Theoretical Analysis of Porosity in an Ordered Porous Copper Fabricated by Continuous Unidirectional Solidification

2018 ◽  
Vol 933 ◽  
pp. 136-141
Author(s):  
Rong Cao ◽  
Qing Lin Jin
Keyword(s):  
High Pressure ◽  
Theoretical Model ◽  
Theoretical Analysis ◽  
Processing Parameters ◽  
Unidirectional Solidification ◽  
Hydrogen Gas ◽  
Porous Copper ◽  
Gas Atmosphere ◽  
Ordered Porous ◽  
Good Agreement

Ordered porous copper with elongated pores has been fabricated by a continuous unidirectional solidification method in a hydrogen gas atmosphere with high pressure. The porosity of the ordered porous copper is significantly affected by the pressure of hydrogen. A theoretical model is developed to get the relation between the porosity and the processing parameters. The calculated values are in good agreement with the experimental results. Key words: Unidirectional solidification; Ordered porous copper; Porosity; Modeling.

Fabrication of Lotus-Type Porous Copper-Aluminum Alloy by Unidirectional Solidification in Hydrogen Atmosphere

2007 ◽  
Vol 539-543 ◽  
pp. 1898-1902 ◽  
Author(s):  
Soong Keun Hyun ◽  
Tsuyoshi Awadu ◽  
Teruyuki Ikeda ◽  
Hideo Nakajima
Keyword(s):  
Aluminum Alloy ◽  
Pure Copper ◽  
Hydrogen Atmosphere ◽  
Unidirectional Solidification ◽  
Hydrogen Gas ◽  
Al Alloy ◽  
Round Shape ◽  
Porous Copper ◽  
Gas Atmosphere ◽  
Copper Aluminum

Lotus-type porous Cu-5at.%Al alloy whose elongated pores are aligned in one direction was fabricated by unidirectional solidification in pressurized hydrogen gas atmosphere. The porosity of the Cu-Al alloy was higher than that of pure copper under the same fabrication conditions because of difference in hydrogen solubility. The pore structure was not round shape because the directional pore growth was interrupted with dendrite arms formed during the solidification; the pores grew to detour the obstacle of the dendrite arms.

High-Pressure Elastic Constant of Some Materials of Earth’s Mantle

2016 ◽  
Vol 71 (5) ◽  
pp. 433-437
Author(s):  
Quan Liu
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Theoretical Model ◽  
Elastic Behaviour ◽  
Exponential Relationship ◽  
Earth’S Mantle ◽  
Simple Theoretical Model ◽  
Volume Dependence ◽  
Theoretical Investigations ◽  
Good Agreement

AbstractIn the present work, an exponential relationship for the volume dependence of the Anderson–Grüneisen parameter along isotherm and the formulation derived from Tallon’s model have been used to develop a simple theoretical model for the elastic constants as a function of pressure. Applying it to some materials of earth’s mantle at different pressure ranges, the calculated results are in good agreement with the earlier theoretical investigations and available experimental data and thus show that our theory can be applied for predicting the elastic behaviour of earth materials at high pressure.

Dry Wear Properties of Porous Copper Fabricated by Unidirectional Solidification

2007 ◽  
Vol 124-126 ◽  
pp. 1805-1808
Author(s):  
Yong Su Um ◽  
Hideo Nakajima ◽  
Hwan Goo Seong ◽  
Bo Young Hur
Keyword(s):  
Wear Test ◽  
Porous Metal ◽  
Unidirectional Solidification ◽  
Test Method ◽  
Air Bearing ◽  
Wear Properties ◽  
Porous Copper ◽  
Gas Atmosphere ◽  
Cylindrical Pores ◽  
Pin On Disk

We have been investigated application of the lotus type porous metal that is manufactured by the unidirectional solidification of the melt in pressurized gas atmosphere such as hydrogen or nitrogen for an air bearing development. In this study, wear properties of porous copper having cylindrical pores have been investigated. Generally, wear test is influenced by a shape, a wear test method, atmosphere and a way of lubrication. Wear test used pin on disk type's wear test.

Synthesis and Decomposition of Pure Ca(AlH4)2

2007 ◽  
Vol 26-28 ◽  
pp. 869-872 ◽  
Author(s):  
Naoto Morisaku ◽  
Kenji Komiya ◽  
Yu Zhan Li ◽  
Hiroshi Yukawa ◽  
Masahiko Morinaga ◽  
...  
Keyword(s):  
Ball Milling ◽  
Hydrogen Gas ◽  
Peak Temperature ◽  
Decomposition Reactions ◽  
Gas Atmosphere ◽  
The One ◽  
Catalytic Effects ◽  
Decomposition Properties ◽  
Good Agreement

Pure Ca(AlH4)2 is synthesized and its decomposition reactions are investigated in a fundamental manner. The XRD profile observed is in good agreement with the one reported by Fichtner et al. From TDS measurements, Ca(AlH4)2 appears to decompose into CaH2+2Al+3H2 in three steps. The peak temperature of the first reaction is about 470K which is higher than that for Mg(AlH4)2 (about 450K), indicating that Ca(AlH4)2 is more stable hydride than Mg(AlH4)2. In addition, the catalysis of TiCl3 is doped into Ca(AlH4)2 by ball milling under a hydrogen gas atmosphere and catalytic effects on the decomposition properties are investigated.

