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Volume 45, Issue 9
Displaying 1-21 of 21 articles from this issue
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Minoru Saito, Wataru Hino, Hisashi Suzuki1998 Volume 45 Issue 9 Pages 785-789
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSMicro-grained WC-13mass%Co alloys with a fixed content of VC (2.5mass% in binder) and two sorts of Cr3C2 contents (5 and 8mass% in binder) were sintered and then HIP-ed. Different properties of the alloy were studied relating to the Cr3C2 content and carbon content of the alloy. Among the results obtained, the fact that the (W, V, Cr)C phases formed in the alloy, and the amount of the phases increased with higher content of Cr3C2 and with increasing carbon content of the alloy, was noted. The fact that the strength (TRS) of the alloy was affected by the size of segregated area of complex carbides as above, was also noted.View full abstractDownload PDF (3799K) -
Yoshihiro Tada, Isao Tsutsui1998 Volume 45 Issue 9 Pages 790-795
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSAn expansion forming technique for the production of foamed cellular metal parts with very low apparent densities has been studied. Gas-tight fully densed beads and wires made from Pb-30Sn powder mixed with a powdered foaming agent, oxibisbenzenesulfonylhydrazide (OBSH), are used as a foamable raw material. Expansion forming into porous cellular parts is successfully performed by heating the foamable raw materials in a die to decompose the foaming agent to evolve gas and to adhere to each other. The foamable wires applied in a die show an expansion to the radial direction to fill the die cross-section which is followed by an expansion in the longitudinal direction, and have the advantage of single-bar preform to achieve a complete fill to the die cavity. As released gas staying in the die cavity leads to insufficient filling, supply of the raw materials and/or adding of the foaming agent play important roles especially in a closed die forming in which foamable beads are applied.View full abstractDownload PDF (2173K) -
Yoshihiko Kunieda, Yoshio Nakai, Tetsuo Inoue, Hideyuki Kanematsu, Hir ...1998 Volume 45 Issue 9 Pages 796-800
Published: September 15, 1998
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSThe sintered porous Ni is very important as electrode materials and have been used widely. In this work, the effect of the sintering environments and characteristics of raw Ni powders of the three kinds on the specific surface area of the sintered porous Ni compact was investigated. They were sintered at 1173K and 1273K for 1 hour under the both sintering environments, capsule free HIP (CFHIP) of 120MPa of argon gas and vacuum. The specific surface area was measured by interfacial impedance method.. The specific surface area of the sintered porous compact formed from the smallest particle size Ni was the largest under the both sintering environments, CFHIP and vacuum, and at the each sintering temperature. The specific surface area of the porous Ni compact sintered in CFHIP was larger than in vacuum for every raw Ni powder.View full abstractDownload PDF (344K) -
Kinichi Honda, Tadayuki Fujii1998 Volume 45 Issue 9 Pages 801-805
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSA large-scale and multi-layer crystal was prepared from hot-rolled multi-laminated molybdenum sheet doped and stacked alternately with different amounts of dopant by means of secondary recrystallization. It was found that the potential nucleus of the secondary grain from layers with different amounts of dopant occurred first at layer with a small amount of dopant and then grew into the layer with a large amount of dopant during a higher temperature annealing. The orientation of secondary grain developed from each layer was also closely related to the texture gradients in the thickness direction for primary recrystallized sheet. Most of the orientation of multi-layer crystal sheet corresponded to very weak components in the primary recrystallization textures and were related by a rotation of approximately 15°C-30°C about <100> and <110> axes relative to the strong primary {001}<110> and {111}<112> components. Consequently, the main orientations of the secondary grains developed from quintuple-layer molybdenum crystal are composed of a near {100}<001> for the surface layer, a near {112}<111> for the central layer and a near {113}<332>+{112}<111> for the layer between surface and central ones.View full abstractDownload PDF (2063K) -
