METAL PROPERTIES, CHAR, USES, AND CODES - OD1643 - LESSON 1/TASK 1
some cases, it may consist of one or more metals and a nonmetal.
Examples of alloys are iron and carbon, forming steel, and the great
variety of copper alloys, such as brass and bronze.
c.
Physical Properties. These properties are related to the atomic
structure and density of the material, as described in the following
paragraphs.
(1) Co-efficient of Linear Expansion.
The co-efficient of linear
expansion is the increase in length of a body for a given rise in
temperature.
The increase is the changed length of a rod for each
degree that the temperature is increased. Metal expands when heated
and contracts when cooled. It increases not only in length, but also
in breath and thickness. The increase in unit length when a solid is
heated one degree is called the co-efficient of linear expansion.
(2) Heat and Electrical Conductivity.
Heat and electrical
conductivity is the ability of a material to conduct or transfer heat
or electricity.
(3) Magnetic Susceptibility.
Magnetic susceptibility is the
ability of a material to hold a magnetic field when it is magnetized.
(4) Reflectivity.
Reflectivity is the ability of a material to
reflect light or heat.
(5) Specific Gravity.
Specific gravity is the ratio of weights
between two objects of equal volume, one of which is water.
(6) Melting Point. The melting point is the temperature at which
a substance passes from a solid state to a liquid state.
d.
Mechanical Properties.
(1) Strength.
The strength of a material is the property of
resistance to external loads or stresses while not causing structural
damage. Ultimate strength is the unit stress, measured in pounds per
square inch, developed in the material by the maximum slowly applied
load that the material can resist without rupturing in a tensile
test.
The strength of metals and alloys depends upon two factors:
the strength of the crystals of which the metals are constructed, and
the tenacity of adherence between these crystals.
The strongest
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