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Файл:Materials processing and manufacturing technologies. Учебное пособие
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structures. Further, the reinforcement is transported and placed into
the formwork by auxiliary equipment as jigs and cranes.
Task 1. Match Russian and English equivalents.
1. Reinforcement
a) гидравлический домкрат
2. Reinforcement rod
b) арматурная сталь
3. Reinforcement steel
c) перемещение
4. Reinforcement grid
d) стержневая арматура
5. Contact-welding
e) раскатывание
6. Hydraulic jack
f) извлечение
7. Power-driven cutter
g) арматура
8. Shifting
h) скрепление
9. Clamping
i) автоматический режущий станок
10. Ejecting
j) контактная сварка
11. Unrolling
k) установка опор
12. Setting footings
l) арматурная сетка
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Task 2. Match two parts from columns A and B to make up
a sentence.
A
B
1. The preparation of
reinforcement rods supplied in
reels with a diameter of less than
10 mm is carried out on …
a) pre-made rods by means
of contact and electric-arc
welding
2. The preparation of
reinforcement rods from largediameter steel, supplied in rods,
is carried out by …
b) units which perform the
operations of unrolling,
measuring out the length,
cutting, and assembling
the packs
3. Transportation and setting up
the reinforcement into the
formwork are carried out by …
c) ensure the proper quality
of the welded
reinforcement
4. Reinforcement grids are made
out of …
d) hydraulic jacks
5. Such methods of control as
illumination by gamma rays,
the magneto-graphic method
are used in order to …
e) precision automatic
cutting units
6. Reinforcement for prestressed
reinforced-concrete structural
members is manufactured by …
f) previously manufactured
three-dimensional or flat
frameworks and individual
rods
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7. This tensioning of the
reinforcement is carried out by …
g) joining them together on
contact-welding machines
8. The assembly and installation
of reinforcement in monolithic
concrete construction, setting
footings under equipment is
carried out with …
h) jigs, cranes, and other
auxiliary equipment
Task 3. Mark the statements as TRUE (T) or FALSE (F).
Correct the false statements.
1. Reinforcement grids and frameworks are made out of pre-
made rods.
2. The preparation of reinforcement rods from reinforcement
steel, is carried out on rotational machine.
3. Single-contact stationary machines are never used for
contact welding.
4. Such methods of control as illumination by gamma rays,
the magneto-graphic method, are used to ensure the proper
quality of the welded reinforcement.
5. The reinforcement is lengthened before being placed in the
form by means of heating it to a temperature of 100 °C.
6. The transporting and setting up the reinforcement into the
formwork are carried out with the help of cranes, jigs, and
other auxiliary equipment.
Task 4. List the operations for the manufacture of
reinforcement and give their brief description.
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Text 5. Read the text.
PRODUCTION AND REFINING OF METALS
Fig. 11. Production and refining of metals
Metals are a whole group of chemical substances and their
alloys, which have found wide application in various fields of
industry. There are many systems of classifying metals and one of
them is the division of metals into ferrous and nonferrous.
Non-ferrous metals are a special class of stainless metals and
alloys which do not contain iron. Tin, copper, zinc, nickel, silver and
gold are non-ferrous metals. Metals are called non-ferrous because
each of them has a certain color. These metals are strong and durable
because they form a protective oxide film on their surface and show
resistance to the negative factors of the environment.
Ferrous metals (or chermet) are iron and alloys on its base
(steel, ferroalloys, cast iron). Ferrous metals also often include
manganese (92 % used in metallurgy) and, chromium (65 % used in
metallurgy) and vanadium (90 percent used to alloy cast iron and
steel). These metals are mainly used in cast iron and steel production.
55
In the production and refining of metals, valuable components
are separated from worthless material in a series of different
physical and chemical reactions. The end-product is a metal
containing controlled amounts of impurities. In primary smelting
and refining metals are obtained directly from ore concentrates,
while in secondary smelting and refining metals are obtained from
scrap and process waste.
Scrap includes pieces and parts of metal, bars, turnings, sheets
and wire that are out of specification or worn-out but can be recycled.
Two metal recovery technologies are generally used to
produce refined metals: pyrometallurgical and hydrometallurgical.
Pyrometallurgical processes use heat to separate desired metals
from other materials. Due to hydrometallurgical technologies the
desired metals are separated from other materials by methods that
use differences between the solubility of components and/or their
electrochemical properties in water solutions.
Aluminium alloys are widely used for the manufacture of
rolled sections. Items manufactured of aluminium alloys are easy to
produce, pleasing in appearance, resistant to seismic action and
cold. Pure aluminum cannot be used in building structures. About
60 alloys of alluminium are known and used now.
Classification of alloys is carried out by composition,
properties, and the ability to heat treatment.
Brass is an alloy of copper and zinc (up to 40 %). Bronze is
an alloy of copper with tin or any other metal except zinc. Brasses
and bronzes have sufficient strength, excellent corrosion resistance;
they can be produced with high surface hardness.
