Ordering in clusters of uniaxial anisotropic particles during homogeneous nucleation and growth

2019 ◽  
Vol 150 (5) ◽  
pp. 054903 ◽  
Author(s):  
Takuma Nozawa ◽  
Paul E. Brumby ◽  
Sho Ayuba ◽  
Kenji Yasuoka
Keyword(s):  
Homogeneous Nucleation ◽  
Nucleation And Growth ◽  
Anisotropic Particles

Polymorphic Crystallization of Metal-Metalloid-Glasses above the Glass Transition Temperature

1990 ◽  
Vol 205 ◽  
Author(s):  
U. Köster ◽  
U. Schünemann ◽  
G.B. Stephenson ◽  
S. Brauer ◽  
M. Sutton
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Homogeneous Nucleation ◽  
Nucleation And Growth ◽  
Time Dependent ◽  
Nucleation Sites ◽  
Temperature Time ◽  
Initial Results ◽  
Temperature Crystallization

Crystallization of metal-metalloid glasses is known to proceed by nucleation and growth processes. Using crystallization statistics in partially crystallized glasses, at temperatures below the glass transition temperature, time-dependent heterogeneous nucleation has been found to occur at a number of quenched-in nucleation sites [1]. Close to the glass transition temperature crystallization proceeds so rapidly that partially crystallized microstructures could not be obtained. Initial results from fully crystallized glasses exhibit evidence for a transient homogeneous nucleation process at higher temperatures [1,2].

Nucleation and Growth of Bubbles in Elastomers

1971 ◽  
Vol 44 (5) ◽  
pp. 1363-1379 ◽  
Author(s):  
Charles W. Stewart
Keyword(s):  
Surface Tension ◽  
Homogeneous Nucleation ◽  
Nucleation And Growth ◽  
Experimental Results ◽  
Dissolved Gas ◽  
Rate Of Growth ◽  
High Degree ◽  
Approximate Expressions ◽  
Temperature Surface

Abstract The theory of homogeneous nucleation of bubbles is combined with an expression, for their rate of growth in elastomers to obtain approximate expressions for calculating the number of bubbles formed under a high degree of supersaturation. Experimental results are given for several elastomers with argon as the dissolved gas under a variety of foaming conditions. The theory adequately describes the manner in which the number of bubbles formed depends on the temperature, surface tension of the polymer, and permeability of the dissolved gas.

Nucleation and Growth of Voids in Silicon

1997 ◽  
Vol 490 ◽  
Author(s):  
P. S. Plekhanov ◽  
U. M. Gösele ◽  
T. Y. Tan
Keyword(s):  
Void Growth ◽  
Homogeneous Nucleation ◽  
Nucleation And Growth ◽  
Vacancy Formation ◽  
Limited Time ◽  
Dislocation Loops ◽  
Nucleation Barrier ◽  
Different Temperatures ◽  
Type Dislocation ◽  
Growth Of Voids

ABSTRACTNucleation of voids and vacancy-type dislocation loops in Si under vacancy supersaturation conditions has been considered. Based upon nucleation barrier calculations, it has been found that voids can be nucleated, but not dislocation loops. The homogeneous nucleation rate of voids has been calculated for different temperatures by assuming different enthalpy values of Si vacancy formation. The process of void growth due to precipitation of vacancies has been numerically simulated. Comparing results of the nucleation and the growth modeling and taking into account the competition between the two processes, the limited time available, and the crystal cooling rate after growth, it has been shown that homogeneous nucleation of voids to experimentally observed densities and void growth to observed sizes is possible if enthalpy of Si vacancy formation is within the range of 2.9 to 3.6 eV with the nucleation temperature in the range of 980–1080 °C.

HREM observation of stacking faults in Guinier-Preston zones for Al-Ag alloys

1990 ◽  
Vol 48 (4) ◽  
pp. 182-183
Author(s):  
P. Schwander ◽  
Ph.A. Dubey ◽  
G. Kostorz
Keyword(s):  
Solid Solution ◽  
Electron Beam ◽  
Single Crystals ◽  
Incubation Time ◽  
Homogeneous Nucleation ◽  
Optical Axis ◽  
Stacking Faults ◽  
Nucleation And Growth ◽  
Miscibility Gap ◽  
Spark Erosion

The decomposition of Al-rich Al-Ag-alloys quenched from the solid solution (α) and aged within the metastable miscibility gap, follows the sequence GP zones → γ' → γ (Ag2Al). Nearly spherical GP zones (Guinier-Preston zones) coherent with the fee matrix are formed by homogeneous nucleation and growth, whereas γ' plate-like precipitates with an hdp structure — lying on {111}-planes of the fee matrix — nucleate heterogeneously at dislocations after a certain incubation time. In the present work HREM was used to investigate the internal structure of the GP zones.Single crystals of Al-3 at.% Ag grown by strain-annealing were cut along (110) by spark erosion. The samples were homogenized for 2 h at 580°C prior to ageing for 43 h at 160°C. They were electrolytically thinned at −30°C in a methanol-HNO3 (2:1) solution. The TEM work was performed on a Philips CM 30 fitted with a Super Twin Lens and a double tilt holder. To bring the electron beam parallel to the optical axis the coma-free alignment was used. At 300 kV the instrumental point resolution was determined to be 1.9 Å using the Young’s fringes method.

Homogeneous nucleation and growth of melt in copper

2007 ◽  
Vol 127 (16) ◽  
pp. 164503 ◽  
Author(s):  
Lianqing Zheng ◽  
Qi An ◽  
Yun Xie ◽  
Zehui Sun ◽  
Sheng-Nian Luo
Keyword(s):  
Homogeneous Nucleation ◽  
Nucleation And Growth
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