Answer the following questions:
1. What are the raw materials for the production of copper?
2. Why must all copper ores be concentrated by flotation?
3. Whаt purpose is pure copper chiefly used for?
4. What properties does the alloying of copper with other elements increase?
5. What main groups do copper alloys comprise?
6. What alloys of copper are called bronzes?
7. Into what groups are bronzes divided?
8. Why are aluminium bronzes frequently used in foundry practice?
TITANIUM AND ITS ALLOYS
As an engineering material titanium has been widely applied only in the last years.
Titanium is a silvery-white metal which melts at approximately 1668°C and has a specific gravity of 4.505. Commercially pure titanium possesses high strength properties. The tensile strength of most titanium alloys ranges from 100 to 140 kg/mm2, in conjunction with high elongation.
The hardness, tensile strength and yield point of titanium are increased with the degree of cold deformation. The elongation value drops rapidly when the degree of cold deformation (reduction) exceeds 50 per cent and becomes equal to 10 per cent. Impurities found in commercial titanium can be divided into two groups: elements which form interstitial solid solutions with titanium (O2, N, C and H2) and elements which form substitution solid solutions (Fe and other metallic elements). The first have a much greater effect on the mechanical properties than those in the second group.
Even very small amounts of oxygen and nitrogen in titanium alloys sharply reduce the ductility. A carbon content of more than 0.2 per cent reduces both the ductility and impact strength of a titanium alloy. It is supposed that the brittleness of titanium is a result of strain ageing and is connected with the presence of dissolved hydrogen in the beta-phase.
Titanium and its alloys are hardened either by a surface heat treatment followed by ageing at 400°—500° C or by producing a case which contains nitrogen, carbon and boron Industrial titanium alloys contain vanadium, molybdenum, chromium, manganese, aluminium, tin, iron or other elements, singly or in various combinations.
A combination of high mechanical properties with low specific weight and excellent corrosion resistance enables titanium to be used in building supersonic air craft.
Answer the following questions:
1. What is titanium?
2. What does the hardness, tensile strength and yield point of titanium depend upon?
3. Do very small amounts of oxygen and nitrogen in titanium alloys reduce the ductility?
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4. How are titanium and its alloys hardened?
5. What constituents do industrial titanium alloys contain?
GRAMMAR TEST
1. What is this? … is my dictionary.
a. it
b. these
c. those
d. they
e. them
2. There is … pencil on the table.
a. some
b. such
c. an
d. a
e. three
3. … car is this?
a. what
b. who’s
c. why
d. whom
e. whose
4. I’m cold. …open the window.
a. a not
b. don’t
c. no
d. none
e. –
5. He … to the University by bus.
a. is going
b. can
c. goes
d. go
e. are going
6. Paul … a book now.
a. is reading
b. are reading
c. read will read
d. had read
7. I like bananas, but I … them every day.
a. haven’t eat
b. not eat
c. doesn’t eat
d. don’t eat
e. isn’t eating
8. I … to see my friend tomorrow.
a. are going
b. have going
c. is going
d. were going
e. am going
9. She didn’t … breakfast yesterday.
a. had
b. has
c. have
d. having
e. haved
10. I can swim, but my friend …
a. is not
b. can’t
c. don’t
d. needn’t
e. aren’t
11. … I take your pen?
a. may
b. will be able
c. does
d. has
e. had
12. Must I wear these shoes? – No, you…
a. mustn’t
b. can’t
c. weren’t
d. isn’t
e. aren’t
13. My grandfather … to leave school when he was 15.
a. must
b. can
c. is
d. are
e. had to
14. I … speak French last year.
a. can’t
b. may not
c. must not
d. couldn’t
e. hasn’t
15. You will … speak English in 3 years.
a. can
b. has
c. had
d. be able to
e. were able to
16. When I called him, he … supper.
a. has having
b. was have
c. was having
d. is having
e. were having
17. They … up late yesterday.
a. get
b. got
c. has got
d. gets
e. getting
18. It is the … book I have ever read.
a. best
b. better
c. well
d. good
e. worse
19. Where … go? Let’s go to the cinema.
a. won’t we
b. is we
c. have we
d. shall we
e. are we
20. What has she … ?
a. doing
b. do
c. did
d. done
e. does
21. There … many students in the room now.
a. were
b. was
c. is
d. are
e. will
22. There … a university in the centre of the city.
a. is
b. are
c. be
d. shall
e. were
23. I can’t see … on my table.
a. nothing
b. nobody
c. anything
d. anywhere
e. somewhere
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24. What … you going to do tonight?
