1. BY SYNDICATE NO 2

2. INTRODUCTION WHAT ARE SHAPE MEMORY ALLOYS.
MATERIALS WHICH REMEMBERS ITS SHAPE.
COMMONLY KNOWN AS SMA.
AFTER IT IS DEFORMED, IT REGAINS ITS ORIGINAL GEOMETRY BY ITSELF DURING HEATING (ONE-WAY EFFECT) OR, AT HIGHER AMBIENT TEMPERATURES, SIMPLY DURING UNLOADING (PSEUDO-ELASTICITY).
RAPIDLY FINDING ITS PLACE IN MOST OF THE INDUSTRIES.
FURTHERANCE OF PHASE TRANSFORMATION KNOWLEDGE.

3. PHASES PH 1 : BRIEF ON SMA. PH 2 : THEORY BEHIND SMA.
PH 3 : SHAPE MEMORY EFFECT & PSEUDO- ELASTICITY.
PH 4 : APPLICATIONS OF SMA.
CONCLUSION.

4. BRIEF ON SMA METALS THAT REMEMBER ITS ORIGINAL SHAPE.
EXHIBIT TWO UNIQUE PROPERTIES :-
PSEUDO-ELASTICITY.
SHAPE MEMORY EFFECT.
ARNE OLANDER FIRST OBSERVED THESE UNUSUAL PROPERTIES IN 1938, BUT NOT UNTIL THE 1960'S WERE ANY SERIOUS RESEARCH ADVANCES MADE IN THE FIELD OF SHAPE MEMORY ALLOYS.

5. BRIEF ON SMA
DIVERSE APPLICATIONS MADE THEM INCREASINGLY IMP & VISIBLE TO THE WORLD.
NITINOL OR NICKEL-TITANIUM ALLOY MOST IMP.
NITINOL IS Ni-Ti NAVAL ORD LABARATORY.
SHAPE MEMORY PROPERTY OF NITINOL WAS DISCOVERED BY ACCIDENT.
AT A LABORATORY MANAGEMENT MEETING, A STRIP OF NITINOL WAS PRESENTED THAT WAS BENT OUT OF SHAPE MANY TIMES. ONE OF THE PEOPLE PRESENT, DR. DAVID S. MUZZEY, HEATED IT WITH HIS PIPE LIGHTER, AND SURPRISINGLY, THE STRIP STRETCHED BACK TO ITS ORIGINAL FORM.

6. THEORY BEHIND SMA
HOW DOES SMA “REMEMBERS” ITS SHAPE WAS THE QUESTION AFTER ITS DISCOVERY.
THIS OCCURS DUE TO SOLID STATE PHASE CHANGE.
TYPICALLY WHEN ONE THINKS OF A PHASE CHANGE A SOLID TO LIQUID OR LIQUID TO GAS CHANGE IS THE FIRST IDEA THAT COMES TO MIND. A SOLID STATE PHASE CHANGE IS SIMILAR IN THAT A MOLECULAR REARRANGEMENT IS OCCURRING, BUT THE MOLECULES REMAIN CLOSELY PACKED SO THAT THE SUBSTANCE REMAINS A SOLID.
PHASES INVOLVED ARE AUSTENITE AND MARTENSITE.

7. THEORY BEHIND SMA
INVOLVES THE REARRANGEMENT OF THE POSITION OF PARTICLES WITHIN THE CRYSTAL STRUCTURE OF THE SOLID.
TRANSITION TEMP OF THESE PHASES IS VERY LOW.
THE TRANSITION TEMPERATURE VARIES FOR DIFFERENT COMPOSITIONS FROM ABOUT -50 ° C TO 166 ° C.
BELOW TRANSITION TEMP IS MARTENSITE AND ABOVE IT IS AUSTENITE.
IN THE MARTENSITE PHASE, NITINOL CAN BE BENT INTO VARIOUS SHAPES.

8. THEORY BEHIND SMA
TO FIX THE "PARENT SHAPE" (AS IT IS CALLED), THE METAL MUST BE HELD IN POSITION AND HEATED TO ABOUT 500 ° C.
THE HIGH TEMPERATURE CAUSES THE ATOMS TO ARRANGE THEMSELVES INTO THE MOST COMPACT AND REGULAR PATTERN POSSIBLE RESULTING IN A RIGID CUBIC ARRANGEMENT KNOWN AS THE AUSTENITE PHASE.
ABOVE THE TRANSITION TEMPERATURE, NITINOL REVERTS FROM THE MARTENSITE TO THE AUSTENITE PHASE WHICH CHANGES IT BACK INTO ITS PARENT SHAPE. THIS CYCLE CAN BE REPEATED MILLIONS OF TIMES.

9. SHAPE MEMORY EFFECT
TRANSITION TEMP DEPENDS UPON THE COMPOSITION OF THE ALLOY.
THE TEMPERATURES AT WHICH EACH OF THESE PHASES BEGIN AND FINISH FORMING ARE REPRESENTED BY VARIABLES : MS, MF, AS, AF.
MS & MF ARE START & FINISH TEMP OF AUSTENITE TO MARTENSITE TRANSFORMATION.
AS, AF ARE START & FINISH TEMP OF MARTENSITE TO AUSTENITE TRANSFORMATION.
WHEN THE ALLOY IS COOLED BELOW THE TRANSITION TEMP IT TAKES THE TWINNED MARTENSITE STRUCTURE.

