Term
| Heat (Q) is the amount of _____ that is transferred from an area at high temperature to low temperature |
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Definition
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Term
| When the temperature of a material is increased, the ____ of the lattice vibrations increase |
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Definition
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Term
| For a mole of material, the increment of heat (dQ) added to the material divided by the change in temperature (dT) is the ____. |
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Definition
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Term
| The heat capacity is also known as the ______. |
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Definition
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Term
| Specific heat (c) is the heat per unit _____. |
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Definition
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Term
| The primary reason for the high specific heat of polymers is their ______. |
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Definition
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Term
| In semi-crystalline polymers, there is a spike in the specific heat when the crystallites start to ____. |
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Definition
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Term
| The sum of kinetic and potential energy is equal to the ____. |
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Definition
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Term
| For a material that has no applied fields, the major contribution to the potential energy is the energy of _____. |
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Definition
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Term
| The ____ is the internal energy plus the pressure times the volume. (E + PV) |
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Definition
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Term
| Internal energy is a _____. |
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Definition
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Term
| In a solid, the average kinetic energy is equal to the ______. |
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Definition
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Term
| The high-temperature heat capacity at constant volume for a solid or liquid is equal to ___. |
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Definition
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Term
| The change in length of a material per degree divided by the original length is the _____. |
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Definition
| linear coefficient of thermal expansion |
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Term
| A(n) ____ material has the same properties in all directions. |
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Definition
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Term
| For a polymer filament, the linear coefficient of thermal expansion would be ____ in the axial direction than in the transverse direction. |
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Definition
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Term
| A material with an interatomic potential perfectly symmetric about the equilibrium interatomic separation would have a coefficient of thermal expansion equal to ____. |
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Definition
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Term
| Copper melts at 1085 C and platinum melts at 1769 C. Which material should have the smaller coefficient of thermal expansion? |
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Definition
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Term
| In heat transfer, the heat flux is directly related to the ____. |
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Definition
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Term
| Diamond has a notably high thermal conductivity because of its ____. |
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Definition
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Term
| What has the higher thermal conductivity, metallic aluminum or aluminum oxide? |
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Definition
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Term
| Which should have the higher thermal conductivity, a sign-crystal gas-turbine blade or a polycrystal turbine blade? |
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Definition
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Term
| HDPE is more crystalline than LDPE, and ____ should have a lower thermal conductivity. |
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Definition
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Term
| The diffusion of atoms of similar size depends upon the presences of ____. |
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Definition
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Term
| The entropy of a perfect crystal at absolute zero kelvin with the atoms at rest is equal to ____. |
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Definition
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Term
| A mole of pure argon gas has ___ less entropy than a mixture of a half mole of argon and a half mole of neon. |
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Definition
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Term
| What has the greater entropy, ice or water? |
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Definition
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Term
| When the equilibrium concentration of vacancies is present in a crystal at constant temperature and pressure, the Gibbs free energy is at a(n) _____. |
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Definition
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Term
| The probability that the energy to create a vacancy in a crystal is present in excess of the average energy in the crystal is given by the _____. |
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Definition
| Maxwell-Boltzmann probability distribution |
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Term
| If at constant temperature and pressure a change in a system produces a negative change in Gibbs free energy, the change is _____. |
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Definition
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Term
| The rate of change in a system depends upon the _____. |
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Definition
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Term
| If the natural log of the rate of a thermally activated process is plotted on the y-axis as a function of the inverse of the absolute temperature on the x-axis, the slope of the plot is the ______ divided by _____. |
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Definition
| activation enthalpy, Boltzmann's constant |
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Term
| The activation enthalpy for vacancy diffusion contains two contributions: the activation enthalpy for ______ and ______. |
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Definition
| vacancy formation, atom migration |
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Term
Which would have the higher activation energy for diffusion, carbon in iron or nickel in iron?
Atomis radius of carbon = .077nm
Atomic radius of nickel = .124nm
atomic radius of iron = .124nm |
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Definition
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Term
| The activation enthalpy for self-diffusion is directly related to the ____. |
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Definition
| strength of chemical bonding |
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Term
| The activation enthalpy for vacancy diffusion along a grain boundary is ___ than that for diffusion through a bulk. |
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Definition
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Term
| In the most general form of the first law of diffusion, the gradient of the Gibbs free energy with respect to the position of the B-type atoms is equal to the ____ on the B-type atoms. |
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Definition
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Term
| Amorphous polymers are ____ subject to mixing with solvents than are crystalline polymers. |
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Definition
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Term
| The solubility parameter of polycarbonate is 20.3 (MPa)^.5 and for carbon disulfide is 20.4 (MPa)^.5. Should carbon disulfide dissolve polycarbonate? |
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Definition
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Term
| The solubility parameter of polyethylene is 16.6 (MPa)^.5 and for ethanol is 26.0 (MPa)^.5. Should ethanol dissolve polyethylene? |
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Definition
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Term
| The solubility parameter of a polymer is related to the _____ for the polymer. |
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Definition
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Term
| The enthalpy of mixing for a pair of polymer molecules is related to the ____ of the two molecules. |
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Definition
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Term
| The science of changing the activation enthalpy of a process is called ___. |
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Definition
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Term
| The internal energy of a material depends on what? Does not depend on what? |
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Definition
Energy of defects in the material
Kinetic energy of the vibrating atoms
Bond energy between atoms
Net energy resulting from a history of heating and cooling |
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Term
Correctly order from high to low thermal conductivity
HDPE, PMMA, LDPE, OUHMWPE |
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Definition
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Term
| What results in high thermal conductivity? What does not? |
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Definition
Strong bonding
Free electrons
Small interatomic distances
Grain boundairs |
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Term
Which of the following material states has the highest entropy?
