α -
Fe and
γ -
Fe.
α -
iron (Fe)
it can exist in two temperature ranges: at temperatures below 911
0 C and at temperatures up to 1392 0
C-1539
0 C.
α -
The crystal lattice structure of iron (Fe) is
centered cubic lattices.
g -iron
(Fe) exists in the temperature range of 911
0
C to 1392
0 C, and its crystal
lattice structure is an edge-centered cubic lattice.
137
The process of transition of metal atoms from a liquid state in motion to a
solid state in which atoms are arranged in an orderly manner is called
the
crystallization process .
In 1878, the Russian scientist DKChernov was the first in the world to
discover the law of crystallization of metals. According to him, the crystallization
process of metals consists of two elementary processes:
1. Formation of crystallization centers;
2. Growth of crystals around the formed centers.
The size of the formed crystals depends on the number of crystallization
centers
(MS)
and the crystal growth rate
(KT) .
It should be said that various oxides
and non-metallic particles that are not dissolved in metals also play the role of
crystallization centers.
WORK PROCEDURE
Acquiring theoretical knowledge about the internal structure of metals and
crystal lattices and analyzing the crystal bonds of the materials used.
3 – Laboratory work
REPORT
Topic: Internal structure of metals and crystal lattices
1. Purpose of work.
2. Necessary equipment and measuring instruments.
3 . Summary of the work done.
Questions.
1.
State and explain the types of crystal lattice
2.
What is called crystallization.
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