10. SHAPE MEMORY EFFECT
HAS SAME SHAPE AND SIZE AS AUSTENITE SO NO VISIBLE DIFFERENCE OBSERVED UNLESS ITS DEFORMED/LOADED
WHEN DEFORMED IT TAKES THE DESIRED SHAPE
IF ALLOY HEATED ABOVE TRANSITION TEMP; TAKES THE PREVIOUS SHAPE IN AUSTENITE STRUCTURE

11. SHAPE MEMORY EFFECT

12. SHAPE MEMORY EFFECT

13. SHAPE MEMORY EFFECT

14. PSEUDO-ELASTICITY
PSEUDO-ELASTICITY OCCURS IN SHAPE MEMORY ALLOYS WHEN THE ALLOY IS COMPLETELY COMPOSED OF AUSTENITE.
UNLIKE THE SHAPE MEMORY EFFECT, PSEUDO- ELASTICITY OCCURS WITHOUT A CHANGE IN TEMPERATURE.

15. PSEUDO-ELASTICITY
THE LOAD ON THE SHAPE MEMORY ALLOY IS INCREASED UNTIL THE AUSTENITE BECOMES TRANSFORMED INTO MARTENSITE SIMPLY DUE TO THE LOADING.
THE LOADING IS ABSORBED BY THE SOFTER MARTENSITE, BUT AS SOON AS THE LOADING IS DECREASED THE MARTENSITE BEGINS TO TRANSFORM BACK TO AUSTENITE SINCE THE TEMPERATURE OF THE WIRE IS STILL ABOVE AF, AND THE WIRE SPRINGS BACK TO ITS ORIGINAL SHAPE.

16. Load Diagram of the pseudo-elastic effect Occurring
PSEUDO-ELASTICITY
Load Diagram of the pseudo-elastic effect Occurring

17. PSEUDO-ELASTICITY

18. APPLICATIONS OF SMA AERONAUTICAL APPLICATIONS.
AIRCRAFT MANEUVERABILITY DEPENDS HEAVILY ON THE MOVEMENT OF FLAPS FOUND AT THE REAR OR TRAILING EDGE OF THE WINGS.
MOST AIRCRAFT IN THE AIR TODAY OPERATE THESE FLAPS USING EXTENSIVE HYDRAULIC SYSTEMS. THIS COMPLEX SYSTEM OF PUMPS AND LINES IS OFTEN RELATIVELY DIFFICULT AND COSTLY TO MAINTAIN.

19. APPLICATIONS OF SMA AERONAUTICAL APPLICATIONS.
THE SHAPE MEMORY WIRE IS USED TO MANIPULATE A FLEXIBLE WING SURFACE.
THE SHAPE MEMORY EFFECT IS INDUCED IN THE WIRES SIMPLY BY HEATING THEM WITH AN ELECTRIC CURRENT, WHICH IS EASILY SUPPLIED THROUGH ELECTRICAL WIRING, ELIMINATING THE NEED FOR LARGE HYDRAULIC LINES.

20. Hinge less shape memory alloy Flap
APPLICATIONS OF SMA
Typical Wing and Flap
Hinge less shape memory alloy Flap

21. APPLICATIONS OF SMA MEDICAL APPLICATIONS REPAIRING FRACTURES
ORTHODONTIC TREATMENTS
TWEEZERS
MUSCLE WIRES IN ROBOTICS INDUSTRY
FIRE SPRINKLERS
FUTURE APPLICATIONS
USE OF MECH ENERGY FROM SHAPE TRANSFORMATION IN CAR ENGINES
ENGINE COOLING
LUBRICATION CONTROL
CONTROL OF RADIATOR BLIND

22. APPLICATIONS OF SMA TYPICAL OSTEOSYNTHESIS TOOLS
CONVENTIONAL BONE PLATE USED TO REPAIR JAW FRACTURE
TYPICAL OSTEOSYNTHESIS TOOLS

23. EVEN A BADLY FRACTURED FACE CAN BE RECONSTRUCTED USING BONE PLATES
APPLICATIONS OF SMA
EVEN A BADLY FRACTURED FACE CAN BE RECONSTRUCTED USING BONE PLATES

24. USE OF SMA IN ROBOTICS INDUSTRY
APPLICATIONS OF SMA
USE OF SMA IN ROBOTICS INDUSTRY

25. APPLICATIONS OF SMA

26. CONCLUSION USES & APPLICATION ENSURE BRIGHT FUTURE OF THESE ALLOYS
RESEARCH AT ROBOTICS & MAT SC DEPARTMENTS ALL OVER THE WORLD
INNOVATIVE IDEAS FOR USING SMA
USE OF SMA IN VAST NO OF FIELDS ENSURES IT PROMISING FUTURE.

28. THANK YOU