Characteristics of Heat Transfer for Hydrogen and Wall During Filling Hydrogen Into Actual Tank at High Pressure

2007 ◽  
Author(s):  
Peter L. Woodfield ◽  
Toshio Takano ◽  
Masanori Monde
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Governing Equation ◽  
Hydrogen Gas ◽  
Tank Wall ◽  
Filling Process ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Filling Time ◽  
Good Agreement

An experiment has been made to measure the rise in temperature of hydrogen and tank wall during filling of actual tanks to 35 and 70 MPa. Three different tank configurations are used, having volumes of 205, 130 and 39 liters. The filling time is 5 to 20 minutes. A governing equation for the filling process is proposed, which includes unknown values for heat transfer coefficients between the hydrogen and the wall and the wall and surrounding air. The values are tentatively assumed to be 500 W/(m2K) during filling and 250 W/(m2K) after filling for the inside tank wall and 4.5 W/(m2K) for the outside tank wall. The measured temperatures of the hydrogen gas and the wall are in good agreement with the calculated ones.

scholarly journals Theoretical and Experimental Demonstration on Grating Lobes of Liquid Crystal Optical Phased Array

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Xiangru Wang ◽  
Liang Wu ◽  
Man Li ◽  
Shuanghong Wu ◽  
Jiyang Shang ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Theoretical Model ◽  
Theoretical Analysis ◽  
Phased Array ◽  
High Order ◽  
Main Lobe ◽  
Experimental Demonstration ◽  
Optical Phased Array ◽  
Fringe Effect ◽  
Good Agreement

High deflection efficiency is one of the urgent requirements for practical liquid crystal optical phased array (LC-OPA). In this paper, we demonstrate that high order grating lobes induced from fringe effect are the most important issue to reduce occupation of main lobe. A novel theoretical model is developed to analyze the feature of grating lobes when the device of LC-OPA is working on the scheme of variable period grating (VPG) or variable blazing grating (VBG). Subsequently, our experiments present the relevant results showing a good agreement with the theoretical analysis.

PHOTOINDUCED NONLINEAR OCTUPOLAR POLARIZATION: TRANSIENT AND PERMANENT REGIMES

1996 ◽  
Vol 05 (04) ◽  
pp. 653-670 ◽  
Author(s):  
CÉLINE FIORINI ◽  
JEAN-MICHEL NUNZI ◽  
FABRICE CHARRA ◽  
IFOR D.W. SAMUEL ◽  
JOSEPH ZYSS
Keyword(s):  
Theoretical Analysis ◽  
Second Harmonic ◽  
Experimental Results ◽  
Polar Field ◽  
Rotational Spectrum ◽  
Dual Frequency ◽  
One Dimensional ◽  
Ethyl Violet ◽  
Disperse Red 1 ◽  
Good Agreement

An original poling method using purely optical means and based on a dual-frequency interference process is presented. We show that the coherent superposition of two beams at fundamental and second-harmonic frequencies results in a polar field with an irreducible rotational spectrum containing both a vector and an octupolar component. This enables the method to be applied even to molecules without a permanent dipole such as octupolar molecules. After a theoretical analysis of the process, we describe different experiments aiming at light-induced noncentrosymmetry performed respectively on one-dimensional Disperse Red 1 and octupolar Ethyl Violet molecules. Macroscopic octupolar patterning of the induced order is demonstrated in both transient and permanent regimes. Experimental results show good agreement with theory.

scholarly journals The Enrichment of (Cu, Sn) Solid Solution Driven by High-Pressure Torsion

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 766
Author(s):  
Boris Straumal ◽  
Askar Kilmametov ◽  
Anna Korneva ◽  
Pawel Zięba ◽  
Yuri Zavorotnev ◽  
...  
Keyword(s):  
Solid Solution ◽  
High Pressure ◽  
Theoretical Analysis ◽  
Annealing Temperature ◽  
High Pressure Torsion

Cu–14 wt% Sn alloy was annealed at temperatures of 320 and 500 °C. The concentration of tin cinit in the copper-based matrix increased with annealing temperature. The annealed samples were subjected to high-pressure torsion (HPT) at 6 GPa, 5 turns, 1 rpa. HPT led to the refinement of Cu grains. The shape of the colonies of α + ε phases changed only slightly. The HPT-driven enrichment of the Cu-based solid solution with Sn atoms cHPT–cinit decreased with increasing cinit. The performed theoretical analysis explained this behavior of the HPT-driven enrichment.

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