Module 7 ENGINEERING MATERIALS (Решение → 73578)

Module 7 ENGINEERING MATERIALS

KEY VOCABULARY

Exercise 1. Read and guess the meanings of the new words. If you have some difficulties, use the dictionary at the end of this book. It will help you to read and discuss the texts and dialogues, arrange the role-plays and present the projects.

1) access. The earliest humans had an access to only a very limited number of materials.

2) property. A lot of materials with specialized properties were produced.

3) to encompass. Material science encompasses various classes of materials.

4) alloy. Metallic materials include metals and alloys.

5) ferrous metals. Metallic materials which contain iron are called ferrous metals.

6) non-ferrous metals. Metallic materials which do not contain iron are called non-ferrous metals.

7) cast iron. The most common ferrous metals are cast iron and steel.

8) to influence. Different elements in alloys influence properties of materials.

9) brittleness. Large amount of carbon in cast iron increases its brittleness.

10) to rust. Steel containing nickel or chromium does not rust.

11) tungsten. Steels which contain tungsten or cobalt are extremely hard.

12) copper. Aluminium and copper are widely used.

13) ductile, malleable. Copper is a ductile and malleable metal.

14) frequent. Copper is a frequent element of various metal alloys.

15) brass, tin, lead. Brass contains copper and zinc, bronze contains copper and tin/lead.

16) representative. Polymers are representatives of non-metallic materials.

17) rubber. One of the best-known natural polymers is rubber.

18) thermoplastics, thermosets. Plastics can be divided into thermoplastics and thermosets.

19) to mould. Thermoplastics can be heated and moulded numerous times.

20) indispensable. The properties of plastics are indispensable.

21) flexible. Plastics are flexible.

22) relevantly. Plastics are relevantly cheap.

23) subsequent cooling. Ceramic materials are formed by the action of heat and subsequent cooling.

24) clay. Clay was one of the earliest materials used to produce ceramics.

25) stiff. Ceramics tend to be strong, stiff, brittle, and chemically inert.

26) to vary. Ceramics properties vary widely.

27) insulator. Porcelain is widely used to make electrical insulators.

28) available. A lot of engineering materials are available to engineer.

29) to choose. Engineers have to choose the engineering materials.

30) purpose. Engineers have to choose the engineering materials best suited the given purpose.

31) to memorize. Have you memorized the groups of engineering materials?

32) to exist. A wide variety of materials exists nowadays.

33) to decline. Some materials tend to have a declining usage.

34) to save. The manufacturers are switching from steel to aluminium to save weight of a car.

35) to change. The materials technology is constantly changing.

36) to substitute. Aluminium can substitute steel.

37) to increase. The popularity of aluminium is increasing.

Exercise 7. Think over the definitions of the words which appear in the texts and dialogues and then:

a) agree or disagree with the following definitions

1. Common means happening frequently or existing in large amounts or numbers.

2. Rubber is a strong substance that can bend easily and is used for making things such as tyres or boots.

3. Non-ferrous metals are metals that do not contain iron.

4. Ferrous metals are metals that contain iron.

5. Amount is a quantity of something.

b) match each word with its correct definition

cast iron, property, conductor, insulator, copper

1. Quality or a feature of something.

2. Ferrous metal.

3. Non-ferrous metal.

4. Substance that allows heat or electricity to pass through it.

5. Substance that reduces the amount of heat or electricity that can pass through something.

c) find the definitions for some other words which you consider to be important for the topic “Engineering Materials”. Use the website

READING

Exercise 10. Read the text, try to focus on its essential facts and choose the most suitable heading given below for each paragraph.

1) Metallic Materials

2) Ceramics

3) Various Classes of Materials

4) Polymers

5) Choosing Materials

DIFFERENT KINDS OF ENGINEERING MATERIALS

1) to influence b) thermoplastics

2) to contain c) material

3) to change d) properties

4) to choose e) nickel

5) to mould f) technology

6) to substitute g) popularity

7) to increase h) steel

8) to save i) groups

9) to memorize j) weight

Exercise 14. Try to enrich your vocabulary:

a) find words in the text which have the same meanings as the following words:

for example, people, to embrace, big, an element, different, to manufac-

ture, aim;

find words in the text whose meanings are opposite to the meanings of the following words:

the latest, unlimited, synthetic, small, decrease, soft, heavy, low, rare, the

worst, stiff, expensive, organic

, conductors;

b) replace the words in italics with the words with similar meanings:

1. Materials science includes different classes of materials. 2. Materials science embraces the traditional classes of engineering materials: metallic and non-metallic materials. 3. Clay was used to manufacture ceramics. 4. There are a lot of alloys containing copper, for example, brass, bronze, etc. 5. Ancient people had an access to a very limited number of natural materials.

Exercise 15. Complete the sentences: change the word in capitals at the end of each sentence to form a word that fits suitably in the blank space.

1. … steels which contain nickel do not rust STAIN.

2. Materials were very important in the … of societies DEVELOP.

3. Carbon increases … in cast iron BRITTLE.

4. There are … kinds of engineering materials DIFFER.

5. Corrosion … is one of the aluminium properties RESIST.

Exercise 16. Insert the words at the sentence level: fill in the blanks with the missing words (the first letter of each word is given).

