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Контрольная работа № 5. 'Designed materials' or Smart material is a material whose structure and composition has been deliberately




По английскому языку для студентов всех технических специальностей заочного отделения

Вариант 5

V семестр

 

I. Прочитайте и переведите текст (устно).

'Designed materials' or Smart material is a material whose structure and composition has been deliberately manipulated to affect the material’s properties in a controlled fashion to achieve a specific functionality unexpected or significantly different from the original material.

Quest for a material to suit the service performance is almost as old as human civilization. So far materials engineers have developed a series of alloys, polymers, ceramics, and composites to serve many of the performance requirements in a modern society. However, challenges appear when one needs to satisfy more than one boundary condition. For example, a component with negative Coefficient of Thermal Expansion (CTE) using a ductile metal was almost impossible until recently. Synthesis of various technologies such as Direct Metal/Material Deposition (DMD) Homogenization Design Method (HDM) and multi material Computer Aided Design (CAD) was necessary to achieve this goal. Rapid fabrication of three-dimensional shapes of engineering materials such as H13 tool steel and nickel super alloys are now possible using Direct Materials Deposition (DMD) technique as well as similar techniques such as Light Engineered New Shaping (LENS) or Directed Light Fabrication (DLF). However, DMD has closed loop capability that enables better dimension and thermal cycle control. This enables one to deposit different material at different pixels with a given height directly from a CAD drawing. The feedback loop also controls the thermal cycle. H13 tool steel is one of the difficult alloys for deposition due to residual stress accumulation from martensitic transformation. However, it is the material of choice for the die and tool industry. DMD has demonstrated successful fabrication of complicated shapes and dies and tools, even with H13 alloys. This process also offers copper chill blocks and water-cooling channels as the integral part of the tool. On the other hand ZrO2 was co-deposited with nickel super alloys using DMD. Flexibility of the process is enormous and essentially it is an enabling technology to marterialize many a design. Using DMD in conjunction with HDM and multi-material CAD, one can produce components with predetermined performance such as negative co-efficient of expansion, by synthesis of designed microstructure.



II. Выберите правильный вариант ответа на вопросы к тексту.

1. What term is synonymous for term “smart materials”?

a)composite materials;

b) designed materials;

c) durable materials.

2. What is told about a component with negative Coefficient of Thermal Expansion (CTE) using a ductile metal?

a) that was almost impossible until recently ; b)that it isimpossible now; c)that it has been always possible. b) 25 – 30  

3.What doesDMD have that enables better dimension and thermal cycle control?

a) open cycle capability;

b) closed loop capability;

c) incomplete connection capability.

III. Закончите предложения по содержанию прочитанного текста.

4.Smart material is a material whose structure and composition has been deliberately manipulated …

a) … to affect the material’s design;

b) … to affect the properties of the working facilities;

c) … to affect the material’s properties.

5. Rapid fabrication of … shapes of engineering materials are now possible using Direct Materials Deposition (DMD) technique .

a) … two-dimensional …; b)… five-dimensional …; c)… three-dimensional ….

6. ZrO2 was co-deposited with nickel super alloys using …

a) … Direct Metal/Material Deposition.

b) … Directed Light Fabrication.

c)… Computer Aided Design.

IV. Подберите эквивалент к данному русскому слову или словосочетанию .

7 . намеренно

a) deductively b) deliberately c) desparately

8. сплавы

a)mixtures b)alloys c) dozens
9. распространение, увеличение a) expansion b) exclamation c)exposition

10. пластически деформируемый, вязкий, ковкий

a)rough b) harsh c) ductile

11. элемент изображения

a) pixel b) dot c) signature

12. заготовка, деталь, матрица

a)lock b) die c)stage

13. предвычисленный

a) prescribed b) pretended c) predetermined

V. Выберите соответствующее определение данным словам из текста.

a) edge; b) to enure ; c) circle; d) to gain ; e) trace; f)searching; g)extension; h) problem.

 

14.quest

15.toserve

16. challenge

17. boundary

18.to achieve

19. loop

20. residual

21. expansion

VI. Прочитайте предложения и укажите соответствует ли данное утверждение действительности: если соответствует напишите после предложения T- true, если не соответствует то F-false, при этом письменно подтвердите ваш ответ примером из текста.

22. Quest for a material to suit the service performance is as old as human civilization.

23. Engineers have developed a series of alloys, polymers, ceramics, and composites to serve many of the performance requirements in a modern society.

24.DMD hasn`t demonstrated successful fabrication of complicated shapes and dies and tools.

VII. Выберите правильную видовременную форму глагола.

25. Designed materials is a material whose structure and composition ______.

a) have been manipulated b) has been manipulated c) having been manipulated

26. Materials engineers _________ a series of alloys, polymers, ceramics.

a) have developed b) has developed c) were developed

27. Challenges ______ when it is necessary to satisfy more than one boundary condition.

a) appears b)appearing c) appear

28. The feedback loop _____ the thermal cycle.

a) controls b)iscontrolled c) was controlled

29. This process _______copper chill blocks and water-cooling channels.

a) offer b) offers c) are offered

30. Components with predetermined performance can ________.

a) are produced b)will producec)be produced

VIII. Переведите текст письменно.

"Smart" materials respond to environmental stimuli with particular changes in some variables. For that reason they are often also called responsive materials.
Depending on changes in some external conditions, "smart" materials change either their properties (mechanical, electrical, appearance), their structure or composition, or their functions.
Mostly, "smart" materials are embedded in systems whose inherent properties can be favorably changed to meet performance needs.For example, photochromic materials change reversibly colour with changes in light intensity.
Usually, they are colourless in a dark place, and when sunlight or ultraviolet radiation is applied molecular structure of the material changes and it exhibits colour. When the relevant light source is removed the colour disappears.
Changes from one colour to another colour are possible mixing photochromic colours with base colours. Thermochromic materials change reversibly colour with changes in temperature.
They can be made as semi-conductor compounds, from liquid crystals or using metal compounds. The change in colour happens at a determined temperature, which can be varied doping the material. They are used to make paints, inks or are mixed to moulding or casting materials for different applications.

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