МИНИСТЕРСТВО ОБРАЗОВАНИЯ РЕСПУБЛИКИ БЕЛАРУСЬ

УЧРЕЖДЕНИЕ ОБРАЗОВАНИЯ

«БАРАНОВИЧСКИЙ ГОСУДАРСТВЕННЫЙ УНИВЕРСИТЕТ»

ENGINEERING MATERIALS

КОНСТРУКЦИОННЫЕ МАТЕРИАЛЫ

Методические рекомендации

для аудиторной и самостоятельной работы

студентов инженерных специальностей

дневной и заочной форм получения образования

Барановичи

РИО БарГУ

2010

УДК

ББК

Рекомендовано к печати методической комиссией

совета общеуниверситетских кафедр

Составители:

М.О. Гайдук

П.Н. Бушейко

Рецензенты:

Л.С.Зубрицкая, старший преподаватель кафедры

иностранных языков УО БарГУ;

И.А.Якобсон. старший преподаватель кафедры

грамматики и фонетики английского языка

факультета иностранных языков УО БарГУ.

Английский язык“Engineering materials” - «Конструкционные материалы»:методические рекомендации для аудиторной и самостоятельной работы студентов инженерных специальностей дневной и заочной форм получения образования/ сост. М.О. Гайдук, П.Н.Бушейко – Барановичи: РИО БарГУ, 2010, - с. - экз.

Данные методические рекомендации предназначены для организации аудиторной и самостоятельной работы студентов первого и второго курсов инженерных специальностей дневной и заочной форм получения образования. Предлагаемые в буклете материалы обеспечивают изучение таких тем, как «Конструкционные материалы», «Металлы и их сплавы», «Пластмассы», «Композитные материалы».

Цель рекомендаций – помочь студентам развивать умения и навыки устной и письменной речи по темам профессионально ориентированного блока.

УДК

ББК

Введение

Данные методические рекомендации предназначены для организации аудиторной и самостоятельной работы студентов первого и второго курсов инженерных специальностей дневной и заочной форм получения образования. Предлагаемые в буклете материалы обеспечивают изучение таких тем, как «Конструкционные материалы», «Металлы и их сплавы», «Пластмассы», «Композитные материалы». Весь материал подобран таким образом, что одна тема логично продолжает предыдущую, повторяя и закрепляя лексические единицы и языковой материал. Каждый раздел имеет задания предназначенный для формирования устойчивого интереса к изучению иностранного языка студентами неязыковых специальностей, a также задания для развития умений и навыков письма (Writing Practice). Устные упражнения имеют разные уровни сложности, что даст возможность преподавателю организовать индивидуальную и групповую работу на занятиях с учётом способностей и уровня подготовленности каждого студента.

Методическими целями рекомендаций являются:

- активизация умений и навыков устной речи студентов;

- обогащение активного и пополнение пассивногоcсловарей ;

- систематизация языковых лексических знаний;

- развитие навыков дискутирования и аргументации.

Методические рекомендации основаны на принципах коммуникативного метода и обеспечивают мотивацию речевой деятельности студентов. Основной структурной единицей являются тематические циклы (Units), которые имеют внутритематическое подразделения на более мелкие методически законченные единицы (Sections). Каждый последующий цикл структурно повторяет предыдущий. Для более эффективного усвоения материала предлагаются различные виды опор.

Пособие отредактировано с учётом требований программы по английскому языку для неязыковых специальностей высших учебных заведений.

Unit 1

S ection I

Conversational topic: “ENGINEERING MATERIALS”

I. Warming up and Vocabulary Work

I.1 Read the dialogues and do the tasks given after them:

Dialogue A:

Julia: Is this a workshop?

Instructor: Yes, you are quite right. It is a workshop and there are many tools for you practice here. They are made of different engineering materials.

Paul: What are these materials called?

Instructor: They are called plastic, glass, wood, rubber and metal.

Michael: I think steel, iron, copper are widely used for making tools.

Instructor: That is right. These metals are widely used for making bolts, screws, pipes, nuts, wires, etc.

Dialogue B:

Paul: Look. There is a box of nuts and bolts. They are made of steel.

Julia: And that wire is made of copper isn’t it?

Michael: Yes, it is. What about this hammer? Is it made of copper too?

Paul: No, it is not. It is made of wood and steel. This handle is made of wood and the head is made of steel.

Julia: Michael, give me that beaker, please.

Michael: Be careful, Julia. Don’t drop it. It is made of glass. Put it here on the shelf.

I.2 Translate the marked words into Russian, and remember them.

I.3 Match the English phrases with the Russian equivalents:

1. cast iron	a. пластмассовая коробка
2. a plastic box	b.железный болт
3. a steel pipe	c. стеклянная ваза
4. a copper cup	d. чугун
5. a glass	e. медная чашка
6. an iron bolt	f. стальная труба.

I.4 Learn the words to the topic; translate them into Russian and remember them:

Nouns	Adjectives	Verbs
alloy conductivity density hardness heat elasticity load manufacturing property mixture plasticity machinery resistance quality	valuable elastic (non)ferrous malleable stiff strong resistant superior stainless chemical mechanical physical brittle crystal	design operate test contain corrode apply (to) harden withstand determine pertain (to) preserve

Pay attention to the use of prepositions in the following word-groups:

To relate to; to vary in; to be widely used in; to form by; to classify into; to be weak (strong, resistant) in; to group in

1.5 Analyze the way of formation of the following words; say what part of speech they are formed from; make all the possible word combinations with them:

Example: superior density (hardness, resistance, conductivity)

Machinery, property, density, conductivity, hardness, resistance, resistant, useful, valuable,

manufacturing, mechanical, physical, mixture.

1.6 Define the syntactical function of the italicized words; translate them into Russian:

1. Engineers in the field of machine construction design, build, operate and test machinery of all types.

2. All metals vary in density, hardness, heat, and electrical conductivity.

3. Alloys steels are those in which some alloying elements in addition to the carbon are presented.

4. Three chief groups of copper alloys used in machine design are brasses, bronze and nickel-copper alloys.

5. Today the most important are alloy steels, which have a lot of special characteristics.

II. Reading Activity and Speech Practice

II. 1 Before reading the text discuss with your group mates some questions:

1. Why do engineers have to know the materials they are going to work with?

2. What groups are all engineering materials divided into?

3. What is cast iron? And what is steel?

4. Which non-ferrous metal is the most essential one today?

5. What materials are usually called non-metals?

II.2 Read the text attentively, translate it into Russian, be ready to discuss its contents:

Text A: Engineering Materials

Engineers in the field of machine construction design, build, operate and test machinery of all types. Moreover, they work on various kinds of structures. It goes without saying that engineers must know the most economical and valuable materials to use in the field of manufacturing. Mechanical engineers have to understand the properties of these materials and how they can be worked.

As is known, all engineering materials are divided into metals and non-metals. Metals are materials which widely used in machine-building industry because of their useful properties. All metals vary in density, hardness, heat and electrical conductivity, and weight; they can be formed by drawing, rolling, extrusion and hammering and worked using machine-tools such as lathe, shaper, grinder and a milling machine. We normally classify metals into ferrous and non-ferrous. The former contain iron and the latter do not contain iron. Iron is the world’s most common metal. Cast iron and steel, which are both alloys, or mixtures of carbon and iron, are the two most important ferrous metals.

Cast iron is a general term applied to iron-carbon alloys containing more than 1.7 % of carbon. Cast iron without the addition of alloying elements is weak in tension and shear, strong in compression and has low resistance to impact. However, grey cast iron is soft, easily machined, and only moderately brittle. Malleable cast iron is made by heating white iron castings for a period of several days in airtight pots filled with an oxide of iron.

