1. No category

12. A common metal is known to have a cubic unit cell with an edge length of 0.288 nm. If this metal
has a density of 7.20 g/cm3 and an atomic weight of 52.0 g/mole, what is its atomic packing factor?
Why?
4 marks
13.
Determine the Miller indices for the directions shown below:
4 marks
A)
B)
C)
D)
14. Determine the Miller indices of the planes shown below
A)
B)
C)
A)
B)
C)
6 marks
11. Steel initially containing 0.002% N is to be nitrided to obtain a concentration of
0.12% N at a distance of 0.0051 cm below the surface. The surface concentration is
maintained at 0.15% and the temperature is 625°C. How long will this treatment take?
Diffusing
Species
N
4 marks
Host Metal
D0 (m2 /s)
Qd (kJ/mol)
α-Fe
4.7 x 10-7
76.6