MICRO
MATERIALS
Bringing nanomechanical
measurements into the real-world
MEASURING NAN OTEC HNOL OGY
An Introduction to
Nanomechanical testing
Nanoindentation
Nanoscratch/nanowear
On bio-Materials and other samples
Dr Krish Narain, Micro Materials Ltd., Wrexham
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
Why do we need nanoindentation?
• Coatings are getting more complex
• Mechanical properties are critical
• If we can understand them then we can
engineer better materials
• Yield, cost and performance benefits
MICRO
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MEASURING NAN OTEC HNOL OGY
• The NanoTest investigates properties
on coatings from 5nm to 200 microns
• Provides hardness and toughness data
of many types
• Automated running for multiple analysis
• Looks at materials under working
conditions
• Single, multiple layer or bulk properties
MICRO
MATERIALS
Bringing nanomechanical
measurements into the real-world
MEASURING NAN OTEC HNOL OGY
Key advantages for biomaterials testing
• The NanoTest system is based around a
pendulum (see next slides for more details)
which gives these key advantages for testing
biomaterials…
• Nanoindentation testing with ultra-low thermal
drift (typically 0.005 nm/s or less)
• Nanoscratch testing without bending springs
• Nanoscale impact/fatigue testing (no other
instrument can do this)
Micro Materials –
Innovation track record
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
Founded 1988, based in Wales
• Application labs in UK, USA, Germany, Japan
• Worldwide support network: LOT Oriel in Europe...
Aim: to become the world leader in the development and
manufacture of nanomechanical testing equipment
Pioneering and progressive approach:• First commercial nano-impact tester for measuring
toughness and fatigue resistance
• First commercial high temperature nanomechanical
testing stage
Bringing nanomechanical measurements into the real-world
MICRO
MATERIALS
NanoTest nanomechanical test capability
MEASURING NAN OTEC HNOL OGY
To use the NanoTest system..
1) Nanoindentation module to obtain accurate
hardness (H) and reduced modulus (Er) values for
the coating
2) Scanning module to obtain critical load in scratch
test
3) Nano-impact module to assess fracture
resistance and durability under dynamic loading
4) High temperature stage to assess coating
performance at elevated temperatures (to 750
degrees C)
Road-map for development
of advanced materials
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
Nanoindentation
Nano-scratch
Nano-impact
High temp testing
Lab tests at
development
stage
Mechanical properties
Design-in
reliability
Tribological properties
Hardness
Stiffness
Fracture toughness
Load support
Optimised performance
of thin film/coating system
Test under
industrially relevant
conditions …at the nanoscale
MICRO
MATERIALS
Friction
Adhesion
Resistance to
•Abrasive Wear
•Sliding Wear
•Brittle fracture
•Fatigue wear
•Dynamic Loading
•Corrosion
Durable product
= Satisfied customer!
Nanoindentation principle
MEASURING NAN OTEC HNOL OGY
unloading
substrate
coating
loading
Indentation curve
• No other
coating
substrate
technique
provides
quantitative
information about
both the elastic
and plastic
properties of thin
films and small
volumes
• force, displacement and time are recorded throughout indentation of sample by a diamond probe
Beyond nanoindentation…
Scanning = transverse sample movement during loading
Impact = sample oscillation at constant load
MICRO
MATERIALS
Viscoelastic Effects during Indentation
MEASURING NAN OTEC HNOL OGY
16
12
250
Polyester
200
150
100
10
8
6
4
Aluminum
50
0
1 mN/s
0.1 mN/s
0.001 mN/s
Hold time = 100 sec
14
Epoxy
300
Load (mN)
Creep displacement (nm)
350
2
Steel
0
20
40
60
80
Hold time (s)
Creep at constant load
100
0
0
500
1000
1500
2000
2500
Depth (nm)
Creep effects as a function of
loading rate
Data: Courtesy Dr Raman Singh, SUNY Stonybrook
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
ISO standards – ISO 15477
4 mandatory user calibrations are needed:
• Load
• Depth
• Diamond area function
• Frame compliance
For example without DAF – you can measure
Martens hardness – but this is only applicable
to Micro Hardness measurements according
to ISO standards
Bringing nanomechanical
measurements into the real-world
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
The NanoTest pendulum
MICRO
MATERIALS
Advantages of the pendulum
include…
• large samples possible
• calibrated contact load
• high temperature stage
• sample oscillation (impact)
• options such as pin-ondisk wear testing and 2D
levelling stage
• symmetrical indents
• scratching in
high stiffness
direction
NanoTest platform system
MEASURING NAN OTEC HNOL OGY
a flexible
nanomechanical
property testing centre...
