巻号一覧
41 巻, 9 号
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鰐部 吉基1994 年 41 巻 9 号 p. 1030
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (81K) -
石川 秀雄1994 年 41 巻 9 号 p. 1031-1036
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーThe annual growth rate of P/M parts weight per vehicle in Japan has been held steadily 6% during the past decade, while the sales of P/M parts for automobiles fell in 1993 for the first time over the three decades. The P/M industry in Japan, as well as other metal forming industries, is faced with the recession of domestic market and the increase of overseas manufacturing.
In this paper, the status of Japanese P/M industry is reviewed. The technical, management and information problems are pointed out and several tentative solutions are proposed from user's point of view. These solutions are; (1)promoting studies on new powder and new process for drastic cost-reduction, (2)collaborating with several P/M companies in order to both overcome technical difficulties and shorten development period, (3)enlarging standardization and propagating the integrated P/M technical knowledge to automotive designers for digging out new P/M applications. Future prospects of ferrous P/M and advanced P/M in the vehicle is also mentioned in brief.抄録全体を表示PDF形式でダウンロード (4961K) -
山崎 裕司, 内富 宏, 礒部 剛彦, 駒井 正雄, 高木 研一1994 年 41 巻 9 号 p. 1037-1041
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーThe liquid phase sintering mechanisms of Cr-containing Mo2NiB2 base hard alloys were studied for Ni-6mass%B-58.6mass%Mo-(0, 10)mass%Cr compositions. A fine composite microstructure of a M3B2 hard phase and a Ni binder phase was formed from the powders of MoB, Ni, Mo and Cr by a reactive sintering process with a liquid phase. During the solid state sintering stage, there are two reactions of boride formation. First, orthorhombic M3B2 was formed in the compact by a reaction of 2MoB+Ni=Mo2NiB2. Second, orthorhombic M3B2 transformed to tetragonal M3B2 prior to the liquid formation. During the second stage above 1313K, a quasi-eutectic reaction between the M3B2 hard phase and the Ni base binder phase formed a liquid phase, which resulted in considerable densification of the compact.
The microstructures of the hard alloys at various sintering stages were also investigated.抄録全体を表示PDF形式でダウンロード (2740K) -
山松 純子, 野村 武史1994 年 41 巻 9 号 p. 1042-1047
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーPowder properties and sintering behavior of Ni powders for multilayer ceramic capacitors (MLCCs) have been studied. It is shown that the Ni powders prepared by chemical vapour deposition (CVD) have high dispersibility, compactibility, and crystallinity. Sintering behavior of the Ni powders have been different from those prepared by liquid-phase reduction method (LRM). This is well explained by the particle size distribution. Use of fine Ni powder prepared by CVD has enabled to make thin and plain inner electrodes. We have developed new MLCCs with high reliability by using CVD Ni-powders.抄録全体を表示PDF形式でダウンロード (3512K) -
今村 正人, 中島 紀一, 柳沢 章, 中川 威雄1994 年 41 巻 9 号 p. 1048-1053
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーIn the reaction sintering of aluminum-alumina green compact in air, size change (expansion) due to the direct oxidization of the aluminium has been observed. The expansion amount of the compact is not equal (smaller than) to the shrinkage of the slurry cast. But it has been made to correspond by changing the size distribution of the alumina powder, so that the binder amount decrease, the initial fillings improve, the shrinkage decrease, and as aresult the expansion amount increase). It was also confirmed that the deviaton of dencity can be reduced by adding alumina fiber.抄録全体を表示PDF形式でダウンロード (301K) -
Koji Yamakata, Ken Hirota, Osamu Yamaguchi, Hideki Kume, Suguru Inamur ...1994 年 41 巻 9 号 p. 1054-1060
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーAlumina/3 mol% yttria-doped zirconia composite powders have been prepared by the hydrazine method. As-prepared powders are AIO(OH) gel solid solutions and the mixtures of this and amorphous ZrO2 below and above 10 mol% ZrO2, respectively. Formation process leading to α-Al2O3-t-ZrO2 composite powders is examined. Hot isostatic pressing has been performed for 1 h at 1500°C under 196 MPa using the composite powders of α-Al2O3 and t ZrO2 obtained by heating for 1 h at 1350°C. The resulting dense ZrO2-toughened Al2O3 (ZTA) ceramics with 30 mol% ZrO2 show excellent mechanical strength (1100 MPa). The grain sizes of α-Al2O3 and intergranular ZrO2 in ZTA decrease with increased ZrO2 addition. Intragranular ZrO2 grains are 0.3 μm regardless of the starting composition. Mechanical properties are discussed in connection with relative densities and microstructures.抄録全体を表示PDF形式でダウンロード (4317K) -