Steel is a ferrous metal with carbon content. It is stiff and strong, but corrodes easily through rusting, although stainless and other special steels are corrosion resistant. Today the most important are alloy steels, which have a lot of special characteristics. Alloy steels are those in which some alloying elements in addition to the carbon are present. The principal alloying elements used in steels are nickel, chromium, vanadium, manganese, and to lesser extent, copper, tungsten, cobalt and beryllium. Heat treatment and mechanical working at cold or hot temperatures may give steel alloys superior qualities, such as hardness, strength, toughness, wear resistance and workability.

Among non-ferrous metals copper is the most essential one. Because of its high electrical conductivity this metal is used in electrical work. Three chief groups of copper alloys used in machine design are brasses, bronzes and nickel-copper alloys.

Wood, stone, rubber, concrete, ceramics and plastics are non-metals. However, plastics may be machined like metals. There are two types of plastics – thermosets and thermoplastics. Thermoplastics can be shaped and reshaped by heat and pressure but thermosets cannot be reshaped by heat because they undergo chemical changes as they harden. Ceramics are often employed by engineers when materials which can withstand high temperatures are needed.

So, it’s impossible to live without various engineering materials.

II.3 Now, give full answers to the questions given in exercise II.2 using the text.

II.4 Choose in the text the sentences about:

• metals and their use;

• characteristics of pure iron;

• the main alloying elements of steel;

• the chief groups of copper alloys;

• materials related to non-metals.

II.5 Find in the text the sentences to describe the main properties of ferrous and non-ferrous metals. Compare them and define the difference.

II.6 Put the items of the following plan in the proper order according to the text:

1. Metals and their properties.

2. Cast iron and iron-carbon alloys.

3. Steel and its alloys.

4. Plastics and their types.

5. Non-ferrous metals.

II.7 Express your opinion why it is so necessary for an engineer to know the engineering materials and their characteristics.

III. Writing Practice

III.1 Divide the following words into groups:

Density, hardness, heat, conductivity, weight, drawing, rolling, extrusion, resistance, hammering, lathe, shaper, grinder, iron, steel, alloy, carbon, nickel, chromium, toughness, workability, rubber, stone.

III.2 Write out from the text the words that describe:

• metals;

• alloys and alloying elements;

• properties of metals;

• processes of metal working.

III.3 Translate the following sentences into English using your active vocabulary:

1. Эти детали сделаны из различных технических материалов.

2. Существуют два типа технических материалов: металлы и неметаллы.

3. Сталь, медь, литейный чугун широко используются для изготовления болтов, винтов, гаек.

4. Как металлы, так и неметаллы обладают определёнными свойствами, поэтому они широко

используются в производстве технических изделий.

5. Ручка этого молотка сделана из дерева, а обух – из стали.

6. – Олег, дай мне, пожалуйста, эту стеклянную колбу.

7. Будь осторожен, не урони этот предмет. Он сделан из стекла.

8. – Дима, не используй этот медный провод, возьми стальной.

9. Пластик – очень лёгкий материал.

Section II

I. Reading Activity and Speech Practice

Text B: “Metals and their Properties”

I. 1 Read the text and say what major groups the properties of metals can be divided into.

It is noted that the chemical elements are divided into metals and non-metals. All metals can be divided into ferrous and non-ferrous. Different metals are widely used in the machine-building industry. Metals to be applied for industrial purposes are called “engineering metals”. To use metals in practice we must know their properties because they influence their manufacture and application. The properties of metals can be grouped into certain categories. The major categories to be considered are:

a). chemical properties that are material characteristics which relate to the structure of a material and its formation out of the elements; these properties are usually measured in a chemical laboratory and they cannot be determined by visual observations.

b). physical properties such as colour, density, crystal structure, electrical and heat conductivity, etc. Physical properties are characteristics of materials that pertain to the interaction of these materials with various forms of energy and with other forms of matter.

c). mechanical properties that are of foremost importance in selecting materials for structural machine components.

Mechanical properties are characteristics of a material that are displayed when a force is applied to the material. Let us consider some of the mechanical properties of metals such as: strength, elasticity, plasticity, and hardness.

Strength of metals is the property of hard materials to be subjected to the influence of external forces without changing their shape.

Elasticity is the ability of a material to change its shape under the influence of external loads and return to its original form upon removal of the loads. All materials are elastic but the range of elasticity varies for different materials.

Plasticity is the opposite of elasticity. It is the ability of a material to change its form without breaking under the influence of load and preserve this changed form after removal of the load.

Hardness is the property of a metal to resist deformation under applied load. Hardness is the most important property of metals. It can also be defined as the ability of metals to resist penetration of other harder materials or as resistance to wear.

Add to your active vocabulary:

1. property (ies) – свойство (свойства);

2. density – плотность;

3. conductivity – проводимость;

4. interaction – взаимодействие;

5. force – сила, усилие;

6. elasticity – эластичность;

7. plasticity – пластичность;

8. hardness – твёрдость;

9. wear – изнашиваемость;

10. strength - прочность;

11. external – внешний;

12. load – нагрузка;

13. pertain to – иметь отношение к;

14. resist (resistance) – сопротивляться (-ние);

15. apply – применять.

I.2 Answer the questions to the text.

1. What groups are chemical elements usually divided into?

2. There are two kinds of metals usually, aren’t there?

3. What branch of industry are metals used in? How are they called?

4. What are chemical properties relate to?

5. Do physical properties pertain to the interaction of metals only with energy?

6. Where are mechanical properties displayed?

I.3 Find in the text and read out the words related to – physical properties of metals;

- mechanical properties;

- chemical properties.

I.4 Find the corresponding parts in the chart.

1. Strength	a. the property to resist deformation under applied load and to resist penetration of other harder materials or as resistance to wear
2. Elasticity	b. the ability of a material to change its form without breaking under the influence of load
3. Plasticity	c. the ability of a material to change its shape under the influence of external loads and return to its original form upon removal of the loads
4. Hardness	d. the property of hard materials to be subjected to the influence of external forces without changing their shape

I.5 Get ready to speak on the main properties of metals. Say what property to your mind is the most necessary in machine building.

III. Writing Practice

III.1 Complete the following word-groups with the passing nouns:

1. Valuable… 2. strong … 3. superior … 4. mechanical … 5. apply to ….6. determine …. 7. preserve …. 8. pertain to ….. 9. vary in ….10. to be weak in ….

III.2 Choose the passing word from the brackets:

1. Engineers should know the most economical and (valuable/useful) to use in the field of machine-building.

2. Mechanical engineers have to understand the (qualities/properties) of engineering materials.

3. Metals are widely used in machine- building industry because of their (useful/superior) properties.

4. All metals (vary/differ) in density, hardness and electrical conductivity.

5. Ferrous metals contain (steel/iron) and non-ferrous do not.

6. Cast iron and steel are both (mixtures/alloys).

7. Heat treatment and mechanical working give steel alloys superior (properties/qualities), such as hardness, strength, toughness and some others.

8. Among non-ferrous metals copper is the most (important/essential) one.

9. Wood, stone, rubber and ceramics are (plastics/non-metals).

10. It’s impossible to live without various (metals/non-metals/engineering materials).

III.3 Translate into English the following word combinations with the help of the text:

1. химические элементы; 2. металлы и неметаллы; 3. широко применяться в машиностроении;

4. использоваться для промышленных целей; 5. главные категории; 6. влиять на их производство;

7. структура материала; 8. кристаллическая решётка; 9. детали машин; 10. взаимодействие с различными видами энергии и материалов; 11. проявляются, если прикладывается сила; 12. подвергаться воздействию внешних сил; 13. под влиянием внешней нагрузки; 14. возвращать первоначальную форму; 15. диапазон эластичности; 16. способность изменять свою форму не разрушаясь; 17. противостоять разрушению.

