Материаловедение: свойства металлов. Матросова Т.А - 8 стр.

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including properties such as electrical and thermal conductivity, specific heat, and
magnetism; and third, their macroscopic properties, such as their mechanical
behavior under load, which can be explained in terms of impurities and
imperfections in the lattice structure and the procedures used to modify that
behavior.
In the selection of materials for industrial applications, many engineers
normally refer to their average macroscopic properties, as determined by engineering
tests, and are seldom concerned with microscopic considerations.
Others, because of their specialty or the nature of their positions, have to deal
with microscopic properties.
The average properties of materials are those involving matter in bulk with its
flaws, variations in composition, and variations in density that are caused by
manufacturing fluctuations. Microscopic properties pertain to atoms, molecules,
and their interactions. These aspects of materials are studied for their direct
applicability to industrial problems and also so that possible properties in the
development of new materials can be estimated.
In order not to become confused by apparently contradictory concepts when
dealing with the relationships between the microscopic aspects of matter and the
average properties of materials, it is wise to consider the principles that account for
the nature of matter at the different levels of our awareness. These levels are the
commonplace, the extremely small, and the extremely large. The commonplace level
deals with the average properties already mentioned, and the principles involved are
those set forth by classical physics. The realm of the extremely small is largely
explained by means of quantum mechanics, whereas that of the extremely large is
dealt with by relativity.
Relativity is concerned with very large masses, such as planets or stars, and
large velocities that may approach the velocity of light. It is also applicable to
smaller masses, ranging down to subatomic particles, when they move at high
velocities. Relativity has a definite place in the tool boxes of nuclear engineers and
electrical engineers who deal with particle accelerators. For production engineers,
relativity is of only academic interest and is mentioned here for the sake of
completeness.
Glossary
№ English word Translation
1. bonding связывающий
2. force сила
3. arrangement расположение
4. aggregation скопление, концентрация
5. conductivity проводимость
6. specific удельный, специфичный
7. heat тепло

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