西田 俊彦, 岡田 成司, 竹本 一也, 山田 雅幸, 田中 謙次1994 年 41 巻 9 号 p. 1061-1066
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーSome kinds of dielectric ceramic powder were encapsulated in stainless steel(SUS 304) mold with a dimensions of 22(O.D.) - 10(I.D.) x 30h mm. The mold containing ceramic powder was preheated at 1000°- 1300°C for 8 minutes, and press-forged rapidly under uniaxtial compressive load. By comparing some microstructural features between the forged products and the normally sintered ones, it was clarified that the hot-forge processing may be promising for the densification of some dielectric ceramics powder.抄録全体を表示PDF形式でダウンロード (4640K) -
三浦 秀士, 山西 祐司, 安藤 新二, 本田 忠敏1994 年 41 巻 9 号 p. 1067-1070
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーAlthough remarkable progress has been made in the techniques of metal injection molding (MIM) process, application of MIM process to wide variety of alloy steel powders is necessary to fully extend this novel mass production technique. In this paper, MIM process for the Cr-Mo steels has been investigated by using prealloyed fine powder (average particle size : 12μm) contained 0.17wt% carbon. The results were summarized as follows:
1) By using continuous process which went on through the thermal debinding and the sintering, the compacts were considerably densified to a relative density of about 95%.
2) In the case of using the hydrogen and nitrogen gas mixture as the final thermal debinding atmosphere, residual carbon content was little in the sintered compacts. However, the residual carbon content was widely controlled by adjusting the carbon monoxide gas content during the thermal debinding.
3) Heat treated SCM415 MIM steels showed a tensile strength of 1200 MPa, which is equivalent to those of the powder forged steels.抄録全体を表示PDF形式でダウンロード (3628K) -
三浦 秀士, 安永 成司, 小笠原 直人, 安藤 新二, 本田 忠敏1994 年 41 巻 9 号 p. 1071-1074
発行日: 1994/09/15
公開日: 2010/07/12
ジャーナル フリーOne of the important features of metal injection molding (MIM) process is its potential to eliminate secondary working operations such as machining. This is hoped to be a suitable production route for hard materials such as martensitic high carbon stainless steels. In this paper, the effects of debinding and sintering atmosphere on the carbon content, and the mechanical properties of heat treated steels have been investigated by using a SUS440C powder. The results were summarized as follows:
(1) The carbon content of both specimens debound in argon and hydrogen was higher than that of the original powder. Thermal debinding in hydrogen produced sound compacts, because the hydrogen gas assisted in the depolymerization of binder from low temperature.
(2) High density and high carbon stainless steel was produced by using hydrogen gas as the sintering atmosphere.
(3) Tensile strength and hardness of the heat treated steels increased with an increase of the sintering temperature. However, the tensile strength of the sintered steels above 1523K abruptly declined because of the precipitation of network of the chromium carbides along the boundaries.抄録全体を表示PDF形式でダウンロード (3015K) -
京極 秀樹, 小松 眞一郎, 篠原 和充, 地主 弘幸, 戸田 拓夫1994 年 41 巻 9 号 p. 1075-1079
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーThe sintering behavior and mechanical properties of Ti-4%Fe alloy compacts shaped by means of a metal injection molding method have been studied. The specimens with addition of 4%Fe powder were debound at 473K, 573K and 673K and sintered at 1373K, 1473K and 1523K in Ar gas. It was found that the microstructure of the sintered body consisted of α, β-Ti and TiC phases and was not varied by the debinding temperature. The relative density was increased with increasing the debinding temperature, and the maximum value was greater than 96%. The higher the sintering temperature was, the greater the flexural strength became, and the maximum value was 750MPa.抄録全体を表示PDF形式でダウンロード (2899K) -
湯浅 栄二, 師岡 利政, 角田 誠, 村里 紀英1994 年 41 巻 9 号 p. 1080-1083
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーCu-8mass%Ti-4mass%B mixture powders were mechanically alloyed ror various times. They were compacted and then sintered at 1173K for 108ks. Change of the structure during the sintering was investigated. The mechanically alloyed powders with different milling times were piled up in four layers and compacted. They were sintered at 1173K for various times. The volume fraction of pore in the layer of the as-mixed powder increases with the increasing sintering time, but the porosity in the layer of the powder mecanically alloyed for long time decreases, thereby, the form of the sintered lamellate compact bent. The distribution of Vickers hardness in thickness direction in the sintered lamellate compact changes from stair-like to parabola with the increasing sintering time. The as-mixed and mechanically alloyed powders were piled up and compacted. 3-point-bending test of the sintered lamellate compact was carried out. In the bending test, fracture strength when tensile stress was applied in the layer of the as-mixed powder is higher than that in the layer of the mechanically alloyed powder.抄録全体を表示PDF形式でダウンロード (1726K) -
