No Slide Title

Transcript No Slide Title

NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
CONTENTS OF PRESENTATION
Introduction
Novel NiTi Films
1. One Dimensional NiTi Films
2. Gradated NiTi Films
3. NiTi (Ms1)/NiTi(Ms2) Films
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
Corrugated Films - Complicated Stress Distribution
d
300
0.0
0.5
200
1.0
x/a
Displacement d (m)
film
Corrugated
1.5
Flat
100
2.0
substrate
2.5
0.0
0.5
1.0
1.5
2.0
2.5
y/c
0
-100
0
100
o
Temperature ( C)
Report on ”Corrugated ” Film that can be easily analyzed
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
Gradated Films - Not Easy to Prepare
Report on Gradated Films
prepared by varying substrate temperature
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
Report on “Corrugated “ Films that can be easily analyzed
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
“Geometrically Novel” NiTi Films
Film
Substrate
wf
L
tf
ts
g
W
(a) 1-D/1-D
(b) 2-D/2-D
(c) 1-D/2-D
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
Sample
Nr.
Width of strip
wf /m
1
2
3
4
2.9
5.4
54
1000
Distance between
strips
g /m
2.1
4.6
46
1000
Aspect ratio
tf/wf
0.31
0.16
0.016
0.0009
Actual areal
density
wf/(wf+g) [%]
58.0
54.0
54.0
50.0
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
L
d
C
Principle of measurement, the cantilever deflection is determined
from the change of the resonance frequency,  r  1 LC
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
Normarized deflection  (m)
1300
1200
1100
1000
900
800
700
600
-200
-100
0
100
200
300
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
o
Temperature ( C)
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
(a)
Stress analysis of a 1-D
/ 2-D composite:
 Lf
(b)
wf
 wf
-ws
-ws
 Lf
-Ls
(c)
 Lf > 0
 wf  0
(a) unstressed
components
(b) components stressed
biaxially
(c) patterned film and
substrate stressed
uniaxially.
ws0
 Ls < 0
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
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.
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
Cantilever deflection, Stoney’s Eq.:
'
 bi

6t f E f (1   s )

2 E (1   )
ts s
f
Martensite biaxial
 0

1 0
2
0

0
0 
0 0


0
0   1 0 0
2

0 0
0  0 

0   2  0

0  0


 0   0

1
0
1
2 0
0
0 
0 

 0 

Thermal
T
Martensite uniaxial
0 0

1 0 
0
2
0 0

0 
0 0


0   1 0 0
2

0 0
 0 

0  0 0
 
0   0 0
  0   0 0
0 

0 
  0 
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
Evaluation of slopes of deflection and comparison of ratios.
Slope of deflection
'
T
d
dT
tf /wf
*)
Low
(Bi)
T > Af
T < As
High
(Uni)
Low
(Bi)
As <T< Af
High
(Uni)
6t f
t s2
Modulus
term
Strain
term
Estimated
ratio
Pest
Experimental
ratio
Pexp
0.7
0.84(A)
0.85(M)
1.4
1.28
(avg.)
(1   s ) E f
(1   f ) E s
 T
6t f
t s2
Ef
Es
 T
6t f
t s2
(1   s ) E 'f
(1   'f ) E s
 M d (T )
 dT
6t f
t s2
Ratio
 d 


 dT 

H
 d ' 


 dT 

L
'
E 'f
Es
1  f
1  s
1   'f
M
d (T )
dT
1  s

Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
Report on Structurally Gradated Films
prepared by varying substrate temperature
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
Martensite/Martensite
Composite NiTi Films
500
400
The nature of the martensitic
transformation depends on
the deposition temperature.
Therefore:
Intensity / Counts
Previous Experiments Show:
double layer
300
200
o
385 C
100
o
250 C
It is possible to create martensite/martensite
composites by varying the substrate
temperature during deposition.
0
35
40
45
2
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
50
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
385
T[oC]
semi-continuous
250
385
discontinuous
10
Variation of the substrate
temperature during
sputter deposition of the
films.
250
385
continuous
top, semi-continuous,
center, discontinuous,
bottom, continuous
250
0
50
t [min]
100
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
14
Internal Friction of NiTi
double layer film
12
-4
6
Q x 10
8
-1
10
Deposited while semicontinuously cooling,
;
4
Single layers deposited at
250 deg C, 
385 deg C,   
2
0
-150
-100
-50
0
50
100
150
200
o
Temperature [ C]
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
Natural and Artificial Multiferroics
New UMD-based MURI
SMA/SMA Composite With Large Damping
 SMAs display large damping, up to 50%, at large amplitudes of vibration,
useful for mitigation of earth quake damage
 -scale R-M SMA Composites display 11% damping at small amplitudes,
useful for mitigation of (small amplitude) mechanical noise
Craciunescu/Wuttig, J. Thin Solid Films
Damping Q-1 [%]
Rhombohedral Phase
-Scale R-M Composite
Monoclinic Phase
12
12
8
8
0
=
+
4
-100
0
100
-100
0
100
4
-100
0
Temperature [C]
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
100
0
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
Analysis of Enhanced Damping
  g /   g /  

g( ,1,2)  g(0,0,0)  L(1)  L(2) 11  22 1212
(1  2)
 

  2g /  2    2g /  2   2

1 0
2 0 12

Q1    
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
Displacement curves of the
NiTi double layer films;
Displacement [  m]
500
400
Depositions on cooling;
 semi-continuous,
 discontinuous,
 continuous.
300
200
100
0
-100
-150
-100
-50
0
50
100
o
Temperature [ C]
150
200
Depositions on heating;
   semi-continuous,
 discontinuous,
 continuous.
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
0.005
0.00
0.000
M/M
M/M
-0.01
-0.02
-0.005
-0.010
-0.03
-0.015
-200
-100
0
100
o
Temperature [ C]
200
-100
0
100
o
Temperature [ C]
Modulus curves for the double layer film deposited on cooling and heating
left, cooling: semi-continuous,  discontinuous,  continuous
right, heating:    semi-continuous,  discontinuous,  continuous
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
200
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
No Modulus
Defect
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
Large
Displacement
Large
Damping
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
SUMMARY
Two Kinds of Novel NiTi Films:
1.
2.
1-D Films;
large displacement
Martensite/Martensite Films;
large displacement
large damping
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
COLLABORATORS
Kiyotaka Mori
Grad. Student
Panasonic Res./Boston
Corneliu Craciunescu
Research Associate,
U. Timisoara
Supported by
Office of Naval Research
National Science Foundation
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]
NOVEL NiTi SHAPE MEMORY ALLOY FILMS
Manfred Wuttig
Ehemaliger Dresdner,
Anhänger des damaligen DSC:
mehrmaliger Deutscher Meister,
Heimat-mannschaft von Helmut Schön,
des Trainers der Deutschen
Fussballmannschaft.
Manfred Wuttig  Tel 301-405-5212  Fax 301-314-9467  Email [email protected]