What is the main effect of strain hardening in metals?

The primary effect of strain hardening, also known as work hardening, in metals is the increased strength and hardness that results from the plastic deformation of the material. When metals are subjected to mechanical stress beyond their yield strength, they undergo dislocation movements within their crystalline structure. This process increases the density of dislocations, making further movement of these defects more difficult.

As a result, the material becomes harder and stronger because the dislocations interact with each other, forming a network that impedes additional deformation. This increased dislocation density enhances the metal’s resistance to further deformation, thereby raising its yield strength and hardness.

In terms of other effects of strain hardening, while it does reduce plasticity, this is a secondary consequence of the primary increase in strength and hardness. Strain hardening is generally not associated with improvements in thermal conductivity or enhanced ductility; in fact, it typically results in decreased ductility because the metal becomes less able to deform plastically without fracturing. Therefore, the key takeaway is that the main outcome of strain hardening is the increase in strength and hardness of metal materials.