1. A lot of materials with specialized p… have been developed. 2. Metallic materials which contain iron are called f… metals. 3. Steels which contain t… are extremely hard. 4. Copper is a m… metal. 5. Copper is a f… element of various alloys. 6. R… is a natural polymer. 7. T… can be moulded numerous times. 8. The plastics properties are i… . 8. Ceramics are strong and s… . 9. Materials science e… different groups of materials. 10. Metallic materials include metals and a… .

Exercise 28. Translate the following sentences from Russian into English. You will have a story on the topic as a pattern.

1. Современные технологии сделали возможным производство новых материалов. 2. К настоящему времени созданы более 50 000 материалов с определенными свойствами. 3. Металлические и неметаллические материалы — традиционные группы конструкционных материалов. 4. Металлические материалы включают черные и цветные материалы. 5. Самые распространенные черные металлы — чугун и сталь. 6. Самые широко используемые цветные металлы — алюминий и медь. 7. Полимеры — представители неметаллических материалов. 8. Синтетические полимеры могут быть разделены на две категории: термопластические и термореактивные пластмассы. 9. Свойства пластмасс незаменимы: они легкие, твердые, нержавеющие, хорошо формуются и красятся. 10. Керамические материалы также являются представителями неметаллических материалов, и их свойства имеют большой диапазон.

ADDITIONAL READING

Exercise 32. Make a summary of the text using the following phrases:

1. The title of the text is…

2. The text is about… The text deals with…

3. The text covers such points as… first… second… third…

4. It should be underlined that…

5. In conclusion, I may say that…

6. To my mind… In my opinion…IMPORTANT METAL PROPERTIES FOR MANUFACTURING

One of the most important aspects in manufacturing is to choose the right material for a particular application. There are some important properties of metals: ductility, malleability, elasticity, hardness, durability, etc.

Ductility is a solid material ability to be stretched into a wire. Malleability, a similar property, is a material ability to form a thin sheet by hammering or rolling. Both of these mechanical properties are aspects of plasticity, the extent to which a solid material can be plastically deformed without fracture. Ductility and malleability are not always coextensive, for example, while gold is both ductile and malleable, lead is only malleable.

Elasticity is an ability of a material to stretch easily and then return to its original shape quickly. Springs are usually made out

of elastic materials such as spring steel, titanium, and bronze.

Hardness is an ability of a material to resist to various kinds of shape change when a force is applied. Common examples of hard materials are not only certain metals but also ceramics. Hardness of a material affects its durability. Generally, hard metals are more durable than soft ones.

The properties of a metal can be changed by heat treating. The main types of heat treating are quenching, annealing, tempering. Quenching is a heat treating process when metal is heated, and then dipped in water or oil to cool it rapidly. It makes metal to be harder but more brittle. While annealing, metal is also heated, but then is allowed to cool slowly. Annealed metal is softer and more elastic. While tempering, metal is heated and kept at high temperature for a period of time. As a result, tempered metal has a balance between hardness and elasticity. Materials played a major role in the development of societies. Civilizations were named by the level of their materials development, e.g. the Stone Age, the Bronze Age, and the Iron Age. The earliest humans had an access to only a very limited number of natural materials. Modern technologies have made it possible to produce new materials. We believe more than 50,000 materials with specialized properties to have been developed by now. Materials science encompasses various classes of materials, but the traditional groups of engineering materials are metallic materials (metals and alloys) and non-metallic materials (polymers, ceramics, etc.).

Metallic materials include ferrous (those that contain iron) and non-ferrous (those that do not contain iron) metals. It should be noted that while describing alloys which are metallic materials it is possible to use the term “metals”. The most common ferrous metals are cast iron and steel, which are both alloys. Different elements in alloys influence properties of materials: large amount of carbon in cast iron increases its brittleness; stainless steels containing nickel or chromium do not rust; steels, which contain tungsten or cobalt, are extremely hard, etc. We consider the most widely used non-ferrous metals to be aluminium and copper. Aluminium alloys are widely used in engineering structures and components where light weight or corrosion resistance is required. Copper is a ductile, malleable metal with a very high thermal and electrical conductivity. It is a frequent element of various metal alloys: brass (copper and zinc), bronze (copper and tin/lead).

Polymers are representatives of non-metallic materials. One of the best known natural polymers is rubber. However, most of the polymers used in industry are not natural but synthetic; they are generally called ‘plastics’. Plastics can be divided in two categories: thermoplastics and thermosets. Thermoplastics can be heated and moulded numerous times. Common engineering thermoplastics are ABS (acrylonitrile butadiene styrene); polycarbonate; PVC (polyvinylchloride). Thermosets can be heated and moulded only once, they cannot be remoulded. The most common engineering thermosets are epoxy resins and polyamides. The properties of plastics are indispensable: they are lightweight, hard, easy to shape and colour, flexible, non-rusting, relevantly cheap, etc.

Ceramic materials are inorganic, non-metallic materials which are formed by the action of heat and subsequent cooling. Clay was one of the earliest materials used to produce ceramics, but many different ceramic materials are now being used in domestic and industrial products. Ceramics tend to be strong, stiff, brittle, chemically inert. They are non-conductors of heat and electricity, but still their properties vary widely. For example, porcelain is widely used to make electrical insulators, but some ceramic compounds made from a metal and a non-metal are superconductors.

Thus, at present a lot of engineering materials are available to engineer, who has to choose the one best suited to serve the given purpose.