Amorphous solid, vapor, liquid, single crystal |
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Definition
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Term
Which is not a thermodynamic state variable?
GFE, Entropy, Heat, Enthalpy |
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Definition
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Term
The mixing of which pair of atoms does not occur by vacancy diffusion?
Gold and silver
Copper and nickel
Platinum and palladium
Hydrogen and palladium |
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Definition
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Term
Which of the following polymer combinations is least likely to mix?
Liquids of two different LCMs with a negative enthalpy of mixing.
A liquid solvent and solid polymer with solubility parameters of 19 MPa^.5 and 20 MPa^.5, respectively
Liquids of two different LCMs with a positive enthalpy of mixing
Liquid of two different short molecules with a positive enthalpy of mixing |
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Definition
| Liquids of two different LCMs with a positive enthalpy of mixing |
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Term
| If a transformation from a solid --> liquid occurs such that the solid and liquid are always in equilibrium, than the transformation is ____. |
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Definition
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Term
| A transformation occurs in a material, and the GFE change in the material is negative, then the transformation is ____. |
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Definition
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Term
| When α-phase iron is in equilibrium with iron carbide, the iron atoms in the two phases have equal ____. |
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Definition
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Term
| Nickel and silver have lattice parameters of 0.352 nm and 0.408 nm, respectively; an electronegativity of 1.8 for each, an FCC structure, and a similar valence. Should they be able to form a continuous-solid solution? |
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Definition
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Term
| In a phase digram, the ____ gives the temperature where the first solid forms upon cooling an alloy of given composition C0 from the liquid phase. |
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Definition
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Term
| In a phase diagram, the ____ gives the temperature where the first liquid forms upon heating an alloy of given composition C0 from the solid phase. |
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Definition
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Term
| When a liquid copper-nickel alloy is rapidly cooled, the center of the grains has a higher concentration of nickel atoms than the average concentration. This is ____. |
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Definition
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Term
| The purity of an alloy is given by the ___. |
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Definition
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Term
| The ___ gives the weight of material present in each phase of a two-phase region, but this says nothing about the phase purity. |
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Definition
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Term
| For a binary phase diagram in a two-phase region, use the ____ to find the atom or weight fraction of the phases present. |
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Definition
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Term
| The ____ in a phase diagram separates the α-phase field from the α+β-phase field, and it gives the maximum solubility of the B-type atoms in the A-type crystal. |
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Definition
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Term
| Solders are made from metals with a(n) _____, because alloys of the metals melt at a temperature lower than that of either of the two components individually. |
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Definition
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Term
| When two elements form a eutectic phase diagram, in the eutectic reaction the atoms of the solid elements ____ or ____. |
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Definition
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Term
| At a pressure of 1 atmosphere, a mixture of two metals (A and B) has the three phases α, β, and γ in equilibrium. Can the temperature be changed and still have the α, β, and γ phases in equilibrium? |
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Definition
| No (this equilibrium lies on isotherm) |
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Term
| At a pressure of 1 atmosphere, a mixture of two metals (A and B) has the two phases α and β equilibrium at the selected temperature (T). Can the chemical composition of the α phase be changed by adding more A-type atoms at temperature (T)? |
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Definition
| No (at constant temperature, cannot change composition) |
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Term
| In a(n) _____, liquid transforms to two solids α and β. |
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Definition
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Term
| In a(n) ____, one solid γ phase transforms to two solids α and β. |
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Definition
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Term
| In a(n) _____, one solid α phase and a liquid phase react to form one solid phase β. |
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Definition
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Term
| In a(n) _____, two solid phases α and γ react to form one solid phase β. |
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Definition
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Term
| The microstructure of the grains of solid α and β phases that form in the lead-tin eutectic reaction is ____ or ____ of the α and β phases. |
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Definition
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Term
| If elements A and B chemically bond to each other more strongly than a random mixture of A and B elements chemically bond, it is expected that a _____ of A and B should form. |
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Definition
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Term
| The Ga-As phase diagram has a compound GaAs (γ-phase) that is a single vertical line at 50 atomic % As. Can γ-phase be produced that has 55 atomic % As? |
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Definition
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Term
| An ____ can have a wider region of possible compositions than does an intermediate compound. |
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Definition
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Term
| When an intermediate phase melts with no change in chemical composition, this is a(n) _____. |
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Definition
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Term
| In the aluminum-nickel phase diagram in Figure 5.15, what is the reaction type that leads to the formation of Al3Ni at 854°C? |
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Definition
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Term
| A(n) ____ is when one liquid transforms to another liquid and a solid upon cooling. |
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Definition
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Term
| In polymer blends, the enthalpy of interaction is determined from the experimentally determined _____. |
