Metals Imagine world without METALS. There would be no cars or aeroplanes, and skyscrapers would fall down without the metal frames that support them. Metals have countless uses because the poses a unique combination of qualities. They are very strong and easy to shape, so they can be used to make all kinds of objects from ships to bottle tops. All metals conduct electricity. Some are ideal for wires and electrical equipment. Metals also carry heat, so they make good cooking pots
Metals continue These qualities can be improved by mixing two or more metals to make alloys. Most metallic objects are made of alloys rather than pure metals. There are more than 80 kinds of pure metals, though some are very rare. Aluminium and iron are the most common metals. A few metals, such as gold, occur in the ground as pure metals; the rest are found as ores in rock. Metal can also be obtained by recycling old cars and tins. This reduces waste and costs less than processing metal ores. http://www.bbc.co.uk/dna/h2g2/A3935955 http://www.bbc.co.uk/schools/ks2bitesize/science/materials/characteristic_materials/read3.shtml
Aluminium The most common metal in the Earth’s crust is aluminium. The metal comes from an ore called bauxite, which contains alumina, a compound of aluminium and oxygen. Aluminium is light, conducts electricity and heat, and resists corrosion. These qualities mean the metal and its alloys can be used in many things, including:
aircraft and bicycles,
and electricity supply cables.
Alloys Most metal objects are made of steel or other alloys. This is because alloys are often stronger or easier to process than pure metals. Copper and tin are weak and pliable, but when mixed together they make a strong alloy called bronze.
How is copper used in the Statue of Liberty?
http://www.statueofliberty.net/flash/solflashtour_v2.html Brass is a tough alloy of copper and zinc that resists corrosion. Alloys of aluminium are light and strong and are used to make aircraft.
Pure metals The rarity and lustre of gold and silver have been prized for centuries. What is gold use for ? http://www.gold.org/technology/uses/ Other pure metals have special uses: - electrical wires are made of copper, which conducts electricity very well - mercury, a liquid metal is used in thermometers.
metalworking There are many ways of shaping metal. Casting is one method of making objects such as metal statues. Hot, molten metal is poured into a mould where it sets and hardens into the required shape. Metal can also be pressed, hammered, or cut into shape. Watch an animation about steel-rolling: http://www.matter.org.uk/steelmatter/forming/5_1_6.html