1. What is the original grain size of the copper wire? What is the grain size after annealing? How did you measure these grain sizes? What is the amount of scatter in your data?

2. How has the wire center-to-center distance changed after annealing? Report this figure along the axis of the spool and along the radius of the spool. How do you explain this?

3. What is your estimate of the change in surface energy per cm3 of Cu after annealing of the specimen? The surface energy of copper is about 1 J/m2. How does this compare with the change in grain boundary energy because of the grain growth? Take grain boundary energy as one half of the surface energy. Do these numbers bear any relation to each other? If so, why? If not, why not?

4. Calculate the void fraction in the sample and the "rugiosity" (the perimeter of the void divided by the circumference of a circle of equal area). What are the initial and final possible values of rugiosity?

5. Try to find and illustrate areas in your sample where void disappearance is more rapid than the average. Discuss why this occurs.