English language for technical colleges

b>Toughness is the resistance of a material to breaking when there is a crack in it. For a material of given toughness, the stress at which it will fail is inversely proportional to the square root of the size of the largest defect present. Toughness is different from strength: the toughest steels, for example, are different from the ones with highest tensile strength. Brittle materials have low toughness: glass can be broken along a chosen line by first scratching it with a diamond. Composites can be designed to have considerably greater toughness than their constituent materials. The example of a very tough composite is fiberglass that is very flexible and strong.

Creep resistance is the resistance to a gradual permanent change of shape, and it becomes especially important at higher temperatures. A successful research has been made in materials for machine parts that operate at high temperatures and under high tensile forces without gradually extending, for example the parts of plane engines.

Vocabulary

ability -- способность

amount -- количество

absorb -- поглощать

amount -- количество

application -- применение

brittle -- хрупкий, ломкий

car body -- кузов автомобиля

constituent -- компонент

crack -- трещина

creep resistance -- устойчивость к ползучести

definition -- определение

density -- плотность

ductility -- ковкость, эластичность

failure -- повреждение

gradual -- постепенный

permanent -- постоянный

rigid -- жесткий

to sink -- тонуть

square root -- квадратный корень

stiffness -- жесткость

strain -- нагрузка, напряжение, деформация

strength -- прочность

stress -- давление, напряжение

tensile strength -- прочность на разрыв

toughness -- прочность, стойкость

yield strength -- прочность текучести

Young modulus -- модуль Юнга

General understanding:

1. What is the density of a material?

2. What are the units of density? Where low density is needed?

3. What are the densities of water, aluminium and steel?

4. A measure of what properties is stiffness? When stiffness is important?

5. What is Young modulus?

6. What is strength?

7. What is yield strength? Why fracture strength is always greater than yield strength?

8. What is ductility? Give the examples of ductile materials. Give the examples of brittle materials.

8. What is toughness?

9. What properties of steel are necessary for the manufacturing of: a) springs, b) car body parts, c) bolts and nuts, d) cutting tools?

10. Where is aluminium mostly used because of its light weight?

Exercise 3.3. Find the following words and word combinations in the text:

1. количество массы в единице объема

2. килограмм на кубический метр

3. мера сопротивления деформации

4. отношение приложенной силы на единицу площади к частичной упругой деформации

5. жесткая конструкция

6. прочность на сжатие

7. способность материала деформироваться не разрушаясь

8. поглощать энергию путем деформации

9. обратно пропорционально квадрату размера дефекта

10. постепенное изменение формы

11. повышенные температуры

12. высокие растягивающие усилия

Exercise 3.4. Translate into English the following:

1. Плотность измеряется в килограммах на кубический метр.

2. Большинство материалов имеют более высокую плотность, чем вода и тонут в воде.

3. Плотность материала очень важна, особенно в авиации.

4. Модуль Юнга -- отношение приложенной силы к упругой деформации данного материала.

5. Чем более металл жесткий, тем менее он деформируется под нагрузкой.

6. Когда металл растягивают, он сначала течет, то есть пластически деформируется.

7. Свинец, медь, алюминий и золото -- самые ковкие металлы.

8. Сопротивление ползучести является очень важным свойством материалов, которые используются в авиационных моторах.

«FAMOUS PEOPLE OF SCIENCE AND ENGINEERING»

Sikorsky Igor Ivanovich was a well-known aircraft engineer and manufacturer.

Sikorsky was born in 1889 in Kiev, in the Ukraine, and got his education at the naval college in St. Petersburg, and later in Kiev and Paris. He was the first to make experiments in helicopter design. In 1913 he designed, built, and flew the first successful aeroplane. Later he built military aircrafts for Russia and France.

In 1919 Sikorsky moved to the United States and later helped to organize an aircraft company that produced a series of multiengine flying boats for commercial service. Sikorsky became an American citizen in 1928. In the late 1930s he returned to developing helicopters and produced the first successful helicopter in the west. Helicopters designed by Sikorsky were used mostly by the US Army Air Forces during World War II. He died in 1972 at the age of 83.

Tupolev Andrey Nikolayevich, famous aircraft designer, was born in 1888. He graduated from the Moscow Higher Technical School, where he designed the first Russian wind tunnel. He helped to found the Central Aerohydrodynamics Institute in 1918 and later worked as the head of its design bureau. During his career he directed the design of more than 100 military and commercial aircraft, including the TU-2 and TU-4 bombers used in the World War II. In 1955 he designed the TU-104, the first passenger jet airliner. His TU-144 supersonic jet liner began its commercial passenger flights in 1977.

UNIT 4

MACHINE-TOOLS

I. Text A: «Machine-tools», Text B: «Lathe»,

Text C: «Milling, boring, drilling machines. Shapers and Planers», Text D: «Dies»

II. Famous people of science and technology: George Stephenson, Robert Slephenson.

Text A: «MACHINE-TOOIS»

Machine-tools are used to shape metals and other materials. The material to be shaped is called the workpiece. Most machine-tools are now electrically driven. Machine-tools with electrical drive are faster and more accurate than hand tools: they were an important element in the development of mass-production processes, as they allowed individual parts to be made in large numbers so as to be interchangeable.

All machine-tools have facilities for holding both the workpiece and the tool, and for accurately controlling the movement of the cutting tool relative to the workpiece. Most machining operations generate large amounts of heat, and use cooling fluids (usually a mixture of water and oils) for cooling and lubrication.

Machine-tools usually work materials mechanically but other machining methods have been developed lately. They include chemical machining, spark erosion to machine very hard materials to any shape by means of a continuous high-voltage spark (discharge) between an electrode and a workpiece. Other machining methods include drilling using ultrasound, and cutting by means of a laser beam. Numerical control of machine-tools and flexible manufacturing systems have made it possible for complete systems of machine-tools to be used flexibly for the manufacture of a range of products.

Vocabulary:

machine-tools -- станки

electrically driven -- с электроприводом

shape -- форма

workpiece -- деталь

accurate -- точный

development -- развитие

to allow -- позволять, разрешать

interchangeable -- взаимозаменяемый

facility -- приспособление

relative --относительный

amount -- количество

fluid -- жидкость

to lubricate -- смазывать

spark erosion -- электроискровая обработка

discharge -- разряд

by means of -- посредством

beam -- луч

drilling -- сверление

flexible -- гибкий

range -- ассортимент, диапазон

Text B: «LATHE»

Lathe is still the most important machine-tool. It produces parts of circular cross-section by turning the workpiece on its axis and cutting its surface with a sharp stationary tool. The tool may be moved sideways to produce a cylindrical part and moved towards the workpiece to control the depth of cut. Nowadays all lathes are power-driven by electric motors. That allows continuous rotation of the workpiece at a variety of speeds. The modern lathe is driven by means of a headstock supporting a hollow spindle on accurate bearings and carrying either a chuck or a faceplate, to which the workpiece is clamped. The movement of the tool, both along the lathe bed and at right angle to it, can be accurately controlled, so enabling a part to be machined to close tolerances. Modern lathes are often under numerical control.

Vocabulary:

lathe -- токарный станок

circular cross-section -- круглое поперечное сечение

surface -- поверхность

stationary -- неподвижный, стационарный

sideways -- в сторону

variety -- разнообразие, разновидность

depth -- глубина

headstock -- передняя бабка

spindle -- шпиндель

chuck -- зажим, патрон

faceplate -- планшайба

lathe bed -- станина станка

to enable -- давать возможность

tolerance -- допуск

General understanding:

1. What are machine-tools used for?

2. How are most machine-tools driven nowadays?

3. What facilities have all machine-tools?

4. How are the cutting tool and the workpiece cooled during machining?

5. What other machining methods have been developed lately?

6. What systems are used now for the manufacture of a range of products without the use of manual labor?

7. What parts can be made with lathes?

8. How can the cutting tool be moved on a lathe?

9. How is the workpiece clamped in a lathe?

10. Can we change the speeds of workpiece rotation in a lathe?

11. What is numerical control of machine tools used for?

Exercise 4.1. Find English equivalents in the text:

