Development of New Materials



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Development of New Materials



 

Development of new constructional nonmetallic materials characterized by high strength and fracture toughness as well as chemical inertness in combination with high resistance to aggressive media over a wide temperature range is an urgent problem of modern science of materials. One of such materials is cermet – the composition of ceramics and metal. A cermet is ideally designed to have the optimal properties of both a ceramics, such as high temperature resistance and hardness, and those of a metal, such as the ability to undergo plastic deformation. The metal is used as a binder for an oxide, boride, carbide, or alumina. Generally, the metallic elements used are nickel, molybdenum, and cobalt.

Cermets are used in the manufacture of resistors (especially potentiometers), capacitors, and other electronic components which may experience high temperatures. Cermets are being used instead of tungsten carbide in saws and brazed tools due to their superior wear and corrosion properties. More complex materials, known as Cermet 2 or Cermet II, are being utilized since they give considerably longer life in cutting tools. Some types of cermets are also being considered for use as spacecraft shielding as they resist the high velocity impacts of micrometeoroids and orbital debris much more effectively than more traditional spacecraft materials such as aluminum and other metals.

Another prominent constructional material is partially stabilized zirconia (PSZ). It is a solid solution of zirconium dioxide with small additions of yttrium, calcium or magnesium and other rare earth and alkaline-earth metal oxides. Ceramic (polycrystalline) types of these materials are extensively used worldwide today.

The technology for manufacture of new synthetic cubic zirconia (fianit) was originated by General Physics Institute of the Russian Academy of Sciences in the seventies when it developed a procedure for cold melting dielectric materials.

The new technology of synthesis of single crystals is highly efficient and the project completely meets the ISTC (International Science and Technology Centre) tasks and goals because the specific technologies and methods previously developed for military application will be used for synthesis and investigation of new advanced materials for wide peaceful use.

Experimental data accumulated by the authors of the project provide evidence for principle possibility to govern synthesis of PSZ crystals with a variety of pre-assigned physico-chemical properties that may be used to produce components of various applications, such as:

- cutting tools in machinery and medicine;

- components of spacecraft equipment;

- heavy-duty units with resistance to thermal stress and fretting corrosion for aerospace application;

- Tribo-conjugations in car and air craft engines;

- Sliding and rolling bearings and other heavy-duty friction units for operation under extreme conditions.

The governable synthesis technology will guarantee a many-fold increase in reliability and service life of equipment operating under extreme mechanical stress, corrosive media, radiation, intense electromagnetic fields, elevated temperature, absence of lubrication, etc. (bearings, engine values, dies, guides, cutters, prisms in precise equipment).

 

Exercise 1. Write out of the text the derivative words with the given suffixes, define the parts of speech of the derived and original words and translate them:

 

-ive, -ic, -ture, -al.

 

Exercise 2. Pay attention to different meanings of the conjunction “as” and translate it in the following contexts:

1. Development of new materials with nigh strength as well as chemical inertness is very urgent task.

2. Cermet possesses such properties as high temperature resistance.

3. Cermet has the properties of metal, such as the ability to undergo plastic deformation.

4. The metal is used as a binder for some substances.

5. More complex materials, known as Cermet 2, are used in cutting tools.

6. Some types of cermets are being utilized as spacecraft shielding as they greatly resist the impacts of orbital debris.

7. Cermet shielding resists the high velocity impacts of meteorites more effectively than traditional materials such as aluminum or other metals.

8. PCZ crystals may be used in various applications, such as cutting tools in machinery.

 

Exercise 3. Complete the sentences:

1. New constructural materials are characterized by the properties: …

2. The problem of modern science of materials is the development …

3. New material, cermet, is the composition of …

4. Cermets are used in devices and components which experience …

5. Another prominent constructional material is PSZ- …

6. The manufacture of fianit was originated by …

7. The synthesis of single crystals may be used for …

8. A variety of pre-assigned properties of crystals may be used to produce …

9. The governable synthesis will guarantee …

 

Exercise 4. Insert the proper words into the sentences:

1. (Разработка) of new materials is very important task.

2. Constructional materials are characterized by (высокой стойкостью) and (прочностью на излом).

3. Such materials (выдерживают) aggressive media and high temperatures.

4. Cermet possesses (свойствами) of both a ceramics, and of metals.

5. Cermet (может подвергаться) to plastic deformation.

6. The metal is used as (связующее вещество) for some materials.

7. Cermets have (чрезвычайную износоустойчивость) and (антикоррозийные свойства).

8. Cermets give longer life to (режущим инструментам).

9. General Physics Institute developed (методику) for cold melting dielectric materials.

10. The new technology (удовлетворяет) the (международным техническим стандартам).

 

Exercise 5. Choose synonyms to a Russian word:

1. разработка a) elaboration c) devise

b) working out d) development;

 

2. прочность a) strength c) hardness

b) toughness d) resistance;

 

3. среда (окружение) a) sphere c) environment

b) media d) joining;

 

 

4. срочный а) quick c) urgent

b) pressing d) important;

5. деформация a) crush c) deformation

b) strain d) stress;

 

6. деталь a) detail c) part

b) component d) unit;

 

7. опыт (испытание) a) text c) experience

b) experiment d) control;

 

 

8. использовать a) apply c) utilize

b) use d) realize;

 

9. начинать a) begin c) originate

(давать начало) b) start d) root.

 

Exercise 6. Translate into English:

1. Новые неметаллические материалы обладают (possess) улучшенными свойствами.

2. Прочность и сопротивляемость к высоким температурам – неотъемлемое (inalienable) свойство этих материалов.

3. Неметаллические материалы могут противостоять высоким нагрузкам (loads) и коррозии.

4. Cermet – это соединение керамики и металла.

5. Cermet используется для изготовления приборов, работающих при высоких температурах.

6. Cermet может заменять такой прочный материал, как вольфрам (tungsten).

7. Cermet используется для обшивки космических кораблей.

8. Циркон – это твердый раствор двуокиси циркония и других многочисленных металлов.

9. Синтетический циркон – это фианит, используемый в различных областях.

10. Ученые могут придавать (provide) новым материалам предопределенные (pre-assigned) свойства.

 

Speaking:

Exercise 7. Give the summary of the text using key vocabulary and tell about:

 

a) the aim of developing new constructional materials;

b) the properties of such materials;

c) the field of applying cermets;

d) the composition of partially stabilized zirconia;

e) the branches of its usage.

Checklist for Section IX:

1. How is Continuous Tense Passive formed?

2. What are the meanings of the suffixes -ness, -ive, -ic, -ture, -al.

3. What are the properties of new constructional nonmetallic materials?

4. What are such materials and where are they applied?

Section X

Modern Machining Methods

Grammar:Functions of Infinitive (repetition).

Word-formation: Word composition.

Speaking:Laser Cutting Technology.

Practise the reading of the words:

precision [prI′sIჳən]
equipment [I′kwIpmənt]
grinding [′graIdIη]
edge [edჳ]
decade [dI′keId]
power [pauə]
driven [drIvn ]
automotive [/ɔ:tə′moutIv]
current [′kΛrənt]
hybrid [′haIbrId]
contour [′kɔntuə]

 

Learn the meaning and pronunciation of the words:



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