Submicron Conductor Array Fabricated from a Recrystallized Eutectic Thin Film

1982 ◽  
Vol 13 ◽  
Author(s):  
H. E. Cline
Keyword(s):  
Thin Film ◽  
Eutectic Alloy ◽  
Solidification Rate ◽  
Eutectic Structure ◽  
Alloy Thin Film ◽  
Directionally Solidified ◽  
Two Phase ◽  
Glass Substrates ◽  
Solid Liquid Interface ◽  
Solid Liquid

ABSTRACTA submicron conductor array was fabricated without using lithography by selectively etching a recrystallized A1-A12Cu eutectic alloy thin film. The 2 micron thick eutectic films were deposited on glass substrates and directionally solidified with both a quartz-iodine lamp and a scanning laser at rates between .0016 and .14 cm/sec. The resulting structure consisted of alternate parallel stripes of the two eutectic phases with a spacing between .5 and 4 microns that was controlled by the solidification rate. An array of submicron Al- rich conductors was fabricated by selectively etching away the Al2 Cu phase. At solidification rates greater than .004 cm/sec using the lamp heater the solid-liquid interface became non-planar while with the laser the structure was well alligned at the highest rates used, .14 cm/sec. At the maximum theoretical solidification rate that produces a two phase aligned eutectic structure the width of the Al wires would be 100A.

Microstructure and Solid/Liquid Interface Evolutions of Directionally Solidified Fe-Al-Ta Eutectic Alloy

2019 ◽  
Vol 34 (3) ◽  
pp. 656-661 ◽  
Author(s):  
Chunjuan Cui ◽  
Songyuan Wang ◽  
Meng Yang ◽  
Haijun Su ◽  
Yagang Wen ◽  
...  
Keyword(s):  
Eutectic Alloy ◽  
Liquid Interface ◽  
Directionally Solidified ◽  
Solid Liquid Interface ◽  
Solid Liquid

Equilibrium and Metastable Eutectics Near the Ni3Al Composition

2005 ◽  
Vol 486-487 ◽  
pp. 257-260
Author(s):  
Y. Lu ◽  
J.S. Lee ◽  
Je Hyun Lee ◽  
Dang Moon Wee ◽  
Myung Hoon Oh
Keyword(s):  
High Temperature ◽  
Directional Solidification ◽  
Solidification Rate ◽  
Eutectic Structure ◽  
Research Area ◽  
Solidification Behavior ◽  
Considerable Research ◽  
Increasing Temperature ◽  
Solid Liquid Interface ◽  
Solid Liquid

Ni3Al has been considerable research area due to its high temperature behavior increasing strength with increasing temperature. A series of directional solidification studies showed that the eutectic occurred between g’/b and the metastable eutectic of g/b forms under slightly different conditions, however, it is not well established whether the eutectic is composed of g/g‘, g’/b, or g/b . In order to understand solidification behavior of the eutectic structure, directional solidification experiments have been carried out with solidification rate near the Ni3Al composition in this study. The effects of the solidification rate and composition on formation of the equilibrium and metastable eutectics have been discussed. The (g’+g) coupled phase was also shown to form with the eutectic at the solid/liquid interface.

Investigations on Columnar-to-Equiaxed Transition in Binary Al Alloys with and without Grain Refiners

2006 ◽  
Vol 508 ◽  
pp. 419-424 ◽  
Author(s):  
Laszlo Sturz ◽  
Gerhard Zimmermann
Keyword(s):  
Temperature Gradient ◽  
Solidification Rate ◽  
Processing Parameters ◽  
Cylindrical Sample ◽  
Critical Parameters ◽  
Directionally Solidified ◽  
Deterministic Models ◽  
Columnar To Equiaxed Transition ◽  
Solid Liquid Interface ◽  
Solid Liquid

We have investigated the columnar to equiaxed transition experimentally in directionally solidified hypoeutectic binary AlSi alloys with and without grain refinement particles and for different processing parameters in the framework of the ESA-MAP CETSOL (Columnar-to-equiaxed transition in solidification processing). A power-down technique was used in a Bridgman-Stockbarger type gradient-furnace to simultaneously increase the solidification rate and decrease the temperature gradient in the cylindrical sample during directional solidification vertically upwards. The position of the CET was determined from the cut and polished samples and correlated to the applied cooling rate for different experiments. Critical parameters for the temperature gradient and the solidification rate at the transition were determined from cooling curves measured within the sample and from a time-of-flight analysis of ultrasonic pulses propagated in the solid part of the sample and being reflected at the solid-liquid interface. The critical values found are compared to the deterministic models of Hunt and of Martorano et al. The objective of this contribution is the presentation of preliminary results for the different alloys and processing parameters of ground-based experiments. These results will be used for the testing of different models describing the CET within the framework of the ESA-MAP CETSOL and for the preparation of comparative microgravity experiments.