1. обрабатываемый материал

2. электропривод

3. более точный

4. отдельные детали

5. процесс массового производства

6. приспособления для держания резца и детали

7. операции по механической обработке детали

8. высоковольтный разряд

9. сверление ультразвуком

10. резание с помощью лазерного луча

11. гибкие производственные системы

12. детали круглого сечения

13. поворачивать деталь вокруг ее оси

14. двигать в сторону, двигать по направлению к детали

15. глубина резания

16. непрерывное вращение детали

17. движение резца вдоль станины

Exercise 4.2. Translate into English:

1. Токарный станок позволяет производить детали круглого сечения.

2. Деталь зажимается в патроне или на планшайбе токарного станка.

3. Резец может двигаться как вдоль станины, так и под прямым углом к ней.

4. Современные токарные станки часто имеют цифровое управление.

Text С: «MILLING MACHINE»

In a milling machine the cutter (фреза) is a circular device with a series of cutting edges on its circumference. The workpiece is held on a table that controls the feed against the cutter. The table has three possible movements: longitudinal, horizontal, and vertical; in some cases it can also rotate. Milling machines are the most versatile of all machine tools. Flat or contoured surfaces may be machined with excellent finish and accuracy. Angles, slots, gear teeth and cuts can be made by using various shapes of cutters.

Drilling and Boring Machines

To drill a hole usually hole-making machine-tools are used. They can drill a hole according to some specification, they can enlarge it, or they can cut threads for a screw or to create an accurate size or a smooth finish of a hole.

Drilling machines (сверлильные станки) are different in size and function, from portable drills to radial drilling machines, multispindle units, automatic production machines, and deep-hole-drilling machines.

Boring (расточка) is a process that enlarges holes previously drilled, usually with a rotating single-point cutter held on a boring bar and fed against a stationary workpiece.

Shapers and Planers

The shaper (поперечно-строгальный станок) is used mainly to produce different flat surfaces. The tool slides against the stationary workpiece and cuts on one stroke, returns to its starting position, and then cuts on the next stroke after a slight lateral displacement. In general, the shaper can make any surface having straight-line elements. It uses only one cutting-tool and is relatively slow, because the return stroke is idle. That is why the shaper is seldom found on a mass production line. It is, however, valuable for tool production and for workshops where flexibility is important and relative slowness is unimportant.

The planer (продольно-строгальный станок) is the largest of the reciprocating machine tools. It differs from the shaper, which moves a tool past a fixed workpiece because the planer moves the workpiece to expose a new section to the tool. Like the shaper, the planer is intended to produce vertical, horizontal, or diagonal cuts. It is also possible to mount several tools at one time in any or all tool holders of a planer to execute multiple simultaneous cuts.

Grinders

Grinders (шлифовальные станки) remove metal by a rotating abrasive wheel. The wheel is composed of many small grains of abrasive, bonded together, with each grain acting as a miniature cutting tool. The process gives very smooth and accurate finishes. Only a small amount of material is removed at each pass of the wheel, so grinding machines require fine wheel regulation. The pressure of the wheel against the workpiece is usually very light, so that grinding can be carried out on fragile materials that cannot be machined by other conventional devices.

Vocabulary:

milling machine -- фрезерный станок

series -- серия, ряд

cutting edge -- режущий край, острие

circumference -- окружность

to feed -- подавать

longitudinal-- продольный

horizontal -- горизонтальный

vertical -- вертикальный

versatile -- универсальный

flat -- плоский

contoured -- контурный

angle -- угол

slot -- прорезь, паз

gear teeth -- зубья шестерни

drill -- дрель, сверло, сверлить

hole -- отверстие

to enlarge -- увеличивать

thread -- резьба

portable -- портативный

unit -- единица, целое, узел

previously -- ранее

to slide -- скользить

stroke -- ход

lateral -- боковой

displacement -- смещение

straight -- прямой

idle -- на холостом ходу

workshop -- цех, мастерская

to mount -- крепить

holder -- держатель

to execute -- выполнять

simultaneous -- одновременный

multiple -- многочисленный

grinder -- шлифовальный станок

wheel -- круг, колесо

bonded -- скрепленный

to remove -- удалять

pass -- проход

fine -- точный

conventional -- обычный

device -- устройство, прибор

fragile -- хрупкий

General understanding:

