Smart Metals

A smart metal, or memory shape alloy, is an alloy that returns to its cold forged shape after the application of high heat. They have a range of uses in aerospace, surgery, dentistry, piping, robotics and medicine.

-Slides by Melwin Dmello (ph: 9482482055)

1. SMART METALS
BY,
MELWIN D’MELLO
MECHANICAL ENGINEERING
ALVA’S INSTITUTE OF ENGINEERING
AND TECHNOLOGY
, MANGALORE

GUIDED BY,
ASST. PROF. JAYA NAIK J
MECHANICAL ENGINEERING
ALVA’S INSTITUTE OF ENGINEERING
AND TECHNOLOGY
, MANGALORE

2. 1. Introduction
2. History
3. Manufacturing Process
4. Types
5. Applications
6. Practical Limitations
7. Conclusion

3. A Metal :
• A metal is an element , compound ,
or alloy that is a good conductor of
both electricity and heat.


• Metals are usually malleable, ductile and
shiny, that is they reflect most of incident
light.

4. An Alloy:

• An alloy is a mixture or metallic Solid
solution composed of 2 or more elements
or metals .


• Alloy is made to obtain different
properties of metals as required by man.

5. SMART
metals
• A smart metal (shape-memory alloy) is an alloy that "remembers" its
original, cold-forged shape: returning the pre-deformed shape by heating.

• The application of thermal energy returns them to the shape it
was in before cooling.

6. •The first reported steps towards the discovery of the shape-memory
effect were taken in the 1930s.According to Otsuka and Wayman,
A. Ölander discovered the pseudoelastic behavior of the Au-Cd
alloy in 1932.

•The nickel-titanium alloys were first developed in 1962–1963 by
the United States Naval Ordnance Laboratory and commercialized
under the trade name Nitinol (an acronym for Nickel Titanium
Naval Ordnance Laboratories).

7. •Shape-memory alloys are typically made by casting, using vacuum arc
melting or induction melting. The ingot is then hot rolled into longer sections and
then drawn to turn it into wire.

•The way in which the alloys are "trained" depends on the properties wanted.
The "training" dictates the shape that the alloy will remember when it is heated.

•This occurs by heating the alloy so that the dislocations re-order into stable
positions. They are heated to between 400 °C and 500 °C for 30 minutes for
more than 5 minutes.

•They are then shaped while hot and are cooled rapidly by quenching in
water or by cooling with air.

8. • Alloys of metals having the memory effect at different temperatures and at
different percentages of its solid solution contents.
Au-Cd 46.5/50 at.% Cd
Cu-Al-Ni 14/14.5 wt.% Al and 3/4.5 wt.% Ni
Ag-Cd 44/49 at.% Cd
Cu-Sn approx. 15 at.% Sn
Cu-Zn 38.5/41.5 wt.% Zn
Cu-Zn-X (X = Si, Al, Sn)
Fe-Pt approx. 25 at.% Pt
Mn-Cu 5/35 at.% Cu
Fe-Mn-Si
Pt alloys
Co-Ni-Al
Co-Ni-Ga
Ni-Fe-Ga
Ti-Pd in various concentrations
Ni-Ti (~55% Ni)
Ni-Ti-Nb
Ni-Mn-Ga

9. • Industrial

• Aircraft

• Automotive


• Telecommunication

• Robotics

• Medicine

10. • Response time and response symmetry

• Fatigue and functional fatigue

• Unintended actuation




• SMA actuation is typically asymmetric, with a
relatively fast actuation time and a slow deactuation time. A
number of methods have been proposed to reduce SMA
deactivation time, including forced convection, and lagging
the SMA with a conductive material in order to manipulate
the heat transfer rate.

11.  The many uses and applications of shape memory
alloys ensure a bright future for these metals. Research is
currently carried out at many robotics departments and
materials science departments. With the innovative ideas
for applications of SMAs and the number of products on
the market using SMAs continually growing, advances in
the field of shape memory alloys for use in many
different fields of study seem very promising.

12. L. Case, Z. Kreiner, J.Redmond, B. Trease : Shape Memory Alloy
Shape Training Tutorial [ME559 – Smart Materials and Structures
Fall 2004 ]

Catherine Jordan: Nitinol: Memory Metal Explore the properties of
this very smart material. Department of Education Cornell
University.