Notes on the Text
if not the very first — если не самый первый
it should be noted — необходимо отметить
to account for — объяснять
Mass-produced materials — изделия массового производства
TEXT. THE NATURE OF CERAMICS
One of the first solid materials, if not the very first, that man learned to use was a ceramic natural stone. It was used in a variety of applications because of its characteristic prop
erties such as hardness, strength to chemical attack which make it comparatively easy to shape. Thus natural ceramics provided man with tools, durable containers and even a rdof. It is not surprising that man got greatly interested in ceramics and tried to create ceramics such as: pottery, bricks, concrete, glass. These products are spoken of as main industrial products to this day.
Ceramic materials have been extended greatly. They range from dull clay to lustrous ruby, from the refractory linings to electronic control devices.
What is ceramics? Can this question be answered? Essentially it is defined as a combination of one or more definite metals with a non-metallic element, usually oxygen. The comparatively large oxygen atoms serve as a matrix with the small metal atoms.The main characteristic of the construction of ceramic crystals is that the atoms are linked by bonds that are -primarily ionic but also to a significant extent covalent. These bonds are responsible for the stability and strength of ceramic materials. In the combination of oxygen atoms with metal atoms the ionic bonds are particularly strong. It should be noted that each oxygen atom with two electronic vacancies in its outer shell borrows two electrons from its metal neighbours, thus both kinds of atoms become highly ionized—one negatively, the other positively.
As highly oxidized compounds the ceramics are strongly resistant to attack by nearly all chemicals. This accounts for many of their uses, even the making of steel depends on the use of ceramics.
A lot of analyses have been made by chemists. They found that the principal elements, for instance, in natural clays were oxygen, silicon and aluminium. They form the compounds known as aluminosilicates.
But a giant step forward in ceramic science came when crystal structures were analysed by means of X-ray diffraction. It has been found out that in the construction of ceramic materials much depends on how the atoms are stacked.
Many scientists both in the Soviet Union and abroad work at the investigation of the properties of ceramic products. Many ceramic materials are being mass-produced now. They can be drawn into rods, cast or pressed. These ceramics are light in weight, but very strong. Some of them are so hard that they can cut steel. You can hardly find any branch of industry where ceramic products are not used.
solid to range; outer .
variety .'Лчу dull resistant
because ot&i -refractory neighbour
hardness Ы. to define to account for
strength bond v- to find . •> t -•
comparatively primarily to find out^
to provide significant to cast
durable to be responsible for to cutr^L
to try stability oven
pottery particularly
Ex. 10. Answer the following questions. (Work in pairs.)
1. What was the very first solid material that man began to use? 2. What did natural ceramics provide man with? 3. Why was ceramics used in a variety of applications? 4. Why did man get interested in ceramics so much? 5. What is ceramics? 6. What is a main characteristic of the construction of ceramic crystals? 7. Why are the ceramic materials so strongly resistant? 8. What are the principal elements in natural clays? 9. What does the construction of ceramic materials depend on? 10. Why are ceramic materials mass-produced? 11. Why is the ceramic industry so important?
Ex. 11. Open the brackets using the correct verb form:
1. Last year our plant (produced, produces) many ceramic goods which (are used, were used) widely. 2. At first man (baked, has baked) vessels of clay in the sun. 3. Recently ceramic compounds (are used, have been used) even in making steel. 4. Numerous analyses (have been carried out, had been carried out) before they stated the exact composition of this compound. 5. Now many scientists (are working, work) at the investigation of the new properties of ceramics. 6. Many new discoveries (took place, have taken place) since the last century. 7. Last week they (analysed, analyse) crystal structure of those new materials by means of X-ray diffraction. 8. For many years considerable work (has been carried out, was carried out) to convert ethylene into motor fuel. 9. Many beautiful articles made of ceramics (provided, provides) man with tools even in ancient time.
