| PART A (8
MARKS)
Explain in a few sentences, together with a diagram where appropriate,
in each case, any FOUR of the following techinical terms .
| 1. |
Allotropy |
| 2. |
Polymorphism |
| 3. |
Point defects |
| 4. |
Microstructure |
| 5. |
Edge dislocation |
| 6. |
Carburzing |
| 7. |
Self-diffusion |
| 8. |
Fick's first law for diffusion |
PART B
(7 MARKS)
| 9. |
For all cubic crystals, the Burgers vector is
b=a/2[hkl] where a is the unit cell length and [hkl] is the crystallographic
direction having the greatest linear atomic density.
Calculate bº |b| for a
-Fe, which has a BCC crystal structure with an atomic radius R=1.24Å.
( 4Marks )
|
| 10. |
Show that Fick's second law takes on a form
similar to the first law in steady diffusion. ( 3 Marks )
|
END
|