Section III

I. Reading Activity and Speech Practice

Text C: New Steels Meet Changing Needs

III.1 Rearrange the paragraphs of the text according to the following plan to it:

• Requirements to modern engineering materials;

• Properties of steel;

• Drawbacks and advantages of steel.

1. Since steel is the most popular structural material available, steel-makers make every effort to meet the changing needs of these markets. New, more sophisticated processes for steel- making and treatment have led to steel products of higher grade and greater variety.

2. As a structural material steel has two drawbacks; its weight and its susceptibility to rust. However, due to its advantages, steel has long been used, and in great quantities, in structural applications from bridges and buildings to ships, automobiles and household appliances. Steel is superior to other structural materials in strength, toughness, workability and other properties that are critical for such applications, and it is mass-produced with uniform, reliable quality and at low cost.

3. The need for lighter weight is really a requirement for materials having higher specific strength (strength/ specific gravity). Materials offering new properties not found in conventional materials will include new breeds of steel, hybrid materials and truly novel materials such as amorphous metal. The need for maximum performance calls for materials approaching the limits of durability, toughness and the like. Finally, the need to reduce costs is leading to materials diversification in which steel materials precisely suited to a specific application are developed.

4. Yet, it can no longer be said that a steel product is satisfactory if it is simply a good structural material. Today’s market needs can be classified broadly as: 1). the need for lighter weight; 2). the need for new propertied; 3). the need for maximum performance; and 4). the need for cost reduction.

III.2 Write out from paragraphs 3 and 4 word combinations to speak about the main requirements to modern engineering materials.

III.3 Complete the scheme using the information from the text. Be ready to speak about modern engineering materials.

S teel has

A dvantages and Drawbacks

1. 2. 1. 2. 3.

III. 4 Translate paragraphs 3 and 4 into Russian in written form.

U nit 2

Section I

Conversational topic: “METALS AND THEIR ALLOYS”

I. Warming up and Vocabulary Work

I.1 Read the dialogues; remember the words to characterize metals.

Dialogue A:

Paul: Alex, help me, please. This pipe is very heavy.

Alex: Is it really? What material it made of?

Paul: Actually, it is made of metal.

Alex: Why is it made of metal?

Paul: Well, because it is a very strong material. In any case, it is stronger and more rigid than, for example, rubber.

Alex: Is metal an expensive material?

Paul: Yes, it is. It is the most expensive material, as a matter of fact.

Dialogue B:

Alice: Paul, take that pipe, it is rather light.

Paul: Oh! It is very light. What material is it made of?

Alice: It is made of aluminium.

Paul: Why is it made of aluminium?

Alice: Well it is an easy material, but aluminium is less flexible than rubber. In fact, it is the lightest but not the least expensive one.

I.2 Complete the dialogue. Use the words from the previous dialogues.

- Look here… I bet that … is very heavy.

- I’m sure it is not!

- Hmm, What material …?

- …, to my mind …

- … not! Can’t you see?! It’s made of …

- … strong?

- Well. On the one hand, it is …than …. On …, it is less … than ….

I.3 Study the chart and make sentences about different metals and their use.

Example: Aluminium is soft and light. So it is used for aircraft building.

Materials	Properties	Applications
Aluminium	Light, soft, corrosion-resistant, highly conductive	Engine components, aircraft
Copper	Heavy, tough, highly conductive, corrosion-resistant	Electric wiring, tubing
Mild steel	Iron with 0.15 – 0.3% of carbon	General purposes
High carbon steel	Hardest of carbon steels, tough, wear-resistant	Cutting tools (drills, files, saws, etc.)

I.4 Discuss with your partners the following questions.

• Why are bridges made of steel, not of copper?

• Why are electric wires made of copper, not of plastics?

• Why are aircraft made of aluminium, not of steel

• Why are cutting tools made of steel, not of pure iron

I.5 Learn the words to the topic; translate them into Russian and remember them:

I.6 Learn the words to the topic; translate them into Russian and remember them:

Nouns	Adjectives	Verbs
metallurgy alloy separation fracture wire lead grain orientation composition toughness fabrication conductivity	dense ductile coarse elastic electric rigid heavy hard soft cheap brittle flexible regular pure	slide deform bend draw influence machine

I.7 Find the corresponding definitions to the given words:

1. metallurgy 2. separation 3. fracture 4. grain 5. orientation 6. composition 7. fabrication

a. the craft of making and using metals b. the parts that make something c. from Latin: fabricare – to make or forge d. the breaking of something e. a small hard seeds or similar particles f. the process of dividing into parts g. a piece of work or method of working

I.8 Match the given adjectives on the left with the nouns that collocate them on the right:

1. malleable … wire

2. ductile … metal

3. elastic … alloy

4. rigid … material

5. soft … fracture

6. brittle … pipe

7. flexible … detail

I.9 Find the endings of these sentences:

A red material; aluminium; in engineering; the three metals;

a grey elastic metal

1. Steel, copper and aluminium are widely used ….

2. Steel is the hardest and the strongest of ….

3. Copper is ….

4. Steel is ….

5. The lightest and the most flexible is ….

II. Reading Activity and Speech Practice

II.1 Try to answer these questions before you read the text.

1. What are metals?

2. Do metals very greatly from each other?

3. Properties of metals depend on their crystalline structure, don’t they?

4. What are the two main groups of metals?

5. Where are different metals used?

6. Which metals are mostly used in machine-building to your mind?

II.2 Read the text and check your answers. Translate the text into Russian.

Text A: Metals

Metals are materials most widely used in industry because of their properties. The study of the production and properties of metals is known as metallurgy.

The separation between the atoms is small, so most metals are dense. The atoms are arranged regularly and can slide over each other. That is why metals are malleable (can be deformed and bend without fracture) and ductile (can be drawn into wire). Metals vary greatly in their properties. For example, lead is soft and can be bent by hand, while iron can only be worked by hammering at red heat.

The regular arrangement of atoms in metals gives them a crystalline structure. Irregular crystals are called grains. The properties of the metals depend on the size, shape, orientation, and composition of these grains. In general, a metal with small grains will be harder and stronger one with coarse grains.

All chemical elements are divided into metals and non-metals. They are widely used in making tools, instruments, and devices. Metals and non-metals have different properties.

Copper, cast iron, aluminium are examples of metals. Rubber, plastic and ceramics are examples of non-metals. Today different metals are widely used in machine-building industry.

We can divide all metals into ferrous and non-ferrous. Steel and cast iron are in the group of ferrous metals. They are alloys of iron with carbon, manganese, silicon and other components.

Non-ferrous metals are metals and alloys the main component of which is not iron but some other elements such as aluminium, copper and others. Some of the characteristics of nonferrous metals are high electric and heat conductivity, high corrosion resistance, light weight and easiness of fabrication.

The combination of metals and non-metals is known as an alloy. For example, steel is an alloy of carbon and iron. The alloy of copper and zinc is known as brass. The properties of alloys are often better than the properties of their constituents. That is why the majority of engineering products are made of various alloys.

I.3 Answer the questions given before the text.

II.4 Say whether you agree or disagree with these statements.

1. All engineering materials are divided into metals and non-metals.

2. Copper, cast iron, aluminium are examples of non-metals.

3. Today different metals are widely used in machine-building industry.

4. Steel and cast iron are in the group of ferrous metals.

5. Non-ferrous metals are metals and alloys the main component of which is not iron.

6. Some of the characteristics of non-ferrous metals are high electric and heat conductivity.

7. Rubber, plastic and ceramics are examples of non-metals.

II.5 Find the sentences to describe:

• metallurgy as a science;

• interdependence between metal properties and their crystalline structure;

• ferrous metals;

• non-ferrous metals;

• the use of different metals.

II.6 Make a plan to the text to speak about metals and their properties and the main kinds of metals.

