Roma TRE STM group presentation - STM DIMI Uniroma3

Presentation of the
Material Science and Technology Research Group
University Roma TRE
Roma, Italy
WEB SITE: www.stm.uniroma3.it and www.lime.uniroma3.it
Address: Via Vasca Navale, 79 00146 – Roma
28/07/2009
Edoardo Bemporad

WHERE IS THE UNIVERSITY “ROMA TRE”?
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ROMA TRE, SOME NUMBERS…
www.uniroma3.it
Founded in 1992.
One of the 4 State University in
Rome (9 in total).
175.000 m 2 .
More than 40.000 000 students
(4.100 enrolled in Engineering)
More than 700 Researchers e s and
Professors.
Faculty of Engineering:
• Civilil
• Computer Science
• Electronic
• Mechanical
Materials Science and Technology
research group (STM Group)
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MORE INFO..
www.stm.uniroma3.it
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MORE INFO..
www.lime.uniroma3.it
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OUTLINE
Research Group presentation
• People and research Partners
• Vision
• Facilities
Ongoing g research
Research topics on surface mechanical
measurements and microstructure concerns,
future activities
6

STM GROUP:
2 Full professors
1 researcher
1 graduated technician
mechanical engineer, Graduate Technician
3 Ph.D Students
materials science and engineering
2 fellowships
(1 Sr + 1Jr mechanical Engineers)
1 staff
3 undergraduate (average) doing their
“Laurea” thesis
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PRINCIPAL RESEARCH PARTNERS (CUSTOMERS)
Private Firms
INFN – Laboratori Nazionali di
Legnaro (Pd)
ENEA Casaccia dipartimento
Materiali (RM)
Centro Sviluppo Materiali (RM)
National Research Council
(CNR)
• Department of Molecular
Design
• Others involved in surface
engineering
University of Oxford
Department of Engineering
Science
National Universities
• Ancona
• Brescia
• Cagliari
• Firenze
• Milano
• Modena
• Napoli
• Roma 1
• Roma 2
• Torino
SIO and Technische Universität
Chemnitz (Germany)
Central University of
Venezuela, School of Metallurgy
and Materials Science
Lille University Laboratoire de
Mécanique
University of Rosario
(Argentina)
Karlsruhe Forschungszentrum
(Germany)
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STM GROUP: VISION
Product/process
optimization
Characterization
methods: tuning
and/or specific
development
Improving of
understanding
capabilities
Needs of
phenomena
explanation
Development
Advanced d use
Routine use
9

STM GROUP: RESEARCH STRATEGY
Development of methodologies for materials
processing optimisation by the use of the paradigm:
Coated system Design
nanostructure-microstructure–properties-performancesperformances
Optimization and failure analysis
Multiscale and multidisciplinary
approach.
Modelling and simulating in
service behaviour, reliability
and degradation modalities (materials oriented)
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WE KEEP ATTENTION TO:
Workflow concerns
• Privacy
• Timing
• Cost control
• Reporting
Data and samples handling concerns
• Redoundancy
• Affordability
• Accessibility
• Privacy
• Report standardization (Corporate Identity)
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STM FACILITIES: 3 LABORATORIES + 1 (IN DEV.)
1. LIME, Electron Microscopy lab
• Optical / Electronic / Stylus / (Ion Probing)
2. MatEDP, Materials Modeling lab
• 10 PC stations, Thermocalc, ANSYS, ABAQUS,
Elastica, EFS,…
3. MaTec, Materials Technology lab
• Mechanical characterization (Hardness, Microhardness,
Abrasive Wear, Scratch), Salt Spray,
Fretting
4. CoaTec, Coating technologies Lab
• Work in progress, coating facility to be acquired
within year 2010 (enhanced PVD process)
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STM FACILITIES: CONNECTION LAYOUT
Building one
Internet
Offices 2° floor
WAN Roma TRE
EXTRANET
HTTPS - Certificates
MatEDP 1° floor
Building two
PHILIPS XL 30 LaB 6
ANALYTICAL
CoaTec base floor
Optic Fibers
LIME
and
MaTec
PHILIPS CM 120 TEM
EDX (EDAX 134 Ev)
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LIME AND MATEC, FROM THE VERY BEGINNING…!
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LIME AND MATEC: LAB LAYOUT
Digital Optical
Microscopy,
Macro-Micro-Nano
Indenters
Macro-nano-scratch
Classroom
Prep line
SEM
TEM
Prep room
AFM
Dualbeam
15

LIME LAB: SEM (FEI)
• 30 Kv LaB 6 filament
• Secondary electrons
• Backscattered electrons
• EDS to B, line & maps
• Cathode luminescence
• Specimen Current
16