2 loading heads
Nano - 10 µN - 500 mN
Micro - 0.1 N - 20 N
3 modules
Indentation
Scanning
Impact
10 options including
High temp testing
Continuous compliance
Pin-on-disk wear
Microscopes/AFM
3D imaging
NT head
MT head
Microscope
Stage Assembly
+Z
+Y
+X
Repositioning to 0.5 µm
Transfer stage
(indenter/microscope)
NanoTest Options
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
NanoTest options…
• High Temperature Stage
• Automatic 2D levelling stage
• High Load Head (20 N)
• Micro-scale Pin-on-disk
• Continuous Compliance
• Humidity Control
• Spherical Indentation
• Powder Adhesion
• Acoustic Emission
• High Resolution Microscope
• Zoom Microscope
• In-situ AFM
• Piezo stage Imaging
• Open access to signals
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
How homogeneous is my
coating?
An example of nanoindentation
as a QA tool
• rapid, automatic scheduling
of arrays of indentations - 10,000 points
per single run - or 100 scratches
Indentation: mapping (1)
MICRO
MATERIALS
Nanoindentation of bone
MEASURING NAN OTEC HNOL OGY
Nanoindentation into osteonal bone…
• NanoTest high resolution microscope used to exactly place indents
• Osteonal bone is stiffer than interstitial bone
MICRO
MATERIALS
Bone: Nanoindentation creep
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Bone is viscoelastic, so to
obtain accurate H and E
values, the tests need:• Slow loading
• Long hold period at max.
load for creep (180s)
• Good thermal drift (as
creep recovery can be
important)
Creep of osteonal
bone fitted
to a log function
• Only the NanoTest system has additional software for investigating this
creep deformation – which provides additional characterisation information
on rate and extent of creep
MICRO
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MEASURING NAN OTEC HNOL OGY
Use of Nanoindentation to assess new candidate
surface modification technologies for biomedical applications
Data from European project
“Ion Beam Surface Modification of Polymers for
Improved Friction and Wear Properties”
Micro Materials Ltd (UK)
University of Birmingham (UK)
Technical University of Clausthal (Germany))
SC Plasmaterm (Romania)
Hungarian Academy of Sciences (Hungary)
Wear resistance predicted from H/E ratio
correlates to Pin-on-Disk wear tests
and Nano-tribology results
Follow-up project – dynamic loading and fatigue
MICRO
MATERIALS
No thermal drift correction necessary…
MEASURING NAN OTEC HNOL OGY
Loading history on polymer = load then hold for 30 s
Variation in loading curve and creep with loading
rate
displacement (nm)
100
80
after
60
before
40
creep
20
0
0.0001
0.001
0.01
0.1
loading rate (mN/s)
1. After 30s hold period at maximum load depth is the same in very
slow and fast tests
2. Only an instrument with negligible thermal drift could perform
these tests, with loading rates varying by x300
Nanoindentation of PEO/Clay
Nanocomposites
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
Improving polymer performance…
1
• to produce advanced materials
with improved mechanical properties
by PEO intercalation between clay layers
2
• to accurately characterise their
nanomechanical properties so synthetic
and fabrication methods can be optimised
2 key aims…
Nanoindentation of polymer-clay nanocomposites…
Ben Beake (MML), Shuaijin Chen, J Barry Hull and Fengge Gao
(Polymer Engineering Centre, Nottingham Trent)
MICRO
MATERIALS
Nanoindentation of PEO/Clay
Nanocomposites
MEASURING NAN OTEC HNOL OGY
Pure PEO
PEO/ 20 % clay
Indentation on
melt-synthesised PEO
Very high hardness at
High clay loadings
Low hardness influenced by creep?
G-105 clay/solution-synthesised PEO
• Hardness and stiffness of PEO film are dramatically
improved by addition of high clay loading
Ben Beake*, Shuaijin Chen J. Barry Hull and Fengge Gao J Nanosci. Nanotech. 2002 vol 2, 73-79.