II.7 Give answers to the given questions and reproduce the dialogue with your partner.

• There are two kinds of engineering materials, aren’t they?

• …..

• What are they?

• ….

• Can you give any examples of non-metals?

• Sure. ….

• Are engineering materials widely used?

• Certainly. ….

III. Writing Practice

III.1 Complete the sentences with these words: rigid, soft, elastic, hard, brittle, expensive, valuable. Translate them into English in writing.

1. Gold is the most ... of all the metals.

2. Glass is more … than cast iron.

3. This tank is the … one because it is made of steel.

4. This material is the … of these new materials.

5. The … of these materials is aluminium.

6. Copper is the … than rubber.

7. This metal is more … than iron.

III.2 Complete the sentences.

1. Different metals … used in....

2. Steel is a grey … metal. It is … than aluminium.

3. Copper is a red ….

4. Steel is harder and stronger … copper, but copper is … flexible than steel.

5. Copper is the most ….

6. Aluminium is the … flexible material.

7. Steel is the hardest and the … of all these three materials.

III.3 Correct mistakes in the given sentences.

1. This pipe is made of plastic because it is a rigider material than rubber.

2. Rubber is the more elastic than steel.

3. Metal is more stronger than plastic.

4. Glass is brittler than wood.

5. This tank is the harder one because it’s made of steel.

6. This material is very flexible than that one.

7. What this material is made of?

8. Copper is harder then aluminium.

III.4 Translate the following sentences into Russian.

1. Этот материал самый ценный из всех материалов.

2. Мне кажется, эти трубы очень лёгкие, потому что они сделаны из алюминия.

3. С одной стороны, алюминий – менее гибкий материал, чем резина, но, с другой стороны, он самый лёгкий и не очень дорогой.

4. Он обладает свойством пластичности, поэтому этот материал широко используется.

5. Литейный чугун – тяжёлый, но он легче чем, медь.

6. Стальные трубы – самые тяжёлые и наименее гибкие.

7. Алюминий легче литейного чугуна и стекла, но твёрже резины.

8. Эти пружины сделаны из стали, потому что сталь – эластичный металл.

9. Стекло – очень хрупкий материал.

10. Сталь – самый эластичный материал из всех этих материалов.

Section II

I. Reading Activity and Speech Practice

T ext B: Steel and its Alloys

I.1 Read the text given below and find in it the following information:

• kinds of alloys;

• constituencies of steel;

• alloying elements;

• properties of alloy steels;

• names of the technological processes mentioned in the text.

The value of alloys was discovered in very ancient times; brass (copper and zinc) and bronze (copper and tin) were especially important. Today the most important are alloy steels, which have a lot of special characteristics.

The most important metal in industry is iron and its alloy steel. Pure iron is soft, ductile and malleable, useful only as an ornamental material. However, the addition of carbon hardens it greatly and changes its properties. Steel is known as an alloy of iron and about 2% or less carbon. It is strong, stiff, but corrodes easily through rusting, although stainless and other special steels resist corrosion. The amount of carbon in

a steel influences its properties considerably. Steels of low carbon content (mild steels) are quite ductile and are used in the manufacture of sheet iron, wire, and pipes. Medium-carbon steels containing from 0.2 to

0.4 % carbon are tougher and stronger and are used as structural steels. Both mild and medium-carbon steels are suitable for forging and welding. High-carbon steels contain 0.4 to 1.5%carbon, are hard and brittle and are used in cutting tools, surgical instruments, razor blades and springs. Tool steel, also called silver steel, contains about 1% carbon and is strengthened and toughened by quenching and tempering.

Steel for special applications may contain other alloying elements besides carbon. This modifies and improves the physical properties of the base steel. For example, small percentages of nickel, chromium, manganese and vanadium may be used for strengthening steels for construction work. Heat treatment (i.e. tempering) and mechanical working at cold and hot temperatures may also give steel alloys superior qualities, such as strength, hardness, toughness, wear resistance, corrosion resistance, electrical resistivity and workability.

The inclusion of other elements affects the properties of the steel. Manganese gives extra strength and toughness. Steel containing 4% silicon is used for transformer cores or electromagnets because it has large grains acting like small magnets. The addition of chromium gives extra strength and corrosion resistance, so we can get rust-proof steels. Heating in the process of carbon or nitrogen-rich materials is used to form a hard surface on steel (case-hardening). High-speed steels, which are extremely important in machine-tools, contain chromium and tungsten plus smaller amounts or vanadium, molybdenum and other metals.

Steel making processes are known as melting, purifying (refining) and alloying at about 2,900 ºF

(1,600 Cº). Molten steel may be first cast into ingots. Later ingots are worked into finished products. This may be done by two major methods: hot-working and cold-working. The latter is generally used for making bars, tubes, sheets, and strips. Molten steel may also be cast directly into products.

II.2 Choose the right option to complete the sentences.

1. Steel is a general name for ….

a. non- metals b. ferrum c. iron-and carbon alloys

2. Pure iron is used ….

a. as an ornamental material b. for construction work

c. in machine tools

3. Physical properties of iron may be modified by the addition of ….

a. iron ore b. hydrogen c. carbon

4. Steel for special applications usually contains ….

a. carbon b. various alloying elements c. vanadium

5. Heat treatment and mechanical working at cold and hot temperatures result in … of steel.

a. a different carbon content b. better qualities

c. finished products

6. Melting, purifying and alloying are stages of steel ….

a. cold-working b. refining c. making

7. Bars, wire, tubes, sheets, and strips are the results of ….

a. melting steel b. hot-working c. cold-working

III.3. a Consider the advantages and disadvantages of various steels carefully; use the information given in the text.

Class of steel	Advantages	Disadvantages
Carbon steels	…..	…..
Tool steels	…..	…..
Stainless steels	Corrosion resistant…	…..

b. Decide which steels you will use for making the objects named below.

Knives, nails, hammers, cables, automobile bodies, ships, containers, machine tools, bank vaults,

aircraft undercarriages.

IV.4 Explain how you understand the following statements from the text.

1. The most important metal in industry is iron and its alloy – steel.

2. Steel is known as an alloy of iron.

3. Steel for special applications may contain different alloying elements beside carbon.

4. There are different steel making processes known in modern metallurgy.

IV.5 Choose any of the following situations and get ready to speak on it.

1. You are a team engineer and you are going to deliver a short speech on a new project. Your task is to explain what engineering materials you are going to use. Think over the main points of your future speech.

2. You are going to make a short report to a group of students coming to your workshop. You are going to speak about the engineering materials. Make notes to your future report.

III. Writing Practice

III.1 Replace the following definitions by one word.

1. A hard mineral substance that melts when it is heated;

2. Material which has nothing metallic in its structure;

3. a suffix-form to nouns meaning “carrying” or “providing” (from Latin ferre = carry);

4. a metal formed by mixing two or more metals;

5. anything used for making something from Latin material = matter;

6. a characteristic, something that is special in a person or thing;

7. a quality or a characteristics of something.

III.2 Choose the appropriate words to the gaps.

1. The most important metal in industry is …. and its … - steel. 2. It is strong and …, but …. easily through rusting. 3. Pure iron is soft … and …, useful only for as an … material. 4. Carbon … and improves the physical properties of the … steel. 5. Steel making … are known as …, … and alloying.

6. Heat … and hot and … temperatures may also give steel alloys … qualities. 7. Molten steel may also be … directly into finished products.

III.3 Translate the following passage into Russian in writing. Use the dictionary if necessary.

Owing to the valuable properties of stainless steel its application may very from spoons to bank vaults. This steel does not rust because of the interaction between its alloying elements and the environment. Stainless steel contains iron, chromium, manganese, silicon, carbon and significant amounts of nickel and molybdenum. These elements react with oxygen from water and air and a very stable film of metal oxides and hydroxides, which may prevent additional corrosion because it limits the access of oxygen and water to the metal layers below. This film may not be seen without a powerful microscope that is why steel seems stainless when it is in fact corroded at the atomic level.

