2. INTRODUCTION
Metal can be classified as alloys, ceramics, glasses, composites, semiconductor etc.
The dream of an engineer to have materials with high strength, good magnetic
properties, better corrosion resistance, ease of fabrication can be achieved through
metallic glasses.
Which is the newly developed engineering materials.
Metallic glasses are materials which have the properties of both metals and
glasses.
Amorphous metals:- Disordered atomic scale structure.
metallic glasses are strong, ductile, malleable, opaque and brittle. They also have
good magnetic properties and high corrosion resistance.
METALLIC AMORPHOUS
GLASSES METALS
3. Conventional solidification
METHODS OF PREPARATION AND
PRINCIPLE
PRINCIPLE :
The principle used in making metallic glasses is extreme rapid cooling of the molten alloy. The
technique is called as RAPID QUENCHING.
To avoid
crystallization
RAPID COOLING
Production of a Metallic Glass
4. METHOD OF PREPARATION
Various rapid cooling technique such as spraying, spinning and deposition are used for the
production of metallic glasses.
Here we will see the spinning technique.
A melt spinner consists of a copper roller over which a
refractory tube with fine nozzle is placed.
The mixture of alloy has taken in refractory tube and is
provided with induction heater . The metal alloy is
melted by induction heating under inert gas atmosphere
(helium or argon).
The properly superheated molten alloy is ejected
through the fine nozzle at the bottom of the refractory
tube.
The molten alloy falls on the copper roller which is
rotated at high speed. Thus, the alloy is suddenly cooled
to form metallic glass.
In this method a continuous ribbon of metallic glass can
be obtained.
5. PROPERIES
OF MATELLIC
GLASSES
Mechanical Properties
Extremely High Strength.
High Elasticity
High ductile.
They are not work-harden
they are work soften.
Electrical properties
High electrical resistivity
Does not vary much with
temperature.
Eddy current loss is very
small.
Temperature coefficient is 0
or –ve.
Magnetic properties
Both soft and hard
magnetic properties.
High saturation
magnetization.
Less core losses.
Chemical properties
Highly resistance to
corrosion.
Highly reactive and
stable.
Acts as catalyst.
Structural Properties
Do not have any
crystal defect.
They have Tetrahedral
close packing
structure.
6. APPLICATION OF MATELLIC
GLASSES
STRUCTURAL APPLICATION
They are very useful as reinforcing elements
in concrete, plastic and rubber(Due to
high tensile strength).
They are also used as razor blades and different
kind of spring(Due to good strength, high
ductility, rollability and good
corrosion resistance).
TRANSFORMER CORE
MATERIAL
Excellent magnetic properties Due to this
gives maximum magnetic flux b/w primary
and sec. Coils hence reduce flux leakage
losses.
7. USE IN ELECTRICAL AND ELECTRONICS
Since they have soft magnetic properties, they
are used as tape recorder heads, core of high
power transformer and magnetic shield .
Since they have high electrical resistance, they
are used to make accurate standard resistance,
computer memories and magneto resistance
sensor.
NEUCLEAR REACTOR
ENGINEERING
Its magnetic properties do not effect by
irradiation and so they are used in
prepairing containers for nuclear waste
and disposal and magnets for fusion
reactor.
They are also usedin iner surface of
reactor vessels
8. BIO MEDICAL INDUSTRIES
Due to their high resistance
to corrosion, metallic glasses are
used for making surgical instrument.
They are used as prosthetic
materials for implantation in human
body.
