1. 김 석 범 MSM Lab. ( Graduate Student ) 2013. 10. 14 디자인과 재료 문제풀 이

2. 2 Problem 5.1 Vacancy distortion of planes Boltzmann's constant (1.38 x 10 -23 J/atom-K) (8.62 x 10 -5 eV/atom-K)  N v N  exp  Q v kT      No. of defects No. of potential defect sites Activation energy Temperature   Entropy

3. 3 Problem 5.1 Calculate the fraction of atom sites that are vacant for lead at its melting temperature of 327 ℃ (600K). Assume an energy for vacancy formation of 0.55eV/atom.  Prob. 5.3

4. 4 Problem 5.11 Conditions for substitutional solid solution (S.S.) W. Hume – Rothery rule –1.  r (atomic radius) < 15% –2. Proximity in periodic table i.e., similar electronegativities –3. Same crystal structure for pure metals –4. Valency All else being equal, a metal will have a greater tendency to dissolve a metal of higher valency than one of lower valency

5. 5 Problem 5.11  Prob. 5.11, 5.12

6. 6 Problem 5.15  Prob. 5.14, 5.19, 5.20 What is the composition, in atom percent, of an alloy that consists of 30wt% Zn and 70wt% Cu?

7. 7 Peierls-Nabarro Stress Closed Loop

8. 8 Peierls-Nabarro Stress

9. 9 Peierls-Nabarro Force -It is the frictional force that must be overcome to move an individual dislocation -Depend upon the amount the lattice is distorted by the dislocation

10. 10 Peierls-Nabarro Stress

11. 11 Problem 5.40  Prob. 5.42, 43 100um 600um 100X (a) Avg. = 8.7 grains Avg. = 8.7 grains (b) 12 grains

12. 12 Chapter 7 Same as Mechanics of Materials  Remind

13. 13 Problem 7.3 A specimen of aluminum having a rectangular cross section 10mm*12.7mm is pulled in tension with 35500N force, producing only elastic deformation. Calculate the resulting strain  Prob. 7.5, 7.7, 7.9, 7.19, 7.35 10mm*12.7mm Al = 69GPa

14. 14 Problem 7.12  Prob. 7.14 = 0

15. 15 Problem 7.39

16. 16 HW -5.3 -5.11 -5.12 -5.14 -5.19 -5.20 -5.42 -5.43 -7.5 -7.7 -7.9 -7.14 Due to Midterm-Exam -7.19 -7.35 -7.42 -7.49