In summary, stainless steel does not rust because it may form a corrosion product layer for the protection against further attacks of oxygen.

Section III

I. Reading Activity and Speech Practice

Text C: Ferrous Metals. Cast Iron.

I.1 Scan the text and learn about iron and its alloys as much as possible.

As it is known, metals can be divided into ferrous and non-ferrous. The former contain iron and the latter do not contain it. It is to be noted that pure iron* is ductile, soft and relatively weak. It is not normally used as an engineering material because of its low strength. That is why iron has to be combined with other elements such as carbon, silicon, phosphorus, etc. The two most important forms of ferrous metals are cast iron and steel which are both alloys, and mixtures of iron and carbon. And carbon is the most important of all elements present in ferrous alloys*. Steel and cast iron differ in the quantity of carbon content: iron-carbon alloys with more than approximately 2% by weight of carbon are cast irons.

Cast iron is the cheapest of all the ferrous metals. Cast iron is a general term to be applied to iron-carbon alloys containing more than 2% of carbon. Cast iron without the addition of alloying elements is weak in tension and shear, strong in compression and has low resistance to impact.

Grey cast iron is an alloy of iron and carbon in which the carbon is present in free or graphite state. Grey cast iron has its term because of special colour of its fracture; it is soft, easily machined* and only moderately brittle. It is used for the parts not to be subjected to great tensile stresses.

However, many castings* that were formerly made of grey cast iron are now made of malleable iron because malleable castings do possess a degree of toughness and this is probably why they have been so named. Malleable iron castings can be made much thinner in section. But they are seldom used in the form they come from the moulds*, as they are hard and brittle and therefore they should be annealed*. Malleable iron is the most easily machined of all the ferrous metals.

Malleable iron before annealing is usually spoken of as the “white” iron. White iron is difficult to machine because most of the carbon present is in chemical combination with iron. It is desirable to use it in those machines which require some resistance to abrasion*. The tensile strength of white cast iron is about 30,000pei (pounds per square inch).

Vocabulary to the text:

1. pure iron* - чистое железо;

2. ferrous alloys* - железистые сплавы;

3. machined* - подвергнутый механической обработке;

4. castings* - отливка;

5. moulds* - литейная форма;

6. annealed* - отожжённый;

7. abrasion* - шлифовка.

I.2 Answer the questions to the text “Cast iron”.

1. What is the difference between ferrous and non-ferrous metals?

2. What properties does pure iron possess?

3. Why is cast iron more useful for industrial purposes?

4. What kind of alloy is grey cast iron?

5. Does it differ in any kind of properties from cast iron? And from pure iron?

6. What is “white” iron?

7. Why it is desirable to use “white” iron in machines that require resistance to abrasion?

I.3 Choose the correct ending to the following statements.

1. Ferrous metals contain …

a. iron b. steel c. copper

2. Pure iron is …

a. soft and weak b. ductile and elastic c. heavy and hard

3. Cast iron and steel are alloys of ….

a. manganese and iron b. iron and carbon

c. ferrum and copper

4. Cast iron is … of all the ferrous metals.

a. the most expensive b. the most popular c. the cheapest

5. Grey cast iron has got its name because of special ….

a. taste, colour and weight b. colour, shape and structure

c. colour and fracture

6. Grey cast iron is usually used for the parts do not to be subjected to great ….

a. high and low temperatures b. tensile stresses

c. tension and load

7. “White” cast iron is usually malleable before …

a. casting b. annealing c. melting

8. “White” cast iron is desirable to use in these machines which require some

a. resistance to abrasion b. heat resistance

c. resistance to wear

I.4 Prove the sentences with the help of the text

1. Pure iron is seldom used as an engineering material.

2. It is usually combined with other chemical elements.

3. Steel and cast iron differ from each other by their chemical composition.

4. Carbon is the basic alloying element.

5. Grey cast iron is a specific kind of ferrous alloys.

6. Malleable iron is the most workable alloy.

7. “White” iron requires special environment to use.

I.5 Complete the chart according to the text. Get ready to comment on its contents. Use the word-groups ;

Pure iron

+ Carbon, silicon, phosphorous

… iron

Grey … M… iron

W… iron

I.6 Make a report on the problem of ferrous metals and their use in modern industry.

Section IV

I. Reading Activity and Speech Practice

IV.1 Can you read the names of the given chemical elements? Guess their Russian equivalents.

carbon	cobalt	copper	silicon
tungsten	nickel	selenium	lithium
molybdenum	titanium	nitrogen	osmium
vanadium	aluminium	manganese	mercury
chromium	niobium	phosphorus	magnesium

IV.2 Match the given English words given on he left with their Russian equivalents on the right.

1. offer a wider variety of characteristics	a. изобилие
2. availability	b.иметь более широкий спектр особенностей
3. abundance	c. придавать металлу доступные формы
4. convert the metals into useful forms	d. доступность
5. the most abundant metal	e. в два раза тяжелее
6. be used as coatings	f. использоваться для основного слоя
7. nuclear materials	g. самый тугоплавкий
8. minor constituents in other systems	h. меньшие количества в других системах
9. twice the weight of	i. радиоактивные материалы
10. the highest melting point	j. самый распространённый метал на земле

IV.3 Read the text to find the answers to the following questions:

1. Which metals have a wider variety of characteristics: ferrous or non-ferrous?

2. What non-ferrous metal is the lightest (the heaviest)?

3. What non-ferrous metal is the most abundant?

4. What metal has the highest melting point?

Text D: Non-Ferrous Metals

Although ferrous alloys are specified for more engineering applications than all non-ferrous metals combined, the large family of non-ferrous metals offers a wider variety of characteristics and mechanical properties. For example, the lightest metal is lithium, 0, 53 g/cm³, the heaviest, osmium, weighs 22,5 g/cm³ - nearly twice the weight of lead. Mercury melts at around – 38 ºF, and tungsten, the metal with the highest melting point, liquefies at 6,170 ºF.

Availability, abundance, and the cost of converting the metal into useful forms – all play important parts in selecting a non-ferrous metal. One ton of earth contains about 81,000 g of the most abundant metal of land, aluminium. One ton sea water, on the other hand, contains more magnesium than any other metal (about 1,272g). All sources combined, magnesium is the most abundant metal on the Earth. But because magnesium is difficult to convert to a useful metal, it may cost several times that of the least expensive and most easily produced metal, iron billet.

Although nearly 80% of all called “metals”, only about two dozen of these are used as structural engineering materials. Of the balance, however, many are used as coatings, in electronic devices, as nuclear materials, and as minor constituents in other systems.

IV.4 Explain how you understand the following statement from the text:

“Although ferrous alloys are specified for more engineering applications than all non-ferrous metals combined, the large family of non-ferrous metals offers a wider variety of characteristics and mechanical properties.” (Use the text if necessary).

Text E: Some more about Non-ferrous Metals

Non-ferrous are metals and alloys the main component of which is not iron but some other elements such as aluminium, copper and others. Some of the characteristics of non-ferrous metals are high electric and heat conductivity, high corrosion resistance, light weight and ease in fabrication.

We know aluminium to be one of the best known light metals. Aluminium was first produced in the laboratory in 1825 by reducing aluminium chloride. However, wide acceptance of aluminium as an engineering material did not occur until World War II. Since then usage of aluminium has steadily increased each year.

