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.

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 Ni-(15, 28 and 31) at.% Al Alloys by Unidirectional Solidification in Hydrogen Atmosphere

2007 ◽  
Vol 544-545 ◽  
pp. 323-326
Author(s):  
Soong Keun Hyun ◽  
Teruyuki Ikeda ◽  
Hideo Nakajima
Keyword(s):  
Liquid Metals ◽  
Hydrogen Atmosphere ◽  
Zone Melting ◽  
Al Alloys ◽  
Unidirectional Solidification ◽  
Hydrogen Gas ◽  
Solidification Velocity ◽  
Melting Technique ◽  
Cylindrical Pores ◽  
High Frequency Induction

Lotus-type porous Ni- (15, 28 and 31) at.% Al alloys whose long cylindrical pores are aligned in one direction were fabricated by continuous zone melting technique under high-pressure gas of hydrogen of 2.5 MPa. A part of 5-10 mm in length of the rod in the vicinity of the coil was melted by high frequency induction heating, and was moved downwards by electric motors at a constant velocity of 330 μms-1 to 500 μms-1 for unidirectional solidification. The pores are formed as a result of precipitation from the supersaturated hydrogen gas when the liquid metals dissolved with gas atoms is solidified. The porosity and the pore size decrease with increasing aluminum content. An increase of solidification velocity from 330 μms-1 to 500 μms-1 leads to a decrease of pore diameter and an increase of pore number in the porous Ni-28at%Al.

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.

Morphology of [011]-tilt Σ3 boundaries in pure copper and copper–aluminum alloy tricrystals

2000 ◽  
Vol 282 (1-2) ◽  
pp. 8-15 ◽  
Author(s):  
T Okada ◽  
K Urushihara ◽  
M Tagami ◽  
F Inoko ◽  
S Hashimoto
Keyword(s):  
Aluminum Alloy ◽  
Pure Copper ◽  
Copper Aluminum

AMBRALOY 928

Alloy Digest ◽  
1958 ◽  
Vol 7 (10) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Shear Strength ◽  
Aluminum Alloy ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Strength ◽  
General Corrosion ◽  
Copper Aluminum

Abstract AMBRALOY-928 is a copper-aluminum alloy having high strength, hardness and excellent resistance to general corrosion. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength. It also includes information on corrosion resistance as well as forming, machining, and joining. Filing Code: Cu-69. Producer or source: American Brass Company.

Gold Nanoparticle-Enhanced Laser-Induced Breakdown Spectroscopy and Three-Dimensional Contour Imaging of an Aluminum Alloy

2020 ◽  
pp. 000370282097304
Author(s):  
Amal A. Khedr ◽  
Mahmoud A. Sliem ◽  
Mohamed Abdel-Harith
Keyword(s):  
Gold Nanoparticles ◽  
Aluminum Alloy ◽  
Three Dimensional ◽  
Plasma Temperature ◽  
Spectral Lines ◽  
Laser Induced Breakdown Spectroscopy ◽  
Al Alloy ◽  
Boltzmann Plot ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

In the present work, nanoparticle-enhanced laser-induced breakdown spectroscopy was used to analyze an aluminum alloy. Although LIBS has numerous advantages, it suffers from low sensitivity and low detection limits compared to other spectrochemical analytical methods. However, using gold nanoparticles helps to overcome such drawbacks and enhances the LIBS sensitivity in analyzing aluminum alloy in the current work. Aluminum was the major element in the analyzed samples (99.9%), while magnesium (Mg) was the minor element (0.1%). The spread of gold nanoparticles onto the Al alloy and using a laser with different pulse energies were exploited to enhance the Al alloy spectral lines. The results showed that Au NPs successfully improved the alloy spectral lines intensity by eight times, which could be useful for detecting many trace elements in higher matrix alloys. Under the assumption of local thermodynamic equilibrium, the Boltzmann plot was used to calculate the plasma temperature. Besides, the electron density was calculated using Mg and H lines at Mg(I) at 285.2 nm and Hα(I) at 656.2 nm, respectively. Three-dimensional contour mapping and color fill images contributed to understanding the behavior of the involved effects.

Hole Expansion by Using Al-Alloy Specimen and 0.45% Carbon Steel Specimen

2010 ◽  
Vol 452-453 ◽  
pp. 601-604
Author(s):  
Muhammed Sohel Rana ◽  
Md. Shafiul Ferdous ◽  
Chobin Makabe ◽  
Masaki Fujikawa
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Carbon Steel ◽  
Cold Work ◽  
Fatigue Crack Initiation ◽  
Steel Specimen ◽  
Expansion Method ◽  
Al Alloy ◽  
2024 Aluminum Alloy ◽  
Cold Worked

The enhancement method of fatigue life and the crack initiate and growth behavior of a holed specimen was investigated by using the 2024 Aluminum alloy and 0.45% Carbon steel. The purpose of present study is to propose a simple technical method for enhancement of fatigue life in a notched specimen. Also, the effect of local plastic deformation by cold work on fatigue crack initiation behavior was examined. This paper presents a basic experimental kinematic cold expansion method by inserting and removing a pin through the specimen hole. The shape of cross-section of pin was a circle or an ellipse. It was shown that the fatigue life of the specimen with the cold-worked hole was longer than that of the specimen with non-cold-worked hole for the case of same stress level in aluminum alloy and carbon steel. Also, the fatigue strength was higher in the case of the cold expanded hole. In this study, a methodology of lengthening of fatigue life of holed specimen is shown. Also, the improvement conditions of fatigue life were significantly affected by shape of pin, local hardening and residual stress conditions. The fatigue life improvement of the damaged component of structures was studied.

Infrared Spectroscopy of Molten LiCl−KCl under Hydrogen Gas Atmosphere

2004 ◽  
Vol 108 (21) ◽  
pp. 4567-4569 ◽  
Author(s):  
Hironori Nakajima ◽  
Toshiyuki Nohira ◽  
Yasuhiko Ito
Keyword(s):  
Infrared Spectroscopy ◽  
Hydrogen Gas ◽  
Gas Atmosphere

scholarly journals Precipitation during Quenching in 2A97 Aluminum Alloy and the Influences from Grain Structure

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2802
Author(s):  
Xiaoya Wang ◽  
Jiantang Jiang ◽  
Guoai Li ◽  
Wenzhu Shao ◽  
Liang Zhen
Keyword(s):  
Aluminum Alloy ◽  
Grain Structure ◽  
Water Quenching ◽  
Al Alloy ◽  
Air Cooling ◽  
Quenching Rate ◽  
Subsequent Aging ◽  
Nucleation Sites ◽  
Aging Response ◽  
Δ Phase

The quench-induced precipitation and subsequent aging response in 2A97 aluminum alloy was investigated based on the systematic microstructure characterization. Specifically, the influence on precipitation from grain structure was examined. The results indicated the evident influence from the cooling rate of the quenching process. Precipitation of T1 and δ′ phase can hardly occur in the specimen exposed to water quenching while become noticeable in the case of air cooling. The yield strength of 2A97-T6 alloy de-graded by 234 MPa along with a comparable elongation when water quenching was replaced by air cooling. Sub-grains exhibited a much higher sensitivity to the precipitation during quenching. The presence of dislocations in sub-grains promoted the quench-induced precipitation by acting as nucleation sites and enhancing the diffusion of the solute. A quenching rate of 3 °C/s is tolerable for recrystallized grains in 2A97 Al alloy but is inadequate for sub-grains to inhibit precipitation. The study fosters the feasibility of alleviating quench-induced precipitation through cultivating the recrystallization structure in highly alloyed Al–Cu–Li alloys.

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