Shape memory alloys, propitiates, manufacturing, types, mechanisms and its use in textile
The different between shape memory alloys and shape memory polymers
Shape memory polymers yarns and fibers and its programming method
The applications of shape memory polymers in textile
2. Introduction
Properties of shape memory alloys
Manufacturing of SMAs
Types of shape memory alloys
Mechanism of Shape Memory Alloy
Smart Textile
Content
3. Shape Memory alloy in Yarns
SMP Fibers
SMP Yarns and Fabrics
SMP Programming
Shape-Memory Applications in Textile
Using of shape memory alloy in Orthodontics
Content
4. JensMartensson
Introduction
Shape memory alloys
1- The shape memory effect
characterized by the capability of a
material to be deformed at a low
temperature and then to revert to its
prior shape upon heating above a
temperature associated with the
particular alloy.
2- The second is super plasticity which is
the ability of a material to exhibit large
recoverable strains (up to approximately
15%), while deformed within a range of
temperature characteristic of a specific
alloy.
4
5. Schematic illustration of atomic arrangements during martensitic transformation. P: parent
phase, M: martensitic phase subscripts A and B stand for the martensite crystals with different
shear directions
Mechanism of Shape Memory Alloy
7. JensMartensson
7
Properties of SMAs
Shape Memory EffectPseudo elasticity
The SMA reverts to its original shape when
the applied deformation stress is removed. It
is done by the subsequent recovery of the
deformation strain when the stress is
removed
Shape memory effect retains a deformed
state after the removal of an external force
and then recovers to its original shape upon
heating
8. JensMartensson
8
Manufacture of
SMAs
The shape memory alloys (SMAs) are
considered as difficult to machine (DTM)
materials.
ISMAs possess poor machinability that
subsequently lead to the problems like
progressive tool wear, deterioration of
surface quality, burr formation, and high
consumption of energy and resources,
which are encountered during their
machining.
For example, Fig shows some drawbacks
while machining Nitinol (NiTi) SMA
during conventional grinding and
turning processes.
9. JensMartensson
9
Embedding of SMA
wires in textile
structures
• Used for embedding SMA wires into a
textile structure is stitching, as used by
Leenders to produce her “moving
textiles”.
• Another method of embedding SMA
wires is via a weaving process, using a
hand-weaving loom, as in most of the
cases reported in literature
10. Types of shape
memory alloys
1. Iron-based alloy Fe–Mn–Si
2. Copper-based SMAs such as Cu–Zn–
Al; Cu–Al–Ni, Cu–Al–Ni–Mn, and Cu–Sn
3. Nickel–Titanium based alloys such as
NiTi, NiTiCu, NiTiPd, NiTiFe, NiTiNb,
NiFeGa, and NiTiCo
4. Kovar (29% Ni, 17% Co, 0.3% Si, 0.1%
C and Fe balance)
5. High-temperature shape memory alloys
such as TiNiPd, TiNiPt, NiTiHf, NiTiZr,
ZrRh, ZrCu, ZrCuNiCo, ZrCuNiCoTi, TiMo,
TiNb, TiTa, TiAu, UNb, TaRu, NbRu, and
FeMnSi
6. Magnetic shape memory alloys,
namely, NiMnGa, FePd, NiMnAl, FePt, Dy,
Tb, LaSrCuO, ReCu, NiMnIn, and CoNiGa
11. JensMartensson
11
Shape Memory
alloy in Yarns
• Yarns can be designed with trained
Ni-Ti SMA wires as core component,
wrapped with conventional fibers such
as polyester, viscose and polyamide
13. JensMartensson
13
Shape Memory
alloy in Yarns
2. Programming SMA
SMAs are normally ‘trained’ to
remember one or two particular shapes
while they are in the austenite phase.
As conventional textile materials are not
able to withstand the high temperatures
required for the programming, use of
SMAs in textiles normally requires
programming of the alloy before yarn
spinning, weaving or knitting.
14. Smart Textile
Smart textiles are textile products that
can detect and react to an external
effect or effect change (light, heat,
pressure, electromagnetic waves,
sound and ultrasonic waves, motion
etc.).
The shape memory effect is the
ability to recover the original shape
when a material is activated with
appropriate stimuli.
15. Smart Textile
Shape-memory polymers (SMPs)
SMPs can sense and respond to
external stimuli such as temperature,
pH, chemicals, and light in a
predetermined way
These materials have various
elasticities from hard glass to soft
rubber. SMPs have very low cost in
comparison with Shape-Memory
Alloys.
16. JensMartensson
16
Differences Between Shape Memory
Polymers and Alloys
• The ability to reverse completely to their
original pre-determined shape
• better mechanical properties.
Shape Memory Polymers
• SMPs are lighter
• easy to process
• economical compared to SMA’s
• high shape transformations and high
recovery,
• soft touching and the adjustment of key
temperature
• Some SMP’s are also biodegradable,
which can be useful in medical
applications
Shape Memory Alloys
17. JensMartensson
17
SMP Fibers
• Macro-scaled shape memory fibers
can be produced with wet, dry
spinning
• And melt spinning methods Shape
memory polyurethane (SMPU) fibers
were prepared for the first time in
2006 with wet-spinning
19. JensMartensson
19
SMP Yarns and
Fabrics
Shape memory fibers can be turned into
yarns together with other fibers by
using friction or ring technology. The
yarns were woven and knitted into
three-dimensionally changing
structures.
Knitting and weaving of the material did
not raise difficulties, as in the case of
knitting the SMA.
20. JensMartensson
20
SMP
Programming
Unlike SMA, which has to be
programmed before incorporation in
the textile structure because of the high
treatment temperature, SMPs are
treated after their incorporation into
yarns and fabrics.
21. Shape memory recovery of smart textile having SMA spring varied with temperature when
T=50oC: (a) 0 s; (b) 10 s; (c) 20 s
Shape-Memory Applications in
Textile
23. Shape memory recovery of SMP composite woven uniformly and densely of SMP yarn at 50oC
with recovery time (a) 0 s, (b) 15 s, and (c) 30 s"
Shape-Memory Applications in
Textile
24. JensMartensson
Other applications
• Fashion and entertainment
• Health care
• Life belt
• Life jacket
• Military defense
• Sports wear
• Purpose clothing
• Future development
24
Shape-Memory Applications in
Textile
25. Conclusion
Shape memory materials (SMMs)
are a set of materials that, due to
external stimulus, can change their
shape from some temporary
deformed shape to a previously
‘programmed’ shape. The shape
change is activated most often by
changing the surrounding
temperature, but with certain
materials also stress, magnetic
field, electric field, pH-value, UV
light and even water can be the
triggering stimulus.