1. What is the shape of a cutter in a milling machine?

2. What moves in a milling machine, a table or a cutter?

3. What possible movements has the table of a milling machine?

4. What kind of surfaces and shapes may be machined by a milling machine?

5. What can we use a drilling machine for?

6. What kinds of drilling machines exist?

7. What is rotated while boring, a cutter or a work-piece?

8. Describe the work of a shaper (planer).

9. What must be done to execute multiple simultaneous cuts on a planer?

10. What is the working tool in a grinder?

11. Can we obtain a very smooth surface after grinding and why? 12. Can we grind fragile materials and why?

Exercise 4.3. Translate into English:

1. Токарный станок все еще остается самым важным станком.

2. Все современные токарные станки оборудованы электроприводами.

3. Движение инструмента контролируется с высокой точностью.

4. Электропривод позволяет обрабатывать заготовку на различных скоростях.

Text D: «DIES»

Dies are tools used for the shaping solid materials, especially those employed in the pressworking of cold metals.

In presswork, dies are used in pairs. The smaller die, or punch, fits inside the larger die, called the matrix or, simply, the die. The metal to be formed, usually a sheet, is placed over the matrix on the press. The punch is mounted on the press and moves down by hydraulic or mechanical force.

A number of different forms of dies are employed for different operations. The simplest are piercing dies (пробивной штамп), used for punching holes. Bending and folding dies are designed to make single or compound bends. A combination die is designed to perform more than one of the above operations in one stroke of the press. A progressive die permits successive forming operations with the same die.

In coining, metal is forced to flow into two matching dies, each of which bears a engraved design.

Wiredrawing Dies

In the manufacture of wire, a drawplate (волочильная доска) is usually employed. This tool is a metal plate containing a number of holes, successively less in diameter and known as wire dies. A piece of metal is pulled through the largest die to make a coarse wire. This wire is then drawn through the smaller hole, and then the next, until the wire is reduced to the desired measurement. Wiredrawing dies are made from extremely hard materials, such as tungsten carbide or diamonds.

Thread-Cutting Dies

For cutting threads on bolts or on the outside of pipes, a thread-cutting die (резьбонарезная плашка) is used. It is usually made of hardened steel in the form of a round plate with a hole in the centre. The hole has a thread. To cut an outside thread, the die is lubricated with oil and simply screwed onto an unthreaded bolt or piece of pipe, the same way a nut is screwed onto a bolt. The corresponding tool for cutting an inside thread, such as that inside a nut, is called a tap (метчик).

Vocabulary:

chip -- стружка

sharp -- острый

friction -- трение

content -- содержание

range -- диапазон

inexpensive -- недорогой

to permit -- позволять, разрешать

common -- обычный

tungsten -- вольфрам

ingredient -- ингредиент

diamond -- алмаз

tips -- наконечники

ceramic -- керамический

truing -- правка, наводка, заточка

die -- матрица, штамп

matrix -- матрица

to employ -- применять

to pierce -- протыкать, прокалывать

to punch -- пробивать отверстие

matching -- сочетающийся, парный

coarse -- грубый

wire -- проволока

to draw -- тащить, волочить

thread -- резьба

hardened -- закаленный

to lubricate -- смазывать

to screw -- привинчивать

nut -- гайка

outside -- наружный, внешний

inside -- внутри, внутренний

Exercise 4.4. Find English equivalents in the text:

1. удалять металлическую стружку

2. острый режущий край

3. содержание углерода

4. режущая способность

5. сталь для скоростного резания

6. правка шлифовальных кругов

7. гидравлическое или механическое давление

8. различные формы штампов

Exercise 4.5. Translate the following sentences into Russian:

1. Все резцы и фрезы должны иметь острую режущую кромку.

