Unit5 Materials Science

Exercise 1. Practice pronunciation of the following words and remember them. The stressed part is in bold type.

Material, technology, modern, physics, plastics, metallurgy, elastic, deformation, metal, vibration, engineering, cyclic, temperature, machine, component, weight, original.

Exercise 2. Fill in the correct prepositions Fill in the correct prepositions: on, from, of, in, at, for, on.

1) Silicon is the important material … an electronic computer chip. Your CD, DVD player, and telephone - all depend … semiconductors.

2) Creep is a slow, permanent deformation resulting … a steady force acting … a material.

3) Paints, plastics and most of the food you eat are made … of polymers.

4) Every part … your body is a material!

5) Material scientists work … labs and universities all over the world.

6) Materials … high temperatures usually suffer … this deformation.

7) Fatigue is the result … external forces.

Exercise 3. Translate the following words and define their parts of speech (noun, adjective, and verb):

Metal, compression, deform, technologist, scientific, vibration, scientist, metallic, compress, technology, chemistry, metallurgy, technological, chemist, deformation, science, chemical, vibrate.

Exercise 4. Match the words and expressions on the left with those on the right.

1) laboratory techniques a) металлический брусок

2) exter­nal forces b) усталость металла

3) elastic deformation c) сжатие

4) compression d) ползучесть

5) bend­ing e) напряжение при растяжении

6) metal fatigue f) уменьшение в объеме

7) torsion (twisting) force g) лабораторные методики

8) rupture h) внешние силы

9) tensile stress i) разрыв

10) creep j) скручивающее усилие

11) metal bar k) упругая деформация

12) Decrease in vol­ume l) сгибание

Exercise 5. Correct the mistakes in the following sentences and translate them paying attention to Passive voice:

1) Ma­terials can are fabricated to have different properties.

2) Most materials is subjected to a torsion (twisting) force.

3) No deformation is saw during fatigue.

4) Rolling can be do either hot or cold.

5) Decrease in vol­ume shall be caused by compression.

6) New laboratory techniques has been used to find new metalworking methods.

7) The metal bar was subjects to a tensional (tensile) force.

8) New materials with the desired properties can be created.

Exercise 6. Read the text and underline all types of forces acting on materials.

Material Science

Materials Science and Technology is the study of ma­terials and how they can be fabricated to meet the needs of modern technology. Using the laboratory techniques and knowledge of physics, chemistry, and metallurgy, scientists are finding new ways of using metals, plastics and other materials.

Engineers must know how materials respond to exter­nal forces, such as tension, compression, torsion, bend­ing, and shear. All materials respond to these forces by elastic deformation returning their original size and form when the external force disap­pears. The materials may also have permanent deforma­tion or they may fracture. The results of external forces are creep and fatigue.

Compression is a pressure causing a decrease in vol­ume. When a material is subjected to a bending, shear­ing, or torsion (twisting) force, both tensile and comp­ressive forces are simultaneously at work. When a metal bar is bent, one side of it is stretched and subjected to a tensional force, and the other side is compressed.

Tension is a pulling force; for example, the force in a cable holding a weight. Under tension, a material usu­ally stretches, returning to its original length if the force does not exceed the material's elastic limit. Under larger tensions, the material does not return completely to its original condition, and under greater forces the mate­rial ruptures.

Fatigue is the growth of cracks under stress. It oc­curs when a mechanical part is subjected to a repeated or cyclic stress, such as vibration. Even when the maximum stress never exceeds the elastic limit, failure of the ma­terial can occur even after a short time. No deformation is seen during fatigue, but small cracks develop and propagate through the material until the remain­ing cross-sectional area cannot support the maximum stress of the cyclic force. Knowledge of tensile stress, elastic limits, and the resistance of materials to creep and fatigue are of basic importance in engineering.

Creep is a slow, permanent deformation that results from steady force acting on a material. Materials at high temperatures usually suffer from this deformation. Loosening of bolts and the deformation of components of machines and engines are all the exam­ples of creep. In many cases the slow deformation stops because deformation eliminates the force causing the creep. Creep extended over a long time finally leads to the rupture of the material.

Exercise 7. Fill in the correct verb from the list below. Use the words only once. Translate the phrases.

Meet, suffer, return, propagate, eliminate, support, respond, fabricate, decrease, loosen, exceed

… original size, … the needs, … bolts, … vol­ume, … cracks, … the material's elastic limit, … to exter­nal forces, … the maximum stress, … from deformation, … material, … the force

Exercise 8. Find the following word combinations in the text.

1) отвечать требованиям современной технологии

2) используя лабораторные методы

4) сжатие, растяжение, изгиб, кручение, срез

5) возвращать первоначальный размер и форму

6) внешняя сила

7) постоянная деформация

8) уменьшение объема

9) растягивающие и сжимающие силы

10) превышать предел упругости материала

11) повторяющиеся циклические напряжения

12) разрушение материала

13) развитие и распространение мелких трещин

14) сопротивление материалов ползучести и устало­сти

Exercise 9. Put the words in the correct order and answer the questions:

1) What size change materials the form and forces of?

2) What of results external are the forces?

3) What compression cause does?

4) What of tension result is the?

5) What we do fatigue call? When occur it does? What of are the fatigue results?

6) What call do creep we? When this does take place deformation? What of results creep are the?

Exercise 10. Translate into English the following sentences paying attention to Participle I:

1) Скручивая материал, мы можем его деформировать.

2) Усталость и ползучесть материалов являются результатом внешних сил, воздействующих на материал.

3) Внешние силы вызывают постоянную деформа­цию и разрушение материала, изменяя его свойства.

4) Растягивающие и сжимающие силы работают одновременно, когда мы изгибаем или скручиваем материал.

5) Растягивая материал выше предела его упру­гости, мы вызваем постоянную деформацию или разрушение.

6) Применяя современные технологии, мы можем получать новые материалы с нужными свойствами.

7) Человек, измеряющий ползучесть и усталость металла, является инженером нашего института.

8) Сжатие – это давление, приводящее к уменьшению объема.

9) Ползучесть – это деформация, которая является результатом постоянной силы, действующей на материал.

10) Превысив предел упругости материала, они разорвали материал.

Exercise 11. Translate the words from Russian into English to complete the sentences.

1) Деформированный material was not used in the production of tools.

2) One side of погнутый metal bar was compressed.

3) The material растянутый did not return to its original length.

4) Вылитый metal into a mold was cooled.

5) Оставленные machine tools were in bad condition.

6) Вымытые instruments were in the laboratory.

Exercise 12. Translate the sentences into Russian paying attention to Participle II:

1) Hydrogen is the lightest element known.

2) The work performed showed good results.

3) The substance obtained contained some admixtures.

4) Unless heated, this substance does not melt.

5) Gold does not rust not even when heated.

6) This substance does not dissolve in water whether heat­ed or not.

7) The temperature of the liquid obtained remained con­stant.

8) This reaction will be of little service unless catalyzed or carried out at high temperature.

9)Metals do not melt until heated to a definite temperature.

10) Given the weight and gravity of a body you can calculate its volume.

Exercise 13. Speak on

What subjects are the most important for you as a future engineer? Prove your reply.