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    Recrystallization takes place, for example, when internal mechanical stress develops in a material due to cold forming then it is annealed at an appropriate temperature. If this happens, new grains are formed from the original crystal grains and the whole crystal structure of the body is renewed, resulting in the reduction of the voltage. The temperature at which the process is triggered, typically about half of the melting temperature in metals, is called recrystallization temperature. Tin is an exception as it is already recrystallized below room temperature. Rearranging normally refines the grains of a crystal and leads to the accumulation of internal stress. Subsequent heating causes the atoms to oscillate until their acceleration energy has reached the maximum, the crystal grains break and form a fine structure, resolving the internal tension. When heated further, grain growth continues and the grain size increases with the increasing temperature. Recrystallization depends on the type of the alloy as well as the type and degree of deformation before heating. If such a material is heated to the recrystallization temperature to relatively low deformation, the grains grow very quickly and sometimes form larger crystals. To induce the recrystallization is not necessarily a great inner tension necessary to satisfy most a few percent. Also for the production of single crystals of iron or nickel or their alloys, this recrystallization method is widely used by heating. Solder alloys (Sn-Pb, etc.) are, however, softened by forming. This is due to the recrystallization of tin or below room temperature. The formed during the hardening stress is relieved immediately by recrystallization. This is known as softening by deformation (work softening).