2. Во время резания режущий инструмент и деталь имеют высокую температуру и должны охлаждаться.

3. Углеродистые стали часто используются для изготовления резцов потому, что они недорогие.

4. Быстрорежущие стали содержат вольфрам, хром и ванадий.

5. Алмазы используются для резания абразивных материалов и чистовой обработки поверхности твердых материалов.

6. Для различных операций используют различные штампы.

7. Волочильные доски для проволоки делаются из очень твердых материалов.

8. Резьбонарезные плашки и метчики используются для нарезки резьбы снаружи и внутри.

FAMOUS PEOPLE OF SCIENCE AND ENGINEERING

George Stephenson

George Stephenson was a British inventor and engineer. He is famous for building the first practical railway locomotive.

Stephenson was born in 1781 in Wylam, near Newcastle upon Tyne, Northumberland. During his youth he worked as a fireman and later as an engineer in the coal mines of Newcastle. He invented one of the first miner's safety lamps independently of the British inventor Humphry Davy. Stephenson's early locomotives were used to carry loads in coal mines, and in 1823 he established a factory at Newcastle for their manufacture. In 1829 he designed a locomotive known as the Rocket, which could carry both loads and passengers at a greater speed than any locomotive constructed at that time. The success of the Rocket was the beginning of the construction of locomotives and the laying of railway lines.

Robert Stephenson, the son of George Stephenson was a British civil engineer. He is mostly well-known known for the construction of several notable bridges.

He was born in 1803 in Willington Quay, near Newcastle upon Tyne, and educated in Newcastle and at the University of Edinburgh. In 1829 he assisted his father in constructing a locomotive known as the Rocket, and four years later he was appointed construction engineer of the Birmingham and London Railway, completed in 1838. Stephenson built several famous bridges, including the Victoria Bridge in Northumberland, the Britannia Bridge in Wales, two bridges across the Nile in Damietta in Egypt and the Victoria Bridge in Montreal, Canada. Stephenson was a Member of Parliament from 1847 until his death in 1859.

UNIT 5

PLASTICS

I. Text A: «Plastics», Text B: «Types of plastics», Text C: «Composite Materials»

II. Famous People of Science: Alfred Bernhard Nobel.

Text A: «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 the monomer (repeating unit) that makes up the chain of the polymer. Polyethene is a polyolefin; its monomer unit is ethene (formerly called ethylene). Other categories are acrylics (such as polymethylmethacrylate), styrenes (such as polystyrene), vinys (such as polyvinyl chloride (PVC)), polyesters, polyurethanes, polyamides (such as nylons), polyethers, acetals, phenolics, cellulosics, and amino resins. The molecules can be either natural -- like cellulose, wax, and natural rubber -- or synthetic -- in polyethene and nylon. In co-polymers, more than one monomer is used.

The giant molecules of which polymers consist may be linear, branched, or cross-linked, depending on the plastic. Linear and branched molecules are thermoplastic (soften when heated), whereas cross-linked molecules are thermosetting (harden when heated).

Most plastics are synthesized from organic chemicals or from natural gas or coal. Plastics are light-weight compared to metals and are good electrical insulators. The best insulators now are epoxy resins and teflon. Teflon or polytetrafluoroethene (PTFE) was first made in 1938 and was produced commercially in 1950.

Plastics can be classified into several broad types.

1. Thermoplastics soften on heating, 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 the polystyrenes especially suitable for radio-frequency insulation and for parts used at low temperatures in refrigerators and in airplanes. PET (polyethene terephthalate) is a transparent thermoplastic used for soft-drinks bottles. Thermoplastics are also viscoelastic, that is, they flow (creep) under stress. Examples are polythene, polystyrene and PVC.

2. 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 a higher density than thermoplastics. They are less flexible, more difficult to stretch, and are less 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.