a. was
b. will
c. were
d. is
e. are
25. There … any sugar in the tea.
a. weren’t
b. wasn’t
c. haven’t
d. hadn’t
e. won’t
26. We … in Moscow last year.
a. lives
b. is living
c. has living
d. live
e. lived
27. Where … she work?
a. do
b. done
c. doing
d. does
e. is
28. ... speaks English well?
a. which
b. why
c. who
d. when
e. what
29. How many theatres … there in your city now?
a. were
b. are
c. have
d. is
e. was
30. What … you do tomorrow?
a. will
b. shall
c. will be
d. shall be
e. are
31. He said that he … at the plant last year.
a. are having
b. living
c. lives
d. had lived
e. lived
32. Let … tell his friends about his city.
a. his
b. him
c. he
d. her
e. she
33. My friend … breakfast when I called him.
a. were having
b. will having
c. are having
d. was having
e. is having
34. What … do you want to read?
a. another
b. yet
c. other
d. still
e. else
35. Which is the … river in our country?
a. long
b. longer
c. longest
d. large
e. larger
36. There was … in the room.
a. somebody
b. somewhere
c. anybody
d. anything
e. some
37. Who … you this story yesterday?
a. speak
b. tell
c. told
d. spoke
e. said
38. When we came in, the film … already begun.
a. are
b. is
c. were
d. was
e. had
39. The work … done well two days ago.
a. has done
b. was done
c. has been done
d. was do
e. did
40. Books by Dickens … many times.
a. is publishing
b. have published
c. are published
d. were published
e. is published
41. What … you do every day?
a. does
b. do
c. did
d. doing
e. done
42. This problem … tomorrow.
a. will be discussed
b. have been discussed
c. is discussing
d. will discuss
e. had discussed
43. I wonder, why there are so … people.
a. no
b. such
c. some
d. much
e. many
44. I am sorry… I come in?
a. could
b. might
c. may
d. must
e. need
45. I … do this work yesterday. I was busy.
a. mustn’t
b. can’t
c. couldn’t
d. aren’t
e. weren’t
46. What … you doing here?
a. are
b. is
c. will
d. be
e. can
47. He … going to translate this article.
a. do
b. have
c. may
d. is
e. are
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48. These pictures … by a young painter last year.
a. are painted
b. were painted
c. is painted
d. will be painted
e. have been painted
49. I … know him.
a. doesn’t
b. haven’t
c. hasn’t
d. isn’t
e. don’t
50. … go to the library.
a. won’t
b. doesn’t
c. don’t
d. haven’t
e. isn’t
51. Do you often … English to your teacher?
a. spoken
b. spoke
c. speak
d. speaking
e. speaked
52. … of you likes to speak French?
a. which
b. who
c. why
d. what
e. whom
53. … of you lives in the centre of Moscow?
a. whom
b. whose
c. who
d. which
e. when
54. How long does your working day …?
a. has lasted
b. is lasting
c. lasted
d. last
e. lasting
55. My sister works ...
a. many
b. much
c. some
d. not many
e. none
56. What … they discussing now?
a. are
b. were
c. will
d. is
e. was
57. Will you … at home tomorrow?
a. is
b. were
c. are
d. be
e. have
58. They … here an hour ago.
a. have
b. have been
c. was
d. were
e. are
59. I wrote him a letter …
a. since
b. today
c. last month
d. this month
e. tomorrow
60. … children don’t like to play football.
a. some
b. no
c. any
d. anybody
e. somebody
61. There … many children in the park yesterday.
a. hadn’t
b. aren’t
c. haven’t
d. wasn’t
e. weren’t
62. Where … we get these journals?
a. do
b. can
c. must
d. were
e. will
63. … I ask you a question? – Certainly.
