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9 Cards in this Set
- Front
- Back
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Will electric conductivity increase or decrease after adding 1% arsenic as an impurity in a semiconductor like silicon? |
Increases because the impurity will contribute to the elections |
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What is the softest microstructure? Hardest? |
Spheorodite; martensite |
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What are 3 reasons a metal may increase in resistivity? |
Adding impurity atoms Decreasing Temperature |
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Describe two methods for strengthening a metal? |
Cold working: creating smaller grain boundaries disabling the movement of dislocations, thus increasing strength Solid Solution: adding of impurity atoms to change the properties of a material |
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What are important properties of dental material? |
Inert and won't corrode. You don't want the material to corrode away or be reactive in your mouth. |
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How does martensite from austenite? |
Only from immediate cooling. Cooling from eutectoid temperature down to about 200 C. Martensite is formed through quick nucleation. |
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What happens to the strength of martensite as a carbon content increases? |
Adding carbon will increase strength. For example, adding carbon to iron increases strength. Therefore, adding carbon to martensite will increase its strength |
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Greater %Cold Work
YS, TA and hardness change of greater % cold work? Ductility %el change? Dislocation Density Change? |
YS, TA and hardness change of greater % cold work: Increases (shrinks grains. No space for dislocations to move) Ductility %el change: decreases (Less room for dislocations to move, preventing elongation) Dislocation Density Change: decreases (Less dislocations) |
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Cold Work and Annealing Item YS, TA and hardness change of greater % cold work?Ductility %el change?Dislocation Density Change? |
YS, TA and hardness change of greater % cold work: decreases (Increases grain size which increases ductility) Ductility %el change: increase (Increases grain size and allows dislocations to move) Dislocation Density Change: increases (More dislocations) |