師岡 利政, 湯浅 栄二, 久世 廣之1994 年 41 巻 9 号 p. 1084-1088
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーCu-50mass%Ti amorphous alloy powder was prepared by mechanical alloying and then sintered under pressure of 1560MPa at 600K. Wear experiments were carried out by a pin-ring type wear testing machine at various sliding speeds and at a contact pressure of 0.75MPa under unlubricated condition. The re-sults obtained are as follows: 1) The wear rate increases with the increasing sliding speed up to V=1.0m/s, due to breaking-away of the amorphous phase at the true contact part between the specimen and the counter face of steel. 2) Under condition of the sliding speed from V=1.2 to 1.6m/s, the wear rate of the amorphous alloy decreases due to the formation of oxide particles. 3) When the amorphous alloy was slid at the sliding speed over V=1.6m/s, the wear rate increases remarkably due to the crystallization from the amorphous phase at the contact part and the adhesion to the counter face. 4) The value of wear rate in the sintered amorphous alloy is smaller than that of the sintered crystalline alloy underthe same sliding condition.抄録全体を表示PDF形式でダウンロード (4372K) -
兼子 正生, 柳沢 章, 今村 正人, 中川 威雄1994 年 41 巻 9 号 p. 1089-1094
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーThe aim of this research was to form long soldered brass fibers by continuously shaving hot dipped brass sheet and form porous metal fiber compacts by using the brazing method instead of sintering. This brazing method are used for materials that melt at temperatures lower than the sintering temperatures of normal metal fibers and enables contact points to be melted and fixed.抄録全体を表示PDF形式でダウンロード (3354K) -
新谷 光二1994 年 41 巻 9 号 p. 1095-1098
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーAluminum nitride blocks were prepared by the usual method of powder metallurgy. The raw material is of ultrafine aluminum particles prepared by arc-prasma processing. The particles were pressed in a steel die, followed by two-step sintering (873K and 1473K) in flowing nitrogen under null pressure.
The nitriding reaction of aluminum is exothermic, thus, it progresses by self-propagating high temperature synthesis when it has once begun.
The structures and the composition of the AlN blocks were examined by SEM, XRD, and FTIR. The pysical property such as density was measured.抄録全体を表示PDF形式でダウンロード (4879K) -
林 卓, 佐藤 公彦1994 年 41 巻 9 号 p. 1099-1103
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーBarium titanate (BaTiO3) powders were prepared by hydrolysis of Ba-Ti bimetallic alkoxides containing octyl groups. The as-prepared BaTiO3 particles were amorphous in submicron size (-0.5μm). Crystalline BaTiO3 particles were obtained on preheating at 393K in a flow of oxygen/water vapor mixed gas and successive heating at 673K in oxygen atmosphere. The introduction of water vapor suppressed the formation of BaCO3, resulting in the formation of highly crystalline BaTiO3. The microstructure of BaTiO3 bodies sintered at 1573K exhibited grain sizes of 10-15 μm. They showed dielectric constant of about 2500 and the loss tangent of about 0.02 at the room temperature (1kHz).抄録全体を表示PDF形式でダウンロード (2238K) -
生川 章1994 年 41 巻 9 号 p. 1104-1110
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーA computer controlled automatic sample preparation and XRF analysis system based on grinding, briquetting techniques for powdered and crushed materials has been established. The system consists of the weigher, grinding mill, pelletizing press, conveyers, simultaneous XRF spectrometer, ignition loss determinator and computer. By this system, major, minor, trace elements and LOI in ceramics, glasses, cements and their raw materials are determined accurately, precisely and rapidly.抄録全体を表示PDF形式でダウンロード (1428K) -
Takashi Itoh, Yoshimoto Wanibe1994 年 41 巻 9 号 p. 1111-1116
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーQuantitative analysis of characteristics in powders and powder processing is essential for the quality control of the products or the processes. The present effort has been focused onto relationship between the fluidity and the particle characteristics of metallic powders. The flow ability [cm3/sec] and the repose angle [deg] have been measured as quantitative values of the fluidity. The fluidity has been discussed with the parameters which characterize the particle properties. The results are summarized as follows:
1. The relation between the flow ability and the repose angle can be expressed quantitatively with an exponential equation.