Nanoindentation of PEO/Clay
Nanocomposites
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
The variation
with clay is striking
when creep data
are fitted to
d = A ln(Bt + 1)
A
Influence of creep on hardness…
200
180
160
140
120
100
80
60
40
20
0
0.25
0.2
0.15
0.1
0.05
0
0
20
40
60
80
% G-105 Clay
Good fit to
logarithmic
creep
equation
A determines extent of creep
B determines rate of creep
More clay – slows creep process
Explains small decrease in
hardness at low loading
MICRO
MATERIALS
Depth profiling with the
load-partial-unload technique
MEASURING NAN OTEC HNOL OGY
Plasma-polymers deposited at 100 W and 25 W power…
100 W
25 W
25 W
100 W
20 cycle load-partial-unload experiment – takes 30 mins
B
MICRO
MATERIALS
Mapping hardness and modulus
MEASURING NAN OTEC HNOL OGY
Nanomechanical properties of burnt
polyurethane foams in resin
450
450
5.5-5.75
400
5-5.25
300
4.75-5
250
4.5-4.75
z
300
250
100
3.75-4
100
50
3.5-3.75
50
375
350
325
300
275
250
225
200
175
150
125
100
75
50
25
0
0
3.25-3.5
400
150
200
200
4-4.25
300
4.25-4.5
150
0
125-150
150-175
175-200
200-225
225-250
250-275
275-300
300-325
325-350
350-375
350
100
300
400
100
200
5.25-5.5
350
200
5.75
4.75
5.25
3.75
4.25
2.75
3.25
1.75
2.25
0.75
1.25
0.25
5.5
4.5
3.5
2.5
1.5
0.5
5
4
3
2
1
0
0
400
z
0
y
y
Modulus (GPa)
Hardness (MPa)
optical image
Nano-mechanical properties of heterogeneous, multi-phase
soft samples can be quantitatively mapped
Ultra-low load nanoindentation
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
Ultra-low load (10 µN) testing of soft samples
IPP Repeat Indentations
0.012
0.01
Load (mN)
0.008
0.006
0.004
0.002
0
0
5
10
15
20
25
30
Depth (nm)
• For slow loading excellent thermal stability is necessary
MICRO
MATERIALS
Room Temperature or real temperature
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The standard nanoscale mechanical/tribological
test techniques are very useful…
Nanoindentation – mechanical properties
(hardness, modulus, creep)
Nanoscratch – tribological properties
(resistance to abrasive/sliding wear)
But…
•
All material properties are temperature-dependent
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
NanoTest hot stage …
Thermal shield
For clarity,
separate diamond
heater not shown
Insulation
Heater
element
Damping
plate
Thermocouple
Power supply +
temperature controller
MICRO
MATERIALS
Nanoindentation of Si(111)
MEASURING NAN OTEC HNOL OGY
At room temperature Si(111)
undergoes phase changes…
At slow unloading rate the popout only in room temp data
Phase changes:Si-I diamond-type to Si-II
β-tin on loading
…to Si-XII and Si-III on
slow unloading
200 deg. C
29 deg. C
“Pop-out”
during
unloading
Nanoindentation Parameters:-
• Different unloading slopes as test temperatures increases
• Elastic modulus reduced by 27% at 200 degrees C
Loading rate = 1.67 mN/s
Hold period at maximum load = 5s
Unloading rate = 0.56 mN/s
MICRO
MATERIALS
• No observable “pop-out” at slow unloading rates
• Implications for microelectronics processing/applications
Nanoindentation of solgel coatings on Si
MEASURING NAN OTEC HNOL OGY
20 µm spheroconical indenter
Room temp modulus agrees well with Berkovich data
Modulus drops with temperature
Er [GPa]
Reduced modulus solgel coating on Si as function of
temperature
10
9.5
9
8.5
8
7.5
7
6.5
6
100C
RT
0
50
100
depth [nm]
Data courtesy Philips Research, Netherlands
150
MICRO
MATERIALS Nanoindentation testing of NiTi at high temperature
MEASURING NAN OTEC HNOL OGY
The NiTi shows
shape memory
behaviour above
the transition
temperature
AJ Muir Wood, V Gergely and TW Clyne, Gordon Laboratory, Dept of Materials
Science and Technology, University of Cambridge. Proc SPIE 2004 (in press)
MICRO
MATERIALS
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High temperature friction
Fused quartz rod
Thermal
shield
Diamond holder
Test
probe
Double force
transducer
Thermal
insulation
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
Friction coefficient at RT and 200ºC
Friction coefficient
Influence of Temperature on Friction
Coefficient
0.5
200C
0.4
0.3
0.2
0.1
Room
temp.