Effect of a magnetic field on the banding phenomenon in aluminium–silicon eutectic alloy

1968 ◽  
Vol 46 (14) ◽  
pp. 1589-1595 ◽  
Author(s):  
E. A. Falquero ◽  
W. Saunders ◽  
W. V. Youdelis
Keyword(s):  
Magnetic Field ◽  
Eutectic Alloy ◽  
Solidification Rate ◽  
Magnetic Field Effect ◽  
Impurity Level ◽  
Directionally Solidified ◽  
Band Formation ◽  
Band Spacing ◽  
Solidification Speed ◽  
Solid Liquid Interface

The effect of a magnetic field on the frequency of transverse band formation in directionally solidified Al–Si eutectic alloy is investigated for a range of solidification speeds. The band spacing for both field and no-field ingots is found to be linearly dependent on the solidification rate, but for a given solidification speed a magnetic field of 30 000 Oe, applied perpendicular to the solidification direction, reduced the band spacing by approximately 35%. The results are explained in terms of the effects of the solidification rate and magnetic field on the impurity concentration ahead of the solid–liquid interface, a fluctuating impurity level being the direct cause of the banding phenomenon. It is shown that the magnetic-field effect on band spacing is consistent with the theories (previously published) developed to account for the observed effects of a magnetic field on alloy diffusion and solidification.

scholarly journals Solid-liquid interface morphology of white carbide eutectic during directional solidification

2017 ◽  
Vol 62 (1) ◽  
pp. 365-368 ◽  
Author(s):  
M. Trepczyńska-Łent
Keyword(s):  
Longitudinal Section ◽  
Argon Atmosphere ◽  
Liquid Interface ◽  
Interface Morphology ◽  
Directionally Solidified ◽  
Constant Temperature Gradient ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Scanning Electron ◽  
Made In

AbstractIn this paper the analysis of solid-liquid interface morphology in white carbide eutectic was made. In a vacuum Bridgman-type furnace, under an argon atmosphere, directionally solidified sample of Fe - C alloy was produced. The pulling rate was v = 125 μm/s (450 mm/h) and constant temperature gradient G = 33.5 K/mm. The microstructure of the sample was frozen. The microstructure of the sample was examined on the longitudinal section using an light microscope and scanning electron microscope.

Analytical Modeling of Outward Solidification With Convective Boundary in Cylindrical Coordinates

2020 ◽  
Author(s):  
Minghan Xu ◽  
Saad Akhtar ◽  
Ahmad F. Zueter ◽  
Mahmoud A. Alzoubi ◽  
Agus P. Sasmito
Keyword(s):  
Moving Boundary ◽  
Two Phase ◽  
Convective Boundary ◽  
Interface Motion ◽  
Stefan Number ◽  
Melting Phenomenon ◽  
Approximate Analytical Solutions ◽  
Highly Nonlinear ◽  
Solid Liquid Interface ◽  
Solid Liquid

Abstract Solidification consists of three stages at macroscale: subcooling, freezing and cooling. Classical two-phase Stefan problems describe freezing (or melting) phenomenon initially not at the fusion temperature. Since these problems only define subcooling and freezing stages, an extension to characterize the cooling stage is required to complete solidification. However, the moving boundary in solid-liquid interface is highly nonlinear, and thus exact solution is restricted to certain domains and boundary conditions. It is therefore vital to develop approximate analytical solutions based on physically tangible assumptions, like a small Stefan number. This paper proposes an asymptotic solution for a Stefan-like problem subject to a convective boundary for outward solidification in a hollow cylinder. By assuming a small Stefan number, three temporal regimes and four spatial layers are considered in the asymptotic analysis. The results are compared with numerical method. Further, effects of Biot numbers are also investigated regarding interface motion and temperature profile.