Aluminium is said to be a white silvery metal which does not rust in the air. Its good corrosion resistance and law density permit it to be widely used in the field of transportation. It is to be noted that aluminium is highly ductile and can be shaped easily by a wide variety of methods and can be rolled. The tensile strength* of aluminium is low in comparison with that of iron. The good electrical conductivity of the metal makes it suitable for many applications in the electrical industry. Everybody knows aluminium to be used extensively for coatings that must be light in weight, light in colour or that must not rust. To make aluminium harder it is necessary to add some other metals to it. Copper, zinc and iron are the metals that alloy freely with aluminium.

Historically, copper became one of the first engineering metals. It is known to have been used in prehistoric times for making weapons and tools. Later it was alloyed with tin to form bronze. Having very high electric conductivity and high corrosion resistant qualities, pure copper is a good conductor. However, copper alloys qualities, are stated to be more widely employed, chief among them are brasses* and bronzes*. Brasses are alloys of copper and iron in different proportions. Bronze is an alloy containing primarily copper and tin*, but other elements can be added to the alloy to improve its properties such as hardness and resistance to wear. Additions of some other elements to copper alloys permit certain properties to be made better.

Vocabulary to the text:

1. tensile strength* - прочность на разрыв(на растяжение);

2. brass* - латунь;

3. bronze* - бронза;

4. tin* - олово.

IV.5 Answer the questions to the text.

1. What kinds of metals are called non-ferrous?

2. What are the main characteristics of non-ferrous metals?

3. When aluminium was first produced?

4. What colour is aluminium?

5. Is it more widely used in machine-building or in transportation?

6. What are the basic characteristics of aluminium?

7. Are there any metals that alloy freely with it?

8. What was the first engineering metal used by a man?

9. What property of copper is the most attractive for modern engineering technologies?

10. Which alloys with copper are the most widely known and used today?

IV.6 Study the table given below. Compare the properties of various copper alloys. Get ready to speak about the ways these alloys are used. Don’t forget to express your own opinion.

Name	Metals present	Uses
Aluminium bronze	Copper, aluminium	High tensile strength, can be cold-worked or cast, resistant to corrosion
Bell metal	Copper, tin (30%), lead	Casting bells
Brass	Copper, zinc	Cast and cold-worked in gears
Bronze	Copper, tin	general
Cupro-nickel	Copper, nickel (15-30%)	Very ductile, doesn’t lose strength or crack when its shape is changed
Gunmetal	Copper, tin, zinc	Cast into gears, bearings
Phosphor bronze	Copper, tin, phosphorus, (not a metal)	Cast to form gears and bearings where resistance to corrosion and wear is needed, as in sea water

III. Writing Practice

III.1 Make derivatives to complete the sentences.

1. Non-ferrous metals have high electric (conduct), high (corrode), light weight and ease of (form).

2. Wide (accept) of aluminium did not occur until World War II.

3. Aluminium is known to be a white (silver) metal which does not rust in the air.

4. The good electrical (conduct) of the metal makes it suitable for many (apply) in the electrical industry.

5. It is (extensive) used for castings that must be light in weight.

6. Copper was one of the first (engineer) metals.

7. It was used in (history) times for making weapons and tools.

8. Other elements than tin added to copper improve its properties such as (hard) and (resist) to wear.

III.2 Translate into English.

1. Сплавы цветных металлов – это сложные вещества, основным элементом которых являются медь, алюминий или другие цветные металлы.

2. Цветные металлы обладают хорошей проводимостью и устойчивы к коррозии.

3. Самые распространённые металлы этой группы – алюминий, медь, магний, марганец.

4. Некоторые цветные металлы не имеют кристаллической решётки.

5. Вольфрам – самый тугоплавкий метал, а литий – самый лёгкий.

6. Цветные металлы широко распространены в природе, но их трудно добывать и дорого использовать в промышленных целях.

7. Самый распространённый цветной метал – алюминий, а тонна морской воды содержит около 1 кг магния.

8. В основном, цветные металлы используют в электронных приборах, в медицине и как радиоактивные материалы, и в меньшей степени в других сферах.

III.3 Translate the text into Russian in writing. Give the title to it.

Titanium was discovered twice. A British scientist, William Gregor, found it first and called it menachanite, and six years later, in 1977, M.H.Klaproth, a German chemist, also found it and gave it its present name. For many years titanium was of interest only to research chemists – it was considered too brittle to be of any practical value. As it forms compounds easily with rarely every known element, it was the impurities* that made it brittle. The chemists in many countries made endless efforts to isolate titanium in its pure form.

Titanium has one surprising property – it is completely inert in biological media. This metal is extensively used in medical industry. Titanium instruments do not corrode, and are 30% lighter than instruments made of stainless steel. Titanium’s high standard of corrosion resistance, lightness, tensile strength and the ease of forging* and rolling* are finding it more and more uses. A combination of high mechanical properties with a low specific weight and excellent corrosion resistance enables titanium to be used in building supersonic* aircrafts. Titanium alloys are very useful in mechanical engineering and for chemical apparatus. Industrial titanium alloys contain vanadium, molybdenum, aluminium, tin, iron, and other elements, singly or in various combinations.

Vocabulary to the text:

• impurities – примеси;

• forging – ковка;

• rolling - прокат;

• supersonic – сверхзвуковой.

Unit 3

Section I

Conversational topic: “PLASTICS”

I. Warming up and Vocabulary Work

I.1 Discuss the following questions.

1. Are plastics widely used today as engineering materials? (Give examples)

2. What properties do plastics possess useful for industrial purposes?

3. Can plastics be widely used in machine-building?

I.2 Alice and Andrew are talking about plastics in the library. Read their dialogue; say what new things you have learnt about plastics.

Alice: Hi, Andrew, are you busy now?

Andrew: yes, I am. I have to draw up a laboratory report. Can you help me do it properly?

Alice: Well as far as I know, a laboratory report must contain the object of the experiment, the results that were obtained and the conclusions.

Andrew: And what about the procedure and the equipment? Must I include them into the report, too?

Alice: In my view, both of them must be included if you need a detailed report. By the way, Andrew, what did you have to determine during your experiment?

Andrew: We had to compare the properties of different plastics.

Alice: And what results did you get?

Andrew: Well, you know that plastics may be divided into thermoplastics and thermosetting plastics. So we have come to the conclusion that thermoplastics may be heated several times, while thermosetting plastics may be heated only once.

Alice: Oh, this is very interesting. And as far as I understand, this peculiarity of plastics must be taken into account when different engineering products are produced.

Andrew: Certainly. And I will have to prove it in my report.

I.3 Give answers to the questions given before the text according to the dialogue.

I.4 Learn the words to the topic; translate them into Russian and remember them:

Nouns	Adjectives	Verbs
molecule chain chemistry cellulose wax coil rubber polyurethane resin plastic thermosets thermoplastics foam sheet film	identical stretched transparent similar sufficient flexible synthetic	synthesize soften harden decompose subject prevent extrude shape mould

I.5 Analyze the formation of the verbs; define the original word as a part of speech.

1. to synthesize 2. to softe 3. to harden 4. to decompose

I.6 Find the corresponding pairs.

1. воск	a. resin
2. молекула	b. rubber
3. химическое вещество	c. plastic
4. резина	d. wax
5. смола	e. chemical
6. пластмасса	f. transparent
7. одинаковый	g. cellulose
8. прозрачный	h. subject
9. подвергать	i. film
10. клетчатка	j. molecule
11. плёнка	k. sheet
12. лист	l. identical

I.7 Make the following nouns plural if possible.

Molecule, chain, chemistry, cellulose, wax, coil, rubber, polyurethane, resin, plastic, film, sheet, foam.

II. Reading Activity and Speech Practice

II.1 While reading the text try to find the information to answer the questions.

1. What does the word “plastic” mean?

2. Who was the first scientist to make the first plastic?

3. What were the first man-made plastics?

4. How were the first plastics used?

Text A: The Plastic Age

It’s in our homes. It’s the most common material in the workplace. Sometimes it’s even in our bodies. We may be moving into the Information Age, but it’s hard to believe that we are not living in the Plastic Age.

