Uses of alloys
alloyAn alloy is a mixture of two or more elements, at least one of which is a metal. have different properties to the pure metal. For any particular use, an alloy is matched that has the most suitable range of properties.
Aluminium and copper are useful metalShiny element that is a good conductor of electricity and heat, and which forms basic oxides.. This table shows examples of common alloys that contain these metals:
Alloy | Composition | Uses |
Duralumin | Aluminium and copper | Aircraft parts |
Magnalium | Aluminium and magnesium | Aircraft parts |
Bronze | Copper and tin | Propellers for ships, bells |
Brass | Copper and zinc | Coins, musical instruments |
Jewellery gold | Gold and copper | Jewellery |
Solder | Tin and copper | Joining copper pipes and electrical components |
Alloy | Duralumin |
---|---|
Composition | Aluminium and copper |
Uses | Aircraft parts |
Alloy | Magnalium |
---|---|
Composition | Aluminium and magnesium |
Uses | Aircraft parts |
Alloy | Bronze |
---|---|
Composition | Copper and tin |
Uses | Propellers for ships, bells |
Alloy | Brass |
---|---|
Composition | Copper and zinc |
Uses | Coins, musical instruments |
Alloy | Jewellery gold |
---|---|
Composition | Gold and copper |
Uses | Jewellery |
Alloy | Solder |
---|---|
Composition | Tin and copper |
Uses | Joining copper pipes and electrical components |
The uses of metals are related to their propertiesThe characteristics of something. In chemistry, chemical properties include the reactions a substance can take part in. Physical properties include colour and boiling point..
Aluminium and its alloys
Aluminium does not react with water. Its surface is protected by a natural layer of aluminium oxide that allows the metal to resist corrosionThe destruction of a metal by oxidation or chemical action, eg rusting.. Aluminium foil is used for wrapping and storing food because it does not react to substances in food. It is malleableCapable of being hammered or pressed into a new shape without being likely to break or return to the original shape., so it is easily folded into shape around the food.
Aluminium has a low densityA measure of compactness and the ratio of mass to volume. It is usually measured in kilograms per metre cubed (kg/m3) or grams per centimetre cubed (g/cm3)., so pieces of aluminium are relatively lightweight.
The alloys duralumin and magnalium are stronger than aluminium alone but still have low densities. They are used to make aircraft parts.
Question
Suggest an explanation for why magnalium is used to make aircraft parts.
Magnalium alloy is stronger than aluminium but still has a low density. This makes it suitable for aircraft parts, which must be light and also strong.
Copper and brass
Copper and brass resist corrosion and are good electrical conductors. Copper is a better conductor than brass so it is used in electrical wiring. Brass is stronger than copper.
Question
Suggest why brass, not copper, is used for the pins on electrical plugs.
The pins on an electrical plug have to conduct electricity but they must also be strong and not break when the plug is used. Although copper is a better conductor, brass still does conduct electricity well. The strength of brass makes it a more suitable material to choose.
Gold
Gold is a very soft and malleable metal. It is also very unreactiveA substance is unreactive or inert if it does not easily take part in chemical reactions. so it resists corrosion and stays shiny. The visors on space helmets are coated with a layer of gold. This is thin enough for the astronaut to see through but thick enough to reflect sunlight. The gold used for jewellery is gold alloyed with other metals, often copper. This makes the jewellery much stronger while keeping its ability to stay shiny.