The Experts below are selected from a list of 402 Experts worldwide ranked by ideXlab platform
工藤 昌行 - One of the best experts on this subject based on the ideXlab platform.
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Formation and wear resistance of composite - hardened layer in centrifugally cast Al-Ni-Si duplex pipes
日本鋳造工学会, 2005Co-Authors: 大参 達也, 工藤 昌行, 上田 誠, 井口 学Abstract:The solidification structure, hardness and wear resistance of Al-Ni-Si duplex pipes produced by two-step centrifugal casting were investigated. In this process, two kinds of molten metals, i.e., first melt and second melt with higher liquidus temperature, were cast in sequence at a given interval into a Rotating Mold of a centrifugal caster. Al-12mass%Si alloy and Al-30mass%Ni alloy were used as the first melt and the second melt respectively. The second melt was cast after the solidified shell of the first melt had formed. The centrifugally cast pipes consisted of an outer layer and a composite layer containing fine Al-Ni intermetallic crystals. The origin of the outer layer was a survived part of the solidified shell of the first melt. The composite layer consisted of one or two layer(s). When the volume of the remelted part of the solidified shell was large, all the second melt mixed into the first melt and the resultant mixed melt formed the composite layer. On the other hand, the composite layer originated only in the second melt when the temperature of the solidified shell was low. In the intermediate case, the composite layer consisted of these two types of layers. The composite layer which formed from the mixed melt exhibited higher wear resistance than the other type of layer despite its lower hardness
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Hardness and Wear Resistance of Functionally Graded Hyperperitectic Al-Cr Alloys Produced by Centrifugal Duplex Casting
'Japan Institute of Metals', 1999Co-Authors: 大参 達也, 木村 欣晃, 伊藤 洋一, 松浦 清隆, 工藤 昌行Abstract:Centrifugal Duplex Casting (CDC process) is applicable to produce an aluminum-cast pipe with an in-situ composite layer containing fine intermetallic crystals. In this process, two kinds of molten metal, i.e. molten aluminum (the first melt) and molten Al-Cr alloy with a higher liquidus temperature (the second melt), are cast in sequence at a given interval into the Rotating Mold of a centrifugal caster. In the present paper, the solidification structure, hardness and wear resistance of Al-Cr alloy pipes produced by the CDC process were investigated. In the composite layer, there was a slightly graded hardness distribution: the hardness decreased gradually as the distance from the outer periphery of the pipe increases. The profile of hardness resembled that of the volume fraction of intermetallic crystals. The hardness and wear resistance of the outside surface of the CDC pipes increased as the chromium concentration of the second melt or the rotation speed of the Mold increased. The pipes with coarse intermetallic crystals, which were produced by the conventional centrifugal casting process, were fractured in the course of wear tests. On the other hand, the CDC pipes exhibited homogeneous-wear behavior because of the refinement of intermetallic crystals
Kiyotaka Matsuura - One of the best experts on this subject based on the ideXlab platform.
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Refinement and Localization of Primary Intermetallic Compounds in Hyperperitectic Al-Cr Alloy by Centrifugal Duplex Casting
Journal of the Japan Institute of Metals, 1996Co-Authors: Tatsuya Ohmi, Yoshiaki Kimura, Youichi Itoh, Masayuki Kudoh, Kiyotaka MatsuuraAbstract:A novel process named Centrifugal Duplex Casting has been proposed: it is a manufacturing process of aluminum cast pipes with in-situ composite layer which contains fine intermetallic compounds. In this process, two kinds of molten metals, i. e. molten aluminum (first melt) and molten Al-Cr alloy with higher liquidus temperature (second melt), are cast in sequence at a given interval in a Rotating Mold. The second melt collides with the meniscus of the spinning first melt, and is dispersed as fine fluid clumps. These fluid clumps are rapidly quenched, migrate toward the outer periphery, and accumulate to form the composite layer. The intermetallic compounds in this composite layer are much smaller in particle size than the Al-Cr alloy centrifugally cast by the conventional process. The solidification structure of the cast pipe produced by Centrifugal Duplex Casting is controlled by cooling capacity of the first melt. For instance, when the first melt has superheat at the time of the pouring of the second melt, coarse intermetallic particles grow inside of the refined composite layer. On the other hand, when the first melt has partially been solidified, the growth of the particles is suppressed. Therefore, the time interval from first to second pouring is an important parameter in this process
Matsuura Kiyotaka - One of the best experts on this subject based on the ideXlab platform.
