Question

The dislocations can be generated by using

• A. Schottky mechanism
• B. Burger’s vector
• C. Twist
• D. Frank-Read source mechanism

Hint:

Frank-Read source is the primary mechanism responsible for dislocation multiplication during plastic deformation.

Answer 1

The Correct Option is D

Step 1: Understanding dislocations.
Dislocations are line defects in crystals that play a crucial role in plastic deformation. Their generation and multiplication directly influence material strength.
Step 2: Frank-Read source mechanism.
The Frank-Read source is a well-known mechanism for the multiplication of dislocations. It involves a pinned dislocation segment that bows out under applied stress and produces new dislocation loops repeatedly.
Step 3: Eliminating other options.
(A) Schottky mechanism: Related to point defects such as vacancies, not dislocations.
(B) Burger’s vector: Describes the magnitude and direction of a dislocation but does not generate it.
(C) Twist: Refers to a type of grain boundary, not a dislocation generation process.
Step 4: Conclusion.
Thus, dislocations are generated by the Frank-Read source mechanism.