Task 5. 1-T, 2-F, 3-F, 4-T, 5-F, 6-T, 7-T, 8-F, 9-T, 10-F

Date: 2015-10-07; view: 365.

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.

B) Discuss with your partner new ways and techniques in tool sharpening. 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.

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 friend.

Task 10. Watch the video manual on sharpening 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 9. Make 5 different type questions to the previous text on sharpening and ask your partner answer them.

Task 11.

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.

Keys

1. Tool breakage and an excessive rate of wear indicate that the tool is not operating correctly and steps should be taken to correct this situation

2. Wear is also caused by diffusion or alloying between the work material and the tool material.

3. In regions where the conditions of contact are favorable, the work material reacts with the tool material causing an attrition of the tool material.

4. The rate of this attrition is dependent upon the temperature in the region of contact and the reactivity of the tool and the work materials with each other.

5. Chemical reactions between the active constituents in some cutting fluids sometimes accelerate the rate of tool wear.

6. Tool wear occurring on the flank of the tool below the cutting edge is called flank wear.

7. Sometimes cratering cannot be avoided and a slow increase in the size of the crater is considered normal.

8. Chipping can be recognized by the appearance of the cutting edge and the flank wear land.

9. The principal cause of a poor surface finish is the built-up edge which forms along the edge of the cutting tool.

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

Task 6.

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

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