LIME LAB: TEM (FEI)
• 120kV LaB 6 filament
• Double tilt
• EDS to B, point & line
• nanoprobe
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LIME LAB: AFMS (1 NT-MDT + 1 DI)
•50x50x5 microns range
•All modes (contact, non
contact, lateral force,…)
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LIME LAB: DUALBEAM (FEI) HELIOS 600 NANOLAB
early 2008
-Omnprobe
-GIS(4 gases)
-STEM
- EDS (Oxford)
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DUALBEAM (FEI)
SEM Column: spatial resolution
0,76 nm @ 15 kV
FIB Column: spatial resolution
5 nm @ 30 kV
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PRINCIPAL FIB MODES:
Deposition
Imaging
Milling
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LIME LAB: DUALBEAM (FEI)
0,76 nm res
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LIME LAB: DUALBEAM (FEI)
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LIME LAB: NON-CONTACT PROFILOMETRY (TALYSURF
CCI L LITE) )
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LIME-LAB SELF-PRODUCING OF STANDARD
SAMPLES FOR INSTRUMENTS CALIBRATION
Calibration of the profilometer
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LIME-LAB SELF-PRODUCING OF STANDARD
SAMPLES FOR INSTRUMENTS CALIBRATION
Calibration of the profilometer
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MATEC LAB: HARDNESS TESTERS
Vickers
Knoop
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MATEC LAB: SCRATCH TESTER
Depth profiling
Applied force feedback controlled
Acoustic emission sensor
Friction force measurement
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MATEC LAB: NANOINDENTATION –NANOSCRATCH
Agilent Nano Indenter
G200
End of 2007
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MATEC LAB: SALT SPRAY 1M 3 CHAMBER
30
30

MATEC LAB: CONTACT ANGLE AND WETTABILITY
Uni en 828 and ASTM D5725 - 99
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SEMI-AUTOMATED INSTRUMENT FOR CONTACT ANGLE MEASUREMENT AND
SURFACE FREE ENERGY MODELS
SFE models:
1. Zisman
2. Neumann
3. Girifalco
4. Fowkes
5. Owens-Wendt
6. Van Oss-Chaudhury-Good
Light source,
polarized filter,
screen diffuser
Sample holder(three
axes movement)
12X objectives
Digital Camera to
acquire images on a
PC
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IMPROVEMENT AND OPTIMIZATION OF THE SURFACE FREE
ENERGY OF POLYMERIC SUBSTRATES BY FLAME TREATMENT
Process parameters observed:
1. Total flow rate;
2. Oxygen/propane ratio;
3. Distance sample-tip nozzle;
4. Frequency of sample pass on
flame;
5. Total time treatment.
Some results obtained through
DOE Technique
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MACRO-SCALE INSTRUMENTED SPHERICAL
INDENTATION
Prototipal ti instrument t for macroscale
spherical indentation
The stress-strain curve is obtained by
least-square fitting of exp data with a
FEM-modelled database of L-h curves
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MATEC LAB: WEAR TEST
Wear test device (prototype)
Dynamic measurement of wear and friction coefficient at
the sub-micron scale
001
002 003 004 005
Campione 004
-502
60
-502,5
50
[um]
Affondamento [
-503
-503,5
-504
-504,5
Affondamento
Carico
R 2 =0,98
40
30
20
10
0
Carico [g]
-505
-10
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150
Tempo [s]
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OUTLINE
Research Group presentation
• People and research Partners
• Vision
• Facilities
Ongoing g research
Research topics on surface mechanical
measurements and microstructure concerns,
future activities
36

ONGOING RESEARCH
Residual stress: FIB & Digital Imaging Correlation, FIB & nanoindentation
Analysis of wear mechanisms by FIB-SEM techniques
The use of statistical nanoindentation techniques for the mechanical
characterization of cement pastes
FIB-based failure analysis and nano-mechanical characterization of MEMS
structures
Scratch testing of thin coatings: failure modes mapping by FIB-SEM
morphological analysis
Improvement and optimization of the surface energy of polymeric substrates
by Flame treatment
Development of a semi-automated instrument for surface energy
measurement
Microstructural and mechanical characterization of cellular ceramics obtained
by gel casting
Instrumented spherical indentation at the
macro-scale for the assessment the stress-strain curves of metals
Use of nano-silica for preventing expansive alkali-silica reaction in concrete
Microstructural and mechanical characterization of sputtered niobium thin
films for accelerating cavity applications
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COATINGS: FAILURE MODES STUDY
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SCRATCH TESTING OF THIN COATINGS: FAILURE MODES
MAPPING BY FIB-SEM MORPHOLOGICAL ANALYSIS
Wedge spallation
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SCRATCH TESTING OF THIN COATINGS: FAILURE MODES MAPPING
BY FIB-SEM MORPHOLOGICAL ANALYSIS
Duplex Ti/TiN multilayer on WC-CO Planar:
L c3: 38,5 N
• FIB section in correspondence of the first
chipping with substrate appearence
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SCRATCH TEST
Duplex Ti/TiN
multilayer on WC-
CO Planar;
• Adhesion can be worsen by an
high h compressive residual
stress that is additive with the
scratch stress in front of the
contact area
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ANALYSIS OF WEAR MECHANISMS BY FIB-SEM
TECHNIQUES
FIB analysis of mechanisms and crosssectional
microstructural evolution during inservice
wear of a Stellite 6B cobalt-based
alloy subjected to sliding contact conditions
FIB section of the worn surface FIB section outside the worn surface 42