0
0
50
100
150
200
250
Scan distance (microns)
1 mm dia. stainless steel ball + glass substrate
Scan speed 4 µm/s
Normal load 4 mN
MICRO
MATERIALS
Stiction at 400ºC
MEASURING NAN OTEC HNOL OGY
1 mm dia. stainless steel ball + glass
substrate
Scan speed 4 µm/s
Normal load 4 mN
Friction coefficient
Stiction at 400C and a Load of 4 mN
2
1.5
1
0.5
0
0
50
100
150
200
250
Scan distance (microns)
1 mm dia. stainless steel ball + glass
substrate
Scan speed 4 µm/s
Normal load 0.4 mN
Friction coefficient
Stiction at 400C and a Load of 0.4 mN
14
12
10
8
6
4
2
0
0
50
100
150
Scan distance (microns)
200
250
MICRO
Influence
MATERIALS
of temperature on adhesion
MEASURING NAN OTEC HNOL OGY
Adhesion of Stainless Steel to Glass
100
Displacement (nm)
50
0
-1
-0.5
0
0.5
1
1.5
2
2.5
3
3.5
-50
RT
400C
-100
-150
-200
-250
Load (mN)
1 mm dia. stainless steel ball + glass substrate
MICRO
MATERIALS
Nano-and Micro-scratch test principle
MEASURING NAN OTEC HNOL OGY
Sample motion during loading makes nano-scratch tests possible…
transverse sample
motion with XYZ stage
loading
coating
substrate
1.
Force, displacement, friction, acoustic emission and
time are recorded throughout the scratching of a test
sample by a diamond probe
2.
Can test much thinner coatings and more local scratch
behaviour than conventional scratch test
MICRO
MATERIALS
Nanoscratching of thin hard
ta-C films on Si for MEMS
MEASURING NAN OTEC HNOL OGY
Carbon films on Si as protective
overcoats for hard disk, MEMS
Friction
Precise determination of
Critical load (Lc) for film failure
• Friction force data
• Displacement data
• Microscopy
50 µm
Depth
100 µm
Track
end
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
As hydroxyapatite is
the main Calcium
Phosphate in bone,
it is being considered
as a biocompatible
coating for artificial
joint replacements
NanoTest system has
been used to evaluate
the abrasive wear
resistance of HA
coating…
Nanoscratch testing
MICRO
MATERIALS
Nanotribology
MEASURING NAN OTEC HNOL OGY
Multi-pass sub-critical load scratch testing
2, 4, 6
dplast
1, 3, 5, 7
dtotal
Experimental parameters:
25 µm Rockwell probe
scratch load:- ramped to 1 mN
topography load 0.1 mN
scan speed 0.5 µm/s
Nano-scratching wear of PET film
Repeat scratches over the same wear track reveal gradual wear of oriented polyester [PET] film
Nanotribology
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
2 different PET samples clear differences in
nano-scratching wear
with processing history...
• extent of ploughing
• differences in
elastic recovery (dp/dt)
Evaluate sliding
wear resistance of
different coating
formulations
dplast
dtotal
Biaxially drawn PET film - 50% crystalline
dplast
dtotal
Uniaxially drawn PET film ~ 30% crystalline
BD Beake (MML) and GJ Leggett (UMIST), Polymer 2002, 43, 319-327.
MICRO
MATERIALS
Evaluation of Dental Composites
MEASURING NAN OTEC HNOL OGY
Dental composite materials used to be evaluated by standard
macroscale test methods – but results were inconsistent
NanoTest wear depth data
for repeat scratches on
common composites…
Scratch depth
(microns)
So the NanoTest is being used to rapidly evaluate the abrasion
resistance of new improved composite materials
The new composites in this study were shown to have better
abrasion resistance than conventional materials
MICRO
MATERIALS
Nano-impact testing
MEASURING NAN OTEC HNOL OGY
The need for dynamic testing
Materials can fail by fatigue not overload so
optimisation based on nanoindentation/scratch may
be insufficient
for applications where materials are exposed in
service and/or in processing to fatigue wear or erosive
wear (impact wear)
Dynamic nanomechanical tests (nano-impact and
contact fatigue) have been developed by Micro
Materials to address this problem
MICRO
MATERIALS
Impact
MEASURING NAN OTEC HNOL OGY
Nano-impact testing - simulating fatigue wear and failure
2 different methods…
Sample oscillation
Pendulum impulse impact
• High frequency oscillation
• High cycle fatigue
MICRO
MATERIALS
• Accurately controlled impacts
• Known energy to failure
• Wear mechanisms
1N load repetitive contact testing
reveals clear differences….
