Term
|
Definition
When dislocations are present at an interface to relieve strain
Located mostly at dislocations. |
|
|
Term
|
Definition
Steels whose compositions are to the left of the eutectoid |
|
|
Term
|
Definition
A newly formed phase, which can reduce its Gibbs free energy by either growing or dissolving |
|
|
Term
|
Definition
Where 2 phases with same crystal structure and atomic spacing meet
Located throughout the matrix. |
|
|
Term
|
Definition
|
|
Term
|
Definition
When nucleation occurs at random sites in the parent phase |
|
|
Term
The process by which powders are densified at elevated temperature to form nearly fully dense microstructure |
|
Definition
|
|
Term
A two phase microstructure with alternate lamellar microstructure in steels |
|
Definition
|
|
Term
The only phase which can produce martensite as a result of a rapid quench |
|
Definition
|
|
Term
|
Definition
Nucleation occurring at specific locations |
|
|
Term
Increasing the interfacial free energy, _____ the likelihood of homogenous nucleation. |
|
Definition
|
|
Term
Decreasing the amount of undercooling below the eutectoid temperature _______ the pearlite spacing. |
|
Definition
|
|
Term
The __________ process occurs at temperature roughly equal to about 0.5 Tm resulting in a gradual decrease in strength with time. |
|
Definition
|
|
Term
Coring in metal castings is a direct consequence of _________ cooling from the melt to room temperature. |
|
Definition
|
|
Term
Alloys that can form an extensive amount of _______ are materials that have high hardenability. |
|
Definition
|
|
Term
As the undercooling decreases, the barrier to the nucleation event _________. |
|
Definition
|
|
Term
Undercooling / supercooling |
|
Definition
the process of lowering the temperature of a liquid or a gas below its freezing point without it becoming a solid. |
|
|
Term
|
Definition
located at grain boundaries |
|
|
Term
|
Definition
When precipitation forms and becomes solid. |
|
|
Term
If we increase the amt of undercooling, the critical radius will _____. |
|
Definition
|
|
Term
|
Definition
a round metal bar of standard size (indicated in the top image) is transformed to 100% austenite through heat treatment, and is then quenched on one end with room-temperature water.
The farther away from the quenched end that the hardness extends, the higher the hardenability. |
|
|
Term
|
Definition
Size of a stable nucleus -
Smaller particles redissolve into the liquid phase while larger particles will continue to grow |
|
|
Term
Lowering temp of system allows nucleation rate to _____ and atomic mobility to ____. |
|
Definition
|
|
Term
Which has a lower energy barrier? Heterogenous nucleation or homogenous? |
|
Definition
|
|
Term
Which type of interface has largest interfacial energy? |
|
Definition
Incoherent b/c unlike neighbors are present across the interface |
|
|
Term
An increase in interfacial energy , _____ the probability of homogenous nucleation |
|
Definition
|
|
Term
Do homogenous or heterogenous nucleated phases grow faster? |
|
Definition
|
|
Term
|
Definition
An interstitial solid solution of carbon in delta iron (BCC) |
|
|
Term
|
Definition
An interstitial solid solution of carbon in gamma iron (FCC) |
|
|
Term
|
Definition
An interstitial solid solution of carbon in alpha iron (BCC) |
|
|
Term
|
Definition
Eutectoid of alpha-ferrite and cementite with a lamellar microstructure of alternate alpha-Fe and cementite plates. |
|
|
Term
|
Definition
Eutectoid of alpha-ferrite and cementite. |
|
|
Term
|
Definition
Spherical particles of cementite in a matrix of alpha-ferrite. |
|
|
Term
|
Definition
An interstitial solid solution of carbon in a BTC Fe crystal structure. |
|
|
Term
|
Definition
Alloys with compositions to the left of the eutectoid reaction. |
|
|
Term
|
Definition
Alloys with compositions to the right of the eutectoid reaction. |
|
|
Term
|
Definition
Ferrite that forms prior to the eutectoid ferrite. |
|
|
Term
|
Definition
Cementite that forms prior to the eutectoid cementite. |
|
|
Term
As isothermal hold temperature decreases, spacing of pearlite lamella _____. |
|
Definition
|
|
Term
The nucleation rate exhibits a max/min as a function of temp? |
|
Definition
|
|
Term
The time curve exhibits a max/min as a function of temperature? |
|
Definition
|
|
Term
Strongest phase found in steel |
|
Definition
|
|
Term
Most favorable phase found in steel |
|
Definition
|
|
Term
Mos tempt factor controlling hardenability |
|
Definition
|
|
Term
As any substitutional alloy is added, the critical quench ____ and the hardenability of the steel ______. |
|
Definition
|
|
Term
|
Definition
When a heated alloys cools in non-equilibrium conditions. This causes the exterior of the material to solidify before the interior. Coring causes the centers of the grains to retain more of the higher melting temperature element. |
|
|
Term
|
Definition
Plastically deformed at a low temp |
|
|
Term
|
Definition
Crystallization of a polymer |
|
|
Term
As distance from quenched end increases, Rockwell hardness ______. |
|
Definition
|
|
Term
Which one is athermal?
Austenite -> pearlite Austenite -> bainite Austenite -> martensite |
|
Definition
|
|
Term
|
Definition
the process of crystallization in a formerly crystal-free (amorphous) glass. |
|
|