 E = 0.21 GPa
3.9 GPa
2.3 GPa
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Loss Modulus by graphical method
y = 3E-07x + 0.0005R2 = 0.9962
y = 1E-07x + 0.0004R2 = 0.951
0
0.0005
0.001
0.0015
0.002
0.0025
0.003
0 1000 2000 3000 4000 5000 6000
Sqrt (Contact Area)
Dam
ping
(mN
/nm
)
PS - 1PS - 3
E'' = 0.12 GPa
E'' = 0.31 GPa
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0 100 200 300 400 500 600 700 8000.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0
2000
4000
6000
8000
10000
12000
14000
16000O
scill
atio
n A
mpl
itude
(nm
)
Amplitude: dF = 0.3 µ N dF = 1 µ N dF = 3 µ N
Indentation Depth (nm)
Stifness:dF = 0.3 µ NdF = 1 µ NdF = 3 µ N
Stif
fnes
s (N
/m)
PS1: Stiffness dispersion vs. drive amplitude
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0 100 200 300 400 500 600 700 8000.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
-500
0
500
1000
1500
2000Damping:
dF = 0.3 µ NdF = 1 µ NdF = 3 µ N
Osc
illat
ion
Am
plitu
de (n
m)
Indentation Depth (nm)
Amplitude:dF = 0.3 µ NdF = 1 µ NdF = 3 µ N
Dam
ping
(N/m
)
PS1 Damping dispersion vs. drive amplitude
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PS - 3
0
2000
4000
6000
8000
10000
12000
14000
16000
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2
Amplitude (nm)
S, D
(N/m
)
Stiffness (N/m)Damping (N/m)
PS3 Data uncertainty vs. drive amplitude
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0
2000
4000
6000
8000
10000
12000
14000
16000
18000
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
Amplitude (nm)
S, D
(N/m
)
Stiffness (N/m)Damping (N/m)Stiffness F = 3 uNDamping F = 3 uN
Effect of amplitude on dispersion PS3
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10 100 1000
-0.0020.0000.0020.0040.0060.0080.0100.0120.0140.0160.0180.0200.0220.0240.0260.028
( )2222
0
0 ωω mKchF
−+= Run1 Run2 Run3 Run4 Run5 Run6 Run7
Dyn
amic
Com
plia
nce
(m/N
)
Frequency (rad/sec)
Sensitivity to static calibrationAC Force Cal. AC Displacement Cal
57000 1200047000 1500052000 1350057000 1500052000 1350047000 1200052000 13500
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Er' and Er'' calculated from slope of Stiffnes and DamRun Factor 1 Ko (N/m) Factor 2 m (Kg)
1 44.5 0.0082 42 0.0053 44.5 0.0084 47 0.0055 44.5 0.0086 42 0.0117 47 0.0118 53.87 0.008579 35.55 0.0058
Original 43.12 0.00728
Sensitivity of E’, E” to dynamic calibration
Software sensitivitydesign
Run Factor 1 Ko (N/m) Factor 2 m (Kg)1 44.5 0.0082 42 0.0053 44.5 0.0084 47 0.0055 44.5 0.0086 42 0.0117 47 0.0118 53.87 0.008579 35.55 0.0058
Experimental Sensitivitydesign
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PS - 1, 0.5 mN max load, 0.05 s-1 strain rate
00.5
11.5
22.5
33.5
44.5
5
0 100 200 300 400 500
Displacement (nm)
E' (
GP
a)
Run1Run2Run3Run4Run5Run6Run7Run8Run9F = 3 uN -0.0004
-0.0002
0
0.0002
0.0004
0.0006
0.0008
0.001
0.0012
0 500 1000 1500
Area ^1/2
Dam
ping
(mN
/nm
)
Series1Series2Series3Series4Series5Series6Series7Series8Series9F = 3 uN
PS - 3
0
0.0002
0.0004
0.0006
0.0008
0.001
0.0012
0.0014
0 500 1000 1500 2000Area ^ 1/2
Dam
ping
(mN
/nm
)
Series1Series2Series3Series4Series5Series6Series7Series8Series9F = 3 uN
PS - 3, 0.5 mN max load, 0.05 s-1 strain rate
0
0.5
1
1.5
2
2.5
3
0 200 400 600 800 1000Displacement (nm)
E' (
GP
a)
Run1Run2Run3Run4Run5Run6Run7Run8Run9F = 3 uN
Experiment D.o.E
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PS3
-0.00010
0.00010.00020.00030.00040.00050.00060.00070.00080.00090.001
