Fabrication of lotus-type porous carbon steel by unidirectional solidification in nitrogen atmosphere

Kashihara, Makoto; Hyun, Soong‐Keun; Yonetani, Hiroshi; Kobi, T.; Nakajima, Hideo

doi:10.1016/j.scriptamat.2005.10.047

Cited by 27 publications

(13 citation statements)

References 10 publications

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“…[7,8] The use of pressurized gas such as hydrogen, nitrogen, and oxygen was required for the fabrication process of lotus-type porous metal with unidirectional elongated pores. [9][10][11] Especially, hydrogen was the most useful to fabricate the lotus metals. However, hydrogen gas is explosive and inflammable when mixed with a small amount of oxygen, so that its use is not convenient for industrial mass production.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Lotus-Type Porous Aluminum through Thermal Decomposition Method

Kim

Park

Nakajima

2009

Metall Mater Trans A

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Lotus-type porous aluminum with cylindrical pores was fabricated by unidirectional solidification through thermal decomposition of calcium hydroxide, sodium bicarbonate, or titanium hydride. The pore-forming gas decomposed from calcium hydroxide, sodium bicarbonate, and titanium hydride is identified as hydrogen. The elongated pores are evolved due to the solubility gap between liquid and solid when the melt dissolving hydrogen is solidified unidirectionally. The porosity of lotus aluminum is as high as 20 pct despite the type of the compounds. The pore size decreases and the pore density increases with increasing amount of calcium hydroxide, which is explained by an increase in the number of pore nucleation sites. The porosity and pore size in lotus aluminum fabricated using calcium hydroxide decrease with increasing argon pressure, which is explained by Boyle's law. It is suggested that this fabrication method is simple and safe, which makes it superior to the conventional technique using high-pressure hydrogen gas.

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Section: Introductionmentioning

confidence: 99%

Fabrication of Lotus-Type Porous Aluminum through Thermal Decomposition Method

Kim

Park

Nakajima

2009

Metall Mater Trans A

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“…Such a microstructure was typical for the fabricated lotus carbon steel in this study and was similar to that fabricated in a nitrogen atmosphere using the continuous zone melting. [6] The micro-Vickers hardness of the nonporous carbon steel fabricated in argon atmosphere was 148 ± 5. However, the micro-Vickers hardness of the lotus carbon steel shown in Figure 8 was 194 ± 11, which agreed approximately with the reference value of carbon steel AISI1018 solidified in 2.5 MPa nitrogen.…”

Section: Resultsmentioning

confidence: 98%

“…Kujime et al [5] and Kashihara et al [6,7] produced lotus carbon steel by unidirectional solidification using a continuous zone melting technique. [8] It was reported that the yield strength of the lotus carbon steels fabricated in a nitrogen atmosphere is similar to that of the nonporous carbon steel in the porosity range up to 30 pct, which is attributed to the solid-solution hardening as a result of nitrogen in the steel.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Lotus-Type Porous Carbon Steel Slabs by Continuous Casting Technique in Nitrogen Atmosphere

Kashihara

Suzuki

Kawamura

et al. 2010

Metall Mater Trans A

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Lotus-type porous carbon steel slabs with long cylindrical pores aligned in one direction were fabricated by the continuous casting technique in a mixture gas of N 2 0.8 MPa and Ar 1.7 MPa or in N 2 2.5 MPa at various transfer velocities from 2.5 mmAEmin À1 to 20 mmAEmin À1 . The pore size in lotus carbon steel fabricated in the mixture gas of nitrogen and argon was small and homogeneous, whereas the pore size in nitrogen had bimodal distribution depending on the transfer velocity. The large pores were observed mainly at the edge of the slab, which are considered to be merged of several inclined pores. The porosity depended on nitrogen partial pressure, which is explained by Sieverts' law. The hardness of lotus carbon steel matrix increased, which was attributed to the solid-solution of nitrogen.

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“…For materials produced by this method, the term ''Gasar'' was coined, which is a Russian acronym for ''gas reinforced''. It is well established that also other melt-gas systems, which exhibit a solubility gap between the liquid and the solid state, can be used [25,26].…”

Section: Production From Metallic Meltsmentioning

confidence: 99%

Metallic Foams

Baumeister

Weise

2012

Ullmann's Encyclopedia of Industrial Chemistry

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There are numerous processes for making metallic foams or similar highly porous metallic structures. The various processes can be classified into those starting from metallic melts, those starting from powdered metals, and those using deposition techniques. Most methods work for a specific range of metals and alloys and result in a typical foam structure with closed cells or open, interconnected cells. The most important manufacturing methods and a number of established industrial applications are presented. The article contains sections titled: 1. Introduction 2. Production 2.1. Production from Metallic Melts 2.2. Production from Metal Powders 2.3. Production by Deposition Techniques 3. Toxicology and Occupational Health 4. Applications and Outlook

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Fabrication of lotus-type porous carbon steel by unidirectional solidification in nitrogen atmosphere

Cited by 27 publications

References 10 publications

Fabrication of Lotus-Type Porous Aluminum through Thermal Decomposition Method

Fabrication of Lotus-Type Porous Aluminum through Thermal Decomposition Method

Fabrication of Lotus-Type Porous Carbon Steel Slabs by Continuous Casting Technique in Nitrogen Atmosphere

Metallic Foams

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