Energetics and kinematics of undercooled nonequilibrium interfacial molten layer in cyclotetramethylene-tetranitramine crystal

2021 ◽  
pp. 412986
Author(s):  
Arunabha M. Roy
Keyword(s):  
Molten Layer ◽  
Cyclotetramethylene Tetranitramine

EXPLOSIVE CLADDING OF ALUMINIUM 5052-STAINLESS STEEL 304

2019 ◽  
Vol 14 (3) ◽  
Author(s):  
Saravanan S ◽  
Murugan G
Keyword(s):  
Stainless Steel ◽  
Interfacial Microstructure ◽  
Bend Angle ◽  
Flyer Plate ◽  
Layer Formation ◽  
Molten Layer ◽  
Explosive Cladding ◽  
Plate Velocity ◽  
Stainless Steel 304 ◽  
Loading Ratio

This study addresses the effect of process parameters viz., loading ratio (mass of explosive/mass of flyer plate) and preset angle on dynamic bend angle, collision velocity and flyer plate velocity in dissimilar explosive cladding. In addition, the variation in interfacial microstructure and mechanical strength of aluminium 5052-stainless steel 304 explosive clads is reported. The interface exhibits a characteristic undulating interface with a continuous molten layer formation. The interfacial amplitude increases with the loading ratio and preset angle. Maximum hardness is observed at regions closer to the interface

A reactive molecular dynamics study on the anisotropic sensitivity in single crystal α-cyclotetramethylene tetranitramine

RSC Advances ◽  
2015 ◽  
Vol 5 (12) ◽  
pp. 8609-8621 ◽  
Author(s):  
Ting-Ting Zhou ◽  
Yan-Geng Zhang ◽  
Jian-Feng Lou ◽  
Hua-Jie Song ◽  
Feng-Lei Huang
Keyword(s):  
Molecular Dynamics ◽  
Single Crystal ◽  
Shock Compression ◽  
Slip Plane ◽  
Reactive Molecular Dynamics ◽  
Cyclotetramethylene Tetranitramine

Anisotropic sensitivity is related to the different intermolecular steric arrangements across the slip plane induced by shock compression along various orientations.

Pulsed Microwave Processing of High-TC Superconducting Films

1992 ◽  
Vol 269 ◽  
Author(s):  
R. B. James ◽  
R. A. Alvarez ◽  
A. K. Stamper ◽  
X. J. Bao ◽  
T. E. Schlesinger ◽  
...  
Keyword(s):  
Phase Transition ◽  
Barium Copper Oxide ◽  
Precursor Film ◽  
Silicon Substrates ◽  
Molten Layer ◽  
Time Resolved ◽  
Barium Copper ◽  
In Situ Experiments ◽  
Yttrium Barium

ABSTRACTWe have used 2.0-μsec microwave pulses at a frequency of 2.856 GHz to rapidly heat thin amorphous yttrium-barium-copper-oxide (YBCO) films deposited onto silicon substrates. The samples were irradiated inside a WR-284 waveguide by single-pass TE10 pulses in a traveling wave geometry. X-ray diffractometry studies show that an amorphous-to-crystalline phase transition occurs for incident pulse powers exceeding about 6 MW, in which case the amorphous YBCO layer is converted to Y2BaCuO5. Microscopy of the irradiated film reveals that the phase transition is brought about by melting of the YBCO precursor film and crystallization of the molten layer upon solidification. Time-resolved in situ experiments of the microwave reflectivity (R) and transmissivity (T) show that there is an abrupt change in R for microwave pulse powers exceeding the melt threshold, so that measurements of R and T can be used to monitor the onset of surface melting.

Complete Equations of State for Cyclotetramethylene Tetranitramine

2021 ◽  
Author(s):  
Marc J. Cawkwell ◽  
Milovan Zecevic ◽  
Darby J. Luscher ◽  
Kyle J. Ramos
Keyword(s):  
Equations Of State ◽  
Cyclotetramethylene Tetranitramine

Transient Conductance Measurements During Pulsed Laser Annealing

1981 ◽  
Vol 4 ◽  
Author(s):  
M. O. Thompson ◽  
G. J. Galvin ◽  
J. W. Mayer ◽  
R. B. Hammond ◽  
N. Paulter ◽  
...  
Keyword(s):  
Single Crystal ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Interface Velocity ◽  
Laser Pulses ◽  
Molten Layer ◽  
Pulsed Laser Annealing ◽  
Complete Melting ◽  
Solid Liquid Interface ◽  
Solid Liquid

ABSTRACTMeasurements were made of the conductance of single crystal Au-doped Si and silicon-on-sapphire (SOS) during irradiation with 30 nsec ruby laser pulses. After the decay of the photoconductive response, the sample conductance is determined primarily by the thickness and conductivity of the molten layer. For the single crystal Au-doped Si, the solid-liquid interface velocity during recrystallization was determined from the current transient to be 2.5 m/sec for energy densities between 1.9 and 2.6 J/cm2, in close agreement with numerical simulations based on a thermal model of heat flow. SOS samples showed a strongly reduced photoconductive response, allowing the melt front to be observed also. For complete melting of a 0.4 μm Si layer, the regrowth velocity was 2.4 m/sec.

Thermodynamic and Kinetic Studies of Pulsed-Laser Annealing from Transient Conductivity Measurements

1984 ◽  
Vol 35 ◽  
Author(s):  
P.S. Peercy ◽  
Michael O. Thompson
Keyword(s):  
Melting Temperature ◽  
Silicon Germanium ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Kinetic Studies ◽  
Alloy System ◽  
Velocity Versus ◽  
Solidification Velocity ◽  
Molten Layer ◽  
Amorphous Si

ABSTRACTSimultaneous measurements of the transient conductance and time-dependent surface reflectance of the melt and solidification dynamics produced by pulsed laser irradiation of Si are reviewed. These measurements demonstrate that the melting temperature of amorphous Si is reduced 200 ± 50 K from that of crystalline Si and that explosive crystallization in amorphous Si is mediated by a thin (≤ 20 nm) molten layer that propagates at ~ 15 m/sec. Studies with 3.5 nsec pulses permit an estimate of the dependence of the solidification velocity on undercooling. Measurements of the effect of As impurities on the solidification velocity demonstrate that high As concentrations decrease the melting temperature of Si (~ 150 K for 7 at.%), which can result in surface nucleation to produce buried melts. Finally, the silicon-germanium alloy system is shown to be an ideal model system for the study of superheating and undercooling. The Si50Ge50 alloy closely models amorphous Si, and measurements of layered Si-Ge alloy structures indicate superheating up to 120 K without nucleation of internal melts. The change in melt velocity with superheating yields a velocity versus superheating of 17 ± 3 k/m/sec.

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