undercooling


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Related to undercooling: homogeneous nucleation

undercooling

[′ən·dər‚kül·iŋ]
(metallurgy)
Cooling a metal below the transformation temperature without obtaining the transformation.
References in periodicals archive ?
The results reveal that even for extremely low P content and large undercooling the direct nucleation of Si on primary Al does not occur but is triggered by the formation of AlP under clean conditions.
Copper casting alloys are commonly divided into three groups based on their freezing range, which governs the degree of solutal undercooling, associated dendritic growth, and tendency to form microporosity.
For these last ones, which are formed in the middle of the liquid slag for higher degree of undercooling, they can be explained by homogeneous nucleation.
Inoperable, uncalibrated, or poorly adjusted controls Simultaneous heating and cooling Heating or cooling unused spaces Building Not using free cooling automation and Not using temperature reset off-shift control Overheating or undercooling spaces systems Equipment operating when not needed
The extent of albite exsolution is variable, most probably because of difference in the composition of the original homogeneous alkali feldspar grains and/ or degree and rate of their undercooling below the crystallization temperature.
This confirms, the findings of a fast crystallization at little undercooling in isothermal measurements.
Rapid heterogeneous nucleation occurs at the cooler boundaries of the flattened droplets in a large undercooling.
The degree of undercooling from the equilibrium melting temperature of linear PE (417 K) for the VLTCP was several tens of degrees (80-100 K) in contrast to non-emulsified samples, which had only a HTCP at a few degrees of undercooling.
But in many systems, especially when undercooling is small, the solid fraction may be assumed as being dependent on temperature only.
High undercooling achieved prior to nucleation and growth results in a marked refinement of microstructure over conventional alloys.
4][degrees]C), undercooling occurs, which promotes crystal core formation and refines crystal grains, thus leading to the ultra fine and symmetrical microstructure (Figure 4b).
The lack of evidence for quench crystallization on the margins of the dyke suggests that the degree of undercooling was extreme, possibly even as a glass-gas mixture that subsequently devitrified to produce the observed microcrystalline textures and alteration.