0 200 400 600 800 1000 1200Area ̂1/2
Dam
ping
(mN
/nm
)
Run1Run2Run3Run4Run5Run6Run7Run8Run9
PS - 1
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0 1000 2000 3000 4000Area ^ 1/2
Stif
fnes
s (m
N/n
m)
Run1Run2Run3Run4Run5Run6Run7Run8Run9
PS-1
-0.0004
-0.0002
0
0.0002
0.0004
0.0006
0.0008
0.001
0 200 400 600 800 1000Area ^ 1/2
Dam
ping
(mN
/nm
)
Run1Run2Run3Run4Run5Run6Run7Run8Run9
PS - 3
0
0.002
0.004
0.006
0.008
0.01
0.012
0.014
0.016
0 2000 4000 6000 8000Area ^ 1/2
Stif
fnes
s (m
N/n
m)
Run1
Run2
Run3
Run4
Run5
Run6
Run7
Run8
Run9
Li
Software D.o.E
Wednesday, 12 September 2007
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Supplementary Data Acquisition
Supplementary DAQ System
÷2
NanoTest Control Box
Interface
Ultra-fast dynamic indentation
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ON
Dynamic indentation
NanoTest (Micro Materials Ltd, Wrexham)
• Dynamic nanoindentation• High and low rate indentations• Displacement monitored with timevs. Lock-in amplifier Amplitude & Phase
Test Variables
• Impact energy• Oscillation Frequency• Strain rate• Test probe geometry• Temperature
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OFF
Dynamic indentation
NanoTest (Micro Materials Ltd, Wrexham)
• Dynamic nanoindentation• High and low rate indentations• Displacement monitored with timevs. Lock-in amplifier Amplitude & Phase
Test Variables
• Impact energy• Oscillation Frequency• Strain rate• Test probe geometry• Temperature
Wednesday, 12 September 2007
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High-temperature Testing:0.1 mN to 20 N
MicroMaterials NanoTestHot stage – sample temp ≤500°C
Force
Heaters
Depthsensor
Mapping the hardness of tribological coatings
5.2 micron Ion-beam Assisted Deposition (IBAD) Alumina; Stephen Abela, Unversity of Malta
Harder phase to provide abrasive resistance
Softer phase to provide toughness
H(GPa)
ScanScan
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Stage PlansStage 1 (1/4/06 – 31/6/07)
Selection/procurement of materials
Calibration and algorithm sensitivity studies
Development of dynamic calibration method (NPL Report)
Stage 2 (1/4/07 – 31/3/08) Design and test temperature stage
Development of ultra-rapid indentation method
Frequency, sweep and chirp
High rate indentation method (scientific paper)
Stage 3 (1/4/08 – 31/3/09)Visco-elastic models
Evaluation of temperature stage
High Rate indentation method at elevated temperatures (scientific paper)
Validated protocols/Input to ISO standards
Wednesday, 12 September 2007
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Industrial involvement
• Materials supply– Highly reproducible “standard” polymers– Industrial components / materials
• Collaboration for characterisation comparisons– Property data from other test methods as function
of frequency and temperature
• Case studies / feasibility of adoption of method
Wednesday, 12 September 2007
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DeliverablesProject Description
D1: Validated protocols for room temperature measurement of mechanical properties of polymer surfaces or coatings (NPL Report).
D2: Refinement of current methods into intelligent miniaturised tests (scientific paper).
D3: Mechanical properties of polymer surfaces or coatings as a function of temperature (scientific paper).
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SE02 GANNT chart