巻号一覧
61 巻, 11 号
November
選択された号の論文の9件中1～9を表示しています
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特集：粉末成形・加工による特異組織構造形成と高次機能化
総報
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近藤 勝義2014 年 61 巻 11 号 p. 500-
発行日: 2014/11/15
公開日: 2014/11/28
ジャーナル オープンアクセスPDF形式でダウンロード (108K)
受賞記念講演
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－TiNi 系形状記憶焼結材における強度・形状回復率の向上を目指して－近藤 勝義, 米澤 隆行, 梅田 純子, 今井 久志, 早場 亮一2014 年 61 巻 11 号 p. 501-513
発行日: 2014/11/15
公開日: 2014/11/28
ジャーナル オープンアクセスThe Ti–Ni–Fe elemental mixture powder was consolidated by spark plasma sintering and hot extrusion process. The homogenization and aging heat treatment was applied to the Ti–Ni–Fe sintered alloys for uniform precipitation of ultra-fine Ti3Ni4 needle-like intermetallics with 50 − 100 nm length in TiNi matrix. ALCHEMI analysis clarified the additive Fe elements were completely solid-soluted into Ni atom sites of the TiNi alloy after aging heat treatment. The plateau stress gradually increased with increase in Fe content because the Martensite transformation temperature drastically decreased. The measured plateau stress corresponded well with the calculation result by using Clausius-Clapeyron equation. The shape recovery rate under 8 % strain was 89～95 % when Fe content was over 0.3at.%. This is also due to solid-soluted Fe atoms causing the decrease of Austenite transformation temperature. PM Ti–50.5at.%Ni alloy with 1.0at.%Fe after aging heat treatment showed an excellent balance of mechanical properties; 906 MPa plateau stress, 1260 MPa UTS and 95.4 % shape recovery rate.抄録全体を表示PDF形式でダウンロード (1901K)
解説
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伊藤 孝至2014 年 61 巻 11 号 p. 514-520
発行日: 2014/11/15
公開日: 2014/11/28
ジャーナル オープンアクセスBoth of high performance and low cost of the thermoelectric materials are required for the practical use of a thermoelectric power generation using waste heat. The silicide-based thermoelectric materials constituted of the eco-friendly raw materials that are less toxic and abundant in the earth’s crust has been attracting attention. In this study, material developments of the dimagnesium silicide (Mg2Si) and the higher manganese silicide (HMS) have been carried out for high thermoelectric performance using powder metallurgical processes. The Mg2Si compounds were synthesized via the liquid-solid phase reaction process and consolidated by pulse discharge sintering. For production of the HMS compounds, a series of processes of pulverization, mixing and pulse discharge sintering was used. Various synthesizing conditions were attempted for improving the thermoelectric performance of these materials.抄録全体を表示PDF形式でダウンロード (830K)
研究論文
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藤原 弘, 西本 孝志, 宮本 博之, 飴山 惠2014 年 61 巻 11 号 p. 521-525
発行日: 2014/11/15
公開日: 2014/11/28
ジャーナル オープンアクセスHarmonic-structured Cu–Sn alloys were produced via mechanical milling (MM) followed by spark plasma sintering (SPS), and their microstructure and mechanical properties were investigated. Microstructural observation of the MM powders and SPS compacts was achieved using scanning electron microscopy (SEM)/energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The mechanical properties of the SPS compacts were evaluated using results of the tensile test and Vickers hardness test. SEM/EDS micrographs and XRD profile indicated that the harmonic-structured Cu–Sn alloy compacts have the network region with highly Sn solid solution, which is including some γ phase, and the dispersed region with pure Cu. The harmonic-structured Cu–Sn alloy compacts demonstrate the stabilized high strength, sufficient ductility and high hardness compared with the incomplete harmonic-structured Cu–Sn alloy in spite of the same addition of Sn. In the specimen after the tensile testing, many cracks were observed in only network region. This result indicates that advanced ductility of the harmonic-structured materials is attributed to the obstruction of the crack propagation by the dispersed region. The network structure in the harmonic-structured materials is effective for an improvement of the mechanical properties.抄録全体を表示PDF形式でダウンロード (1989K) -