a. am
b. must
c. may
d. was
e. will
64. He … come yet.
a. haven’t
b. didn’t
c. hasn’t
d. doesn’t
e. can’t
65. I was waiting … you at 5 o’clock yesterday.
a. with
b. at
c. for
d. in
e. –
66. Have you … the translation yet?
a. does
b. doing
c. do
d. did
e. done
67. Is … a library at your office?
a. where
b. there
c. anywhere
d. somewhere
e. nowhere
68. These books are too difficult .. me.
a. about
b. at
c. of
d. for
e. with
69. …you know about it yesterday?
a. hasn’t
b. haven’t
c. don’t
d. didn’t
e. doesn’t
70. You can help me, … you?
a. can’t
b. can
c. couldn’t
d. won’t
e. don’t
71. You didn’t see him last week, … you?
a. didn’t
b. did
c. does
d. doesn’t
e. won’t
72. … usually takes me half an hour to get to my office.
a. he
b. I
c. what
d. it
e. she
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73. I’m hurrying … the University.
a. to
b. of
c. at
d. in
e. –
74. What is he afraid … ?
a. to
b. in
c. with
d. of
e. off
75. There … a lot of students at the lecture tomorrow.
a. will
b. will be
c. will have
d. will can
e. were
76. He won’t go to the cinema tomorrow, … he?
a. will
b. won’t
c. won’t be
d. didn’t
e. did
77. Here is the man … wanted to speak to you.
a. which of
b. which
c. who
d. whom
e. whose
78. He will come back … Simferopol in June.
a. –
b. of
c. at
d. in
e. to
79. I didn’t do my work …. I was busy.
a. that’s why
b. because
c. in order to
d. after
e. before
80. … you swim last year?
a. could
b. can
c. was able
d. will be able
e. could able
81. I … seen him this week.
a. hasn’t
b. haven’t
c. didn’t
d. don’t
e. doesn’t
82. You were waiting for me at 2 o’clock yesterday, … you?
a. aren’t
b. didn’t
c. wasn’t
d. weren’t
e. haven’t
83. Mr. Green won’t be able to come, .. he?
a. shall
b. will
c. can
d. has
e. does
84. He … a cup of coffee when the telephone rang.
a. drink
b. are drinking
c. is drinking
d. drank
e. was drinking
85. The company has so … money.
a. little
b. less
c. more
d. many
e. the least
86. I … going to invite you to my birthday party.
a. has
b. have
c. are
d. is
e. am
87. You … English before entering the University
a. has study
b. has studied
c. had studied
d. had study
e. studied
88. New York is the … city in the USA.
a. most large
b. larger
c. large
d. largest
e. much largest
89. Who is your … friend?
a. goodest
b. best
c. better
d. more better
e. most
90. He … always waited for.
a. being
b. been
c. has
d. are
e. is
91. Who … asked when you came in?
a. was
b. been
c. was being
d. were
e. were being
92. Many new houses … built in our city lately.
a. has been
b. had been
c. have been
d. have being
e. being
93. I … wait for him now. I am very busy.
a. can’t
b. couldn’t
c. wasn’t
d. hadn’t
e. hasn’t
94. He … many friends here.
a. have
b. haves
c. has
d. having
e. had had
95. Will you … to come tomorrow?
a. will able
b. had able
c. was able
d. able
e. be able
96. You must … to answer all my questions.
a. was ready
b. be ready
c. is ready
d. are ready
e. ready
97. … you learn English?
a. haven’t
b. aren’t
c. isn’t
d. don’t
e. doesn’t
98. How many lessons … you have every day?
a. do
b. does
c. have
d. has
e. are
99. You like watching TV- programmes, … you?
a. do
b. don’t
c. doesn’t
d. does
e. did
100. What … your favourite subject at school?
a. did
b. has
c. are
d. were
e. was
Литература
- Алехина М.С. Английский для металлургов. М.: Русский язык, 2005.
- Андреев Г.Я., Гураль Л.Л., Лев А.Л. Сборник технических текстов на английском языке. М.: Издательство «Высшая школа», 1972.
- Иллюстрированный словарь английского и русского языка с указателями. М.: Живой язык, 2003.
- Парахина А.В. Пособие по переводу технических текстов с английского языка на русский. М.: Издательство «Высшая школа», 1972.
- А.И. Каменский, И.Б. Каменская. Практическая грамматика английского языка. 2002.
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