MEASURING NAN OTEC HNOL OGY
Collaboration with Ito Tecnologia Cerámica, Castellon, Spain
Impact at
high load =
Contact
fatigue
testing
• A and C fracture easily but B and D do not fracture within 500s
• Can we correlate with fracture toughness data?
• Can we correlate with microstructure?
MICRO
MATERIALS
MEMS: nanostructured Si and SiO2
MEASURING NAN OTEC HNOL OGY
Fracture and fatigue wear by Nano-impact testing
Unimplanted SiO2
1 x 1016 N cm-2
implanted SiO2
Damage regimes in the impact test:
1 = before impact
2 = plastic deformation
3 = slow crack growth (fatigue)
4 = abrupt failure and material removal
5 = further slow crack growth
1 impact every 4 s in these tests
• Fatigue resistance from
time-to-failure
• Ion-implantation
improves toughness
BD Beake (MML), J Lu, Q Xue, and T Xu, (all Lanzhou Institute of Chemical Physics) Proc FMC8 2003
MICRO
MATERIALS
Nano-impact mapping of biomaterials
MEASURING NAN OTEC HNOL OGY
Grids of impacts to determine differences in toughness/ductility…
Variation in fatigue properties across finger nail of
42 yr old woman
500
Impact depth
(nm)
100
200 300 400 500
400
2500-3000
position
300
(microns)
2000-2500
200
1000-1500
100
600
1500-2000
Collaboration in progress
with Universities of Limerick
and Lancaster
500-1000
0-500
position (microns)
• Initial results suggest the nano-impact test can be used to identify
osteopaenia (2-5 times greater risk of osteoporosis in later life)
• No other nanoindentation system has the capability to do nano-impact
so no other system can investigate toughness and fatigue at the nanoscale
MICRO
MATERIALS
Fatigue and Fracture Wear
of ta-C films
MEASURING NAN OTEC HNOL OGY
80 nm
on Si
80 nm
on Si
60 nm
on Si
5 nm
on Si
Damage mechanism in the impact test: before impact - plastic deformation - slow crack
growth (fatigue) - abrupt failure and material removal - further slow crack growth
• time-to-first-failure to rank impact resistance
• some plastic deformation of the substrate does occur (depth at failure)
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
DLC: is it tough enough for your application?
Diamond-like-carbon (DLC) has high hardness and low
friction so it is being considered for many applications
But its fatigue properties have not been fully tested –
this is particularly important as
It is prone to poor adhesion
It has been considered as an inert coating for biomedical devices
The NanoTest is being used to investigate the
toughness and durability of DLC coatings to fatigue
wear with the nano-impact facility…
MICRO
MATERIALS
Impact failure of 550 nm
DLC film on Silicon
MEASURING NAN OTEC HNOL OGY
Coating debonding - adhesion failure
Abrupt depth change at failure > film thickness
CVD Coating
Deposition
RF Power
Coating fracture – cohesive failure
Depth change at failure
less than film thickness
Nano-impact shows how deposition conditions
influence coating performance
• Time-to-failure
• Failure mechanism
BD Beake et al, Diamond and Related Materials, 11, 1606, 2002
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
Nano-impact can be used to assess the toughness
and adhesion of DLC coatings under industrially
relevant conditions
DLC suffers from brittleness
DLC suffers from high stress
DLC suffers from poor adhesion
DLC suffers from poor resistance to fatigue
Nano-impact is a very quick and easy way to
optimise DLC performance
Next slide shows typical brittle fracture and
debonding of DLC after repetitive contacts (impact)
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
Nano-impact can assess DLC performance
1. Under a range of contact conditions (I.e. from light
to severe loading) – important since many tests are
too gentle
2. Quickly
3. Provides clear-cut time-to-failure data
4. Microscopy confirms failure mode…(see next
slide)
5. Can test on actual component
MICRO
MATERIALS
Nano-impact results on commercial DLC
MEASURING NAN OTEC HNOL OGY
Hydrogenated DLC (a-C:H)
50 µm
Ring-cracking
Hydrogen-free DLC (a-C)
50 µm
Delamination occurs for the DLC on the left – it is not
suitable for severe contact conditions
Mapping variations in
high-strain rate deformation
