Alloys
Some
Most
All
• Can you suggest why iron, copper,
gold and aluminium are usually made
into alloys?
• Can you define the term ‘alloy’?
• Can you name some examples of common alloys?
STARTER QUESTIONS - Full sentences
Which 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 Learning
The sentences below are statements about the effect of recycling metals.
Use words from the box to complete the sentences.
age
damages
energy
recycled
local
reduces
money
ores
waste
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.
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.
Hi guys, I’m Kenny.
I need some of your expert help!
I’m setting up a new company.
We’re going to hand-build high
performance sports cars.
Our first model will be the
KenSpeed P1.
ENGAGE
© 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
© Association for Science Education and Centre for Science Education 2010
12
Here’s an outline of my
KenSpeed P1.
Choose the
best alloys
to make
it from.
Give reasons for each choice.
Make them persuasive!
ELABORATE
© Association for Science Education and Centre for Science Education 2010
13
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
ELABORATE
© Association for Science Education and Centre for Science Education 2010
14
SS1
The KenSpeed P1 design sheet
Artist’s impression
Suspension
Roll cage
Material: ___________
Reason:
_____________________
_________________
Material:
____________________
Reason:
_______________________
_________________
Side
Body panels
Material:
________________
Reason:_________________
_______________________
_______________________
________
Spoiler (Wing)
Material:
___________________
Reason:________________
______________________
______________________
________
Wheels
Material:
____________________
Reason:_________________
_________________
Brake discs
Material:
____________________
Reason:________________
________________
Engine
Material:
___________________
Reason:________________
______________________
______________________
_________
Exhaust
Material:
____________________
Reason:_________________
_______________________
_______________________
_____
Internal
Top
Chassis
Material: ___________________________________
Reason:__________________________________________
____________________________________
© Association for Science Education and Centre for Science Education 2010
Wiring
Material:____________
____
Reason:_____________
______________
Wiring connections
Material: _______________
Reason:____________________
____________________
SS2
Metals and alloys data sheet
Name of
material
Main metal(s)
Other alloying
elements, if any
Common 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, Ag
copper, 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
© Association for Science Education and Centre for Science Education 2010
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.