1. SHAPE MEMORY ALLOYS Presented by
Pradeep kumar Jaiswal Mechanical Engineering
NIT KURUKSHETRA

2. Shape memory alloys (SMA's) are metals, which exhibit two very unique properties, pseudo-elasticity, and the shape memory effect. Discovered by Arne Olander in the year The most effective and widely used alloys include Ni Ti (Nickel Titanium), Cu Zn Al and Cu Al Ni The two unique properties described above are made possible through a solid state phase change, that is a molecular rearrangement, which occurs in the shape memory alloy solid state phase change is similar to a molecular rearrangement is occurring, but the molecules remain closely packed so that the substance remain solid
Introduction

3. General principles
Shape memory metal alloy can exist in two different temperature dependent crystal structures (phases) called martensite (lower temperature ) and austenite ( higher temperature or parent phase ).

5. Shape Memory Effect

6. The Shape memory effect is currently being implemented in:
Coffepots
The space shuttle
Thermostats
Vascular Stents
Hydraulic Fittings (for Airplanes)

7. Pseudo-Elasticity
Figure shows the process of pseudo elasticity

8. Examples of applications in which pseudo-elasticity is used are:
Eyeglass Frames
Medical Tools
Cellular Phone Antennae

9. Applications Aircraft Maneuverability
The wire on the bottom of the wing is shortened through the shape memory effect, while the top wire is stretched bending the edge downwards, the opposite occurs when the wing must be bent upwards. The shape memory effect is induced in the wires simply by heating them with an electric current

10. Hinge less shape memory alloy Flap

11. Medical Applications Stents Vena-cava Filters
Dental and Orthodontic Applications

12. Bone Plates
Bone plates are surgical tools, which are used to assist in the healing of broken and fractured bones.
The breaks are first set and then held in place using bone plates in situations where casts cannot be applied to the injured area.
Bone plates are often applied to fractures occurring to facial areas such the nose, jaw or eye sockets.
Repairs like this fall into an area of medicine known as osteosynthesis.

13. Fracture repair

14. Plate and screw

15. Reconstruction of fractured face using bone plates

16. Robotic muscle
Shape memory alloys mimic human muscles and tendons very well. SMA's are strong and compact so that large groups of them can be used for robotic applications,

17. Working of SMA in a Robotic muscle

18. Advantages Disadvantages Bio-compatibility
Diverse Fields of Application
Good Mechanical Properties (strong, corrosion resistant)
Disadvantages
These alloys are still relatively expensive to manufacture and machine compared to other materials such as steel and aluminum.
Most SMA's have poor fatigue properties

19. Future Application
Future applications include engines in cars and airplanes and electrical generators utilizing the mechanical energy resulting from the shape transformations.
Nitinol with its shape memory property is also envisioned for
use as car frames.
possible automotive applications using SMA springs include
engine cooling, carburetor and engine lubrication controls.

20. THANK YOU

21. Q ?