Question

Define the difference between elastic and plastic deformation in terms of the effect on the crystal lattice structure.

Answer 1

Elastic Deformation:

• Elastic deformation is due to the elasticity of the body i.e., the deformation disappears on removal of external forces and the lattice regain its original structure.
• This type of deformation is temporary in nature.
• This type of deformation depends mainly on the chemical bonding of the substance.
• It occurs due to bending or stretching of chemical bond under applied stress where atoms do not slip pass over each other.
• It is a reversible process.

Plastic Deformation:

• Plastic deformation is due to the plasticity of the body i,e., the structure can be easily shaped or molded .
• This type of deformation is permanent in nature.
• This type of deformation occurs mainly due to breakage of chemical bonds(limited in number) between constituent atoms.
• Atoms may slip pass each other causing dislocation of atoms , resulting in permanent deformation even after stress is removed.
• It is an irreversible process.