MSE170-final.pdf - ENGR/MSE 170 B Final exam (Total:105pts)...

ENGR/MSE 170 B Final exam
(Total:105pts)
Exam is closed book
(Two sheets of letter size paper allowed)
Instruction:
1. Place your name and student ID on top page
2. Write legibly
3. Show work as need to justify answers
4. Circle all final numerical answers
Problem 1. Basics (40 points): Answering following questions
a. A hard sphere unit cell of FCC is shown in the figure below. Determine number of
atoms per unit cell, coordination number, and relation between cubic edge a and the
radius R.
b. What are atomic mechanisms for interstitial and vacancy diffusion? Give two reasons
why interstitial diffusion is normally more rapid than vacancy diffusion.

c. Discuss electrical conductivity for pure metals, extrinsic semiconductors, and pure
insulators in terms of electron energy band structure.
d. Will the electrical conductivity of fine-pearlite steels be greater than coarse pearlite
steels? Why?
e. List three methods for strengthening metals and discuss the their mechanisms.