Term
| T/F Metallic materials have directional primary atomic bonding between atoms |
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Definition
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| T/F In ceramics, the degree of ionic bonding is inversly related to the electronegativity difference between the elements |
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Definition
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Term
| T/F Covalent bonds are directional in nature |
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Definition
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Term
| T/F Weak atomic bonds are characterized by low thermal expansion coefficients |
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Definition
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Term
| T/F The atomic packing factor for BCC structures is higher than for FCC structures |
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Definition
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Term
| T/F The stacking sequence of close packed planes of atoms determines whether a structure is FCC or HCP |
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Definition
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Term
| T/F Elastomers stretch when a stress is applied and recover their original shape when stress is removed |
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Definition
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Term
| T/F Thermosetting polymers can reversibly soften and flow when heated or treated with appropriate solvents |
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Definition
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Term
| T/F Grain boundaries are a type of point defect in crystalline materials |
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Definition
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Term
| T/F Intrinsic semiconductors depend on small amounts of dopants for their semiconducting properties |
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Definition
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Term
| Name the two factors that control how ions are packed in ceramic structures |
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Definition
1-ratio of ion radii
2-charge neutrality |
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Term
| Name the two types of solid solutions |
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Definition
1-interstitial replacement
2-substitutional |
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Term
| with the exception of helium, how manuy electrons are in the outer-most shell of the Noble Gases from column VII of the periodic table |
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Definition
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| what is the name of the outer most shell electrons |
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Term
| The element calcium (Ca) is located in row (period) 4 and column II of the periodic table. Write the electron for the outermost shell of calcium using spdf notation |
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Definition
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Term
| the element oxygen is located in row 2 and column V! of the periodic table. Write the electron for the outermost shell of calcium using spdf notation |
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Definition
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Term
| in ionic compounds, does the coordination number increase or decrease as the cation to anion radius ratio increase |
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Definition
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Term
| Metal or nonmetal? 4 or more valence electrons |
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Definition
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Term
| Metal or nonmetal? low electronegativity |
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Definition
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Term
| Metal or nonmetal? forms cations |
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Definition
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Term
| list four considerations required for extensive substitutional solid solution solubility in metal alloys (Hume Rothery Rules) |
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Definition
1-difference in atomic radii<15%
2-same crystal structure
3-same valence electrons
4-low difference in electronegativity |
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Term
| T/F the electrical conductivity of an intrinsic semiconductor decreases with an increasing temperature |
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Definition
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Term
| T/F adding Boron atoms from column II in the periodic table to Silicon from Column IV produces a p-type extrinsic semiconductor |
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Definition
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Term
| T/F electrical resistance is a materials property |
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Definition
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Term
| T/F increasing the yield strength of a metal by cold working will increase the ductility of the material |
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Definition
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Term
| T/F the ultimate strength of ceramics is the same in compression and as in tension |
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Definition
| False: compression>tension |
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Term
| T/F Polymeric materials are brittle at temperatures below the glass transition temperature |
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Definition
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Term
| T/F As the degree of polymerization is increased, the strength of the polymer decreases |
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Definition
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Term
| T/F when a cold worked metal is annealed, new, strain-free grains are nucleated during the grain growth phase of annealing |
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Definition
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Term
| T/F The mechanical properties of a uniaxial fiber reinforced composite are anisotropic |
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Definition
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Term
| if the volume fractions of fiber and matrix are equal, which of these conditions will produce a stronger composite, isostrain or isostress? |
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Definition
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Term
| T/F Austenite is a FCC solid solution of carbon in iron |
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Definition
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Term
| T/F The hardness of martensite is a function of ots carbon content |
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Definition
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Term
| T/F Ferrite (alpha) is a FCC solid solution of carbon in Iron |
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Definition
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Term
| T/F An eutectic reaction is an example of an invariant reaction |
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Definition
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Term
| T/F An eutectoid reaction is an example of a solid-state invariant reaction |
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Definition
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Term
| T/F Interstitial diffusion is slower than vacancy diffusion |
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Definition
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Term
| T/F Fick's first law of diffusion applies only to steady-state diffusion |
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Definition
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Term
| T/F Diffusivity of one element in another is a function of temperature |
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Definition
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Term
| T/F Solidification of cast iron in a sand mold is initiated by homogeneous nucleation |
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Definition
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Term
| T/F An isomorphous phase diagram results when two elements are completely miscible in each other |
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Definition
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Term
| Three steps during the precipitation hardening of alloys in sequence. |
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Definition
1-Soluutionize
2-Quench
3-Aging |
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Term
| T/F The toughness of BCC metals increases as the temperature decreases |
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Definition
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Term
An interstitial solid solution of carbon in BCC iron.
austenite b) ferrite c) pearlite d) cementite e) martensite |
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Definition
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Term
A two phase microstructure which is the result of the eutectoid decomposition of the γ-phase.
austenite b) ferrite c) pearlite d) cementite e) martensite |
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Definition
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Term
An interstitial solid solution of carbon in FCC iron.
austenite b) ferrite c) pearlite d) cementite e) martensite |
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Definition
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Term
A metastable phase produced by fast cooling from the γ-phase.
austenite b) ferrite c) pearlite d) cementite e) martensite |
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Definition
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Term
A stoichiometric compound Fe3C; a hard and brittle phase.
austenite b) ferrite c) pearlite d) cementite e) martensite |
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Definition
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