In general, metals are good conductors of electricity.

 

Вопросы:

1. На какие группы делятся все металлы?

2. Какой основной компонент черных металлов и сплавов?

3. Черные металлы включают железо, сталь и их сплавы?

4. Металлы важны в создании машин?

5. Железнодорожные пути сделаны из черных металлов, не так ли?

6. Где еще используются черные металлы?

7. В чем различие между черными и цветными металлами?

8. К каким металлам относятся медь и алюминий?

9. Могут металлы поддаваться ковке и протяжке?

10. Все металлы твердые вещества?

11. Металлы могут плавиться?

12. Металлы хорошие проводники электричества?

13. Какие основные свойства металлов?

Text 3.

a) Non-ferrous metals.

Some of their characteristics are: high electric and heat conductivity, high corrosion resistance, non-magnetic quali­ties, light weight and easiness to fabrication.

Zink, copper and lead sulphides, aluminium and tin ox­ides, magnesium, carbonate and chloride are the naturally occuring minerals from which these metals are extracted.

b) Aluminium is the oldest and best known light metal. It is a white silvery metal which does not rust in the air. It is soft, that is why it is used only when alloyed with other metals.

The addition of small quantities of other metals in the making of alloys produces materials which are light but very strong. It is one of the commonest metals in industry. Low weight and resistance to corrosion combine with its tough- ness to make aluminium very suitable for the bodies of vehi­cles and also for castings-gear-boxes, pistons, cylinder heads. It is used for making cooking utensils, ladders, refrigera­tors, wrapping material ("silver paper", milk bottle tops). Its shiny surface reflects heat, and aluminium foil is used for the heat insulation of houses. Aluminium paint protects iron­work from rust, obliterates dark paint, and reflects light. Some important aluminium alloys are magnalium and dura­lumin (95% aluminium +- 4% copper + 1/2% manganese + 1/2% magnesium) which is only half as dense as steel (обладает вдвое меньшей плотностью, чем сталь) but twice as strong; unlike aluminium, it can be tempered by heat treatment; it is used for making aircraft, houses, furni­ture and motor pistons.

Vocabulary:

to rust - ржаветь

addition - добавка, добавление, прибавление

quantity - количество

to combine - сочетать, комбинировать

toughness - жесткость, прочность, упругость

suitable - подходящий, годный

body - тело, корпус (судна, например)

vehicle - сухопутное транспортное средство

castings - формы для литья

gear-box - зубчатая передача

piston - поршень

utensils - посуда, утварь; принадлежности

ladder - приставная лестница

to wrap - завертывать, закутывать

shiny - блестящий

surface - поверхность

foil - фольга

insulation – изоляция

paint - краска

to obliterate - стирать, уничтожать

magnalium - магналит, альмаг (алюминиевомагниевый сплав)

duralumin - дюралюминий, дюраль

dense - плотность, густота; удельный вес

to temper - смягчать, умерять; отпускать (металл)

treatment – обработка

furniture - мебель

е) Copper is found in nature in the form of ores but it is sometimes found in pure state. Pure copper is of reddish colour, and it has corrosion resistant qualities. Copper is the best conductor of electricity. It is used a great deal for elec­trical wiring and cables. It is a good conductor and it is sur­passed only by silver for conductivity of electricity and the making of electrical apparatus is the chief use for copper, e.g. telephone and telegraph cables; electric wiring; parts of dynamos and electric motors. Three important copper alloys are brass, bronze and cupro-nickel (75% copper + 25% nick­el), which is used for the present "silver" coins. An alloy of copper and tin is called bronze.

Vocabulary:

to find, found, found - находить

ore - руда

pure - чистый

to surpass - превосходить, превышать

brass - латунь, желтая медь

bronze - бронза

tin - олово

coin - монета

cupro-nickel - мельхиор, медноникелевый сплав.

d) Tin is a silvery metal which is not corroded by air. The chief use is for making tin plate, i.e. sheetiron coated with tin. Tin plate is suitable for cans in which acid fruit and other food-stuffs are packed because tin is not attacked by weak acids. For good containers, iron is coated with tin instead of zinc because tin is not subject to attack by acids in food.

e) Bronze (20% tin + 80% copper) is very tough; it with­stands shock; it wears well. Bronze is used for making ship propellers, parts of machinery subject to hard wear and for doors and windows.

f) Brass (20% zink + 80% copper) is header and cheaper than copper; it can be turned on a lathe, it can be pressed into shape. It resists corrosion (brass hinges are used in pref­erence to steel if they are exposed to weather).

g) Lead and Zink are also metals which occur in combina­tion with sulphur as sulphides. These metals have been known for a very long time, and each has its own uses.

