METALS FOR MOTORING

The parts of your car come in all kinds of different shapes and sizes and, what is equally important, in a wide variety of different materials. Let us have an in-depth look at car materials.

Iron. Obviously the bulk of a motor car is made from metals based on iron. Iron is an element that has a chemical symbol Fe and is the father of the ferrous family. It is obtained by filling a blast furnace with iron oxides or carbonates and coke, setting light to the mass and blowing air through it. The carbon in the coke and the oxygen in the iron oxide combine to produce carbon monoxide that burns and takes more oxygen from the iron part of the furnace charge to give carbon dioxide. As the temperature increases the iron melts and, from time to time, is allowed to flow out of the bottom of the furnace into special troughs cut into the sand floor of the iron works.

Blast furnace-produced iron, the basic material of steels, contains between 3 and 4% of carbon and smaller percentages of impurities such as sulphur, silicon, phosphorus and manganese.

Cast iron. Ordinary cast iron is produced by melting pig iron and pouring it into moulds, made of sand, to get it to set into complex shapes. It is a cheap material that is soft, fairly brittle and unsuitable for anything that takes a tension or bending load. In compression there is virtually no plastic deformation or elasticity; it just suddenly fractures across a plane at about 55°. So cast iron is used for castings such as crank-cases, gearboxes and rear axles. If the pig iron used for casting is specially selected to have smaller amounts of carbon and a low sulphur and phosphorous content and the rate of cooling the casting is controlled to a slow rate, then the structure of the iron is improved. The graphite can be made to form into balls or nodules, which are much stronger than the usual plates or starfish shapes and the iron part tends to form as pearlite. These cast irons are two or three times as strong in tension as ordinary grey cast iron and have a certain amount of elasticity and less brittleness. They are used for crankshafts as it is much easier to cast a crankshaft shape than to forge it.

Copper. The main constituent of the brass/bronze family is copper, which is obtained by roasting the copper sulphide ores to remove the arsenic and antimony impurities and then smelting the ores in a furnace to produce the molten metal. Copper is soft, ductile and easily worked and is difficult to produce in a really pure state. Plain copper is seldom used for anything but electrical components in cars, due to its low resistance. It is used for pipework because of its ductility, but has been replaced by cheaper and better materials.

Aluminium is produced by electrolytic means from bauxite, an aluminium hydroxide, and makes a good clean casting with a fairly coarse grain structure. It is a fair substitute for cast iron except that it is a bit more ductile. On the other hand, it can be rolled or drawn into sheets, rods, and tubes that can be bent due to their ductility whereas cast iron cannot. The aluminium alloys with copper, manganese, silicon and nickel are pretty numerous and are selected either for their corrosion resistance, high electrical conductivity, ductility or higher strength.

2.Find in the text English equivalents to the following words and word combinations:

хімічний символ, отримувати, доменна піч, спеціальний жолоб, процентне співвідношення, компресія, картер, коробка передач, еластичність, відпал, в’язкий.

3.Find odd words:

conductivity, ductility, strength, similarity; shape, model, example, pattern;

aluminium, bronze, copper, zinc; amount, quantity, structure, number.

4.Make word combinations from the following words and translate them into Ukrainian:

5.Put the verbs in brackets either in Present Perfect or in Present Simple Tense.

1. The bulk of a motor car already (to be made) from metals based on iron.

2. Cast iron (to be used) for casting since 20^th century.

3. Iron (to be obtained) by filling a blast furnace with iron oxides or carbonates and coke.

4. As the temperature already (to increase) the iron (to melt).

5. Ordinary cast iron (to be produced) by melting pig iron.

6. Copper (to be used) since the ancient times.

7. Copper (to be used) for electrical components in cars due to its low resistance.

6. Answer the following questions:

1. What is the father of the ferrous family?

2. How is iron obtained?

3. How much carbon does blast furnace-produced iron contain?

4. What is the procedure of producing cast iron?

5. What castings are made of cast iron?

6. What is the main constituent of the brass/bronze family?

7. Why is it difficult to produce copper in a really pure state?

8. What is aluminium produced from?

UNIT 4

Section 1

1. Read and translate the following text:

THE PERIODIC TABLE OF ELEMENTS (I)

This table shows the known elements in the order of the strength of the electrical charge on their nuclei, or inner portions. Elements in the same column are usually similar chemically. At least 88 of the first 92 elements are found in nature. Elements 93 and above were produced synthetically during and after the development of the atomic bomb.

Elements to the left of the heavy zigzag line are metals. Those to the right are non-metals, although boron, silicon, carbon, selenium, and tellurium are sufficiently metallic in character to be called metalloids.

Elements in the two strips below the main table Abe called rare earths. The upper strip contains the lanthanide series. These elements have such close chemical similarities that separation of some of them has been difficult. Most of the actinide series, lower strip, show radioactivity.

In September 1949 the International Union of Chemistry met at Amsterdam and recommended that tungsten henceforth be called wolfram, columbium be called niobium and beryllium be renamed glucinium. Although chemists in the United States have accepted the change from columbium to niobium, many, if not most, metallurgists have not. The other two suggested changes have not made headway. The Union recommended also that the names of elements 71 and 91 be spelled lutetium and protactinium, respectively. This recommendation has been followed.

2. Find in the text English equivalents to the following words and word combinations:

електричний заряд, ядро, виробляти синтетично, атомна бомба, бор, кремній, вуглець, селен, телур, металоїди, віднині.

3. Make up word combinations from the following words and translate them into Ukrainian:

charge, changes, electrical, to produce, actinide, inner, series, portion, to suggest, synthetically.

