巻号一覧
56 巻, 6 号
June
選択された号の論文の16件中1～16を表示しています
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特集： 新成形法，新焼結法と自動車への応用について
総報
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藤木 章, 巻野 勇喜雄2009 年 56 巻 6 号 p. 298
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスPDF形式でダウンロード (124K)
総説
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福島 英沖2009 年 56 巻 6 号 p. 299-305
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスAs the applications to auto-industry using microwave heating in near future, the mass production manufacturing of various materials such as ceramics or metal powders, the heating power supply such as fuel-cell or electric vehicles, and the environmental treatments of emission gas purification or metal recovery will be expected. In our research, a microwave heating of porous ceramics was tried by using newly developed cavity and microwave absorbents. We developed an "ultrahigh-speed heating" method of obtaining above 100°C/s in microwave radiation. Next, we started a research and development of microwave reforming, using a combination of bio-ethanol and microwave heating. Biomass is expected as both the renewable energy and the CO2 reduction. In microwave reforming, only a catalyst layer is selectively heated from the inside at a short time, so it becomes possible to produce hydrogen gas with a simple setup and at a low temperature of 500°C. High reformer efficiency of 80%, twice compared to the conventional one, and the activation energies decreased about 30%. Furthermore, as microwave basic technologies, the relations between dielectric properties and microwave heating of powder materials, the calculations of electro-magnetic field distributions in the cavity, and the heating characteristics of metal powders were investigated.抄録全体を表示PDF形式でダウンロード (1293K)
受賞記念講演
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竹本 恵英2009 年 56 巻 6 号 p. 306-312
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスA lot of PM parts have been used in automobile because of the cost advantage. We have been promoted "Loss-zero activity" such as promoting net shape manufacturing and decreasing rejects in production process in order to increase the competitiveness of PM parts.
For net shaping, we developed technology to prevent slip-crack which is a slipped flat plane get into lower density portion1) and simultaneous sinter-brazing technology that enabled mass production of net shaped synchronizer hubs and PM planetary carriers. In order to decrease rejects, we developed and adopted aeration powder filling technology that decreases weight variation. Furthermore, we are trying to develop apparent density (A.D.) sensor to measure A.D in a filler shoe and filled cavity in-situ to eliminate weight adjustment process after die-change.抄録全体を表示PDF形式でダウンロード (1099K)
研究
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松本 伸彦, 三宅 賢武, 近藤 幹夫, 安藤 公彦2009 年 56 巻 6 号 p. 313-318
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスWe have already reported that the ultra high density and the low dimensional change were realized by means of the developed die wall lubricated warm compaction and the high temperature sintering with controlling the blister. Increasing the sintered density is one of the effective methods to improve the mechanical properties of sintered steels, and the developed highly densified sintered steel had the excellent tensile strength of 2250 MPa. According to the evaluation of fracture surfaces, the crack path transformed from only the areas of inter-particles i.e. the sinter-neck regions to the areas of inter-particles i.e. the sinter-neck regions and trans-particles i.e. the matrix as increasing the sintered density. This transition in the clack path means the necessity of well-balanced strengthening the sinter-neck regions and the matrix to improve the mechanical properties of highly densified sintered steels. In this study, the effect of the strength of the sinter-neck regions and the matrix on the mechanical property was investigated. As the result of this study, the composite structurizing of the ductile martensite for the matrix and the hard martensite for the sinter-neck regions was realized by the combining fine and coarse powders method and was effective to improve the mechanical properties of the highly densified sintered steel.抄録全体を表示PDF形式でダウンロード (1434K) -
宇波 繁, 尾崎 由紀子2009 年 56 巻 6 号 p. 319-324
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスThe effect of copper powder addition on properties of sintered and case-hardened compacts made of the 0.45 mass% Mo prealloyed steel powder has been investigated. The tensile strength of sintered and case-hardened compacts made of the powder increased with 1 mass% Cu addition, but leveled off with 2 mass% Cu addition. The rotating bending fatigue strength of sintered and case-hardened compacts made of the powder increased with 1 mass% Cu addition. However, the fatigue strength decreased with 2 mass% Cu addition and was lower than that of Cu free material. The tensile and fatigue strengths of sintered and case-hardened compacts made of the powder with 1 mass% Cu addition are equal to those made of the conventional 4 mass% Ni diffusion-alloyed steel powder. The reduction of fatigue strength with 2 mass% Cu addition should be attributed to an increase in size of the maximum pore due to Cu liquid phase and probably an increase in fatigue crack growth rate due to Cu addition.抄録全体を表示PDF形式でダウンロード (1126K) -
三浦 秀士, 長田 稔子, 浜本 昭太, 河本 浩介, 土橋 伸浩, 宇波 繁2009 年 56 巻 6 号 p. 325-329