The very name “plastic” means versatility. You can bend it, mould it, model it, twist it and play it in a number of different ways. The finished product can be soft and airy foam or a hard and strong compound rivaling the sturdiest metal alloys. In its many forms, plastic has forever changed the way we live.

The first in the long line of man-made plastics was called Bakelite, after its inventor, Leo Baekeland. Many years of work in his chemistry lab in Yonkers, New York, led him to the invention of the first synthetic polymer (plastic) in 1907, made by linking small molecules together to make larger ones.

Baekeland made his new material by mixing the carbolic acid* (phenol) with the strong-smelling formaldehyde to make a third material that was nothing like the original two. It turned out to be a substance that would change the world.

Some of the early uses for plastics were things like radio cabinets, buttons, billiard balls, pipe-stems, toilet seats, airplane parts and, the object of Baekeland’s research, shellac*. Baekeland’s trick was to take resin produced by the two chemicals and heat it under pressure to produce a soft solid that be molded and hardened or powered and set under pressure. With this innovation, the plastic revolution was under way.

Vocabulary to the text:

• carbolic acid* - я кислота;

• shellac* - шеллак.

II.2 Make lists of words connected with: a. - the ways of working plastics;

- the finished products of plastics;

- materials that were used by Baekeland;

- things made of plastics.

b. Explain what are: Bakelite and shellac.

II.3 Say if the sentences are true or false.

1. The 20^th and the 21st centuries are called the age of plastics.

2. Plastics can be worked in many ways.

3. The finished product is always the same: hard foam like substance.

4. The first plastic was made in England in the beginning of the 20^th century.

5. Leo Baekeland joined small molecules together to make large ones.

6. He mixed two different acids to make a third one different from the two first ones.

7. Early uses for plastics were very versatile.

8. Baekeland worked with resins.

II.4 Make a short story to speak about “The substance that changed the world" according to the plan:

1. Properties of plastics.

2. The first man-made plastics.

3. The early use of plastics.

II.5 Read the text and try to understand it in details; translate it into Russian.

Text B: Plastics

Plastics are non-metallic, synthetic, carbon-based materials. They can be moulded, shaped, or extruded into flexible sheets, films, or fibres. Plastics are synthetic polymers. Polymers consist of long-chain molecules made of large numbers of identical small molecules (monomers). The chemical nature of a plastic is defined by monomer (repeating unit) that makes up the chain of the polymer.

The molecules can be either natural – like cellulose, wax, and natural rubber – or - synthetic in polyethylene (polyethene) and nylon. In co- polymers, more than one monomer is used.

Most plastics are synthesized from organic chemicals or from natural gas or oil. Plastics are light-weight compared to metals and are good electrical insulators. The best insulators now are epoxy resins and teflon.

Plastics can be classified into several broad types: thermoplastics and thermosetting plastics and elastomers.

Thermoplastics soften on heating, and then harden again when cooled. Thermoplastic molecules are also coiled and because of this they are flexible and easily stretched.

Typical example of thermoplastics is polystyrene. Polystyrene resins are characterized by high resistance to chemical and mechanical stresses at low temperatures and by very low absorption of water. These properties make polystyrene especially suitable for radio-frequency insulation in airplanes. PET (polyethene terephthalate) is a transparent thermoplastic used for soft-drinks bottles. Thermoplastics are also viscoelastic.

Thermosetting plastics (thermosets) do not soften when heated, and with strong heating they decompose. In most thermosets, final cross-linking, which fixes the molecules; takes place after the plastic has already been formed.

Thermosetting plastics have higher density than thermoplastics. They are less flexible, more difficult to stretch, and are lass subjected to creep. Examples of thermosetting plastics include urea- formaldehyde or polyurethane and epoxy resins, most polyesters, and phenolic polymers such as phenol-formaldehyde resin.

Elastomers are similar to thermoplastics but have sufficient cross-linking between molecules to prevent stretching and creep.

II.6 Give full answer he questions to the text.

1. What is the basic chemical element of plastics?

2. How plastics can be worked?

3. Plastics are synthetic polymers, aren’t they?

4. What are long-chain molecules made of?

5. What kind of molecules make plastics?

6. Are most plastics synthesized from organic or synthetic chemicals?

7. What are the main types of plastics?

II.7 Define the sentences as true or false.

№	Sentences to be regarded	Yes	No
1. 2. 3. 4. 5. 6. 7. 8. 9. 10.	Thermoplastics soften on heating then harden again when cooled. Thermoplastics are highly resistant to chemical and mechanical stresses. They have also very high absorption of water. Polystyrene is a very nice insulator suitable for low temperatures in refrigerators and in airplanes. Thermosetting plastics do not soften when heated. Thermosetting plastics are stronger than thermosets. They are very flexible and easy to creep. Epoxy resins and polyurethane are typical thermoplastics. Elastomers are similar to thermoplastics. Sufficient cross-linking between molecules prevent their stretching and creep.

II.8 Compare the main characteristics of plastics. Fill in the chart.

	Physical properties	Chemical properties	Application
Thermoplastics
Thermosetting plastics

II.9 Your group mates are going to have a seminar on plastics. Choose any of the given topics to take part in the seminar and get ready to speak on it.

1. Plastics as engineering materials.

2. Thermoplastics and their properties.

3. Thermosetting plastics and their types.

II.10 Scan the text. Analyze each paragraph of it to get the general impression of the information given in them.

Text C: Plastics Today

Plastics are large and varied group of materials consisting of carbon and oxygen, hydrogen, nitrogen, and other organic and inorganic elements. While solid in its finished state, a plastic is at some stage in its manufacture, liquid and capable of being formed into various shapes. Forming is most usually done through the application, either singly or together, or heat and pressure. There are over 40 different families of plastics in commercial use today, and each may have dozens of subtypes and variations.

A successful design in plastics is always a compromise among highest performance, attractive appearance, efficient production, and lowest cost. Achieving the best compromise requires satisfying the mechanical requirements of the part, utilizing the most economical resin or compound that will perform satisfactorily, and choosing a manufacturing process compatible with the part design and material choice.

Most people have now outgrown the impression that plastics are low-cost substitute materials. Those that still view plastics as cheap and unreliable have not kept up with developments in polymer technology for the past ten years.

Many plastics did indeed evolve as replacements for natural products such as rubber, ivory, silk or wool, which became unavailable or on short supply. But the new materials did not necessarily replace the older ones permanently not made them obsolete. In many cases, they met an increased demand that neither could nor be met by the natural product alone.

Today’s engineering resins and compounds serve in the most demanding environments. Their toughness, lightness, strength, and corrosion resistance have won many significant applications for these materials in transportation, industrial and consumer products. The engineering plastics are now challenging the domains traditionally held by metals: truly load-bearing, structural parts.

II.11 Restore the correct order of sentences according to the text.

1. People still view plastics as cheap and not reliable enough as an engineering material.

2. Plastics are a large group of materials organized in 40 different families.

3. Plastics are famous for a compromise among attractive mechanical properties, cost and the efficient production.

4. Today plastics are widely used in industrial and consumer production even challenging the domains of metals.

5. Plastics have been evolved to replace natural products or such products which are on short supply.

II.12 How much do we depend on plastics? Read the following arguments and think over our own ones.

We cannot live without plastics.	We can live without plastics.
1. The soles of your shoes are made of plastics. 2. The photographic film is made of it. 3......	1. We can make leather shoes. 2....... 3.......

II.13 Express your opinion on the use of plastics in our everyday life. Don’t you think we too often use plastics and plastic materials in our life and not only in industry? (Use the information given in the text if necessary).