RESONANT CAVITIES FOR PARTICLE ACCELERATORS
Bulk Niobium
Niobium Coated (PVD)
Copper cavity
Very low Surface
electrical
resistance
(∼nΩ a 1,8 K)
Lower costs
Higher thermal stability
But…
Significantly lower
superconducting properties
– WHY??
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COATINGS ON COPPER SUBSTRATE
BIASED
(e-f) and
UNBIASED
(CERN, g-h)
type coatings
on QUARTZ
substrate
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NANOINDENTATION ON NB THINFILMS
Sample (mN
N)
Load On
1
0,9
08
0,8
0,7
0,6
0,5
0,4
0,3
0,2
0,1
0
0 50 100
Displacement Into Surface (nm)
Niobium film load-depth
curve
Load On Sample (mN)
p
0,03
0,025
0,02
0,015
0,01
0,005
0
0 5 10 15 20 25
Displacement Into Surface (nm)
Niobium film: Detail of a
load-depth curve
Indenter pop-in systematically observed
at depth ~ 10 nm
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TEM ANALYSIS OF THE OXIDE LAYER
TEM sample preparation p by
FIB lamella thinning
The control of surface oxide layer can be
very important in determining the
functional performances of Nb coatings
for superconducting applications
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NANOINDENTATION ON MS-PVD NB THIN FILMS
500 nm
Partial recrystallization
during
plastic deformation;
Relative sliding of
columnar grain
Measurement of
indenter contact
radius
Direct measurement of
piling-up
Evaluation of the effects
of roughness on contact
area
Analysis of deformation
mechanisms
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MICRO INDENTATION ON MS-PVD NB THINFILMS
Biased MS E = 88,95 GPa
unbiased MS E = 54,33 GPa
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NANOINDENTATION ON STRESS RELIEVED PILLARS
Compressive
stress in the
coating
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RESULTS –STRESS CALCULATIONS
a) Pillar – stress free b) Halfspace stressed coating – as measured
c) Modelled: Halfspace coating + RS
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CONTACT AREAS AND NANO STRUCTURAL EFFECTS
Pillar – no RS
Halfspace coating
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RESIDUAL STREESS BY
FIB-DIC TECHNIQUES
Z=0 vs each step
Incremental Milling;
Steps of 200 nm
The pillar size d is
equal to the coating
thickness
The maximum milling
depth is equal to the
coating thickness
(3.8 µm)
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EXPERIMENTAL DATA
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USE OF STATISTICAL NANOINDENTATION TECHNIQUES FOR
THE MECHANICAL CHARACTERIZATION OF CEMENT PASTES
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FIB-BASED FAILURE ANALYSIS AND NANO-MECHANICAL
CHARACTERIZATION OF MEMS STRUCTURES
calculation of the stiffness of MEMS membrane by the use of a wedge
indenter – spring stiffness taken into account
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MULTISCALE MECHANICAL CHARACTERIZATION OF
POROUS CERAMICS
FIB section and analysis
of sub-superficial
porosity
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MULTISCALE MECHANICAL CHARACTERIZATION OF
POROUS CERAMICS
⎛
σ ⎜ max
= σ
0
1+
2
⎝
a ⎞
⎟
ρ
⎠
Radius of curvature
at the apex of this
pore is 55 nm!
High stress
intensification at
crack tip
Vertical drop in
Hardness/Modulus
is due to brittle
failure of subsurface
porosity!
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USE OF NANO-SILICA FOR PREVENTING EXPANSIVE ALKALI-
SILICA REACTION IN CONCRETE
• NS – SEM-FEG and TEM
Analysis
No tendency to particle
agglomeration
Particle dimension
10.5±2.3 nm
• BET specific surface area
345 m 2 /g
TEM-BF 50000x
TEM-BF 380000x
58