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスDue to the continual improvements of powder metallurgy techniques, it is possible for sintered materials to compete the wrought materials even in some of the most demanding applications. However, strength of sintered materials was inadequacy, because they have a lot of pores. This paper describes a study on the effect of rolling on the contact fatigue strength of sintered ferrous alloy compacts. The effects of rolling were evaluated by measuring the hardness and porosity distributions at the vicinity of the surfaces of rolled compacts. The effects of the amount of rolling on the contact fatigue strength, and the contact fatigue damage mechanisms were also investigated. Porosity at the vicinity of the surfaces of rolled compacts was decreased with increasing the amount of radial feed, from which the contact fatigue strength of rolled compacts was improved.抄録全体を表示PDF形式でダウンロード (786K) -
ねじ状工具によるP/M歯車仕上げ転造プロセスの数値歯形解析竹増 光家, 三浦 秀士, 河本 浩介2009 年 56 巻 6 号 p. 330-335
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスNumerical tooth profile analysis of finish P/M gear rolling process using screw-shaped tool was carried out by the combination method of FEM and linear programming for optimum tool design. The deformation behavior of rolled gear teeth was simulated by 3-dimensional FEM model. The rolling tool was designed for simultaneous rolling process in which the tooth flank and the fillet at the root of gears could be burnished in one pass. The concave tooth profile of the modified tool was expressed by 3 straight lines approximation. Rolling experiments were conducted using the modified tool optimized in the analysis. The simulation results agreed well with the experimental ones. Gears with a good involute tooth profile were obtained through the rolling processes for 3 kinds of P/M gears in the wide range of depth of tool indentation from 450 to 600 μm.抄録全体を表示PDF形式でダウンロード (826K) -
修整歯形工具による鉄系焼結合金歯車の各種転造特性三浦 秀士, 竹増 光家, 河本 浩介, 浜本 昭太, 宇波 繁2009 年 56 巻 6 号 p. 336-343
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスSurface finish rolling experiments were carried out using P/M spur gears of 0.6Mo-0.2Mn pre-alloyed sintered steel and of 0.8Mo-0.2Mn partially alloyed sintered steel with the density of 7.10 Mg/m3. A CNC form rolling machine of axis intersection type was employed. Three kinds of screw-shaped rolling tools were prepared: one was an unmodified tool and the others were the modified tools for simultaneous rolling of tooth and fillet surface having concave tooth profiles optimized by numerical tooth profile analysis. Porosity distributions in the surface layer of rolled gear teeth were determined and the effects of the amount of tool radial feed R0 on the selective surface densification behaviors were evaluated. Single tooth bending fatigue test was conducted. Gears with good tooth profiles were obtained by using the modified tools. The porosities in both the tooth flank and the fillet at the root were reduced to the target level at R0=600 μm in simultaneous rolling process. The single tooth bending fatigue durability was much improved to the same level as that of the wrought steel gears of SCM415.抄録全体を表示PDF形式でダウンロード (1210K) -
三浦 秀士, 長田 稔子, 周田 直樹, 河本 浩介, 浜本 昭太, 宇波 繁2009 年 56 巻 6 号 p. 344-349
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスSintered ferrous alloy gears are used in wide engineering fields. However, it is difficult for them to be applied to the parts loading at high stress levels, because their strength is poorer than that of the wrought materials. In this study, sintered ferrous alloy gears were rolled and their tooth root bending fatigue strengths were investigated. The effect of rolling conditions on the porosity distribution and hardness at tooth root, and the tooth root bending fatigue strength were determined. As the amount of stock rolled was increased, the porosity of the vicinity of the surface was decreased and the hardness was increased, and also the tooth root bending fatigue strength was increased to certain level, and then the fatigue strength was decreased. This seemed to be due to the shaving when the gear was rolled.抄録全体を表示PDF形式でダウンロード (1326K) -
榎並 啓太郎, 小野 昌二, 大原 正樹, 五十嵐 貴教2009 年 56 巻 6 号 p. 350-354
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスThe original bulk mechanical alloying installation (Equal Channel Angular Bulk Mechanical Alloying; ECABMA) was developed in this research. The ECABMA installation can produce a magnesium composite billet whose diameter * length is 80 mm * 200 mm. The magnesium composite billet, in which a large quantity of secondary particles was dispersed uniformly, can be produced by the ECABMA installation. AM60 magnesium alloy chip mixed with yttrium oxide powder was processed into a magnesium composite billet by the ECABMA, and then it was heated at 350°C and extruded into a round bar whose diameter * length was 20 mm * 1000 mm. The extruded magnesium composite has high strength and good creep resistance at 175°C.抄録全体を表示PDF形式でダウンロード (1387K)
受賞記念講演
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松木 一弘, 柳沢 平, 佐々木 元2009 年 56 巻 6 号 p. 355-370
