Exercise 23. Make up special questions according to the models, and answer

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als. 3. The most widely used non-ferrous metals are aluminium and copper. 4. 
The most common engineering thermoplastics are ABS and PVC. 5. The most 
common engineering thermosets are epoxy resins and polyamides.
Model B: 
Materials science encompasses various classes of materials.
 
What does materials science encompass?
1. This alloy contains copper. 2. Large amount of carbon in cast iron in-
creases its brittleness. 3. Stainless steel contains nickel or chromium. 4. A com-
pound consists of two or more elements. 5. A mixture includes two or more 
elements or compounds.
Exercise 24. Ask questions and use the words in italics in your answers. The 
words in brackets will help you.
1. Fiberglass is correctly called 
glass-reinforced plastic
(how). 2. 
 
Cast iron 
has a wide range of applications 
in machines and automotive industry parts
(where). 3. At present some car manufacturers are switching from steel to alu-
minium 
to save weight of a car
(why). 4. Car makers try 
to make vehicles lighter
(what). 5. Thermosets can be moulded 
only once
(how many times).
Exercise 25. Read the following dialogue, sum up the information and act out a 
similar dialogue.
APPLICATION OF ENGINEERING MATERIALS
A.: We have been discussing the classification of engineering materials during 
the English classes. Have you memorized the groups of engineering mate-
rials?
B.: Sure. They are metallic and non-metallic materials.
A.: Yes, you are right! There is such a wide variety of materials. And I’d like to 
know where they are all used in mechanical engineering. It seems to me 
that cast irons tend to have a declining usage.
B.: Nothing of the kind. Cast iron has a wide range of applications in machines 
and automotive industry parts. 
A.: Is that really so? But as for the cars, steel but not cast iron makes up by far 
the single largest percentage of materials. 
B.: I agree with you on this point. If I am not mistaken, an average car has 
about 55 per cent of steel. 
A.: But materials technology is constantly changing and at present some car 
manufacturers are switching from steel to aluminium to save weight of 
a car. I wonder if aluminium can fully substitute steel.
B.: New alloys mean that aluminium is now as rigid as steel. Moreover, it is 
corrosion-resistant.

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A.: It’s going to be interesting to see if the popularity of aluminium continues 
to increase in the future.
B.: Not only of aluminium but plastics too. As car makers try to make vehicles 
lighter the plastics percentage is increasing all the time. 
A.: I see. Thanks a lot for your comments.
B.: You are welcome.

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