Types of metal: The range of metals available can be classified as ferrous or non-ferrous, within these two groups, metals can be further separated into alloys or non-alloys.
Key Words:
--> Ferrous Metals = metals that contain iron and carbon
--> Non-Ferrous Metals = metals that do not contain iron
--> Ferrous Alloys = a mixture of two or more metals - at least one of which contains iron and carbon
--> Non-Ferrous Alloys = mixtures of two or more metals - none of which contain iron.
Sources of metal: Gold is the only metal that is found in a useable form; all other metals are found as ores. 25% of the earths crust is made up of metal ores, aluminium is the most common ore, followed by iron. In general, the rarer the material is the more expensive it is, however, some of the more common ores, for example aluminium can be expensive to process.
The structure of metal: All metals are made up of crystals. Each crystal has a boundary that is firmly bonded to the boundary of a neighbouring crystal. For example, steel is made up of iron and carbon.
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