Plastic deformation increases dislocations and strength.
Cold working increases dislocation density, raising yield and hardness while reducing ductility: σ=Kεⁿ. Percent cold work %CW=(A₀-A_d)/A₀×100. Used in wire drawing and rolled sheets; reversed by annealing.
Drawing copper wire can double its yield strength.
Strain hardening explains why cold working makes metals stronger, which is used in wire drawing, rolling and forming.
Plastic deformation increases dislocations and strength.
Strain hardening explains why cold working makes metals stronger, which is used in wire drawing, rolling and forming.
Plastic deformation multiplies dislocations, which tangle and block each other, so more stress is needed to keep deforming.
Yes. Annealing recovers and recrystallises the metal, restoring ductility and reducing hardness.
Typical applications include cold rolling a steel strip to increase its yield strength, forming a copper pipe that becomes harder during bending and understanding why a part that is overstrained becomes less ductile.
Study "Strengthening mechanisms" first (topic 12 of 100 in Materials & Chemical). It covers the groundwork this topic builds on.
Work-hardening exponent n. Bauschinger effect. Springback.
Drawing copper wire can double its yield strength.
The next topic is "Recovery, recrystallisation and grain growth", which builds directly on this one.
It is classed as Beginner in Materials & Chemical (topic 13 of 100). It is an entry-level topic. It relies only on basic school mathematics and the ideas introduced earlier in this discipline.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.