Why is it that dislocations play an important role in contro

Why is it that dislocations play an important role in controlling the mechanical properties of metallic materials, however, they do not play a role in determining the mechanical properties of glasses?

Solution

Metals belong to poly crystalline category of solids while glass is an amorphous solid.

Certain number of defects and dislocations in glass doesn\'t alter the properties because already there is randomness everywhere in the structure. While in metals, as the structure has a uniformity, dislocations play an important role in deciding the mechanical properties of metals.