7.13: Questions
- Page ID
- 36255
Quick questions
You should be able to answer these questions without too much difficulty after studying this TLP. If not, then you should go through it again!
- What is the ratio of the minimum shear stress required to operate a Frank-Read source for work-hardened copper (ρ = 1014 m-2) and annealed copper (ρ = 1010 m-2)?
- Answer
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C
Which of the following about cross-slip is true?
- Answer
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A
Which type of intersection is most important to work hardening?
- Answer
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C
Which of the following is not a pinning site in forest hardening?
- Answer
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C
Which of the following about poly-crystals is/are true?
- Answer
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D
Deeper questions
The following questions require some thought and reaching the answer may require you to think beyond the contents of this TLP.
- Explain why the intersection of two screw dislocations is important to work hardening.
- Answer
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The intersection of two screw dislocations produces jogs of edge orientation in both screw dislocations which can only move by climb. Because dislocation climb is a thermally activated process, the movement of the jogged screw dislocation will be temperature-dependent. At temperatures where climb cannot occur, the motion of screw dislocations will be impeded by jogs (i.e. the jogs are sessile) and so the crystal becomes work hardened.