Question

Frank–Reed source is a

• A. Dislocation multiplier
• B. Multiplier of point defects
• C. Ionic defects multiplier
• D. Multiplier of interstitial defects

Hint:

The Frank–Reed source is a major mechanism in plastic deformation and contributes to strain hardening in metals.

Answer 1

The Correct Option is A

The Frank–Reed source is a mechanism responsible for the multiplication of dislocations in crystalline materials under stress. Step 1: Understanding Dislocation Multiplication - When a material is plastically deformed, existing dislocations move due to applied stress. - The Frank–Reed source allows the formation of new dislocations from an initial segment pinned at both ends. - Under continued stress, the pinned segment bows out and eventually forms a dislocation loop. - This mechanism is crucial in work hardening, where increased dislocation density strengthens the material.

Step 2: Conclusion Since the Frank–Reed source is directly related to the multiplication of dislocations rather than point, ionic, or interstitial defects, the correct answer is (A) Dislocation multiplier.