Topic 4 - Imperfections in Solids

Question 1

What are the solidification mechanisms?

Answer 1

2 steps:
- Nuclei form
-Nuclei grow to form crystals - grain structure.

Question 2

What types of defects arise in solids?

Answer 2

Point, line, and Area defects.

Question 3

Can the number and type of defects be varied and controlled?

Answer 3

The number and type of defects can be varied and controlled (e.g., T controls vacancy conc).

Question 4

How do defects affect material properties?

Answer 4

Defects affect material properties (e.g., grain boundaries control crystal slip).

Question 5

Are defects undesirable?

Answer 5

Defects may be desirable or undesirable (e.g., dislocations may be good or bad, depending on whether plastic deformation is desirable or not.)