Task 6. Put these words into the right word order to make a sentence.

1. entire length / the width of the / ideal conditions / surprisingly / along its / quite frequently / occur / flank wear land / Under /will be very uniform / which .

2. are encountered / the heated metal / also contributes to / Oxidation of / tool wear, / and high cutting temperatures / particularly when / near the cutting edge / fast cutting speeds.

3. and diamond are / Straight titanium carbide /the two principal tool materials/ this category /that fall into.

4. The most / the built-up edge is/ to increase /effective way to eliminate/the cutting speed.

5. occurs on carbide/ Deformation/ and a high feed rate / cutting tools /when taking a very heavy/ cut using a slow cutting speed.

 

Task 7. Match the beginnings (1-10) of the sentences with their endings (a-j).

	beginning		ending
	Breakage of the cutting edge caused by overloading, heavy shock loads, or improper tool design...	a	... at cutting speeds where a good surface finish will result.
	However, if the rate of crater growth is rapid, ...	b	... is enlarged at the nose of the tool.
	Cemented carbide tools can operate successfully at higher cutting speeds, where the built-up edge ...	c	... increase the cutting speed.
	Whenever possible, cemented carbide tools should be operated ...	d	... of the wear land may become somewhat slanted.
	The best measure of tool wear ...	e	... quite large in relation to the subsequent total amount.
	When the depth of cut is uneven the bottom edge ...	f	... is flank wear.
	When a sharp tool is first used, the initial amount of flank wear is ...	g	... leading to a short tool life, corrective measures must be taken.
	Under normal operating conditions, the width of the flank wear land will increase at a uniform rate ...	h	... is not normal wear and should be corrected.
	The most effective way to eliminate the built-up edge is to ...	i	... until it reaches a critical size after which the cutting edge breaks down completely.
	Often the size of the wear land ...	j	... does not occur and where a good surface finish is obtained.

Task 8. Fill in the gaps using the words from the box. Use each word only once.

material, disadvantage, lubricated, reduces, expensive, water, provided, creating, diamond, stones, exposed, polishes, softer, easier, than, sharpening

Sharpening is the process of 1)_____ or refining a sharp edge of appropriate shape on a tool or implement designed for cutting. The substance on the 2)_____ surface must be harder 3)_____ the material being sharpened; 4)_____ is extremely hard, making diamond dust very effective for sharpening, though 5)_____; less costly, but less hard, abrasives are available, such as synthetic and natural Japanese waterstones.

The Japanese traditionally used sharpening 6)_____ lubricated with water (using oil on a waterstone 7)_____ its effectiveness). They have been doing this for many hundreds of years, and the first stones were naturally occurring. The geology of Japan 8)_____ a type of stone which consists of fine silicate particles in a clay matrix. This is somewhat softer than Novaculite.

These 9)_____ Japanese stones have a few advantages over harder stones. First, because they are softer they do not become glazed or loaded with the 10)_____ they are sharpening. New particles are constantly 11)_____ as you work with them and thus they continue to cut consistently. Second, they can be 12)_____ effectively with water (rather than oil, which can ruin the stone) so nothing but 13)_____ is required. Finally, because they are soft, the worn material and the water form slurry that in conjunction with the stone sharpens and 14)_____ the blade.

A 15)_____ is that they become uneven faster than other types of sharpening stone, although at the same time this makes them 16)_____ to flatten.

Task 9. Make 5 questions of different types to the previous text on sharpening and ask your partner to answer them.

Task 10. Watch the video manual on sharpening a cutting tool. Do you know any other ways of sharpening metal cutting tools? Discuss with your partner all dangers and safety precautions working with sharpening tools.

Task 11. a) Why is it important for an engineer to know the properties of engineering materials? List the properties you know. Compare your list with that of your partner.

b) Discuss new ways and techniques in tool sharpening with your partner. Make a dialogue and present it to a group. The following words will help you. That’s how we attract somebody’s attention and express gratitude in English. Study this table.