The first group of metal products includes nets, steel ropes,
profiles with different cross-sectional shapes, fasteners that are used to
connect metal parts. The second group includes building structures.
Metallic items can be manufactured either by pouring molten
iron or steel into special forms, called casting moulds, and then,
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mechanical processing of ingots weighing from 500 kg to several
tons, or by direct casting the finished items of required shape, size
and properties. There are several types of such processing: rolling,
casting, forging.
The technology of reinforcement manufacture
Reinforcement can be bar one and consist of round bars and
can also be rigid (consisting of long steel bars: channels, angles,
rails, pipes). The piece reinforcement is assembled by welding at
the place where concreting will be performed. It is combined into
a reinforcement frame or reinforcement structure of several
separate elements. It is best to use piece reinforcement when the
volume of work is small.
Reinforcement is generally placed at points of a structure that
are subjected to tensile stresses.
Task 1. Find the English equivalents for the Russian words and
word-combinations.
Цветные металлы; черные металлы; химические элементы; характерные свойства; сплавы алюминия, меди и хрома;
прочные и долговечные материалы; физические и химические
реакции; приятный внешний вид; сейсмическое воздействие;
металлические детали и конструкции; механическая обработка;
арматура; тепловая обработка; отдельные элементы.
Task 2. Find the Russian equivalents for the English words and
word-combinations.
Wide application; fields of industry; stainless metals; strong
metals; negative factors of the environment; metallurgy; valuable
components; parts of metal; to use; to heat; to separate; to produce;
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classification of alloys; recovery technologies; building structures;
reinforcement; tensile stresses.
Task 3. Find the synonyms for the following terms in the text 5.
Manufacture; purification; composite; useless metals; shaped
form; needed size and properties; metal rods; water matrix;
recovery techniques; heat processing; ready products.
Task 4. Answer the following questions.
1. Are metals a whole group of chemical substances and their
alloys?
2. What two groups are metals divided into?
3. What metals do not contain iron?
4. Why are non-ferrous metals strong and durable?
5. How are metals obtained in primary smelting and refining?
6. Can pure aluminum be used in building structures?
7. Are there many recovery technologies for the production of
refined metals? What are they?
8. What are metal products used for?
9. What metal elements does a building structure include?
10. How are metal items manufactured?
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Text 6. Read the text.
CERAMICS PROCESSING
Fig. 12. Ceramics processing
Ceramics are broadly defined as inorganic, nonmetallic
materials that exhibit such useful properties as high strength and
hardness, high melting temperatures, chemical inertness, and low
thermal and electrical conductivity but that also display brittleness
and sensitivity to crack-like defects. As practical materials, they
have a long history almost as old as the human race. Traditional
ceramic products, made from common, naturally occurring
minerals such as clay and sand, have long been the object of the
potter, the brick maker, and the glazier.
Modern advanced ceramics are often produced under exacting
conditions in the laboratory and require the skills of the chemist, the
physicist, and the engineer. Containing a variety of ingredients and
manipulated by a variety of processing techniques, ceramics are
made into a wide range of industrial products that are very diverse
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in size, shape, detail, complexity, and material composition,
structure, and cost.
Processed clay and other natural raw materials are used in the
ceramic products manufacturing process. The raw materials are
heated at high temperature until the product takes a rigid shape. The
purity and homogeneity of the raw materials play an important role
in obtaining a high-quality finished ceramic product. If the raw
materials are natural rocks and minerals, they must be carefully
processed beforehand. It provides the control of particle size,
material purity and homogeneity.
If it is necessary to change the shape of the ceramic particles,
the next step –shape forming process is applied. Pressing, extrusion,
injection molding, slip molding and band casting are used for this
purpose. Binders or water are added to form homogeneous particles
to produce a solid finished product. The final step is firing (or
sintering), which is essentially the process of products heat treating.
Task 1. Give the definition of ceramics and ceramics processing.
Task 2. List the positive and negative properties of ceramics as
a building material.
Task 3. Answer the following questions.
1. Are ceramics ancient practical material?
2. What are traditional ceramic products made from?
3. Is there any difference in the manufacture of traditional and
modern advanced ceramics?
4. Can one use natural rocks and minerals as a starting
material for making ceramics?
5. What kind of binders is used in ceramics forming process?
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Text 7. Read the text.
POLYMERS AND PLASTICS PROCESSING
Fig. 13. Polymers and plastics processing
There are several methods used to convert plastics materials
in the form of pellets, granules, powders, sheets, liquids, or
preforms into formed shapes or parts. Plastic materials may contain
various additives that affect the properties and workability of
plastics. In some cases, the product requires additional processing.
After the product is molded, it can be subjected to such operations
as welding, gluing, machining and surface finishing (painting,
metallization).
Injection molding process consists of heating and
homogenizing plastics granules in a cylinder until they are
sufficiently fluid allowing to inject them under pressure into
a relatively cold mould where they solidify and take the shape of
the mould cavity. Injection molding plastics are mainly made from
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