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Materials, their Properties & Uses

Introduction to Materials

Properties of Materials

Metals Plastics

Woods

Composites

Heat Treatment

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Introduction to Materials

Materials are used to make or build objects.

During the past 200 years there has been an

enormous increase in the range of materials

available to us. It is therefore important that thecorrect materials be used for a particular use.

In Selecting the best material you need to look

at 4 things: Physical properties, Cost and Time,Shaping and Forming and Availability.

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Selecting the best materialA checklist

2 WHAT COST?

The materials

The extras (fittings etc)

3 SHAPING & FORMING

Cutting out

Moulding

Casting

Joining

4 AVAILABILITY

Are they easy to obtain

including fittings.

1 PHYSICAL PROPERTIES

Hardness

Tensile Strength

Compressive Strength

Shear StrengthStiffness

Toughness

Malleable

Corrosive

Appearance

Weight

Conductivity

S

E

L

EC

T

IO

N

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Properties of Materials

Each material has many properties. It is

incorrect, for example to describe a material

as just strong or weak as for example

concrete is strong in compression but weak

in tension.

Hardness Toughness Strength

Brittleness Malleability DuctilityElasticity Plasticity Conductivity

Density Fatigue Stiffness

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Hardness

The ability of a material to resist wear

indentation and scratching.

An example of a

hardness test that

can be carriedout in the lab.

Different materials

are used and the

depth of indentationmeasured

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Toughness

The ability of a material to withstand

blows or sudden impact.

Different materials are

used, the hammer is

swung from the same

height each time about

a fixed fulcrum. The

distance travelled

after impact or

fracture is used to find

toughness

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Strength

The ability of a material to withstand

forces of tension, compression and torsion

Tensile Strengththe ability to withstand

pulling forces or Tension forces

Compressive Strengththe ability to withstand

squeezing forces orCompression forces

Torsional Strengththe ability to withstandtwisting forces orTorsion forces

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Brittleness

The same as the

toughness test

however thosematerials that

fracture easily

are said to be

brittle.

A material that is easily fractured by

impact is said to be brittle e.g. Glass

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Malleability

A material that can be rolled or hammered

into shape without rupture.

As ring risesthe side of

Coke can is

thinned out

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Ductility

A material that can be pulled or stretched

into a thin wire or thread.

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Elasticity

The ability of a material to return to its

original shape after deformation.

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Plasticity

The ability of a material to be permanently

deformed without fracture..

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Conductivity

The ability of a material to allow Heat or

electricity to flow through it.

Ball Bearingdrops from most

conductive 1st.

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Density

Is the mass of 1 cubic centimetre (cm3) of a

substance. (Mass per unit Volume)

Q. Which is heavier a tonne of feathers or

a tonne of lead?

Q. Which has the greatest density?

Density =Mass

Volume

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Fatigue

Occurs when materials have become

overworked and fracture or fail.

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Stiffness

The ability of a material to resist bending

deformation.