Hardness and magnetic propertiesYusaku Sakata, Akinori Muto, Md. Azhar Uddin, Manabu Tanihara, Kazumas ...1998 Volume 45 Issue 9 Pages 806-811
Published: September 15, 1998
Released on J-STAGE: July 12, 2010
JOURNAL FREE ACCESSPorous carbon composites with highly dispersed ultrafine metal compounds (carbide, or nitride of Fe, Mo, W) were prepared by carbothermal reduction from metal ion exchanged resin. All the carbonized samples maintained their original spherical shape but their diameters shrunk to 60-80% of their initial sizes. Metal compounds in the carbonized sample were dispersed in the carbon matrix, and their particle diameters were 2-30nm. Some of the carbonized samples displayed a week needle trace or the trace gradually diminished within one minute during the vickers hardness measurement suggesting that the composite had elasticity. All the composites prepared from Fe 3+ adsorbed chelate resin showed strong magnetic properties. Residual magnetization was confirmed only in the carbonized sample which was prepared by heating to 800°C in N2 and cooled rapidly.View full abstractDownload PDF (1919K) -
Tomohiro Iwasaki, Takaomi Koga, Munetake Satoh1998 Volume 45 Issue 9 Pages 812-816
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSThe dynamic characteristics of a high-speed elliptical-rotor-type powder mixer have been investigated experimentally by measuring the torque exerting on the rotation axis of the rotor during powder treatment under several operating conditions. Effects of operating conditions and powder physical properties on the dynamic characteristics of the mixer were clarified. It was indicated qualitatively that the treatment process of powder in the mixer included compression and
shear processes of powder around the clearance region which distance between the vessel wall and the rotor tip was minimum. An empirical formula of the torque including physical properties of powder, operating conditions and equipment constants was proposed, and the validity was indicated.View full abstractDownload PDF (365K) -
Hisamichi Kimura, Akihisa Inoue, Kenichiro Sasamori, Yoshihito Kawamur ...1998 Volume 45 Issue 9 Pages 817-823
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSPowder metallurgy (P/M) alloys of AVFT(Al-6.4%V-4.2%Fe-1.7%Ti)-26P/M, AVFT-75P/M, AVFT-125P/M, AVCF(Al-2.9%V-3.8%Cr-4.3%Fe)-26P/M, AVCF-125P/M, AVFS(Al-6.5%V-3.6%Fe-1.6%Si)-125P/M and AVN(Al-6.7%V-4.1%Ni)-125P/M were prepared by extruding gas atomized powders with the sizes smaller than 26μm, 75μm or 125μm at 673 K. The constituent structure was Q.C. (quasicrystalline)+fcc-Al(Al)+Al11V+Al13Fe4+Al23Ti9 for the AVFT-P/M alloy, Q.C.+A1 for the AVCF-P/M alloy, Q.C.+Al+Al11V+Al13Fe4 for the AVFS-P/M alloy and Q.C.+Al+Al11V+Al3Ni for the AVN-P/M alloy. The quasicrystalline particles in the P/M alloys have an icosahedral structure and their particle size is about 500 nm. The ultimate tensile strength (σUTS), plastic elongation (εP), Young's modulus (E) and Vickers hardness (Hv) of the P/M alloys are in the range of 430 to 570 MPa, 3.3 to 7.3%, 80 to 91 GPa and 150 to 192, respectively, at room temperature. The ours, 0.2% proof strength (σ0.2) and εp at 573 K are 191 to 316 MPa, 171 to 298 MPa and 5.2 to 23.4 %, respectively. The wear rate of the AVFS-125P/M alloy decreases with increasing the sliding velocity (Vs) from 3.5×10-7 mm2/kg at Vs=0.5 m/s to 2.6×10-7 mm2/kg at Vs=2.0 m/s.View full abstractDownload PDF (6657K) -
[in Japanese]1998 Volume 45 Issue 9 Pages 826
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSDownload PDF (93K) -
Takashi Kimura1998 Volume 45 Issue 9 Pages 827-832
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSThis paper discribes a brief historical review of powder metallurgy and personal forecast in the near future. Modern powder metallurgy was born for produing incandescent lamp filaments from tungusten powder which could not be melted because of the high melting point. At an early stage of development, powder metallurgy was introduced when fusion metallurgy was impossible to manufacture. Next, the technology of mass production was developed for producing near net shape parts. Before and after the Second World War, powder metallurgy progressed markedly. As the fundamental approach, the sintering mechanism was clarified. Finally, advanced powder metallurgical materials have been developed with the growth of associated technology. In the future, as the technologies of energy saving recycling powder forging from metal scraps and semi-solid forming will be proposed.View full abstractDownload PDF (533K) -
Mikio Kondoh, Shigehide Takemoto1998 Volume 45 Issue 9 Pages 833-838
