ABSTRACT

In the field of massive and complex manufacturing we are now in need of materials whose properties can be manipulated according to our need. Smart materials are one among those materials. This can change its shape or size by adding little bit of heat. This presentation focuses on smart material such has shape memory alloy and application.

INTRODUCTION

Nature is full of magic materials which are to be discovered in forms suitable to our needs such magical materials also know as intelligent or smart materials can sense, process, stimulate and actuate response. Smart materials have one or more properties that can be dramatically altered. For example: if oil is heated it will become thinner, where as SM with variable viscosity and the fluid which flows easily to solid.

SMART MATERIAL AND THEIR CATEGORIZATION Smart materials Materials that respond with significant

change in a properties upon application of external driving forces-stimuli

“Smart Machines” and “Smart Structures” are composed of smart materials.

Ex of SM: pizoelectric materials, shape memory alloys, Magnetic shape memory, pH- sensitive polymers, photomechanical materials etc.

CATEGORIZATION OF SMART MATERIAL

Based on input and output Based on action/function Based on activation Thermal fields Magnetic fields Electric fields Mechanical fields

SHAPE MEMORY ALLOY’S(SMA) Shape memory can “remember” their shape

when heated above certain transition temperature

Ex: Nitinol & copper- aluminum-nickel.

Shape-memory alloys have different shape-memory effects. Two common effects are one-way and two-way shape memory

Working:

SMA change shape based on a solid state phase transformation and there is change in re arrangement of atoms.

LINEAR MOTION FROM SMA

L1

L1

L2

•SMA at Low temperature

•Stretch the wire a low temperature

•Remove force, new length

•Apply heat, regain original length

cool

hot

Rotational motion is also possible

SHAPE MEMORY EFFECT (2-WAY EFFECT)

Heating Cooling

W

W

W

W

W

W

WORKING OF SMA

TRANSFORMATION OF SMA

heatingcooling

High TemperatureCubic Structure

deformation

Low temperatureDeformed

Low temperatureTwinned monoclinic Structure

AppliedForce

Force removed

Hig

h te

mpe

ratu

reL

ow te

mpe

ratu

re

AsMf

Austenite

Martensite

SHAPE MEMORY ALLOYMEDICAL APPLICATIONS

Orthodontic wire applications

SHAPE MEMORY ALLOY INDUSTRIAL APPLICATION

Greenhouse window systems which close/opendepending on the room temperature

NICKEL-TITANIUM SHAPE MEMORY ALLOYINDUSTRIAL APPLICATION

NiTi eyeglasses frame

NICKEL-TITANIUM SHAPE MEMORY ALLOYINDUSTRIAL APPLICATION

Application of SMAs to an automatic oil-level-adjustment devicein high speed train

APPLICATION IN AIRCRAFT

Location of smart material device used in aircrafts.

1) Propeller

2) Engine monitoring

3) Flutter suppression and Flaps positioning

4) Cabin noise reduction

5) Central control unit

OTHER APPLICATION

Cell phone antenna Eyeglasses Coffee pots Space shuttle

PROBLEMS WITH SMAS Fatigue from cycling

Causes deformations and grain boundariesBegin to slip along planes/boundaries

OverstressA load above 8% strain could cause the SMA to

completely lose its original austenite shape More expensive to manufacture than steel and

aluminum Relatively new

CONCLUSIONS

Smart materials like piezoelectric materials, shape memory alloys, magnetic shape alloy, PH-sensitive polymer, photo mechanical material can be used as actuators for many operation like in aircraft industries, medical industries etc. There fore deeper in site studies can result in better design and development of product

“ smart material can develop smart product”

REFERENCES

Wikipedia.org. Shape Memory Alloys by Marek Novotny. General Applications of Shape Memory Alloys by Dr.Savas

Dlbal. Shape Memory Alloy Research Team Dimitris C.Lagoudas.