What are the effects of cold deformation on the performance of aluminum materials during the processing of aluminum shells?

What is the effect of cold deformation on the performance of aluminum materials during the processing of aluminum shells? The following Zhong Yilong editor will explain to you in detail.

　　What are the effects of cold deformation on the performance of aluminum materials during the processing of aluminum shells:

　　 1. Mechanical properties:

After cold deformation of the aluminum material, due to intra-crystalline and inter-crystalline damage, the crystal lattice is distorted and the second type of residual stress occurs, etc., so that the plastic index drops sharply, and may be close to a completely brittle state in the limit state On the other hand, due to lattice distortion, increased dislocations, elongated and refined grains, and the appearance of substructures, etc., its strength index is greatly improved, that is, work hardening.

　　 2. Structure and anisotropy:

　　After a large cold deformation, the aluminum material is anisotropic due to the texture. For example, aluminum alloy sheets are prone to obvious earing when deep-drawn. Processing conditions should be reasonably controlled to make full use of the advantageous aspects of texture and anisotropy, while avoiding or eliminating their disadvantageous aspects.

　　 3. Physical and chemical properties:

　　 1) Density. After cold deformation, due to defects such as micro-cracks or macro-cracks and crack holes appearing in and between the crystals, the density of the aluminum material is reduced.

　　 2) Resistance. The destruction of intergranular materials causes the direct contact of the crystal grains, the orientation of the crystal grains, the intergranular and intragranular fractures, etc., which have a significant effect on the change of resistance. The first two make the resistance decrease with the increase of the degree of deformation, the latter is the opposite.

　　 3) 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.

The above is the introduction of the effect of cold deformation on the performance of aluminum materials during the processing of aluminum shells. After cold deformation of aluminum materials during the processing of aluminum shells, due to intra- and inter-crystalline damage, the lattice constant It caused the sag change and the appearance of the second-class internal stress, etc., so that the plastic deformation index value dropped suddenly, in some cases it will be close to the situation of brittle fracture; on the other hand, the lattice constant changes during the processing of the aluminum shell , Increased dislocations, optimization of grain lengthening and sub-structures, etc., and its compressive strength index value has been greatly improved, that is, cold work hardening.