藤原 弘, 續木 雄基, 宮本 博之, 飴山 惠2014 年 61 巻 11 号 p. 526-530
発行日: 2014/11/15
公開日: 2014/11/28
ジャーナル オープンアクセスThe harmonic-structured composite that consists of a network fine grain region with a high speed steel and a dispersed coarse grain region with a mild steel was fabricated prepared using a mechanical milling and spark plasma sintering process. The microstructure of harmonic-structured composite compact was observed by a scanning electron microscope and mechanical properties were evaluated by a tensile test and Vickers hardness test. The harmonic-structured composite exhibited high strength and enough ductility compared with a conventional particle-dispersed composite with the same volume fraction of high speed steel/mild steel. The work-hardening rate of harmonic-structured composite is higher than the conventional particle-dispersed composite so that the harmonic-structured material demonstrates a high elongation. The microstructure observation of harmonic-structured composite reveals that the superior elongation of the harmonic-structured composite is attributed to the plastic deformation of the dispersed area around the cracks which initiate at the network area.抄録全体を表示PDF形式でダウンロード (1640K) -
木村 貴広, 中本 貴之2014 年 61 巻 11 号 p. 531-537
発行日: 2014/11/15
公開日: 2014/11/28
ジャーナル オープンアクセスIn this study, the basic characteristics of Al–10%Si–0.4%Mg alloy fabricated by Selective Laser Melting (SLM) were investigated. First, laser irradiation conditions were optimized for densification by using an SLM machine equipped with a 400 W Yb fiber laser. As a result, SLM specimens with almost 100 % relative density were obtained. Secondly, the microstructures and mechanical properties of the dense specimens were investigated. The ultimate strength (UTS > 450 MPa) and breaking elongation (EL > 10 %) of the as-fabricated SLM specimens were much higher than those of high pressure die casting materials. This is because they had almost 100 % relative density and showed sub-micron order dendrite-cell microstructures. Moreover, the effects of T5/T6 heat treatment on microstructures and mechanical properties were also investigated. The behaviors of heat treatments in the SLM specimens were different from those of cast melting alloys. The EL of the SLM specimens in the T6 condition increased to about 20 % although the UTS decreased.抄録全体を表示PDF形式でダウンロード (1494K)
研究ノート
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武舍 翔太郎, 佐藤 仁俊, 鈴木 達, 藤本 憲次郎, 目 義雄2014 年 61 巻 11 号 p. 538-543
発行日: 2014/11/15
公開日: 2014/11/28
ジャーナル オープンアクセスMAX phase materials are known to show unique properties with the combination of metallic and ceramic properties. Recently textured MAX phase materials have been expected to show excellent properties. Here Ti2AlN powders were synthesized from Ti, Al and TiN powders, or Ti and AlN powders heating at 1573 K−1773 K. Then highly textured Ti2AlN was fabricated by slip casting in a strong magnetic field and spark plasma sintering at 1473 K−1773 K and the relative density was nearly 97 %. The c – axis of the Ti2AlN grains were oriented parallel direction of the magnetic field, the lotgering orientation factor was determined 0.96. The nacre like structure was observed in the side surface of the textured sample.抄録全体を表示PDF形式でダウンロード (1649K)
本会記事
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2014 年 61 巻 11 号 p. Pref11_1-
発行日: 2014/11/15
公開日: 2014/11/28
ジャーナル オープンアクセスPDF形式でダウンロード (492K) -
2014 年 61 巻 11 号 p. Mtg11_2-Mtg11_6
発行日: 2014/11/15
公開日: 2014/11/28
ジャーナル オープンアクセスPDF形式でダウンロード (312K)
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