Question
Download Solution PDFWhich of the following is the surface defect?
This question was previously asked in
APPSC Lecturer (Polytechnic Colleges) Held on March 2020
Answer (Detailed Solution Below)
Option 3 : Twin boundaries
Detailed Solution
Download Solution PDFExplanation:
Imperfection/Defect:
- An ideally perfect crystal is one which has the same unit cells and contains some lattice point throughout the crystals
- Imperfections or defect is generally used to describe any deviation of the ideally perfect crystal from the periodic arrangement of its constituents. Defects can exist in any solid material.
Crystalline defects:
- Crystalline defects mean a lattice irregularity having one or more of its dimensions on the order of an atomic diameter
- Defects in the crystalline structure can have a tremendous effect on material behaviour.
- Physical, electrical, magnetic and the optical properties of crystalline materials can be modified by controlling the imperfections in their lattice structure
- For ease of their characterizations defects are classified on the basis of their geometry.
Defects |
Dimension |
Examples |
Point Defects |
Zero-dimensional |
Vacancy, Self-Interstitial, Impurity |
Line Defects |
One-dimensional |
Edge dislocation, Screw dislocation, Mixed dislocation |
Surface Defects |
Two-dimensional |
External surfaces, Grain boundaries, Twin boundaries, Stacking Fault |
Volume Defects |
Three-dimensional |
Precipitates, Dispersants, Inclusions, Pores, Cracks |
Last updated on May 17, 2025
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