One can increase the strength of a metal by adding solute at

One can increase the strength of a metal by adding solute atoms, why is this the case?

Solution

Solid solution strengthening is a type of alloying that can be used to improve the strength of a pure metal.Atoms of another element is introduced in the basse metal. Overall crystalline structure remains same.

The strength of a material is dependent on how easily dislocations in its crystal lattice can propagate. These dislocations create stress fields within the material depending on their character. When solute atoms are introduced, local stress fields are formed that interact with those of the dislocations, impeding their motion and causing an increase in the yield stress of the material, which means an increase in strength of the material. This gain is a result of both lattice distortion and the modulus effect.