Exercises. I. Use the following words and phrases in sentences of your own:

I. Use the following words and phrases in sentences of your own:

brazing, soldering, filler metal, to diffuse, soft soldering, hard soldering, to result in, induction brazing, induction heating, cleaning, smooth fillet, flux, paste, liquid, joint, sequential brazing

II. Answer the following questions:

1. What is soldering? 2. How does the filler metal hold the parts together? 3. How may soldering be classified? 4. What kinds of filler metals are used in soft soldering? 5. What kinds of filler metals are used in hard soldering? 6. Why has soldering reduced the cost of production of many assemblies? 7. What type of heating is used in soldering or brazing? 8. What are the advantages of induction brazing or soldering?

III. Supply synonyms for the following words:

to join, aid, rapid, precise, to decrease, to produce, to improve, clean, melting, clad, promoting

IV. Supply antonyms for the following words and translate them into Russian:

adequate, cooling, dirty, to decrease, to destroy, low-temperature, conductive, heating, to assemble, fortunately

V. Underline the suffixes and prefixes and translate into Russian the following words:

redesign, fabrication, induction, non-corrosive, effectively, facilitate, non-conductive, costly, frequently, reduction, basically, discolouration, primarily, successful, failures, hygroscopic, thoroughly, impossible, electrically, conductive

VI. Find the predicates in the following sentences, then analyze and translate the sentences into Russian:

1. Recently, techniques have been developed for induction brazing in a reducing atmosphere¹ to avoid the use of flux and thus the problems of thorough removal of flux residues. 2. There is a special unit for controlled-atmosphere brazing². 3. In this unit, a purified dry reducing gas, such as hydrogen, enters the unit at the top, displaces the air and surrounds the part to be heated. 4. Upon heating to elevated temperature, oxide films on the metal surfaces to be joined and on the joining alloy are reduced, permitting satisfactory flow of the alloy into the joint by capillary action, thus producing a good bond.

¹. reducing atmosphere - восстановительная газовая среда

². for controlled-atmosphere brazing - для пайки регулируемой газовой средой

VII. Make up questions to which the italicized words are the answers:

1. Soft soldering is used in fabricating radio condenser cans and radiators. 2. Brazing and soldering involve fusion of joining alloy between the surface of metal parts to be joined. 3. In soldering, low-melting-temperature alloys permit joints of limited strength to be made at temperatures below 800°F. 4. Ultrasonic energy is used in fluxless soldering. 5. Suitable fluxes prevent oxidation of the joining alloy and metal surfaces to be joined. 6. Precise heat control is used to permit effective performance of sequential brazing or soldering operations.

VIII. State the forms and functions of infinitives and translate the following sentences:

l. The metals to have been joined included carbon and alloy steels, stainless steel, cast iron, copper and copper alloys, nickel and nickel alloys and, to a limited extent¹, aluminium alloys. 2. The properties of solder may have been changed by addition of some elements such as zinc, aluminium, and phosphorus. 3. A torch should have been used to heat the hard solder and object to be brazed. 4. In order to solder aluminium, flux should be mixed with a special solder used for aluminium. 5. The ternary alloy of silver, copper and phosphorus was largely self-fluxing when used with copper but should have not been used on ferrous metals since it formed a brittle iron phosphide.

¹. to a limited extent - в ограниченной мере

X. Translate the following text in written form without using a dictionary:

It is interesting to note that brazed joints involving cast-iron parts are more dependably gas-tight and liquid-tight and have strength if the parts are electrolytically treated to remove graphitic carbon from the joining surfaces before fluxing and induction heating. Fluxes containing fluorides and alkali salts, preferably potassium, are generally used for induction brazing, particularly with the silver-brazing alloys. These fluxes, normally used in paste form, become fluid and

active below 1100°F, protecting the metal surfaces to be joined, dissolving residual oxides and promoting better flow of me alloy upon melting.

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