2. The fluidity is mainly controlled by the product of two parameters concerned with the mean particle size and the mean particle shape of powders and it can be predicted from the particle characteristics.抄録全体を表示PDF形式でダウンロード (344K) -
庄 豪仁, 野村 武史1994 年 41 巻 9 号 p. 1117-1122
発行日: 1994/09/15
公開日: 2009/12/04
ジャーナル フリーThe densities and properties of MnZn ferrite powder treated at different conditions have been investigated with the purposes to control the density of green compact and to study the relationship between compressibility and the powder properties. The powder properties have been characterized by SEM, BET, mercury porosimetry, and particle size analyzers. It is found that the compressibility of the MnZn ferrite powder, which presented by the densities of compact, is markedly influenced by the heat treatment temperatures and the water vapor pressures of the ambient atmosphere. The powders treated at lower temperatures or lower water vapor pressures show better compressibility and then are thought to be composed of softer agglomeration. The consideration of not only the density of compact but also all other powder properties is required for characterizing the aggregation states of the MnZn ferrite powder.抄録全体を表示PDF形式でダウンロード (1603K) -
師岡 利政, 湯浅 栄二, 石井 聡, 守川 洋1994 年 41 巻 9 号 p. 1123-1126
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーChanges in structure and hardness with heating below the crystallization temperature in the amorphous compact prepared from the mechanically alloyed powder of Ti-43at%Cu were invesitigated by using X-ray analysis and Vickers hardness test. The hardness of the compact increased remarkably by heating at near the crystallization temperature. This hardening phenomenon was attributed to form fine intermetailic phases from the amorphous phase. However, the hardness in the as-compacted state was Hv??520, but this value increased to Hv??20 by heating up the compact to 613K. The hardness of the compact also increased slightly by heating at lower temperatures than the crystallization temperature. This hardening phenomenon was attributed to form small zone caused by diffusion of a few of atoms in the amorphous phase.抄録全体を表示PDF形式でダウンロード (212K) -
武川 淳二郎1994 年 41 巻 9 号 p. 1129-1133
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーEffects of an addition of sintering enhancement element(Co or Ni) were examined through the ball milling or simple mixing process to obtain full dense W-Cu alloy compacts at lower temperature. When using ball milled powders, the effects of 1wt% Ni was distinguished ; by sintering above 1200°C the compacts of with 5wt% Cu were densified close to the theoretical values, and more than 10wt% Cu was required, however, to obtain the same density in the case of Co addition. And in this case, the microstructures of these compacts showed that Cu phase was uniformly dispersed among W particles through sintering process.
When using simply mixed powders, Co was appreciably effective on the densification, whereas Ni was ineffective. And in this case the microstructures showed large Cu particles of irregular shape.抄録全体を表示PDF形式でダウンロード (6208K) -
黒木 英憲, 王 明得, Kim Kwee Wong1994 年 41 巻 9 号 p. 1134-1138
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーA 6%W-5%Mo-4%Cr-2%V-1%C steel powder has been pressed uniaxially into cylindrical compacts, 6mm in diameter and 6mm in height, with 1% acrawax as the powder lubricant, and then sintered continuously without liquid phase in vacuum and with it in argon. Various loads have been applied to the compacts in the pressing direction during sintering in a thermomechanical analyzer, or a kind of a push-rod-type dilatometer.
