Twin Boundaries are Which Type of Crystal Defect?

Explain Surface Defect.

The bond length is longer and more easily breakable due to the orientation mismatch at the grain boundary. Tilt boundary defect: Grain boundaries are referred to as tilt boundaries when there is a 0.5°–1° orientation mismatch at the grain boundary.

Point Defects (Zero dimensional)- The absence of one atom from the lattice is the cause of the vacancy defect. Atom in the lattice fills the interstitial hole, a Frenkel defect. Schottky Defect: A vacancy seems to exist when a cation and anion are combined. When a foreign atom occupies the interstitial site, it causes an interstitial defect. Substitutional defects show up when an ordinary atom is changed for a foreign one.

Line defect or dislocations (One-Dimensional)- When a plane slips and an additional half-plane appears at the dislocation line, force applied to 50% of the area will cause this to happen. Dislocation in the screw is caused by the shear stress that was used to cause the deformation.

Summary:

Twin boundaries are which type of crystal defect? (A) Line defect (B) Point defect (C) Surface defect (D) None of the above  

Twin boundaries are a form of crystal surface imperfection. Twin boundaries appear in pairs, restoring the orientation shift that was caused by the first boundary. The twinned region is the area that lies between the two boundaries.