What is the subject of crystallography?

Why is it easy to see the effects of the crystalline arrangement of atoms?

Why is it important to understand crystal structure?

What experimental method is used to study polycrystalline materials?

Into what classes are materials classified according to their structure?

What concept is used to classify materials into crystalline and non-crystalline?

Do polymers belong to crystalline or non-crystalline materials?

What research methods are used to describe polymers?

Read the text and think of a title to it.

Make sure that you understand the following words and word combinations:

Desired structure – желаемая структура

Engineering standpoint – с точки зрения инженерного дела

Vital - жизненно важный

Require – требовать

Text B

Synthesis and processing involves the creation of a material with the desired micro-nanostructure. From an engineering standpoint, a material cannot be used in industry if no economical production method for it has been developed. Thus, the processing of materials is vital to the field of materials science.

Different materials require different processing or synthesis methods. For example, the processing of metals has historically been very important and is studied under the branch of materials science named physical metallurgy. Also, chemical and physical methods are used to synthesize other materials such as polymers, ceramics, thin films, etc. As of the early 21^st century, new methods are being developed to synthesize nanomaterials such as graphene.

PART IV

1. Learn the words:

stainless steel	нержавеющая сталь
cast iron	чугун
quantity	количество
low/mid/high carbon steel	низко-средне-высокоуглеродистая сталь
carbon	углерод
level	уровень
tensile strength	прочность на разрыв
amount	количество
(to be) present	присутствовать
content	содержание
by weight	в весовом отношении
heat treatment	термообработка
quenching	закалка
tempering	отпуск
however	однако
to increase	увеличить
ratio	отношение
to provide	обеспечивать
shielding	защита; экранирование

2. Guess the meaning of the following words and word combinations:

Proportion, chromium, nickel molybdenum, titanium, copper, magnesium, aluminum, chemical reactivity, electrolytic extraction, strength-to-weight ratio; automotive.

3. Identify the part of speech and translate the words:

Value, valuable; proportion, proportional; significant, significance, significantly, insignificant; require, requirement, required.

Match the words with their definitions

quantity	the amount of a substance that is contained in something, especially food or drink
level	to become bigger in amount, number, or degree
amount	how heavy something is when you measure it
content	an amount of something that can be counted or measured
to increase	something that protects a person or thing from harm or damage
to provide	a relationship between two amounts, represented by a pair of numbers showing how much bigger one amount is than the other; proportion
weight	the amount or degree of something, compared to another amount or degree; the height of something in relation to the ground or to another object
shielding	to produce something useful as a result
ratio	a quantity of something such as time, money, or a substance

Text A.

Metal alloys

The study of metal alloys is a significant part of materials science. Of all the metallic alloys in use today, the alloys of iron (steel, stainless steel, cast iron, tool steel, alloy steels) make up the largest proportion both by quantity and commercial value. Iron alloyed with various proportions of carbon gives low, mid and high carbon steels. An iron carbon alloy is only considered steel if the carbon level is between 0.01% and 2.00%. For the steels, the hardness and tensile strength of the steel is related to the amount of carbon present, with increasing carbon levels also leading to lower ductility and toughness. Heat treatment processes such as quenching and tempering can significantly change these properties however. Cast iron is defined as an iron–carbon alloy with more than 2.00% but less than 6.67% carbon. Stainless steel is defined as a regular steel alloy with greater than 10% by weight alloying content of Chromium. Nickel and Molybdenum are typically also found in stainless steels.

Other significant metallic alloys are those of aluminum, titanium, copper and magnesium. Copper alloys have been known for a long time (since the Bronze Age), while the alloys of the other three metals have been relatively recently developed. Due to the chemical reactivity of these metals, the electrolytic extraction processes required were only developed relatively recently. The alloys of aluminum, titanium and magnesium are also known and valued for their high strength-to-weight ratios and, in the case of magnesium, their ability to provide electromagnetic shielding. These materials are ideal for situations where high strength-to-weight ratios are important, such as in the aerospace industry and automotive engineering applications.

5. Translate the sentence and pay attention to the way of avoiding repetition: