It has been noted that during the cold working of a metal pa

It has been noted that during the cold working of a metal part, the strain hardening rate experienced by the part decreases with the increased amount of cold work. Explain why

Solution

1) Ductile metals become stronger when they are deformed plastically at temperatures well below the melting point.

2 Strengthening by increase of dislocation density (Strain Hardening = Work Hardening = Cold Working) Ductile metals become stronger when they are deformed plastically at temperatures well below the melting point. The reason for strain hardening is the increase of dislocation density with plastic deformation. The average distance between dislocations decreases and dislocations start blocking the motion of each other.