Technical%20Seminar%20Report%20On

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Technical Seminar Report On SHAPE MEMORY
ALLOYS under the guidance of Mr. VIVEK
SHARMA submitted by PRIYANKA MISHRA
EI200199120
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INTRODUCTION
SHAPE MEMORY ALLOYS

• Shape memory alloys are metals that remember
• their original shapes.
• Key characteristic - Martensitic phase
  transformation

• The two unique properties
• shape memory effect
• pseudo-elasticity

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Martensitic transformation

• Deformation of the crystal lattice
• Diffusion less Process

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Shape Memory Effect

• The transformation begins in the absence of
  stress,
• at a temperature M0s

• The transformation continues as the temperature
• is lowered until a temperature M0f

• The reverse transformation begins at the
  temperature A0s
• and at the temperature A0f the material is
  fully austenite

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Pseudo-elasticity

• pseudo-elasticity occurs without a change in
  temperature

• Transformation occurs upon loading and unloading

• Rubber like effect

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STRESS-TEMPERATURE RELATIONSHIP

• Stress plays an important role in the
  Transformation

• An applied stress increases the Transformation
  Temp

TRANSFORMATION TEMPERATURES

• The temperature at which the material transforms
  from
• Martensite to Austenite is controlled by alloy
  composition

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DEFORMATION OF MARTENSITE AND RECOVERY TO
AUSTENITE
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TRAINING OF SMA

• The wire is hot/cold worked when it is in the
  Martensite
• phase

• The wire is then heated to Af to recover its
  shape.

• The wire is then cooled to martensite.

• Effect-The solid exhibits two stable shapes

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APPLICATIONS

• BONE PLATES

• DENTAL AND ORTHODONTIC APPLICATIONS

• STENT

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ADVANTAGES AND DISADVANTAGES OF SHAPE MEMORY
ALLOYS

• ADVANTAGES

• Bio-compatibility

• Diverse field of application

• Good mechanical properties

• DISADVANTAGES

• Expensive

• Poor fatigue properties

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CONCLUSION

• A shape memory effect can undergo plastic
  deformation,
• and then be triggered into returning to its
  original shape

• Led to a proliferation of diverse application

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THANK YOU !!!