Term
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Definition
heat should be viewed as energy in transit across the boundaries of a
material and that the process of heat transfer involves random interactions at the molecular level,
involving a temperature difference |
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Term
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Definition
| strain,or the extension of a spring is in direct proportion with the stress or load applied to it. i.e- σ=εE |
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Term
| different metals have what? (in reference to springs) |
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Definition
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Term
| Hook's law for tensile or compressive loading |
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Definition
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Term
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Definition
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Term
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Definition
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Term
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Definition
| Young's modulus, where the spring doubles in length |
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Term
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Definition
proportionality
factors between stress (break) and strain (bend) |
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Term
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Definition
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Term
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Definition
| size change divided by original size |
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Term
| What is "fatigue" and how does "fatigue strength" depend on the number of cycles applied? |
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Definition
Materials failure through the oft-repeated application of a load which could be supported indefinitely if
applied statically. The failure stress tends to drop with the logarithm of the number of applied cycles. |
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Term
Why are x-rays, rather than visible light, used in determining the structure of crystals such as
iron or copper? |
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Definition
to investigate the atomic structure the wave length of the probe must be less than what you are
examining |
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Term
Materials are frequently classified either as i) crystalline, or ii) non-crystalline. The
characteristic which determines whether a material is crystalline or not is the presence or absence of
___________________________ . |
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Definition
| long-range periodicity ( the tendency to recur at regular intervals) |
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Term
| X rays have _______ wavelength than visible light. |
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Definition
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Term
________relates the direction in which X-rays will be diffracted to the spacing between
planes in the crystal. |
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Definition
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Term
__________interference between the X-rays scattered by a crystal gives rise to the peaks
seen in a diffraction pattern |
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Definition
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Term
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Definition
relates the direction in which X-rays will be diffracted to the spacing between
planes in the crystal |
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Term
| why x rays to determine structures and not visible light? |
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Definition
| smaller wavelength than the spacing of atoms in crystal structures |
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Term
| position of atoms in crystal structures can be determined by x ray because... |
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Definition
| xray can penetrate solids and scatter among atoms or reflect off of atom planes |
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Term
| What is the approximate diameter of a typical atom |
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Definition
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Term
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Definition
| btwn .01 and .1 nanometers |
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Term
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Definition
Volume elements of uniform lattice orientation that are joined to similar volume elements but with
different lattice orientations. |
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Term
| grain boundary is ____dimensional |
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Definition
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Term
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Definition
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Term
| dislocations are______defects |
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Definition
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Term
| Intermixing of alloying atoms (e.g. gold and copper) occurs by a process called______ |
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Definition
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Term
| The primary cause of “plastic” deformation in solids is due to |
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Definition
| the glide of dislocations |
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Term
How does the equilibrium concentration of vacancies in a crystal vary with
temperature? |
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Definition
| increases with increasing temp. |
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Term
| Atomic diffusion in crystals is mostly defined by the |
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Definition
| mobility of point defects |
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Term
| ______ prevent intersecting slip (of dislocations) and increase strength of material |
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Definition
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Term
| youngs modulus measures... |
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Definition
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Term
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Definition
| P/A i.e- applied force, P, divided by the cross sectional area, A |
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Term
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Definition
| ∆L/L i.e.- change in length, ∆L, divided by the original length, L. |
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Term
| Typical elastic limit of metals |
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Definition
| tensile strain, or ε, is approximately 0.2%. |
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Term
| Typical elastic limit of metals |
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Definition
| tensile strain, or ε, is approximately 0.2%. |
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Term
| A material with a large Young's modulus value has... |
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Definition
| greater stiffness. e.g.- Metals typically have large Young's modulus values. |
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Term
| Why do metals plastically deform at forces much smaller than their theoretical strength? |
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Definition
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