Non-ferrous metals. Most of the common non-ferrous metals have good corrosion resistanceMost of the common non-ferrous metals have good corrosion resistance. These include: · Aluminium alloys: lighter than steel, but more expensive and not as strong. · Copper: one of the best electrical conductors. This is commonly used to make electrical wires. · Polymers · The correct term for plastics is polymers. Most polymers are good insulators. Some of the stronger polymers compare favourably with metals. They are not normally painted, but their colour can be changed by adding pigments to them. · Most polymers are made from oil, which is a non-renewable resource. They are made by a chemical reaction called polymerisation. · · There are two main types of polymer: thermosets and thermoplastics. · Thermosets are normally made into products by moulding. Once moulded, they cannot be reshaped and they cannot be recycled. · Thermoplastics soften when heated and can be shaped when hot. The shape will harden when it is cooled, but can be reshaped when heated up again. Thermoplastics are softer and more flexible than thermosets. They can normally be recycled. · Typical uses of some common thermoplastics
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