Sintered density is affected significantly by temperature or by the existence of the liquid phase, but does not change very much with time. Uniaxial loading during liquid phase sintering of compacts strongly influences the dimensional change, but not very much the densification. Increasing the load to tens of kilopascals gives more shrinkage in the pressing direction, while less or no shrinkage, or more expansion in the perpendicular direction.抄録全体を表示PDF形式でダウンロード (320K) -
池 浩之, 寺田 修, 鈴木 寿1994 年 41 巻 9 号 p. 1139-1143
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーThe indentations caused by a hit were often formed on the surface of WC-Co cemented carbide tools such as sleeve, plug, etc., during application. It was found by the authors that, when the tools were heated after removing indentations by grinding, the surface appearance became non-uniform, leading to depreciation of the tools. However, the reason for the above phenomenon seemed not to be studied until now. Then, the model experiment on this subject was carried out, using mainly WC-(10-20)mass%Co specimens. The surface of the specimen was loaded by cemented carbide bar to introduce a groove. Specimens with a groove or specimens ground to remove a groove were heated at different temperatures.
It was suggested that the phenomenon was owing to a small amount of surface-growth, because residual elastic strain existing just beneath the indentation was recovered by heating. It was shown that, under a fixed load, the amount of surface-growth became larger and the region where the elastic strain remained was widened in the alloy with higher Co content.抄録全体を表示PDF形式でダウンロード (1516K) -
段 浩二, 田邊 靖博, 澤岡 昭1994 年 41 巻 9 号 p. 1144-1149
発行日: 1994/09/15
公開日: 2009/05/22
ジャーナル フリーTitanium powders were shock-compressed in capsules having four kinds of cylindrical sample cavities by the flyer plate impact technique. In this study, effects due to shape changing of sample cavities in shock-compressed titanium powders were investigated. The following four types of sample cavity were utilized: type (A); 35 mm length and 6 mm diameter, type (B); 35 mm and 12 mm, type (C); 5 mm and 12 mm and type (D); 2 mm and 12 mm. In the recovered samples shock-compressed in type (A) and type (B) capsules, there observed a conical, cylindrical and spherical region involving small spherical boids. In these areas, lamellar structures due to melting were recognized with a scanning electron microscope and unknown peaks were observed with X-ray diffraction patterns. These areas are thought to be formed by effects of oblique shock waves. On the occasion of shock-compression in capsules having long length cavity, the oblique shock waves from the side wall interact in the powder samples and may generate a high temperature region, which can not be achieved only by plane shock waves. The forms of interaction vary significantly with the shapes of sample cavities.抄録全体を表示PDF形式でダウンロード (3974K) -
高田 仁輔, 河合 伸泰1994 年 41 巻 9 号 p. 1150-1156
発行日: 1994/09/15
公開日: 2009/12/04
ジャーナル フリーThe influence of delubricating conditions on dimensional change of the compacts of the system Fe-2wt%.Cu-0.8wty.C-0.75wt%.Zn-st was examined under an atmosphere of endothermic gas. An abnormal expansion, which increases under slower heat pattern and atmosphere of lower dew point, occurred above about 500°C. As this expansion becomes larger, copper growth decreases, the shrinkage becomes larger and carbon content after sintering becomes higher.The diffusion of carbon is greatly influenced by delubricating conditions but that of copper is little. The delubrication in Ar, N2, H2 and dissociated ammonia atmosphere makes the sintering behaviors and sintered properties stable. In the case of endothermic gas, the similar tendency is observed at the rapid delubrication under the high dew point atmosphere.抄録全体を表示PDF形式でダウンロード (3022K) -
高田 仁輔, 河合 伸泰1994 年 41 巻 9 号 p. 1157-1163
発行日: 1994/09/15
公開日: 2009/12/04
ジャーナル フリーIn order to investigate the mechanism of abnormal expansion observed during delubrication of Fe-Cu-C-Zn-st compacts above 500°C, two extreme conditions were selected. Delubricating condition at a dew point of -35°C, a heating rate of 10°C/min and a holding time of 600°C×60 min in endothermic gas, in which specimen has shown the largest expansion, was compared with the same condition in argon, in which no expansion has been observed.
Abnormal expansion was not caused by vapour pressure of zinc stearate nor deposition of soot but by a lot of fine cementites formed on the surface of iron powders in compacts. The carbon for cementite is supplied by Boudouard reaction and decomposition of methane in endothermic gas. The de-composition residue of zinc stearate, such as zinc oxide plays an important role as a catalyst in this process. The cementite is directly formed as equilibrium phase, because the carbon solubility in ferrite phase is little.抄録全体を表示PDF形式でダウンロード (3504K)
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