What are the effects of cold deformation on aluminum properties

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Cold deformation is the processing of a metal below the recrystallization temperature. Such as steel cold drawing or cold stamping, etc.

The following, Kaixin Aluminum will introduce the influence of cold deformation on aluminum properties:

Physical and chemical property.

Density. After cold deformation, Microcracks appeared in Intracrystalline, which reduced the aluminum density.
Resistance. The damage of intercrystalline material makes the grains contact directly, grain position ordering, and intercrystalline fracture, etc., all have obvious influence on the change of resistance. The former two make the resistance decrease with the increase of deformation degree, while the latter is opposite.
Chemical stability. After cold deformation, the internal energy of the material increases, making its chemical properties more unstable and prone to corrosion, especially stress corrosion.

Mechanical property.

After the cold deformation of aluminum, due to the occurrence of intercrystalline damage, lattice is distorted and the emergence of two kinds of residual stress. Plastic index decreased sharply, It may approach a state of complete brittleness in its limit state . On the other hand, due to lattice distortion, increasing dislocation, elongation and refinement of grains and the occurrence of substructure, the strength index is greatly improved. That is, the phenomenon of machining hardening.

Structure and anisotropy.

After large cold deformation, the aluminum material presents anisotropy due to its texture. For example, aluminum alloy sheet is prone to obvious ear-making during deep drawing. Processing conditions should be reasonably controlled to take full advantage of texture and anisotropy and to avoid or eliminate the disadvantages.