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Refinement and Localization of Primary Intermetallic Compound in Hyperperitectic Al–Cr Alloy by Centrifugal Duplex Casting
'Japan Institute of Metals', 1997Co-Authors: Ohmi Tatsuya, Kimura Yoshiaki, Itoh Youichi, Kudoh Masayuki, Matsuura KiyotakaAbstract:A novel process named Centrifugal Duplex Casting has been proposed: It is a manufacturing process of an aluminum cast pipe with an in-situ composite layer which contains fine intermetallic crystals. In this process, two kinds of molten metal, i.e. molten aluminum (the first melt) and molten Al–Cr alloy with higher liquidus temperature (the second melt), are cast in sequence at a given interval into the Rotating Mold of a centrifugal caster. The second melt collides with the meniscus of the first melt, and is dispersed as a great number of fine fluid clumps. These fluid clumps are rapidly quenched, migrate toward the outer periphery, and accumulate to form the composite layer. The particle size of the intermetallic crystals in this composite layer is much smaller than that of the Al–Cr alloy centrifugally cast by a conventional process. The solidification structure of the cast pipe produced by Centrifugal Duplex Casting is controlled by cooling capacity of the first melt. For instance, when the first melt has superheat at the moment of the second-melt casting, coarse intermetallic crystals grow inside of the refined composite layer. On the other hand, when the first melt has partially been solidified, the growth of the intermetallic crystals is suppressed. Therefore, the time interval between the two casting operations is an important parameter in this process
大参 達也 - One of the best experts on this subject based on the ideXlab platform.
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Formation and wear resistance of composite - hardened layer in centrifugally cast Al-Ni-Si duplex pipes
日本鋳造工学会, 2005Co-Authors: 大参 達也, 工藤 昌行, 上田 誠, 井口 学Abstract:The solidification structure, hardness and wear resistance of Al-Ni-Si duplex pipes produced by two-step centrifugal casting were investigated. In this process, two kinds of molten metals, i.e., first melt and second melt with higher liquidus temperature, were cast in sequence at a given interval into a Rotating Mold of a centrifugal caster. Al-12mass%Si alloy and Al-30mass%Ni alloy were used as the first melt and the second melt respectively. The second melt was cast after the solidified shell of the first melt had formed. The centrifugally cast pipes consisted of an outer layer and a composite layer containing fine Al-Ni intermetallic crystals. The origin of the outer layer was a survived part of the solidified shell of the first melt. The composite layer consisted of one or two layer(s). When the volume of the remelted part of the solidified shell was large, all the second melt mixed into the first melt and the resultant mixed melt formed the composite layer. On the other hand, the composite layer originated only in the second melt when the temperature of the solidified shell was low. In the intermediate case, the composite layer consisted of these two types of layers. The composite layer which formed from the mixed melt exhibited higher wear resistance than the other type of layer despite its lower hardness
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Hardness and Wear Resistance of Functionally Graded Hyperperitectic Al-Cr Alloys Produced by Centrifugal Duplex Casting
'Japan Institute of Metals', 1999Co-Authors: 大参 達也, 木村 欣晃, 伊藤 洋一, 松浦 清隆, 工藤 昌行Abstract:Centrifugal Duplex Casting (CDC process) is applicable to produce an aluminum-cast pipe with an in-situ composite layer containing fine intermetallic crystals. In this process, two kinds of molten metal, i.e. molten aluminum (the first melt) and molten Al-Cr alloy with a higher liquidus temperature (the second melt), are cast in sequence at a given interval into the Rotating Mold of a centrifugal caster. In the present paper, the solidification structure, hardness and wear resistance of Al-Cr alloy pipes produced by the CDC process were investigated. In the composite layer, there was a slightly graded hardness distribution: the hardness decreased gradually as the distance from the outer periphery of the pipe increases. The profile of hardness resembled that of the volume fraction of intermetallic crystals. The hardness and wear resistance of the outside surface of the CDC pipes increased as the chromium concentration of the second melt or the rotation speed of the Mold increased. The pipes with coarse intermetallic crystals, which were produced by the conventional centrifugal casting process, were fractured in the course of wear tests. On the other hand, the CDC pipes exhibited homogeneous-wear behavior because of the refinement of intermetallic crystals
Tatsuya Ohmi - One of the best experts on this subject based on the ideXlab platform.
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Refinement and Localization of Primary Intermetallic Compounds in Hyperperitectic Al-Cr Alloy by Centrifugal Duplex Casting
Journal of the Japan Institute of Metals, 1996Co-Authors: Tatsuya Ohmi, Yoshiaki Kimura, Youichi Itoh, Masayuki Kudoh, Kiyotaka MatsuuraAbstract:A novel process named Centrifugal Duplex Casting has been proposed: it is a manufacturing process of aluminum cast pipes with in-situ composite layer which contains fine intermetallic compounds. In this process, two kinds of molten metals, i. e. molten aluminum (first melt) and molten Al-Cr alloy with higher liquidus temperature (second melt), are cast in sequence at a given interval in a Rotating Mold. The second melt collides with the meniscus of the spinning first melt, and is dispersed as fine fluid clumps. These fluid clumps are rapidly quenched, migrate toward the outer periphery, and accumulate to form the composite layer. The intermetallic compounds in this composite layer are much smaller in particle size than the Al-Cr alloy centrifugally cast by the conventional process. The solidification structure of the cast pipe produced by Centrifugal Duplex Casting is controlled by cooling capacity of the first melt. For instance, when the first melt has superheat at the time of the pouring of the second melt, coarse intermetallic particles grow inside of the refined composite layer. On the other hand, when the first melt has partially been solidified, the growth of the particles is suppressed. Therefore, the time interval from first to second pouring is an important parameter in this process