HOW TO ATTRACT ATTENTION: Well… Listen … I say... Look … Look here … You know …

HOW TO EXPRESS GRATITUDE: Thank you. Not at all. Thanks. You are welcome. Many thanks. That’s all right. Thank you so much. Don’t mention it. Thanks a lot.

Task 12. Translate the following sentences into English:

1. Процес різання супроводжується утворенням теплоти.

2. Частіше за все при обробці різанням застосовують мастильно-охолоджуючі рідини.

3. Абразивне зношування – це механічне зношування матеріалу в результаті різання твердих тіл чи твердих частинок.

4. Інструменти зі швидкорізальної сталі володіють відносно невисокою теплостійкістю, середньою твердістю, невеликими міцністю при вигині і ударною в'язкістю.

5. Зношення різального інструменту залежить від шляху різання.

6. Основними елементами режиму різання є глибина різання, швидкість різання і подача.

7. Значний вплив на зношування здійснює температура нагріву різального леза.

8. При великих швидкостях різання, коли в зоні його розвивається дуже висока температура, твердосплавний інструмент інтенсивно зношується під дією дифузії.

	ARGUMENTATIVE ESSAY Anargumentative composition is a piece of formal writing. There are various types of argumentative compositions such as: outlining the advantages and disadvantages of a certain question, giving your opinion on a subject, provid­ing solutions to problems and discursive essays. You should start a new paragraph for each new point you make. Each paragraph should start with a key sen­tence (a key sentence is a sentence which summarises the paragraph). You should provide examples and reasons to justify your points of view. Using quotations, whether writing the exact words spoken or paraphrasing, is a way of making your argumentative composition more interesting. e.g. "There is enough in the world for everyone's need, but not enough for everyone's greed." Frank Buchman” Before writing your composition, you should first make a plan. Plans for argumentative essays are given below.
	Introduction	Main Body	Conclusion
Advantages/ Disadvantages	Paragraph 1 state topic	Paragraph 2 advantages/ arguments for	Paragraph 3 disadvantages/ arguments against	Final Paragraph І Give a balanced consideration or your opinion without using personal words or expressions
Exoressing opinions	Paragraph 1 state opinion	Paragraph 2 argument 1 & reason	Paragraph 2 argument 2 & reason	Final Paragraph Restate opinion using different words
* When writing an argumentative essay expressing opinion, you may include the opposite point of view (other people`s opinion) in a sperate paragraph before the conclusion.
Providing solutions	Paragraph 1 state the problem	Paragraph 2 suggestion 1& reason	Paragraph 3 suggestion 2 & reason	Final Paragraph summarise opinion or give best suggestion and reason
Discursive essays	Paragraph 1 state topic	Paragraph 2 one point of view (e.g. political)	Paragraph 3 another point of view (e.g. economic)	Final Paragraph give your own opinion based on the points already mentioned

Task 13. Look at the picture and write an argumentative essay (not over 100-120 words) about tool sharpening evolution. Special attention should be given to the problem of tool wear and advantages/disadvantages of modern types of sharpening.

UNIT 7. BEARINGS

 

Task 1. Discuss the following questions:

a) How much do you know about bearings?

b) Where is bearing used today? Make a list of possible applications of bearing. Compare it with those of your groupmates.

c) Do you know any complex machines? What are their constituents?

 

Task 2. A) The students are at the workshop on mechanical parts production. Listen to their discussion and learn what properties bearing has and where it can be used.

B) Decide whether the following statements are true or false:

1. The balls in ball bearings are made from another type of steal than races.

2. A gage check each ring with an acid.

3. Grinding machine check the inner diameter of each ring.

4. Water-based liquid keeps rings from overheating.

5. Abrasive stone lubricated with oil polishes the outer ring until you can see a reflection.

6. Raceways are cleaned with oil.

7. Steel balls are classified according to their shapes.

8. Steel balls are made of steel wires.

9. Just few hours are needed to grind rough balls.

10. Hopper sends necessary quantities of balls through several tubes to the raceways of the bearing.

11. After hardening balls should be washed with cleaning solvent.

12. Ball cage retain the balls in position around the raceways.