Alloys

All

Most

Some

• Can you name some examples of common alloys?

• Can you define the term ‘alloy’?

• Can you suggest why iron, copper, gold and aluminium are usually made into alloys?

STARTER QUESTIONS - Full sentencesWhich other element is mixed with iron to make steel?Why do they mix this element with iron to make steel?

Starter Questions

1. Which other element is mixed with iron to make steel?

Carbon is mixed with iron to make steel.2. Why do they mix this element

with iron to make steel?They mix carbon with iron to made it stronger. This happens because the particles cannot move over one another as easily.

Home LearningThe sentences below are statements about the effect of recycling metals.Use words from the box to complete the sentences.    

Recycling ____________ the amount of energy needed.

Recycling means less mining that _______________ the environment.

Recycling metals uses less energy than extracting them from _________ .

Recycling of aluminium cans eliminates ____________, saves ___________,

conserves natural resources, reduces the use of landfill sites and provides

_____________ for charities and _____________ government.

A number of factors affect the amount of waste that is _____________ .

Household size and the average _________ of residents have significant effects on

recycling.

age damages energy local money

ores

recycled reduces waste

Alloys of Gold

• Pure gold is too soft and too expensive for most people.

• This is why most gold is bought as an alloy.

Alloys of Gold

• Gold alloys are a mixture of gold particles and other metals, such as copper.

• The purity (how many gold atoms is in the alloy) is measured in carats.

• The higher the carat, the higher the purity.

Match the gold carats to the property of the gold

Coins

• Copper is too soft to use as a pure metal so it is alloyed with other elements to make it stronger.

• Most British coins are made from copper that has been alloyed with other metals.

Coins

• Copper coins are actually an alloy of three metals. 97% copper, 2.5% zinc and 0.5% tin; therefore copper coins should really be called bronze!

Coins

• Silver coins are not made from the element silver. They are an alloy of copper (75%) and nickel (25%)

Coins

• The one pound coin is composed of 70% copper, 5.5% nickel and 24.5% zinc, making this a bronze coin.

I’m setting up a new company. We’re going to hand-build high performance sports cars.

Hi guys, I’m Kenny.

I need some of your expert help!

Our first model will be the KenSpeed P1.

ENGAGE© Association for Science Education and Centre for Science Education 2010

ELABORATE 12© Association for Science Education and Centre for Science Education 2010

So what shall I build my cars from? They must be fast, strong and lightweight.

ELABORATE 13© Association for Science Education and Centre for Science Education 2010

Choose the best alloys to make it from.

Here’s an outline of myKenSpeed P1.

Give reasons for each choice. Make them persuasive!

ELABORATE 14© Association for Science Education and Centre for Science Education 2010

Properties needed by components of the KenSpeed P1

Body panels... Malleable and tough

Engine... Lightweight but not too expensive

Roll cage... Strong

Exhaust... Rust-proof

Wiring... Good electrical conductivity

Material to join wires...

Low melting point

Suspension springs... Flexible

Brake discs... Strong, high melting point

Chassis... Strong, lightweight, not too expensive

Wheels... Lightweight and strong, must look good

Spoiler... Strong and stiff

© Association for Science Education and Centre for Science Education 2010

The KenSpeed P1 design sheetSS1

Artist’s impression

Side

Top Internal

Body panelsMaterial: ________________Reason:_______________________________________________________________________

Spoiler (Wing)Material: ___________________Reason:____________________________________________________________________

ChassisMaterial: ___________________________________Reason:______________________________________________________________________________

ExhaustMaterial: ____________________Reason:____________________________________________________________________

EngineMaterial: ___________________Reason:_____________________________________________________________________

WiringMaterial:________________Reason:___________________________

Wiring connections

Material: _______________Reason:________________________________________

Roll cageMaterial: ___________Reason: ______________________________________

SuspensionMaterial: ____________________Reason: ________________________________________

WheelsMaterial: ____________________Reason:__________________________________

Brake discsMaterial: ____________________Reason:________________________________

© Association for Science Education and Centre for Science Education 2010

Name of material

Main metal(s)Other alloying

elements, if anyCommon uses Properties Drawbacks

Copper copper, Cu None Water pipes, electrical cables

Good electrical conductivity, low reactivity

High demand has led to high cost

Lead lead, Pb None Flashing (to make roofs waterproof)

Very soft and malleable, low reactivity

Poisonous

Titanium titanium, Ti aluminium, Al vanadium, V

Racing cars, bicycles, aircraft

Extremely strong for its weight. Tensile strength is about 230 MPa.

Very expensive and difficult to work with

Gold gold, Au nickel, Ni copper, Cu

Jewellery, electrical contacts

Very unreactive, shiny, good electrical conductivity

Extremely expensive, very soft in pure form

Brass copper, Cu zinc, Zn

None Musical instruments, door handles, coins

Malleable, good acoustic properties, low reactivity

High cost

Bronze copper, Cu tin, Sn

None Bells and cymbals, sculptures, ship components

Does not corrode in salty water, good acoustic properties

High cost

Solder tin, Sn silver, Agcopper, Cu or other metals (lead is no longer used in solder in the EU)

Joining electrical wires, plumbing connections

Low melting point Low melting point limits uses

Amalgam mercury, Hg silver, Ag tin, Sn copper, Cu zinc, Zn

Dentistry – fillings Easy to work with, resists bacteria

Concerns about health risks from mercury

Nitinol titanium, Ti nickel, Ni

None Spectacle frames, dental braces

When bent, returns to its original shape on gentle heating (shape memory alloy)

High cost

Metals and alloys data sheetSS2

Which metal is being described?Iron, Copper or Gold?

This metal is too soft and expensive so it

is alloyed with copper.

Which metal is being described?Iron, Copper or Gold?

This metal is too soft and expensive so it

is alloyed with copper.

Which metal is being described?Iron, Copper or Gold?

This metal is alloyed with carbon to make it hard, strong and

resistant to corrosion.

Which metal is being described?Iron, Copper or Gold?

This metal is alloyed with carbon to make it hard, strong and

resistant to corrosion.

Which metal is being described?Iron, Copper or Gold?

Coins are made from an alloy of this

metal.

Which metal is being described?Iron, Copper or Gold?

Coins are made from an alloy of this

metal.

Which metal is being described?Iron, Copper or Gold?

‘Carat’ is used to describe the purity

of this metal.

Which metal is being described?Iron, Copper or Gold?

‘Carat’ is used to describe the purity

of this metal.

Which metal is being described?Iron, Copper or Gold?

This is a pure metal that reacts with

oxygen and rusts.

Which metal is being described?Iron, Copper or Gold?

This is a pure metal that reacts with

oxygen and rusts.