Defini si Shape Memory Alloy SMA Shape Memory Alloys SMAs merupakan kelompok paduan logam yang dapat menemukan kembali dengan baik regangan permanennya bila dipanaskan pada suhu tertentu ID: 564477
Download Presentation The PPT/PDF document "MEMORY SHAPE ALLOY" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
MEMORY SHAPE ALLOYSlide2
Defini
si
Shape Memory Alloy (SMA)
Shape Memory Alloys (SMAs)
merupakan kelompok paduan logam yang dapat menemukan kembali dengan baik regangan permanennya bila dipanaskan pada suhu tertentu.
Slide3
Sejarah SMA
Di
temukan tahun 1932, Oleh Chang dan Read.
Tahun
1938,
kuningan
(
CuZn
).
Tahun
1951
,
Emas kadmium
(
AuCd
).
Tidak ada aktivitas sampai
1962.
Buehler and co-workers
menemukan
Nickel-Titanium (
NiTi
).Slide4
Apa material
shape memory
?Slide5
Prinsip dasar
SMA
mempunyai dua fase stabil – fase suhu tinggi (
austenite
)
dan fase suhu rendah (
martensite
).
M
artensite
dapat muncul dalam dua bentuk yaitu
twinned
dan
detwinned
.
Fase transisi yang muncul antara dua fase di atas ( melalui pemanasan/pendinginan) merupakan dasar untuk menjelaskan sifat unik
SMA.Slide6
Shape Memory Alloys?
Shape Memory Alloys (SMAs)
merupakan paduan logam yang mengalami transisi fase padat –padat dan dapat menunjukkan kembali regangannya.
contoh
:
Nitinol
Martensite
Low temperature phase
Monoclinic Crystal Structure
Austenite
High temperature phase
Cubic Crystal Structure
Twinned Martensite
Detwinned MartensiteSlide7
Induksi termal pada fase transisi SMA
M
f
M
s
A
s
A
f
Austenite
Martensite
TEMPERATURE
M
f
M
s
A
s
A
f
Austenite
Martensite
TEMPERATURE
(twinned)
(twinned)
Characteristic temperatures:
M
f
=Martensitic Finish
M
s
=Martensitic Start
A
s
=Austenitic Start
A
f
=Austenitic FinishSlide8
Efek
Shape
Memory : Stress Free Shape Recovery
TEMPERATURE
STRESS
M
f
M
s
A
s
A
f
TEMPERATURE
STRESS
M
f
M
s
A
s
A
f
Twinned Martensite (unstressed)
Detwinned Martensite (stressed - deformed)
Detwinned Martensite (stressed - deformed)
Detwinned Martensite (unstressed - deformed)
Austenite (undeformed)Slide9
Efek
shape memory (SME)?Slide10
Efek
Shape Memory
s
e
T
Cooling
Detwinning
Heating/RecoverySlide11
Shape Memory Effect: Shape Recovery Under Stress
TEMPERATURE
STRESS
M
f
M
s
Detwinned Martensite
(stressed)
Austenite
A
s
A
fSlide12
The Pseudoelastic Effect
STRESS
TEMPERATURE
M
f
M
s
A
s
A
f
f
s
s
f
Austenite
Detwinned Martensite
(stressed)Slide13
Nanomuscles
Alat-alat bedah
Tissue SpreaderStents (angioplasty)Coronary ProbeBrain SpatulaEndoscopy: miniature zoom device, bending actuatorForce sensorSmart skin (wing turbulence reduction)
Aplikasi
Slide14
SMAs in Bio-medical DevicesSlide15
Aplikasi...
Otot logam yang lentur dengan suhu rendah Penguapan dan kondensasi platina murni pada gas atmosfir tipis akan terkonversi menjadi partikel lebih kecil 5 nanometer.
Partikel-partikel ini dimampatkan dalam tubuh
nanoporous
.
Padatan yang diperoleh selanjutnya dicelupkan ke cairan konduktif
(electrolyte)
dan mengisi rongga.
Melalui elektrolit ini , asam atau basa yang bermuatan listrik dapat dibawa oleh nanopartikel ke padatan.
Slide16
Aplikasi ...
Tegangan listrik menyebabkan muatan elektrolit berubah. Muatan listrik akan menginduksi permukaan nanopartikel.
Perubahan muatan ini membuat perubahan konduksi elektron atom .
http://www.fzk.de/stellent/groups/public/documentsSlide17
NanomusclesSlide18
Discussion of Application
An advantage to this new shape memory alloy is its’ efficiency. No other alloy or polymer can compare to its’ strength and efficiency to weight ratio.
Nanomuscles weigh just one gram but can lift 140 grams, and are preferred to electric motors as they are far cheaper to produce.Slide19
SHAPE MEMORY ALLOY–NITINOL
What is it?
One type of shape memory alloy is
Nitinol
, which is short for Nickel Titanium Naval Ordnance Laboratory and which acknowledges the site of its discovery in 1965
Where does it get its name?
Nitinol
is an alloy of about 56 % Nickel and 44 % Titanium. (Hence the name: Ni–Ti–Naval Ordinance Laboratory)
What does it do?
Nitinol
“remembers” its original shape and springs back up to temperatures up to 500 degrees C. Can be strained 8 to 10 times more than spring steel without permanent deformation. Won’t kink. Coils easily.Slide20
HOW DOES NITINOL WORK?
Nitinol
is made of Nickel and TitaniumMost solids have one crystal structure, but Nitinol has twoThe crystal structure is different at cold and hot temperatures
At cold temps it is soft and easy to bend but at hot temps it is stiff and springy.Slide21
WHY IS NITINOL SO VERSATILE?
It has similar properties to human hair and human tendons and is being used in a wide range of applications.Slide22
Did You Know?
THAT YOU CAN NOW HAVE…
Nitinol’s
amazing properties allows surgeons to perform life saving operations
Ninol
is used to:
Seal holes in the heart
Patch up faulty blood vessels
Attach tendons to bones.
AMPLATZER®
Septal
Occluder
for heart defect repair utilizes the shape memory of
NitinolSlide23
Research scientists, innovators and artists are always finding new creative uses for
Nitinol
. Knee replacements Spectacle frames Medical stents Repair broken bones
Replace damaged discs.
What else?Slide24
Applications Of Nitinol
THE ICEMOBILE
A Nitinol
heat engine, called the
Icemobile
has a loop of
Nitinol
which you immerse in warm water, to make it spin (which then cuts up ice cubes).