Answer:
The effect is hardening by deformation (also called hardening by cold or acidity) is the hardening of a material by a plastic deformation at the macroscopic level that has the effect of increasing the density of dislocations of the material.
Explanation:
Cold plastic strain hardening is the phenomenon whereby a ductile metal becomes harder and more resistant as it is plastically deformed. Generally this phenomenon is also called cold work, because the deformation occurs at a "cold" temperature relative to the absolute melting temperature of the metal.
In order for the hardening of the metal to be maintained, it is necessary that the dislocations that were created during the deformation be maintained in the metal structure. The metal structure has a "normal" number of dislocations. The plastic deformation has caused more dislocations than that "normal" number, so the crystalline structure will tend to make the "extra" dislocations disappear.
Cold work not only causes an increase in dislocations in the metal structure, but also causes the deformation of its grains. Condensation of deformed grains with increased dislocations causes residual stresses within the material. Residual stresses are nothing more than areas of tension or compression that exist within the material without being generated by external forces. Residual stresses can cause the material to weaken, causing it to fail at applied stresses less than its nominal strength.
