Approximately what is the vacancy concentration in a metal a

Approximately what is the vacancy concentration in a metal at a temperature just below its melting point? Approximately what is the dislocation density (in cm/cc) in a heavily deformed metal? When dislocations start to slip in a crystalline solid, what will happen to the solid?

Solution

a) Approximate vacancy concentraion in a metal at temperature just below its melting point = 10^-5 - 10^-4

b) Dislocation density in heavily deformed metal = 10¹¹- 10¹² cm/cc

C) Plastic deformation starts when dislocatons start to slip in a crystalline solid