Focus: Materials and their properties.

Grammar focus: The Participle.

Skills focus: Reading for specific information to know about materials and their properties, learning basic vocabulary and developing speaking skills.

1. What materials have these properties?

1 soft                                                 6 conductive

2 ductile                                            7 durable and hard

3 malleable                                        8 stiff and brittle

4 tough                                              9 corrosion-resistant

5 scratch-resistant                             10 heat-resistant

Materials	Properties	Uses
1. Aluminium	Easy to shape, light, soft, highly conductive, corrosion-resistant.	Aircraft, engine components, cooking foil, cooking utensils.
2. Copper	Very malleable, tough and ductile, highly conductive, corrosion-resis-tant.	Electric wiring, tubing.
3. Brass (65 % copper, 35 % zinc)	Very corrosion-resistant Casts well, easily machined. Good conductor.	Valves, taps, castings, ship fittings, electrical contacts.
4. Mild steel (iron with 0.15 % to 0.3 % carbon)	High strength, ductile, tough, fairly malleable. Cannot be hardened. Low cost. Poor corrosion resistance.	General purpose.
5. High carbon steel (iron with 0.7 % to 1.4 % carbon)	Hardest of the carbon steels but less ductile and malleable. Can be hardened.	Cutting tools such as drills, files, saws.
6. ABS	High impact strength and toughness, scratch-resistant, light and durable. Easy to shape.	Safety helmets, car components, telephones, kitchenware.
7. Acrylic	Stiff, hard, very durable, can be polished easily, easy to shape.	Aircraft canopies, baths, double glazing.
8. Diamond	Hardest natural material, can cut glass and metal.	Industrial cutting and grinding.
9. Glass	Clear, hard, breaks easily	Windows, bottles.
10. Optical fibre	Carries light and coded messages.	Lighting, cable TV, telecommunications.

 

2. Scan the table to find:

1. a metal used to make aircraft

2. a material used to cut hard substances

3. steel which can be hardened

4. an alloy suitable for castings

5. a material which can carry signals more efficiently than copper cables

6. a material suitable for safety helmets

7. a metal suitable for salt-water environment

8. a metal for general construction use but which should be protected from corrosion

9. a material which is transparent and breaks easily

10. a thermoplastic which can be polished and formed easily.

 

3. What are the objects around you made of/from?

Use Passive Voice: to be + Past Participle.

Do not confuse “made of” and “made from”. “Made of X“ implies that

the X is still (visibly) present.

 

4. Study these facts about aluminium:

Aluminium is a light metal.

Aluminium is used to make aircraft.

We can link these facts to make a definition of aluminium.

Aluminium is a light metal which is used to make aircraft.

 

Make definitions of each of the materials in column A. Choose the correct information in columns B and C to describe the materials in column A.

A	B	C
1. An alloy		allows heat or current to flow easily
2. Mild steel		consists of copper and zinc
3. A conductor		does not allow heat or current to flow easily
4. An insulator	a metal	contains iron and 0.7% to 1.4% carbon
5. High carbon steel	a material	becomes plastic when heated
6. Brass	an alloy	contains iron and 0.15 % to 0.3 % carbon
7. Optical fibres		formed by mixing other metals or elements
8. A thermoplastic		mixed with water (it) dries to a hard material
9. Cement		made from glass and are usually about 120 micrometres in diameter

 

5. Read the text and answer the questions after it.

COMPOSITE MATERIALS

Vocabulary

Fibre               – волокно, нить Fibreglass       – стеклопластик Specific strength  – удельная                           прочность

Reinforced      – упрочненный Expansion       – расширение Specific stiffness – удельная жесткость

The combinations of two or more different materials are called composite materials. They usually have unique mechanical and physical properties because they combine the best properties of different materials. For example, 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 materials is polymer matrix composites (PMCs). PMCs consist of fibres made of ceramic materials such as carbon or glass embedded in a plastic matrix. Usually the fibres make up about 60 per cent 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-to-density 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 electrical 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 or the composite material. For example, if a PMC is fabricated so that all the fibres are lined up parallel to one another, then the PMC will be very stiff in the perpendicular direction. The designer who uses the composite materials in structures subjected to multidirectional forces, must take these anisotropic properties into account. 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 a lower cost than is now possible, accelerating the wider exploitation of these materials.

 

1. What is called composite materials?

2. What are the best properties of fiberglass?

3. What do composite materials usually consist of?

4. What is used as matrix in composites?

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

6. What are composite materials with ceramic and metal matrices called?

7. What are the advantages of composites?

8. What are the disadvantages of composites?

9. Why should anisotropic properties of composites be taken into account?

 

Participle I,II

Participle I	Participle II
Verb + ing	Regular verb + ed or V3
Taking	Taken
doing	Done

 

6. Put the verbs in the correct form.

1 The project _____ (develop) by our specialists is being revised by our director.

2 The woman _____ (speak) now is our new manager.

3 This engine _____ (invent) by our engineers from R&D department is a breakthrough.

4 The scientists_____ (conduct) the research are not able to meet the deadline.

5 New materials ______ (produce) at the plant are very popular with car makers.

6 Some of the questions _____ (put) to the foreman were very important.

7 The translation _____ (make) yesterday was not correct.

 

The Participle has two syntactic functions:

	An Attribute	An Adverbial Modifier
Building     Being built   Built   Having built     Having been built	The young man building our house with me is my brother. Молодой человек, который строит дом вместе со мной, мой брат.   The white stone house being built near the park is a new building of our Art museum. Белокаменное сооружение, строящееся у парка, – новое здание нашего музея изобразительных искусств.   They are reconstructing the house built in the 18th century. Они реставрируют здание, простроенное в XVIII веке.                 –                   –	He made his living building summer houses or garages for people. Он зарабатывал на жизнь, строя людям коттеджи и гаражи. Being built with great skill and care, the mansion has been used by the family for centuries. Так как особняк был построен (будучи простроенным) очень искусно, он служит семье уже несколько веков.   If built of the local stone, the road will serve for years. Если построить дорогу из этого местного камня, она будет служить долгие годы.   Having built the house, he began building a green house. Построив дом, он принялся за теплицу.   Having been built of concrete, the house was always cold in winter. Так как дом был построен из бетона, в нем всегда было холодно зимой.

 

7. Translate the sentences from Russian into English.

1. He left the office at three o’clock, saying he would be back at five.

2. Having signed the letter the manager asked the secretary to send it off at once.

3. Informed of the arrival of the ship, they sent a car to the port.

4. Being checked with great care, the report didn’t contain any errors.

5. These machines will be sent to the plant being constructed in this region.

6. When writing an essay we must use new words and phrases.

7. The figures mentioned in his article were published in the newspaper.

8. Receiving the telegram, he rang the manager up.

8. Paraphrase the sentences using participles instead of underlined parts.

Model:  When he discovered that he had a talent for physics, he gave up his job to enter university.

Discovering that he had a talent for physics, he gave up his job to enter university.

As he had done the task, he left the office.

Having done the task, he left the office.

 

1. When the editor learned that his newspaper had been taken by another publisher, he resigned from his position.

2. I declined his offer of a loan and said that I didn’t like owing people money.

3. The demonstrator who protested violently was led away by the police.

4. When I visit a strange city, I like to have a guide-book with me.

5. Now that I have heard your side of the question, I am more inclined to agree with you.

6. As he had been warned that bad weather lay ahead, the ship’s captain changed the course.

 

9. Write a short (about 200 words) passage about new materials and their properties that you will deal with in your future profession.

 

 

UNIT 5. SAFETY AT WORK

Focus: Safety at work.