Lecture 2 - Classification of Materials (2).pdf

Material Science and Metallurgy
Module 1
1.1 Classification of Materials
By
Prof. A.V.Phanse

Basically Engineering Materials can be classified into two categories-
1. Metals
2. Non-Metals
Metals
➢ Metals are polycrystalline bodies which are having number of
differentially oriented fine crystals.
➢ Normally major metals are in solid states at normal temperature.
➢ However, some metals such as mercury are also in liquid state at
normal temperature.
➢ Metals are having high thermal and electrical conductivity.
➢ All metals are having positive temperature coefficient of resistance
means resistance of metals increases with increase in temperature.
➢ Examples of metals – Silver, Copper, Gold, Aluminum, Iron, Zinc, Lead,
Tin etc.

Non-Metals
➢ Non-Metal materials are non-crystalline in nature.
➢ These exists in amorphic or mesomorphic forms.
➢ These are available in both solid and gaseous forms at normal
temperature.
➢ Normally all non-metals are bad conductor of heat and electricity.
➢ Examples: Plastics, Rubber, Leathers, Asbestos etc.
➢ As these non-metals are having very high resistivity which makes them
suitable for insulation purpose in electrical machines.
Metals can be further divided into two groups-
1. Ferrous Metals –
➢ All ferrous metals are having iron as common element.
➢ All ferrous materials are having very high permeability which makes
these materials suitable for construction of core of electrical machines.
➢ Examples: Cast Iron, Wrought Iron, Steel, Silicon Steel, High Speed
Steel, Spring Steel etc.
2. Non-Ferrous Metals -
➢ All non-ferrous metals are having very low permeability.
➢ Example: Silver, Copper, Gold, Aluminum etc.

Classification of Materials (Metals)
Metals can be further classified as Ferrous & Non-
Ferrous, some examples include;
Ferrous Non-Ferrous
Steels Aluminium
Stainless Steels Copper
High Speed Steels Brass
Cast Irons Titanium
Aluminium
Copper
Brass
Stainless Steel
High Speed steel

Classification of Materials
 Materials used in the design and manufacture of
products
• Plastics
• Wood
• Composites
• Ceramics
• Fabrics
Acrylic lens
Balsa wood model
Layers of polycarbonate,
aluminium & acrylic
Tungsten carbide tool bit
Steel, aluminium
Linen, cotton, nylon, Kevlar

Classification of Materials (Plastics)
Plastics can be further classified as;
•Thermoplastic
•Thermoset
•Elastomers
Thermoplastics Thermosets Elastomers
Acrylics Epoxy resins Rubbers
Nylons Phenolic Silicones
PVC Polyesters Polyurethanes
Polyethylene
Polyethylene
PVC gutters
Phenol formaldehyde
Urea formaldehyde
Rubber
Rubber

Classification of Materials (Wood)
 Wood can be further categorised as;
• Hardwood
• Softwood
• Manufactured board
Hardwood Softwood Manufactured
Board
Oak Pine Plywood
Ash Cedar Blockboard
Beech Fir MDF
Sycamore Spruce Melamine
board
Mahogany
Oak
Ash
Beech
Cedar
Chipboard with Veneer
Plywood

Classification of Materials (Composites)
 A composite is a combination of two or more chemically
distinct materials whose physical characteristics are
superior to its constituents acting independently.
 Because of their high strength/stiffness to weight ratio
they are widely used in the;
• Aerospace industry
• Offshore structures
• Boats
• Sporting goods

Classification of Materials (Composites)
 Examples of composites include;
• Reinforced Plastics
• Ceramic-matrix
• Metal-Matrix
• Laminates
Kevlar, taffeta polyester sails
Glass reinforced plastic hull
Carbon reinforced plastic
Thrust chamber for rocket
Combustion chamber of jet engine
Cylinder linings
Cylinder linings
Outer skin panels & fuselage A380

Classification of Materials (Ceramics)

 Ceramics are compounds of metallic and non-metallic
elements, examples include;
• Oxides (alumina – insulation and abrasives, zirconia – dies
for metal extrusion and abrasives)
• Carbides (tungsten-carbide tools)
• Nitrides (cubic boron nitride, 2nd in hardness to diamond)

