NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]CONTENTS OF PRESENTATION Introduction Novel NiTi Films 1. One Dimensional NiTi Films 2. Gradated NiTi Films 3. NiTi (Ms1)/NiTi(Ms2) Films
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NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig
NOVEL NiTi SHAPE MEMORY ALLOY FILMS Manfred Wuttig. Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]. CONTENTS OF PRESENTATION Introduction Novel NiTi Films 1.One Dimensional NiTi Films 2.Gradated NiTi Films 3.NiTi (Ms1)/NiTi(Ms2) Films. - PowerPoint PPT Presentation
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NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
CONTENTS OF PRESENTATION
Introduction
Novel NiTi Films 1. One Dimensional NiTi Films 2. Gradated NiTi Films 3. NiTi (Ms1)/NiTi(Ms2) Films
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
-100 0 1000
100
200
300
Flat
Corrugated
dD
ispl
acem
ent d
(m
)
Temperature (oC)
0.0 0.5 1.0 1.5 2.0 2.52.5
2.0
1.5
1.0
0.5
0.0
film
substrate
y/c
x/a
Corrugated Films - Complicated Stress Distribution
Report on ”Corrugated ” Film that can be easily analyzed
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
Gradated Films - Not Easy to Prepare
Report on Gradated Films prepared by varying substrate temperature
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
Report on “Corrugated “ Films that can be easily analyzed
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
“Geometrically Novel” NiTi Films
Film
Substrate
L
Wg
tstf
wf
(a) 1-D/1-D (b) 2-D/2-D (c) 1-D/2-D
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
Principle of measurement, the cantilever deflection is determined from the change of the resonance frequency, LC1r
L
d C
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
-200 -100 0 100 200 300600
700
800
900
1000
1100
1200
1300
Norm
ariz
ed d
efle
ctio
n (m
)
Temperature (oC)
Deflection of four differently patterned NiTi/Si bimorph cantilevers as a function of temperature. All bimorphs were processed simultaneously and identically. aspect ratio = 0.31 aspect ratio = 0.16 aspect ratio = 0.016 aspect ratio = 0.0009
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
w
fw
f
-ws-w
s
L
f
L
f
-Ls
(b)
w
s0
w
f 0
L
s < 0
L
f > 0(c)
(a)
Stress analysis of a 1-D / 2-D composite:
(a) unstressed components
(b) components stressed biaxially
(c) patterned film and substrate stressed uniaxially.
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
Substrate
SMA
Conceptual martensitic microstructure:biaxially, top, and uniaxially, bottom,stressed SMA films in the two phase temperature region. The light and dark sections represent martensite and austenite, respectively.
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
)1(E)1(E
t
t6
fs
sf2s
f'bi
0
021
021
0
0
0
0
0000
00
0000000
21
0000000
21
0
0
0
0
0
000
00000
0000000
21
0000000
21
Cantilever deflection, Stoney’s Eq.:
Martensite biaxial
Martensite uniaxial
Thermal
T
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
Slope of deflection
dTd
'
T tf /wf
*) Modulusterm
Strainterm
Ratio
L
'H
'
dTd
dTd
Esti-matedratioPest
Experi-mentalratioPexp
Low(Bi)
2s
f
tt6
sf
fs
EE)1()1(
T
T > AfT < As
High(Uni)
2s
f
tt6
s
f
EE
T
s
f11
0.7 0.84(A)0.85(M)
Low(Bi)
2s
f
tt6
s'f
'fs
E)1(E)1(
dTTdM )(
As <T< Af
High(Uni)
2s
f
tt6
s
f
EE'
dTTd
M)(
s
f
11 '
1.4 1.28(avg.)
Evaluation of slopes of deflection and comparison of ratios.
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
Report on Structurally Gradated Films prepared by varying substrate temperature
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
Martensite/MartensiteComposite NiTi Films
Previous Experiments Show:
The nature of the martensitic transformation depends on the deposition temperature.
Therefore:
It is possible to create martensite/martensite composites by varying the substrate
temperature during deposition.
35 40 45 500
100
200
300
400
500
double layer
385 oC
250 oC
Inte
nsity
/ Co
unts
2
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
250
385
385
385
semi-continuous
discontinuous
continuous
t [min]0 50 100
250
250
T[oC]
10
Variation of the substrate temperature during sputter deposition of the films.
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
/g/g
21122211)2(L)1(L)0,0,0(g)2,1,(g
2120
22/g2
021/g2
)21(1Q
Analysis of Enhanced Damping
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
-150 -100 -50 0 50 100 150 200-100
0
100
200
300
400
500
Disp
lace
men
t [
m]
Temperature [oC]
Displacement curves of the NiTi double layer films;
Depositions on cooling; semi-continuous, discontinuous, continuous.
Depositions on heating; semi-continuous, discontinuous, continuous.
-200 -100 0 100 200
-0.03
-0.02
-0.01
0.00
M/M
Temperature [oC]-100 0 100 200
-0.015
-0.010
-0.005
0.000
0.005
M/M
Temperature [oC]
Modulus curves for the double layer film deposited on cooling and heatingleft, cooling: semi-continuous, discontinuous, continuous right, heating: semi-continuous, discontinuous, continuous
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
Supported byOffice of Naval ResearchNational Science Foundation
NOVEL NiTi SHAPE MEMORY ALLOY FILMSManfred Wuttig
Manfred Wuttig Tel 301-405-5212 Fax 301-314-9467 Email [email protected]
Ehemaliger Dresdner,Anhänger des damaligen DSC: mehrmaliger Deutscher Meister, Heimat-mannschaft von Helmut Schön, des Trainers der Deutschen Fussballmannschaft.