Lead is now a very expensive metal. At one time it was used extensively for roofing and for water piping because of its softness and resistance to corrosion, but copper and iron have taken its place. Lead is a gray malleable metal which melts at 327 C, which is low for a metal. Lead is still used for roofing and for making waste pipes and sink traps because it is easily bent into shape; storage battery (accumulator) plates; cable sheaths; storage tanks for sulphuric acid; lead shot; solder; screens to stop harmful radiation from radioactive substances. Other lead alloys are type metal (lead + tin + bismuth + cadmium). Lead monoxide is used for making glass that is brilliant and sparking, i.e. decorative tableware.

H) Zink is a moderately hard grey metal which acquires a protective coating of zink oxide on its surface. It burns in oxygen and in chlorine with a bluish flame.

Its colour is yellow when hot and white when cold. Zink oxide is used in paints because it is non-poisonous and is not discoloured by hydrogen sulphide. It has a soothing effect upon the skin and is used in ointments and lotions. It is added to rubber for making racing motor tyres.

Zink is used in the making of dry batteries and in the process of galvanizing. In this, iron is dipped into molten zink, which forms a protective layer on its surface, and so prevents rusting. Galvanized iron is used in sheets for roof­ing and also for buckets and dustbins.

Vocabulary:

To corrode - ржаветь, разъедать

Sheetiron - листовое железо

To coat - окутывать

Can - банка консервов, жестяная банка

Acid - кислый

food-stuffs - продукты питания

to attack - атаковать, наступать

tough - прочный, стойкий, жесткий

To withstand, withstood, withstood - выдержать, противостоять

Shock - удар

Subject - подверженный

To wear, wore, worn - носить, изнашивать

It can be turned on a lathe - его можно обтачивать на станке

Hinges - петли; шарнир

Preference - предпочтение

Lead - свинец

Zink - цинк

To occur - случаться, происходить

Sulphur - сера

Sulphide - сульфид, сернистое соединение expensive - дорогой (о цене)

Extensively - широко, пространно

Roof - крыша

Piping - трубы, трубопровод

Malleable - ковкий, податливый, уступчивый

To melt - плавить, таять, растапливать

Waste pipes - сточная труба

sink traps –

дренажная труба;

trap - сифон, лопушка, западня, капкан; sink - слив, сток, желоб, раковина (для стока воды), грязеприёмник

To bend, bent, bent - сгибать(ся), гнуть(ся) shape - форма

Sheaths - ножны, футляр для ножен

Tank - бак, резервуар

Sulphic acid - серная кислота

Lead shot - пуля, дробь (свинцовые)

Solder – припой

Screen - щит, экран, ширма

Harmful - вредоносный, вредный, губительный

Radiation - радиация, излучение

Bismuth – висмут

monoxide - моноокись, одноокись

Brilliant - бриллиант, блестящий

Sparkling - сверкающий, блестящий moderately – умеренно

To acquire - приобретать, получать

To burn, burnt, burnt - жечь, сжигать, гореть oxygen – кислород

Chlorine – хлор

Bluish - голубоватый, синеватый

Flame – пламя

Paint - краска

Non-poisonous - не ядовитый

Hydrogen – водород

To soothe - успокаивать, облегчать боль

Ointment - мазь

Lotion - примочка, лосьон

Rubber - резина, каучук

To race - быстро двигаться, гнать

Tyre – шина

To dip погружать

Molten - расплавленный, литой

Layer - слой, пласт

To rust - ржаветь

bucket - ведро, бадья; ковш (экскаватора); лопатка

Dustbin - мусорный ящик

Вопросы:

a)

1. Please give the names of all non-ferrous metals known to you.

2. What are their main characteristics?

3. What are these metals by origin?

4. What is the oldest light metal?

5. What is its colour?

b)

1. Give a short charasteristics of aluminium.

2. Is aluminium used as an addition of small quantities of other metals?

3.Why are the alloys of aluminium very common to be used in industry?