4. Put in appropriate modal verbs in the blank spaces. Choose the one that seems to you the most suitable.

1. You _____ learn the places of the elements in the table; it shows the known elements in the order of the strength of the electrical charge on their nuclear.

2. You _____ learn the strength of electrical charges of all elements.

3. You _____ know the strength of electrical charges of 92 elements.

4. Tungsten _____ be called wolfram.

5. Columbium _____ be changed to niobium, this element is used as columbium all over the world.

5. Transform the following sentences into the Simple Past Tense. Make any necessary alterations to ‘time phrases’.

1. The table must show the known elements in the order of the strength of the electrical charge on their nuclei.

2. These elements must be produced synthetically.

3. The tungsten must be called wolfram.

4. The beryllium must be renamed glucinium.

5. You must follow these recommendations.

6. Answer the following questions:

1. How many elements are found in nature?

2. What metals are called metalloids?

3. When was tungsten decided to be called wolfram?

4. How were columbium and beryllium named?

5. Who accepted the change from columbium to niobium?

Section 2

1.Read and translate the following text:

THE PERIODIC TABLE OF ELEMENTS (II)

When all of the metals are to be considered as a group, an advantage may be gained if their names are set down in tabular form. This table is a modification of an arrangement made by the Russian chemist Mendeleyev about 1870. This table shows the known elements in the order of the strength of the electrical charge on their nuclei, or inner portions. Elements in the same column are usually similar chemically. At least 88 of the first 92 elements are found in nature. Elements 93 and above were produced synthetically during and after the development of the atomic bomb.

In the table the elements are placed in the order of the strength of the positive electrical charge on the nuclei of their atoms. This strength is indicated by the number in the box above each element. Not only does this number, called the “atomic number”, indicate the charge on the nucleus but it specifies, also, the number of electrons surrounding the nucleus. The combined charge of the electron “cloud” – that is, the outer portion of the atom – must be equal in magnitude and opposite in sign to the charge on the nucleus. Otherwise, the atom would not be electrically neutral. The nature of the electron cloud is very important because it determines the chemical and physical properties of the element.

The table makes possible a quick determination of whether an element is a metal or a non-metal. Elements to the left of the heavy, stepped line near the right of the table are metals. Elements to the right of this line are not metals although those immediately to the right, boron, silicon, selenium, tellurium and polonium, are sufficiently metal-like to be called “metalloids”.

While the periodic table is being considered, two points of historical interest may be mentioned. The first refers to the names of metals. One notes that many of the names end in “-ium”. They are the more recently discovered metals, mainly those found in the nineteenth and twentieth centuries. The metals known to the ancient world and those discovered in later times into the eighteenth century were named before the -ium system was established. Examples of such metals are iron, lead, copper, and zinc.

The second point concerns “naturally occurring” and “artificial” elements. With the exception of numbers 43, 61, 85, and 87, all of the elements up to and including 92, uranium, have been found in nature, mainly in ores. Some doubt exists as to whether elements 43 and 61 occur naturally. If they do, the amounts are near the limit of detectability. The four elements mentioned and all of those with numbers higher than 92 have been produced artificially during research related to atomic weapons and nuclear reactors. Including those made artificially, 103 elements are known, of which approximately 75% are metals.

2. Find in the text English equivalents to the following words and word combinations:

отримувати перевагу, модифікація, електричний заряд, внутрішні частини, електрон, ядро, швидке визначення, “штучні” елементи, атомна зброя.

3. Make up word combinations from the following words and translate them into Ukrainian:

portions, artificial, cloud, atomic, electrical, number, charge, inner, electron, elements.

4. Find in the text antonyms to the following words:

disadvantage, different, negative, unequal, natural.

5.Combine the following simple sentences into a complex ones by using relative pronouns who, which, that:

who (used for people), which (used for things), that (used for people and things)

1. This table is a modification of an arrangement. It was made by the Russian chemist Mendeleyev.

2. The strength is indicated by the number in the box above each element. The number is called as “the atomic number”.

3. Mendeleyev was the greatest Russian chemist. He arranged the table of elements in the order of the strength of the electrical charge.

4. The strength is indicated by the number in the box. It can be seen above each element.

5. The table makes possible a quick determination of elements. Elements are indicated as metals and non-metals.

6. Complete the following sentences by adding a clause:

1. Mendeleyev declared that …

2. He said that elements ...

3. Scientists discovered that …

4. He declared that the table …

5. The reporter mentioned that …

6. One notes that …

7. Complete the following sentences by adding the clauses:

1. An advantage may be gained if ...

2. Two points of historical interest may be mentioned while …

3. The nature of the electron cloud is very important, because …

4. Elements to the right of this line are not metals although ...

8. Read the sentences and say whether they are true or false.

1. This table was made by the Russian chemist Mendeleyev about 1870.

2. This table shows the known elements in the order of the strength of the electrical charge on their nuclei, or inner portions.

3. All elements in the table are found in nature.

4. Elements to the left of the heavy, stepped line near the right of the table are non-metals.

5. The names of the recently discovered metals end in “-ium”.

9. Answer the following questions:

1. What does the periodic table show?

2. How are the elements in the table placed?

3. Are the elements in the same column are similar chemically?

4. How many elements shown in the table are found in nature?

5. What does the nature of the electron cloud show?

6. What historical points must be mentioned while searching the table?

7. Why were produced artificial elements?

8. Can one quickly determine from the table whether the element is a metal or a non-metal?

Section 3

1.Read and translate the following text:

Date: 2015-01-02; view: 1437