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
Grids of impacts to determine differences in toughness/ductility…
Mapping of fatigue properties across crab
shell
Toughness map for ABS 25wt% rubber
21
18
15
nm
0
3
6
200-240
0
9 12 15 18 21
950
650
800
350
240-280
3
500
280-320
6
Impact depth
(nm)
50
320-360
200
360-400
12 position
9 (microns)
200 position
(microns)
50
position (microns)
5000-6000
4000-5000
3000-4000
2000-3000
position (microns)
• At this highly localised scale the ductility
varies with distribution of micron/sub-micron
sized rubber particles in the ABS matrix
Applications in Milling Prediction
• Nano-scale ductility of crab shell varies
across the shell
• Finer “mesh sizes” can be used to
investigate this behaviour at much smaller
scale
Collaboration in progress with University of Maryland
MICRO
MATERIALS
Indentation: viscoelastic materials
MEASURING NAN OTEC HNOL OGY
Testing the viscoelastic properties of thin films and
small volumes requires the ability to access a wide
range of strain rates
The NanoTest system has far greater strain rate
choice than other systems because
1. Ultra-slow loading, long creep tests etc, are
possible due to excellent thermal stability (~0.0010.01 nm/s)
2. Very high strain rates accessible – use nanoimpact
Impact behaviour:
brittle and ductile materials
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
Repetitive impact tests on brittle and ductile materials
More ductile
Less ductile
• Little plastic deformation before failure
• Clear fracture event(s)
• Time-to-failure characterises impact resistance
MICRO
MATERIALS
• Focus on ability to absorb energy
• More plastic deformation = more ductile
• Less plastic deformation = less ductile
Nano-impact – ductile materials
MEASURING NAN OTEC HNOL OGY
Nano-impact of Rubber-modified ABS Polymer
1 impact every 7 s; 5 mN impact force; spherical test probe
Incorporation of 25 % rubber leads to greater
depth change on repetitive impact at the same position
Nano-impact
- a new method of ductility testing
MICRO
MATERIALS
MEASURING NAN OTEC HNOL OGY
• Rubber incorporation improves ability to absorb energy on impact
by deforming plastically rather than fracturing (improved ductility)
5 repeat impact
tests at each
composition
Variation in impact-induced plastic
deformation with rubber loading
change in crater volum e
during im pacting (um )^2
Very reproducible
behaviour - error
bars are smaller
than symbols
Geometric
considerations
used to convert
depth to volume
1000
800
600
400
200
0
0
5
10
15
20
25
rubber w t% loading
The technique has considerable potential in evaluating the local fatigue
behaviour and ductility of thin polymer films that are not capable of being tested
by conventional methods that were designed for bulk samples
Ben Beake, Steve Goodes, Jim Smith and Fengge Gao, J Mater Res (2004) 237-247.
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New innovations
• Liquid cell
• In two beta sites
• Nanofretting
About to got Beta-site
status
Bringing nanomechanical
measurements into the real-world
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Conclusions
1.
Nanoindentation is fast becoming an essential tool in the optimisation of
the mechanical and tribological properties of thin coated systems and
advanced materials, for applications where hardness and stiffness are
important.
2.
The pendulum arrangement has key advantages for reliable scratch
testing. Scratching occurs in high stiffness direction for pivot and direct
calibration of tangential (frictional) forces are possible.
3.
Nano-scratch and nano-wear tests can accurately reveal differences in
coating adhesion and wear resistance of coatings and bulk materials.
This information can be used to aid materials processing and coating
design.
4.
Together, the combination of nanoindentation, nanoscratch and nanoimpact provides much information on the plastic, elastic, adhesive,
fatigue wear and fracture properties of biomaterials
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HOW TO FIND FURTHER
INFORMATION:
www.micromaterials.co.uk
• references
• customer profiles
• application notes
krish@micromaterials.co.uk