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

Vocabulary:

carbon -- углерод

flexible -- гибкий

fibre -- волокно, нить

chain -- цепь

identical -- одинаковый, идентичный

molecule -- молекула

branch -- разветвленный

to synthesize -- синтезировать

chemicals -- химические вещества

to soften -- смягчать

cellulose -- клетчатка, целлюлоза

wax -- воск

thermosetting plastics -- термореактивные пластмассы

to harden -- делать твердым

coil -- спираль

stretched -- растянутый

transparent -- прозрачный

rubber -- резина, каучук

to decompose -- разлагаться

soft-drink -- безалкогольный напиток

to subject -- подвергать

polyurethane -- полиуретан

resin -- смола

similar -- сходный, подобный

sufficient -- достаточный

to prevent -- предотвращать

General understanding

1. What is the definition of plastics?

2. What is the basic chemical element in plastics formula?

3. What do polymers consist of?

4. What are long-chain molecules made of?

5. What are the main types of polymers?

6. Give examples of plastics belonging to these types.

7. What plastics are the best electrical insulators?

8. Describe the difference between thermoplastics and thermosets.

9. What are the main types of structures of polymers?

10. What are the most important properties of plastics?

11. Give the examples of various uses of plastics because of their characteristic properties.

Exercise 5.1. Find English equivalents in the text:

1. синтетические полимеры

2. молекулы с длинными цепями

3. характерные свойства полимера

4. синтезируются из органических химических веществ

5. хороший электрический изолятор

6. размягчаться при нагревании

7. затвердевать при охлаждении

8. гибкий и легко растяжимый

9. течь под нагрузкой

10. более высокая плотность

11. менее подвержены ползучести

12. достаточная взаимосвязь между молекулами

Exercise 5.2. Translate into English:

1. Длинные цепи молекул полимеров состоят из одинаковых небольших молекул мономеров.

2. Сополимеры состоят из двух и более мономеров.

3. Пластмассы можно получать в виде листов, тонких пленок, волокон или гранул.

4. Молекулы полимеров могут быть линейными, ветвящимися или с поперечными связями.

5. Малый вес пластмасс и хорошие электроизоляционные свойства позволяют использовать их в радиоэлектронике и электроприборах, а также вместо металлов.

6. Молекулы термопластов имеют извитую форму и, поэтому, они гибкие и легко растяжимы.

7. Эластомеры имеют большое число поперечных связей между молекулами.

Text В: «TYPES OF PLASTICS»
1. Epoxy resin.

Epoxy resin is a thermoset plastic containing epoxy groups. Epoxy resin hardens when it is mixed with solidifier and plasticizer. Plasticizers make a polymer more flexible.

Epoxy resins have outstanding adhesion, toughness, and resistance to attack from chemicals. They form strong bonds and have excellent electrical insulation properties. Large, complex, void-free castings can be made from them. They are also used as adhesives, and in composites for boat building and sports equipment.

2. PVC (polyvinyl chloride)

PVC (polyvinyl chloride) is a thermoplastic polymer made from vinyl chloride is a colourless solid with outstanding resistance to water, alcohols, and concentrated acids and alkalis. It is obtainable as granules, solutions, lattices, and pastes. When compounded with plasticizers, it yields a flexible material more durable than rubber. It is widely used for cable and wire insulation, in chemical plants, and in the manufacture of protective garments. Blow moulding of unplasticized PVC produces clear, tough bottles which do not affect the flavour of their contents. PVC is also used for production of tubes or pipes.

3. Polystyrene.

Polystyrene is a thermoplastic produced by the polymerization of styrene. The electrical insulating properties of polystyrene are outstandingly good and it is relatively unaffected by water. Typical applications include light fixtures, toys, bottles, lenses, capacitor dielectrics, medical syringes, and light-duty industrial components. Extruded sheets of polystyrene are widely used for packaging, envelope windows, and photographic film. Its resistance to impact can be improved by the addition of rubber modifiers. Polystyrene can be readily foamed; the resulting foamed polystyrene is used extensively for packaging.

