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As a result of the polymorphic transformation creates new crystal grains with
different size and shape. Therefore, such
a transformation is called
recrystallization. Polymorphic transformations occur in pure metals, alloys,
chemical compounds. Polymorphous transformation is accompanied by an
abrupt change in the properties of metals and
alloys in the specific volume,
specific heat, thermal conductivity, electrical conductivity, magnetic properties,
mechanical and chemical properties, etc.
Fig. 2.1. Types of crystal lattices:
a) cubic body-centred lattice; b) cubic face-centered lattice
Fig. 2.2. Defects of a crystal structure:
a, e - dot defects,
b - linear defects
178
а б
Fig. 2.3. Freezing of liquid metal and dendrite:
a) dendrite; b) metal granules
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