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UNIT 2 MATERIALS TECHNOLOGY

I Describing specific materials

2a Read the following web page and complete the missing headings using the words in the
box.
Aluminium; Copper; Glass ; Plastic; Rubber ; Steel; Timber;
Recyclable Materials
1 Steel Scrap can be sorted easily using magnetism. If the metal is galvanised
(coated with zinc) the zinc is fully recyclable. If it is stainless steel, other metals mixed with the
iron, such as chromium and nickel, can also be recovered and recycled.
2 Sorting is critical, as there are key differences between the clear and
coloured material used in bottles and jars, and the high-grade material used in engineering
applications, which contains traces of metals.
3 Scarcity makes recycling especially desirable, and justifies the cost of
removing insulation from electric wires, which are a major source of scrap. Pure metal can also
be recovered from alloys derived from it, notably brass (which also contains quantities of zinc,
and often lead) and bronze (which contains tin).
4 The cost of melting down existing metal is significantly cheaper than the
energy-intensive process of electrolysis, which is required to extract new metal from ore.
5 Hardwood and softwood can be reused. However, the frequent need to
remove ironmongery and saw or plane off damaged edges, can make the process costly.
6 Tyres are the primary source of recyclable material. These can be reused
whole in certain applications. They can also be ground into crumbs which have varied uses.
7 An obstacle to recycling is the need to sort waste carefully. While some
types can be melted down for reuse, many cannot, or result in low-grade material.

b Match the materials from the web page (1 -8) in Exercise 2 to the definitions (a-h).

1 stainless steel a metal used to make brass, and in galvanised coatings on steel
2 zinc b the predominant metal in steel
3 iron c type of steel not needing a protective coating, as it doesn't rust
4 bronze d a dense, poisonous metal
5 lead e rocks from which metals can be extracted
6 hardwood f an alloy made from copper and tin
7 ore g timber from pine trees
8 softwood h timber from deciduous trees

C Complete the following sentences using from, with or of.
1 Bronze contains significant amounts_____of______copper.
2 Galvanised steel is steel coated zinc.
3 Steel is an alloy derived iron.
4 Pure metals can usually be recovered alloys.
5 To produce stainless steel, iron is mixed other metals.
6 Stainless steel contains quantities chromium and nickel.
7 Glass tableware contains traces metals, such as lead.
8 When new metal is extracted ore, the costs can be high.

d In pairs, ask and answer questions about different materials using the following phrases.

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