C15.2 Useful alloys Flashcards
What are alloys?
Mixtures of metals
Why are alloys much harder than pure metals?
In the alloy - differently sized metal ions make it harder for the layers to slip - they are jammed in position
How is bronze made?
Mixing copper with tin
What are the uses of bronze?
Used to make ship’s propellers because of its toughness and resistance to corrosion
Also used to make statues and decorative items
How is brass made?
Making copper with zinc
What is the property for brass that makes it useful?
It can be hammered into sheets and pressed into intricate shapes
This property is used to make musical instruments such as trumpets
Why is aluminium alloys useful?
It has a low density for a metal
It is lightweight but strong
They are used to build aircraft or armour plating on tanks
How is jewellery usually made?
Mixing gold with copper
What is a carat?
The purity of gold
How can you calculate the % of gold in your jewellery?
Divide the carat number by 25
What is steel?
Alloys with iron with carbon/ other elements
By controlling the amounts of elements - the properties of steels can be changed for their different users
How are carbon steels made?
By removing most of the carbon from the iron obtained from a blast furnace
What are the uses of carbon steels?
To make bodies such as of : cars, machinery or ships
What are the advantages and disadvantages of High carbon steel?
Very strong - but brittle
What are the advantages and disadvantages of Low carbon steel?
Soft and easily shaped - but not as strong
But much less likely to shatter on impact with a hard object
