Term
| As temperature increases, vacancy concentration ______. |
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Definition
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Term
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Definition
| Forms when oppositely charged ions leave their lattice sites, creating vacancies. |
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Term
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Definition
| Defect in the lattice crystal where an atom or ion occupies a normally vacant site other than its own. |
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Term
| Which defect is more common? Cation or Anion? Why? |
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Definition
| Cation because of the size of it compared to size of anion |
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Term
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Definition
1. Size difference between solute & solent less than ~15%
2. EN of two atomic species must be comparable
3. Valence of two species must be similar
4. Crystal structure of the two must be the same |
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Term
| Factors affecting atomic transport |
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Definition
-Concentration gradient
-Jump distance
-Temperature |
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Term
| As temperature increases, diffusivity _____. |
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Definition
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Term
| What is the source for grain boundary energy? |
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Definition
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Term
| How do grain boundaries aid in diffusion? |
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Definition
| They provide more open regions for transport by diffusion. |
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Term
| Which diffusion dominates as temperature increases? Bulk diffusion or grain diffusion? |
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Definition
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Term
| Are point defects & interstitials thermodynamically stable or unstable? |
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Definition
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Term
| When is Fick's First Law used? |
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Definition
| Under steady state conditions, to calculate the next flux of atoms |
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Term
| When is Fick's Second Law used? |
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Definition
Under non-steady state conditions, to describe diffusion.
It is time-dependent. |
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Term
| Diffusion of C in BCC iron is _____ than in FCC iron. |
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Definition
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Term
| Explain why diffusivity is greater in grain boundaries than in the bulk material? |
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Definition
| Because the grain boundaries are more open than the matrix or the bulk, grain boundary diffusion has lower activation energy than diffusion through the matrix or bulk. |
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Term
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Definition
| The movement of atoms in a pure material |
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Term
| As distance increases, concentration ______. |
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Definition
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