Ex. 12. Choose the Russian equivalents from the right column: because of оба very едва
to provide при условии; the very упорно
если
hardly легко
readily именно этот
hard как
... так и
provided both ... and both
из-за
обеспечивать
очень
Ех. 13. Find the pairs of synonyms and remember them:
because of, to provide, lately, to learn, to explain, due to, to supply, recently, to account for, to find out.
Ex. 14. Find the pairs of antonyms and remember them:
hard, solid, fast, light, dull, difficult, heavy, bright, weak, easy, liquid, slow, soft, strong.
Ex. 15. Open the brackets choosing the suitable word:
(The very, very) first subjects we studied in the first year were mathematics, inorganic chemistry and English.
This was (very, the very) book I needed for my work. 3. Have you (found out, found) what subject he was interested in? 4. I shall use this new material (provide, provided) it is resistant to corrosion. 5. She could (hardly, hard) use this material as it was too brittle. 6. These ceramic materials are (light, heavy) in weight. 7. This solid material was (very, the very) good for construction.
Ex. 16. State parts of speech the words in bold type belong to:
Quartz was used in the form of large, nearly perfect crystals. 2. Quartz, silicates and aluminosilicates together with other minerals form a great amount of naturally occurring ceramic raw materials. 3. Among ceramic products, alumina in both its forms possesses the highest mechanical strength and hardness. 4. At first man could shape vessels of clay by hand. 5. The shape of this vessel was very strange. 6. Ceramic products are light in weight. 7?The light was shed on the use of new ceramic products. 8. The range of application of products made from clay is very wide. 9. The ceramic products may range from bright lustrous ruby to dull clay.
Ex. 17. Translate the text paying attention to the use of the word “very”. Give a summary of the text:
Pottery, porcelain, brick and tile are all very similar in composition and method of manufacture, and with glass they provide the class of materials known as ceramics. These products are made from varying mixtures of clay, silica, and feldspar.
The very first of them are usually prepared from natural clays which already contain silica and feldspar. These natural clays are made into a workable mud with water and then fired
in special ovens. As the temperature rises, water is first driv-. en from the mixture, then various decomposition products are. formed and above 1250° C the feldspar fuses and binds the other materials present.
Porcelain is made from a very fine white clay known as kaolin. Then very pure sands and feldspars am "-"Med. Very soft porcelain is obtained if one adds calciu ^nosphate to the mud.
Ex. 18. Read the texts and render them:
Glass
Silicate materials include glass, porcelain, enamels and cement.
Ordinary glass is a mixture of silicates in the form of supercooled liquid. It is made by melting a mixture of sodium carbonate (or sodium sulphate), lfTnestone and sand.
Ordinary glass contains about 10% sodium, 5% calcium, and 1% aluminum, the remainder is silicon and oxygen. It consists of an aluminosilicate tetrahedral framework, within which are embedded sodium ions and calcium ions.
Cement
Portland cement is an aluminosilicate powder which sets to a solid mass on treatment with water. Portland cement before treatment with water consists of a mixture of calcium silicates and calcium aluminate. When treated with water the calcium aluminate hydrolyzes and forms calcium hydroxide and aluminum hydroxide. These substances react further with the calcium silicates and produce calcium aluminosilicates in the form of crystals.
Ex. 19. Listen to the following tape-recorded text and answer the questions that follow:
With few exceptions, construction materials are solid materials or hardened into solid materials. Solid materials can be grouped into three fundamental types: ceramics, metals, and organics. The ceramic materials are rock or clay minerals, or are compounded from such minerals. Examples are: sand, limestone, glass, brick, cement, gypsum. These are materials which are dug from the earth’s crust. Since they are extracted from the earth, they are relatively inexpensive as compared to metals or the organio materials. The ceramics have been used as building materials since ancient time.
What kind of materials are construction materials?
Into what types can solid materials be grouped?
What are ceramic materials?
What are the examples of ceramic materials?