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスThe densification or sintering processes in spark sintering has systematically investigated from the standpoint of punch-powder compact-die system, unlike the conventional situation such as the simple convenient method for fabricating sintered body. The systematic investigation consists of the following serial subjects; (1) clarification of principle of process, (2) modeling of coupling between micro- and macro-phenomena, (3) generalization of process control, (4) fabrication of high performance and multi-functional materials by optimization of process factors. Especially, the micro-phenomena in and/or between powder particles were coupled with the macro-phenomena such as heat transfer in the punch-compact-die system through micro/macro-coupling model. The coupling analysis for electricity (voltage and current) and heat was carried out by using Ohm's and Fourier's laws on the basis of the thermal energy conservation law. The optimized system for spark sintering process was proposed by the computer simulation based on micro/macro-coupling modeling and enabled to attain full densification even for poor sinterable materials, which led to the successful development of many metallic and ceramic materials in the industrial fields.抄録全体を表示PDF形式でダウンロード (1988K)
解説
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井藤 幹夫2009 年 56 巻 6 号 p. 371-376
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスThe establishment of rapid synthesis process at a low temperature of thermoelectric SrTiO3 was tried by using the polymerized complex (PC) process and the pulsed current heating (PCH) method. The non-doped and La- or Y- doped SrTiO3 powders could be synthesized by the PC process without precipitation of any second phase. The densely sintered bulks could also be obtained from these powders by the PCH method at 1473 or 1573 K for 5 min. In order to reduce electrical resistivity, TiB2 powder was added to the Y-doped SrTiO3. During the sintering, any reaction between SrTiO3 phase and TiB2 powder did not occur, resulting in the formation of Sr1-xYxTiO3/TiB2 composites. The TiB2 addition was quite effective not only for reduction in the electrical resistivity, but also for rapid densification during the sintering. The power factor of the Sr1-xYxTiO3/TiB2 composites over 800 K was similar to that of the Sr0.9Y0.1TiO3 polycrystal synthesized by the conventional solid state reaction method, indicating that the synthesis route via the PC process, the PCH method and TiB2 addition is quite promising as a rapid synthesis process at a low temperature of the thermoelectric SrTiO3 system.抄録全体を表示PDF形式でダウンロード (830K) -
岸本 昭, 森本 徹也, 荻原 康弘, 林 秀考2009 年 56 巻 6 号 p. 377-382
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスBy using 24 GHz millimeter-wave irradiation, a full densification of AlN with the addition of Y2O3 was attained at 1700°C, which is comparable to 28GHz-wave irradiation. Thermal conductivity of thus obtained sample exceeded 200 W/(m·K), which is the highest value among AlN-based ceramics fabricated in non-reducing atmosphere. The full densification was also reached at 1700°C in the Yb2O3 added AlN, which temperature was higher than that for 28GHz-wave irradiated ceramics by ca. 100°C.抄録全体を表示PDF形式でダウンロード (1198K)
研究
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Masao Tokita, Masakazu Kawahara, Kiyoshi Mizuuchi, Yukio Makino2009 年 56 巻 6 号 p. 383-388
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスSPS-fabricated zirconia(3Y)/SUS410L FGM consisting of seven layers was characterized by microfocusing XRD and Raman scattering methods. The formation of monoclinic zirconia phase was verified in the interlayers with lower contents of zirconia(3Y) than 70vol% and the largest amount of monoclinic zirconia was detected in the third interlayer with 60vol% zirconia(3Y). From the Raman peak shift of tetragonal zirconia, the existence of fairly high compressive stress was detected in the interlayers with the zirconia(3Y) of 60vol% and 70vol%, resulting in the formation of monoclinic zirconia. While tensile stress was observed in the interlayes with the content of more than 80vol% zirconia(3Y). Further, the increase of the lattice constant of 410L steel(Fe-Cr alloy) indicates that tensile stress is applied on the 410L steel region in all interlayers. Mechanical instability in the outer interlayers with more than 80vol% zirconia(3Y) is suggested from the drastic change of internal stress mode from compressive to tensile in the region of 70vol%-80vol% zirconia(3Y).抄録全体を表示PDF形式でダウンロード (644K) -
西野 祐輔, 林 秀考, 岸本 昭2009 年 56 巻 6 号 p. 389-394
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセスWe have already innovated superplastically foaming method in which pore expands after densification of the matrix utilizing the superplastic deformation. Based on this superplastically foaming method using 3YSZ (3 mol% yttria stabilized zirconia) and α-SiC as matrix and foam agent, respectively, we have successfully fabricated several dots closed pore pattern and C-shaped as well as S-shaped closed tube patterns by optimizing the amount of matrix 3YSZ. In addition to the shape of the closed pore, the protuberance based on the expansion of the pore changed with the location of the foam agent in the matrix. The shape of the closed pores and the interaction between them can be controlled by the concentration of the foam agent and the amount of the matrix.抄録全体を表示PDF形式でダウンロード (991K)
エラータ (Vol.56, No.4)
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榎本 尚也, 山田 浩介, 党 鋒, 稲田 幹, 北條 純一2009 年 56 巻 6 号 p. 423
発行日: 2009年
公開日: 2009/07/14
ジャーナル オープンアクセス本誌第56巻第4号 p. 194に掲載の榎本尚也氏，山田浩介氏，党 鋒氏，稲田 幹氏，北條純一氏の研究論文，「マグネタイトナノ粒子の合成における定在波型音場効果」の受理日が誤っておりました．
下記の通り訂正させていただきます．大変ご迷惑をお掛けしましたことをここにお詫び申し上げます．
（誤）Received December 4, 2004 → （正）Received December 4, 2008抄録全体を表示PDF形式でダウンロード (14K)
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