III. Writing Practice

III.1 Translate the following words and word-combinations into Russian. Pay attention to the marked words.

Structural material, application, critical properties, uniform properties, popular material, steel product, to classify, specific strength, hybrid material, specific application, automotive industry.

III.2 Fill in the gaps choosing the one word given in brackets.

Plastics

Plastics are usually produced by synthesis from natural materials as water, air, salt, coal and natural gas. The technology is simple and cheap. While … (solid, cheap, uniform) in finished state, plastics are liquid at some stage of manufacture, and it is easy to form plastics into various shapes. Plastics are different in … (hardness, properties, needs), characteristics and … (pressure, application, thermosets). Plastics are … (reliable, available, thermoplastics) ... (expensive, cheap, structural), durable. Plastics resist … (weight, strength, corrosion). Plastics are machined like … (metals, forgings, carbon).

Their … (lightness, high weight, colour), strengths, hardness, chemical resistance and ... (colour, durability, application) make it possible to use plastics in electric and electronic equipment, transportation, agriculture, etc.

The application of plastics is ... (achieving, satisfying, calling for) the requirements of all industries. There is no industry now where plastics are not used.

Section II

I. Reading Activity and Speech Practice

I.1 Discuss with your friends the following questions. 1. What are “composite materials”?

2. Where are they usually used?

3. Do they have a different chemical composition than plastics?

4. Which materials are more widely used today: plastics or composite materials? Why?

5. Plastics or composites will become the main engineering material in future to your mind?

III.2 Find the corresponding pairs in the table. Put down them in your copybooks.

1.composite material	a. иметь высокие анизотропные свойства
2.unique mechanical properties	b.композитные материалы
3. thin glass fibres	c.расположенные параллельно друг к другу
4.synthetic fibres within the matrix	d. уникальные механические свойства
5. polymer matrix composites	e. принимать во внимание анизотропные свойства
6. to be highly anisotropic	f. тонкое стекловолокно
7.lined up parallel to one another	g. связь между отдельными композитными материалами
8.take anisotropic properties into account	h. новые производственные технологии
9.connections between separate composite materials	i. полимерные матричные композитные материалы
10.new manufacturing techniques	j. помещённый в пластмассовую матрицу
11.imbedded in a plastic matrix	k.синтетические волокна , помещённые в матрицу

III.3 Read the text; translate it into Russian; get ready to discuss it in details.

Text A: Composite Materials.

The combination of two or more different materials is called composite materials. They usually have unique mechanical and physical properties because they combine the best properties of different materials. For example, a fibre-glass reinforced plastic combines the high strength of thin glass fibres with the ductility and chemical resistance of plastic. Nowadays composites are being used for structures such as bridges, boat-building, etc.

Composite materials usually consist of synthetic fibres within a matrix, a material that surrounds and is tightly bound to the fibres. The most widely used type of composite material is polymer matrix composites (PMCs). PMCs consist of fibres made of ceramic material such as carbon or glass embedded in a plastic matrix. Usually the fibres make up about 60% by volume. Composites with metal matrices or ceramic matrices are called metal matrix composites (MMCs) and ceramic matrix composites (CMCs), respectively.

Continuous-fibre composites are generally required for structural applications. The specific strength (strength-to-density ratio) and specific stiffness (elastic modulus ratio) of continuous carbon fibre PMCs, for example, can be better than metal alloys have. Composites can also have other attractive properties, such as high thermal or electric conductivity and a low coefficient of thermal expansion.

Although composite materials have certain advantages over conventional materials, composites also have some disadvantages. For example, PMCs and other composite materials tend to be highly anisotropic- that is, their strength, stiffness, and other engineering properties are different depending on the orientation of the composite material. For example, if PMC is fabricated so that all the fibres are lined up parallel to one another, then PMC will be very stiff in the direction parallel to the fibres, but not stiff in the perpendicular direction. The designer, who uses composite materials in structures subjected to multidirectional forces, must take into account these anisotropic properties. Also, forming strong connections between separate composite material components is difficult.

The advanced composites have high manufacturing costs. Fabricating composite materials is a complex process. However, new manufacturing techniques are developed. It will become possible to produce composite materials at higher volumes and at lower cost than is now possible, accelerating the wider exploitation of these materials.

III.3 Answer the questions to the text. Give full answers using arguments from the text.

1. What is called “composite materials”?

2. What are the best properties of fibre-glass?

3. What do composite materials usually consist of?

4. What is used as matrix in composites?

5. What is used as filler or fibres in composites?

6. What are the main advantages of composite materials?

7. Do they have any disadvantages?

8. Are their anisotropic properties an advantage or disadvantage?

III.4 Make a list of advantages and disadvantages of composite materials.

Advantages: Disadvantages:

1. High strength; 1. Highly anisotropic;

2. ....; 2. ....;

3. .... 3. ....

III.5 Translate the sentences into Russian; use the dictionary if necessary.

1. The combination of two or more different materials is called composite materials.

2. Nowadays composites are being used for structures such as bridges, boat-building, etc.

3. Composite materials usually consist of synthetic fibres within a matrix, a material that surrounds and is tightly bound to the fibres.

4. Usually the fibres make up about 60% by volume.

5. Composites can also have other attractive properties, such as high thermal or electric conductivity and a low coefficient of thermal expansion.

6. The designer, who uses composite materials in structures subjected to multidirectional forces, must take into account these anisotropic properties.

7. The advanced composites have high manufacturing costs.

8. It will become possible to produce composite materials at higher volumes and at lower cost than is now possible, accelerating the wider exploitation of these materials.

III.6 Have you ever seen composite materials? Give your ideas on the use of composite materials in modern industry.

II. Writing Practice

II.1Find in B part the English equivalent to the Russian word in part A.

A	B
изменять благодаря достаточный популярность жёсткий усиливать улучшать преимущество	a. to mod b. to cover c. to replace a. because of b. due to c. thank to a. essential b. sufficient c. efficient a. popular b. popularity c. famous a. stiff b. strong c. soft a. to recycle b. to enhance c. to combine a. to increase b. to improve c. to introduce a. disadvantage b. advantage c. edge

II.2 Complete the text with the words given below.

The materials technology has ... a lot over the past years. New more reliable materials have ... the old ones. Other advances in materials science may lead to further ... performance. Let’s have a look at some examples of sport ... .

Poles are often ... from glass-fibre ... that increase their.... Such poles are lighter and less ... than.... poles.

... and glass-fibre composites are also used for ... hockey sticks. This helps to ... stiffness. ..., such hockey sticks can be ... for players. That is why researchers are trying to ... their performance.

Carbon-fibre composites have also replaced aluminium in tennis.... Such composite rackets have a higher ... than aluminium ..., so rackets can be even stiffer and....

____________________________________________________________

changed performance made

improvements improve equipment

carbon-fibre replace aluminium

alloys composites producing

increase dangerous stiff

stiffness lighter rackets

however

II.3 Translate the passage into Russian use the dictionary if necessary.

Despite well-granted criticism, plastics possess numerous advantages. The most important of them is certainly energy conservation. Here are some simple examples.

Food must be kept fresh and healthy. In fact, each pound of plastic packaging reduces 1.7 pounds of food waste. Besides, plastics make packaging more efficient, which ultimately conserves resources. For example, you need 2 pounds of plastic for delivery of 1.000 ounces of juice. You will have to use 3 pounds of aluminium, 8 pounds of steel or 27 pounds of glass for the same amount of juice. Plastics also help to conserve energy on your home. Vinyl windows lower your heating and cooling bills. Plastics parts and insulation help major appliances – like refrigerators or dishwashers – resist corrosion, last longer and operate more efficiently. Indeed, their energy efficiency has improved by 50 percent since 1970s. Health, safety, high performance – plastics help make these things possible.