USE OF NANO-SILICA FOR PREVENTING EXPANSIVE
ALKALI-SILICA REACTION IN CONCRETE
Nano-Silica
RILEM AAR-4 Expansion test at 60 °C - 90 days
RILEM AAR-4 Expansion test at 60 °C - 150 days
025 0,25
0,25
0,2
Aggregate A
Aggregate B
0,2
Aggregate A
Aggregate B
0,15
0,15
0,1
Expansion limit at 60 °C
0,1 Expansion limit at 60 °C
0,05
0,05
0
0 0,2 0,4 0,8 2 5
Nano-silica content (wt %)
0
0 0,2 0,4 0,8 2 5
Nano-silica content (wt %)
Ultima ate test expansion E90 (% l/l)
0,25
0,2
0,15
0,1
0,05
0
Berra et Al. Expansion test at 150 °C - 21 days
Aggregate A
Aggregate B
• Aggregate A:
Expansion
limit a 150 °C
D eff = 0,56% at 60°C - 0,03%
0 0,2 0,4 0,8 2 5
Nano-silica content (wt %)
D eff = 0,58% at 150 °C - 0,12%
The addition of NS is effective in
reducine the expansion of
concrete
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OUTLINE
Research Group presentation
• People and research Partners
• Vision
• Facilities
Ongoing g research
Research topics on surface mechanical
measurements and microstructure concerns,
future activities
60

FUTURE RESEARCH ACTIVITIES
FIB + Nanoindents
• Improving pillar and half space modeling: not only
the edges of the pillars must be taken into into
account, but also the layered character of the
sample. Taking into account properly the real
layered structure and reevaluate the real Young's
modulus of the coating can be crucial.
• A concept for direct access to the contact area
without guess work and / or tip calibration even in
the Angstrom scale (we give support to Norbert
Schwarzer work, Saxonian Institute of Surface
Mechanics)
61

FUTURE RESEARCH ACTIVITIES
FIB + DIC
• Improving stress profiling method, which no other
method can in a site specific way by the use of a
more efficient correlation algorithms
• Extension of the method to different coated
systems, with different elastic and plastic behaviour
at different scale values (i.e. soft materials or
foams)
62

RELATED PUBLICATIONS: 2008-2009
1. A. KORSUNSKY, M. SEBASTIANI, E. BEMPORAD,
Residual Stress Evaluation at the Micrometre Scale: FIB Ring-Drilling and Digital Image
Correlation Analysis,
Acta Materialia, submitted;
2. A. KORSUNSKY, M. SEBASTIANI, E. BEMPORAD,
FIB Ring-Drilling illi For Residual Stress Evaluation,
Materials Letters, in press, doi:10.1016/j.matlet.2009.06.020 ;
3. C. Bartuli, J.M. Tulliani, E. Bemporad, J. Tirillò, G. Pulci, M. Sebastiani, Mechanical properties of
cellular ceramics obtained by gel casting: characterization and modeling, Journal of the
European Ceramic Society, in press, doi:10.1016/j.jeurceramsoc.2009.04.035
4. Jean - Marc Tulliani, Cecilia Bartuli, Edoardo d Bemporad, Valentina Naglieri, Marco Sebastiani,
Preparation and mechanical characterization of dense and porous zirconia produced by gel
casting with gelatin as a gelling agent, Ceramics International 35 (2009) 2481–2491
5. RIZZO A, SIGNORE MA, TAPFER L, PISCOPIELLO E, CAPPELLO A, BEMPORAD E, EBASTIANI M,
Graded selective coatings based on zirconium and titanium oxynitride, Journal of physics d:
apllied physics, 42, 2009, 1-10
10
6. Bemporad E. and Carassiti F. and Sebastiani M. and Lanza G. and Palmieri V. and Padamsee H.,
Superconducting and microstructural studies on sputtered niobium thin films for accelerating
cavity applications, SUPERCONDUCTOR SCIENCE AND TECHNOLOGY, 21, 2008
7. E. BEMPORAD, M. SEBASTIANI, F. CARASSITI, Tribological studies on PVD/HVOF duplex
coatings on Ti6Al4V substrate t , Surface & Coatings Technology 203 (2008) 566–571571
8. CARASSITI F. and SEBASTIANI M. and MANGIALARDI T. and PAOLINI A.E. and BERRA M. , USE
OF NANO-SILICA FOR PREVENTING EXPANSIVE ALKALI-SILICA REACTION IN CONCRETE,
proceedings of the ICAAR 2008 – 13th International Conference on Alkali-Aggregate
Reaction in Concrete
9. BEMPORAD E. , SEBASTIANI M., CASADEI F., CARASSITI F., Modelling, production and
characterisation of duplex coatings (HVOF and PVD) on Ti–6Al–4V substrate for specific
mechanical applications, Surface & Coatings Technology 201 (2007) 7652–7662
10. E. Bemporad, M. Sebastiani, F. Carassiti, R. Valle, F. Casadei, Development of a duplex coating
procedure (HVOF and PVD) on TI-6AL-4V substrate for automotive applications, Ceramic
Engineering and Science Proceedings 28 (3), pp. 145-158158 ISBN 978-0-470-24679-5
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e.bemporad@stm.uniroma3.it
marco.sebastiani@stm.uniroma3.it
i@ t i it
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