Hydrogen Permeation Properties of Nb-Based Two-Phase Compounds

2007 ◽  
Vol 561-565 ◽  
pp. 467-470
Author(s):  
Yuji Yamaguchi ◽  
Kyosuke Kishida ◽  
Katsushi Tanaka ◽  
Haruyuki Inui ◽  
Sho Tokui ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
Hydrogen Permeation ◽  
Membrane Surface ◽  
Hydrogen Permeability ◽  
Eutectic Structure ◽  
Growth Direction ◽  
Directionally Solidified ◽  
Two Phase ◽  
Cast Sample ◽  
Lamellar Type

Nb-NiTi and Nb-CoTi eutectic alloys were directionally solidified in an optical floating zone furnace. Rod-type eutectic structures with Nb rods aligned parallel to the growth direction are obtained for Nb-41Ni-40Ti grown at relatively slow growth rates below 1.0mm/h, while lamellar-type eutectic structures are obtained for Nb-35Co-34Ti grown at the same condition. The hydrogen permeability for the Nb-41Ni-40Ti DS alloy with Nb rods perpendicular to the membrane surface is 2.60×10-8mol H2 m-1 Pa-1/2 at 673K, which is about 2.5 times higher than that of as-cast sample. No hydrogen embrittlement is observed between 573 and 673K, indicating that the Nb-NiTi rod-type eutectic structure effectively suppresses the hydrogen embrittlement of Nb during hydrogen permeation.

Crystal Structure and Magnetic Properties of Co-Based Alloy Thin Film Prepared on Cr Underlayer With Good Crystallite Orientation

1991 ◽  
Vol 232 ◽  
Author(s):  
T. Kawanabe ◽  
J. G. Park ◽  
M. Naoe
Keyword(s):  
Thin Film ◽  
Crystal Orientation ◽  
Flat Surface ◽  
Film Plane ◽  
Recording Media ◽  
Alloy Thin Film ◽  
Crystallite Orientation ◽  
Axis Orientation ◽  
Glass Substrates ◽  
High Density Recording

ABSTRACTCo85Cr15-xTax(x:0, 2at%)/Cr films with microscopically flat surface were investigated for high density recording media. These films were deposited on silicon wafer and glass substrates at the substrate temperature Ts of 350 °C at argon pressure as low as sub-mTorr by using Facing Targets Sputtering (FTS) apparatus. The elevating of Ts promoted the Cr(200) orientation in film plane, leading to the in-plane c-axis orientation of Co crystallites. Addition of some elements such as Si, Ge and Ta in Cr thin film was found to stabilize Cr(110) crystal orientation even at Ts of 300 °C.

Solidification of a Liquid Metal with Natural Convection in a Thick-Walled Container

1999 ◽  
Vol 15 (2) ◽  
pp. 47-55
Author(s):  
H. C. Tien ◽  
C.C. Wang
Keyword(s):  
Natural Convection ◽  
Weighting Function ◽  
Solidification Rate ◽  
Thermal Contact ◽  
Solidification Process ◽  
External Cooling ◽  
Implicit Solver ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Change Material

ABSTRACTThe solidification of a phase change material (PCM), exemplified by a molten metal, in a thick-walled container is analyzed in this paper. The effects of natural convection and several important controlling parameters are investigated extensively. These parameters include the initial temperature of the PCM, external cooling conditions, thickness and thermal properties of the wall, and the thermal contact resistance at the PCM/wall interface. Two representative configurations are examined in this study. A modified version of the enthalpy formulation in which the sensible heat is separated from the latent heat, is employed to construct the energy equation for the PCM. Vorticity-stream-function approach is adopted for solving the flow field. The governing equations pertinent to the problem are discretized by the weighting function scheme and finally solved by the SIS (Strongly Implicit Solver) algorithm. It is demonstrated that for both configurations natural convection has prominent effect on the temperature distribution of the liquid phase of the PCM; however, the effect of natural convection on the shape of the solid/liquid interface and the overall solid fraction is case dependent. It is also shown that the above-mentioned controlling parameters have a direct impact on the solidification process. Specifically, an increase in the Biot number (from 1 to infinity) and the thermal diffusivity of the mold (from 0.8 to 5) enhances the solidification rate. Reverse effect was found for the other controlling parameters.

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