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Definition
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Term
| If an iron-0.77 % C steel is very SLOWLY cooled from 800°C to room temperature, the expected microstructure is described as ____. |
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Definition
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Term
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Definition
| γ --> α + Fe3C (slowly cooled) |
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Term
| If an iron-0.77 % C steel is very RAPIDLY cooled from 800°C to room temperature, the expected microstructure is described as ____. |
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Definition
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Term
| Occurs by deformation of a crystal rather than diffusion of atoms. |
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Definition
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Term
| If as-quenched martensite is heated to 500 C for one hour, it is then ____. |
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Definition
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Term
| The distortion of the FCC unit cell to a tetragonal unit cell after quenching a carbon steel from 800 C to room temperature is the ____. |
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Definition
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Term
| For a martensitic transformation to be reversible there cannot be the production of _____ to accommodate strain. |
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Definition
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Term
| In the shape-memory effect in metals, the martensitic transformation must be _____. |
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Definition
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Term
| In a reversible martensitic transformation, the GFE of the transformation is equal to _____. |
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Definition
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Term
| True or False: For a blend of LCMs, if the enthalpy of mixing is +, polymers should mix in the liquid at all temps above melting. |
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Definition
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Term
| At the equilibrium melting temperature of a solid, if solid --> liquid, the change in GFE is ___. |
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Definition
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Term
| At a temperature below the melting temperature of a solid, if liquid ---> solid, change in GFE is ___. |
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Definition
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Term
Which of the following is NOT true about nucleation and growth transformation from liquid --> solid?
(a.) The transformation rate continuously increases with the amount of super-cooling
(b) The transformation rate is equal to 0 at the equilibrium temperature.
(c) The transformation rate goes to 0 at temperatures approaching 0 kelvin.
(d) The transformation rate reaches a maximum at a temperature between the equilibrium temperature and 0 kelvin. |
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Definition
| The transformation rate continuously increases with the amount of super-cooling. |
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Term
For a mixture of two different elements A and B, at one atmosphere of pressure three phases are in equilibrium (α, β, and liquid), and it is desired to keep all three phases in equilibrium. Which of the following statements is true?
(a) If the temperature is changed, the composition of the α, β, and liquid phases changes. (b) The composition of the α phase is changed by adding more A-type atoms.
(c) The composition of the liquid phase is changed by adding more A-type atoms.
(d) Nothing can be changed. |
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Definition
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Term
Two phases α and β are in equilibrium, and they are made of A-type and B-type atoms. Which of the following statements is true?
(a) The Gibbs free energies of the α and β phases are equal.
(b) The chemical potentials of the A-type atoms in the α and β phases are equal.
(c) The Gibbs free energies of the α and β phases are equal to 0.
(d) The chemical potentials of the A-type and B-type atoms in the α-phase are equal. |
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Definition
| The chemical potentials of the A-type atoms in the α and β phases are equal. |
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Term
Which of the following is not necessary for a continuous-solid solution?
(a) Similar atomic numbers.
(b) Atomic radii differ by less than 15%. (c) The same crystal structure.
(d) A similar electronegativity. |
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Definition
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Term
Which of the following best describes the microstructure resulting from a eutectic reaction?
(a) Alternating grains of α and β-phases.
(b) Grains of the α-phase with precipitate particles of the β-phase.
(c) A volume with only α-phase grains and another volume with only β-phase grains.
(d) The grains contain alternating plates or rods of the α and β phases. |
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Definition
| The grains contain alternating plates or rods of the α and β phases. |
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Term
| Which of the following is a eutectoid reaction? |
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Definition
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Term
| Iron with 0.20% carbon is a(n) _____. |
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Definition
| hypoeutectoid steel (less than 0.77% C) |
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Term
| Bainite is formed by ______, then ______, then _____ with a eutectoid composition carbon steel starting at 800 C. |
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Definition
| Quench to 500 C, hold for 100 seconds, cool to room temperature |
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Term
| The highest-strength carbon steels with some ductility have a microstructure described as... |
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Definition
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Term
| You are asked to design a metal alloy for use in salt water. The most important design parameter is corrosion resistance followed by other mechanical properties such as yield strength. It is known that dissimilar metals in contact in salt water can result in corrosion of one of the materials. What type of metal alloy phase diagrams should you consider first for this application? |
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Definition
| Continuous solid solution |
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Term
| You are asked to design a metal alloy for a high temperature application. What type of metal alloy phase diagrams should you consider first for this application? |
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Definition
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Term
| You are asked to design a metal alloy for a part with a room temperature application. The part is to be made by casting the metal into shape. When casting the part, liquid metal is poured into a mold that has a cavity with the shape of the part. To reduce cost by conserving energy and to utilize an inexpensive furnace that does not have a high temperature capability, it is desired that the metal alloy not have a high melting temperature. What type of metal alloy phase diagrams should you consider first for this part? |
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Definition
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