Term
Edge dislocation line moves ___ to applied stress.
Screw dislocation line moves ___ to applied stress. |
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Definition
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Term
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Definition
| The plane of the dislocation |
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Term
| Crystallographic slip plane |
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Definition
| The highest atomic density plane |
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Term
| Burgers vector connects... |
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Definition
| The atoms of closest approach |
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Term
| What 2 assumptions must Burger's Vector meet in order to be chosen? |
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Definition
1. Connects lattice points (equivalent lattice positions)
2. Shortest vector |
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Term
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Definition
| Reflections across a mirror plane to generate the structure |
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Term
| Decreasing the grain size, _____ the strength. |
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Definition
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Term
In edge dislocation, Burgers vector is _____ to dislocation line.
In screw dislocation, Burgers vetor is _____ to dislocation line. |
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Definition
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Term
| Impeding the motion of dislocations, _____ the strength |
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Definition
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Term
| Dislocations allow plastic deformation to occur at ____ stresses than if they were not present |
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Definition
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Term
| 4 ways to impede motion of dislocations / increase strength |
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Definition
1. Addition of impurities / solute / alloying
2. Increase dislocation density / strain hardening
3. Decrease grain size / grain refinement decrease
4. Presence of volume / precipitation / precipitation hardening |
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Term
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Definition
| The motion of an edge dislocation that occurs when vacancies migrate to the extra half plane of atoms |
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Term
| The probability of a dislocation climb _____ as temperature increases. |
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Definition
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Term
| Are dislocations thermodynamic defects? |
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Definition
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Term
| Is a vacancy a thermodynamic defect? |
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Definition
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Term
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Definition
| A dislocation that is formed by the insertion of an extra half plane into an otherwise perfect region of a crystal. |
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Term
| Why is there a tension and compressive side of a dislocation? |
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Definition
| Because where the dislocation is inserted, the side with the fewer amount of atoms has tension to spread its area further out. Then the side with more atoms, tries to compress its area to fit the smaller side. |
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Term
| Why do edge dislocations tend to form symmetric tilt boundaries? |
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Definition
| Because the edge dislocations act as a wedge that tilts the two halves of the grain about an axis that lies in the plane of the boundary. |
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Term
| The energy of a dislocation is proportional to ______. |
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Definition
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Term
| Simply, how do you strengthen a metal? |
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Definition
| By impeding the dislocation motion. |
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Term
| How does plastic deformation occur, with regards to dislocation? |
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Definition
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Term
| To make material more ductile, do you add or remove dislocation lines? |
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Definition
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Term
| Why is FCC more ductile than HCP? |
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Definition
| Because it has more slip systems and nonparallel slip planes (this means that it is easier to pull apart, bc they're not parallel) |
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