4. Polythene (polyethene, polyethylene)

Polythene (polyethene, polyethylene) is a plastic made from ethane. It is one of the most widely used important thermoplastic polymers. It was first developed by the polymerization of ethane at a pressure of 2,000 bar at 200°C. This produced low-density polythene (LDPE). A relatively high-density form (HDPE) was synthesized in the 1950s using a complex catalyst. Polythene is a white waxy solid with very low density, reasonable strength and toughness, but low stiffness. It is easily moulded and has a wide range of uses in containers, packaging, pipes, coatings, and insulation.

Vocabulary:

adhesion -- прилипание

adhesive -- клей

bond -- связи, узы

insulation -- изоляция

casting -- литье

void -- пустота

solid -- твердое тело, твердый

acid -- кислота

alkali -- щелочь

to obtain -- доставать, получать

granule -- гранула

solution -- раствор

lattices -- латексы

paste -- паста

yield -- выход

durable -- прочный

rubber -- резина, каучук

garment -- предметы одежды

lens --линза

capacitor -- эл. конденсатор

syringe -- шприц

light-duty -- неответственный

envelope -- зд. обрамление

impact -- удар

improved -- улучшенный

modifiers -- модификаторы

addition -- добавление

readily -- легко, с готовностью

foam -- пена

catalyst -- катализатор

wax -- воск

reasonable -- приемлемый, неплохой

coating -- слой, покрытие

General understanding:

1. What are the types of plastics?

2. What are the features of the epoxy resin?

3. What is epoxy resin used for?

4. What is PVC usually used for?

5. What are the typical applications of polystyrene?

6. When was polyethylen synthesized?

7. Under what conditions is polyethylen synthesized?

8. What sorts of polyethylen can be synthesized?

Exercise 5.3. Translate into Russian:

1. Polythene is a plastic made from ethane.

2. Epoxy resins have outstanding adhesion, toughness and resistance to attack from chemicals.

3. PVC is a colourless solid with outstanding resistance to water, alcohols, and concentrated acids and alkalis.

4. Polystyrene is a thermoplastic produced by the polymerization of styrene.

5. Polythene is a white waxy solid with very low density, reasonable strength and toughness but low stiffness.

Exercise 5.4. Translate into English:

1. Эпоксидная смола затвердевает когда смешивается с отвердителем и пластификатором.

2. Эпоксидные смолы используются в качестве клея, а с добавками -- в строительстве лодок и спортивного снаряжения.

3. ПВХ -- бесцветное твердое вещество с выдающейся устойчивостью к воздействию воды, спиртов, концентрированных кислот и щелочей.

4. ПВХ широко используется при производстве изоляции для проводов.

5. Выдувка непластифицированного ПВХ используется при производстве прозрачных бутылок для напитков.

6. Полистирол легко вспенивается и используется для упаковки.

7. Полиэтилен -- воскообразное вещество белого цвета с очень низкой плотностью и малой жесткостью.

Text С: «COMPOSITE MATERIALS»

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, 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 a ceramic material 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 of 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 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 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.

Vocabulary:

fibreglass -- стекловолокно

fibre -- волокно, нить

reinforced -- упрочненный

expansion -- расширение

matrix -- матрица

ceramic -- керамический

specific strength -- удельная прочность

specific stiffness -- удельная жесткость

anisotropic -- анизотропный

General understanding:

1. What is called «composite materials»?

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

3. What do composite material usually consist of?

4. What is used as matrix in composites?

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

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

7. What are the advantages of composites?

8. What are the disadvantages of composites?

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

Exercise 5.5. Find equivalents in the text:

1. композитные материалы

2. уникальные механические качества

3. полимерные матричные композиты

4. составлять 60% объема

5. углепластик

6. привлекательные качества

7. структура, подвергающаяся воздействию разнонаправленных сил

Exercise 5.6. Translate into Russian:

1. PMC is fabricated so that all the fibres are lined up parallel to one another.

2. Forming strong connections between separate composite material components is difficult.

3. Fabricating composite materials is a complex process.

4. Composite materials have certain advantages over conventional materials

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

6. Continuous-fibre composites are generally required for structural applications.

FAMOUS INVENTORS

Alfred Bernhard Nobel was a famous Swedish chemist and inventor. He was born in Stockholm in 1833. After receiving an education in St. Petersburg, Russia, and then in the United States, where he studied mechanical engineering, he returned to St. Petersburg to work with his father in Russia. They were developing mines, torpedoes, and other explosives.