Classification of Materials (Fabrics)
Fabrics can be further classified as natural and
synthetic
Natural Synthetic
Cotton Nylon
Canvas Polyester
Colourful nylon spinnaker
Canvas deck chair
Polyester marine rope- less
stretch than nylon- resists UV light
Polyester kite
Cotton T-shirt (design & print projects)
Materials used in space suits include aluminized Mylar, neoprene
coated nylon, dacron, urethane coated nylon, tricot and spandex.
The outer layer is a blend of Gortex, Kevlar and Nomex

Classification of Materials (Smart
Materials)
A smart material can be described as a material that
has a useful response to external influences or stimuli.
There are many examples of smart materials in everyday
use that are not modern developments they include;
•Metal springs
•Light bulbs self regulate because as
The filament temperature increases
their resistance rises
•Ancient civilisations have long used
porous ceramics for self regulating cooling Wine Cooler

Materials)
Other more modern examples of smart materials
include;
•Shape memory polymers and alloys
Heat shrink tubing and packaging
Automatic actuators – open/close greenhouse windows
Thermostats for heating control
•Smart Wire
Actuators, linear, angular and rotary
Anthromorphic actuation – human like robotic motion
•Smart Link Silicone
Allows rotary motion between shafts up to 3600
•Smart Fluids
Motion control gel – CD tray opening/closing, camera lenses
Ferro fluids – earthquake dampers in buildings, hard disks
•Piezoelectric Materials
Sensors, musical cards, motors, actuators, clocks
•Chameleon Colours
Car paints, printing inks, packaging

Materials)
include;
•Polymorph
This is a unique polymer that
fuses in hot water and can then
be moulded to any form. When
solid it has similar properties to
nylon
Used to make the
moulds for the
vacuum formed seat
and fuel tank of this
motorcycle project

Materials)
include;
•Thermocolour Sheet
This is a self adhesive
sheet whose colour
changes according to the
temperature. Used for
thermometers, heat warning
patches and novelty
advertising of products Inactivated Sheet
Finger placed on sheet
Sheet changes colour according to temp

Materials)
include;
•Phosphorescent Sheet
This is a sheet that absorbs
light energy and re-emits it
as white light for up to eight
hours. Used extensively for
emergency lighting in the
event of a power cut

Materials)
include;
•Magnetic Sheet
This is a flat polymer
magnetic sheet as used in
fridge magnets. Also
available in thin A4 sheets
that can be printed on

Materials)
include;
•Rigid PVC Foam Plastic
This is a new generation of
sheet material used widely
for signs and exhibitions.
Thermoforms very well. It
is widely used for ‘plug and
yoke’ mouldings

Materials)
include;
•Lenticular Sheet
This sheet is about 1mm
thick but gives the illusion
that it is nearer to 6mm
thick. An object placed on
the sheet appears to sink
below the surface
The camera lens does not capture the effect

Materials)
include;
•Anodised Effect Card
This is almost impossible to
tell from the real thing.
Ideal for project mock-ups.
It is relatively cheap and
cuts easily with a scissors
or craft knife

Materials)
include;
•Galvanised Effect Card
This is almost identical to
the real thing. Ideal for
project mock-ups. It is
relatively cheap and cuts
easily with a scissors or
craft knife. Used for
packaging of top branded
goods

Materials)
include;
•Quantum Tunnelling Composite (QTC)
•A QTC in its normal state is a perfect insulator
•When compressed it becomes a perfect conductor
•If only lightly compressed its conductivity is proportional to the
pressure applied
How does it work?
In normal physics an electron cannot pass through an insulation
barrier.
In Quantum physics theory a wave of electrons can pass through an
insulator – this is what is happening!

Materials)
include;
•Quantum Tunnelling Composite (QTC)
Battery
LED
QTC Pill

Materials)
include;
Quantum Tunnelling Composite (QTC)
Before pressure is applied
Light Pressure being applied
Firm pressure being applied

Assignment No. 1
1. Select a product from your day to day life. Search the advancements in
the design or material of that product. Write about it in 10 lines or in
pictorial form
2. Find out the reasons behind change of material for a particular product.

Lecture 2 - Classification of Materials (2).pdf

Recommended

Recommended

More Related Content

Similar to Lecture 2 - Classification of Materials (2).pdf

Similar to Lecture 2 - Classification of Materials (2).pdf (20)

Recently uploaded

Recently uploaded (20)

Lecture 2 - Classification of Materials (2).pdf