In a family-owned factory in Heleneborg, Sweden, he developed a safe way to handle nitroglycerine, after a factory explosion in 1864 killed his younger brother and four other people. In 1867 Nobel achieved his goal: he produced what he called dynamite динамит. Не later produced one of the first smokeless powders (порох). At the time of his death he controlled factories for the manufacture of explosives (взрывчатое вещество) in many parts of the world. In his will he wanted that the major portion of his money left became a fund for yearly prizes in his name. The prizes were to be given for merits (заслуги) in physics, chemistry, medicine and physiology, literature, and world peace. A prize in economics has been awarded since 1969.

UNIT 6

WELDING

I. Text A: «Welding», Text В: «Other types of welding»

II. Famous People of Science and Technology: James Prescott Joule.

Text A: «WELDING»

Welding is a process when metal parts are joined together by the application of heat, pressure, or a combination of both. The processes of welding can be divided into two main groups:

* pressure welding, when the weld is achieved by pressure and

* heat welding, when the weld is achieved by heat. Heat welding is the most common welding process used today.

Nowadays welding is used instead of bolting and riveting in the construction of many types of structures, including bridges, buildings, and ships. It is also a basic process in the manufacture of machinery and in the motor and aircraft industries. It is necessary almost in all productions where metals are used.

The welding process depends greatly on the properties of the metals, the purpose of their application and the available equipment. Welding processes are classified according to the sources of heat and pressure used.

The welding processes widely employed today include gas welding, arc welding, and resistance welding. Other joining processes are laser welding, and electron-beam welding.

Gas Welding

Gas welding is a non-pressure process using heat from a gas flame. The flame is applied directly to the metal edges to be joined and simultaneously to a filler metal in the form of wire or rod, called the welding rod, which is melted to the joint. Gas welding has the advantage of using equipment that is portable and does not require an electric power source. The surfaces to be welded and the welding rod are coated with flux, a fusible material that shields the material from air, which would result in a defective weld.

Arc Welding

Arc-welding is the most important welding process for joining steels. It requires a continuous supply of either direct or alternating electrical current. This current is used to create an electric arc, which generates enough heat to melt metal and create a weld.

Arc welding has several advantages over other welding methods. Arc welding is faster because the concentration of heat is high. Also, fluxes are not necessary in certain methods of arc welding. The most widely used arc-welding processes are shielded metal arc, gas-tungsten arc, gas-metal arc, and submerged arc.

Shielded Metal Arc

In shielded metal-arc welding, a metallic electrode, which conducts electricity, is coated with flux and connected to a source of electric current. The metal to be welded is connected to the other end of the same source of current. An electric arc is formed by touching the tip of the electrode to the metal and then drawing it away. The intense heat of the arc melts both parts to be welded and the point of the metal electrode, which supplies filler metal for the weld. This process is used mainly for welding steels.

Vocabulary:

to join -- соединять

pressure welding -- сварка давлением

heat welding -- сварка нагреванием

instead -- вместо, взамен

bolting -- скрепление болтами

riveting -- клепка

basic -- основной

to manufacture -- изготовлять

to depend -- зависеть от

purpose -- цель

available -- имеющийся в наличии

equipment -- оборудование

source -- источник

gas welding -- газосварка

arc welding -- электродуговая сварка

resistance welding -- контактная сварка

laser welding -- лазерная сварка

electron-beam welding -- электронно-лучевая сварка

flame -- пламя

edge -- край

simultaneously -- одновременно

filler -- наполнитель

wire -- проволока

rod -- прут, стержень

to melt -- плавить(ся)

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