Published: September 15, 1998
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSDimensional tolerance of P/M parts is improved by uniformly filling powders in a die cavity. This study is aimed at clarifying the powder behavior in filling the die cavity. A visual apparatus was developed for observing the powder behavior. Using this apparatus, the powder behavior in filling die cavity and during movement of feed-shoe were investigated for gravity filling of atomized iron powders. It is clarified that the particle size segregation in filling occurs independently on the shoe speed and die cavity shape. Coarse particles segregate in the place where the powder falls along the angle of repose, while fine particles segregate in the thin-walled part and the position where the empty space finally disappears. It is also clarified that the behavior of filled powders during the feed-shoe movement after filling is divided into three regions; where the powders move as rolling, where the powders slide, and where the powders do not slide with the movement of the feed-shoe. Moreover, as the width of the cavity becomes thinner, the powders are more difficult to move; therefore, the none-sliding region increases. When shaking of the feed-shoe is repeated, the moving distance of powders in a vertical direction becomes larger, and the filling density increases. However, the increasing moving distance of powders is greatly affected by the width of the die cavity.View full abstractDownload PDF (5738K) -
High-purity α-Al2O3Yasuo Shibasaki1998 Volume 45 Issue 9 Pages 839-848
Published: September 15, 1998
Released on J-STAGE: December 10, 2021
JOURNAL FREE ACCESSThe slip casting of the fine ceramic powders by using the organic solvent and binder voluminously has a lot of problems in respects of the cost and the environmental pollution, etc. To solve the above problems, water slip casting technique for fine ceramic powders has been constructed by substituting water for organic material. Technological details to solve the problems in establishing water slip casting technique for fine ceramic powders, mainly high purity alumina, are described in this review.View full abstractDownload PDF (3216K) -
Satoshi Uenosono, Yukiko Ozaki, Kuniaki Ogura, Yoshifumi Nakano1998 Volume 45 Issue 9 Pages 849-853
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSAdhesive forces dominating the flowability of the segregation-free iron based powder consist of liquid bridge force, electrostatic force and van der Waals force. They were calculated and the absorption isotherm of water vapor on the segregation-free iron based powder was measured. The result indicated that the van der Waals force between binder on iron powder and lubricant powder and that between lubricant powders are main forces that determine the flowability of segregation-free iron based powder in the relative humidity less than 91%.View full abstractDownload PDF (3542K) -
Keijio Terashita, Kei Miyanami1998 Volume 45 Issue 9 Pages 854-858
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSTo design a composite, it is very important to know the microscopic mixture condition of the particles used as raw material. The capabilities of many composites are determined by the mixture condition.
In this study, particles were mixed at various mixing times to produce three-component systems. Next, an attempt was made to evaluate the mixture condition using microwave-induced plasma emission spectrometry, permitting the analysis of the composition of single particles and quickly measure three-dimensional parameters, including particle count and size distribution.
The results verified that microwave-induced plasma emission spectrometry shortens.
measurement time for particle composition, number, and size distribution. In other words, it can quickly evaluate the microscopic mixture condition of particles. Also calculated was the standard deviation of each of the three component particles. These calculations were then used to determine which mixing time produced the optimal mixture in which standard deviations of components are small. The cracking of agglomerate during mixing was successfully recognized.View full abstractDownload PDF (338K) -
Hidetoshi Kodera, Muneo Sawada, Susumu Shima1998 Volume 45 Issue 9 Pages 859-865
Published: September 15, 1998
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSIn the Cosserat continuum theory, couple stress and micro rotation of the material are taken into account. To simulate the behaviour of magnetic powder during compaction in magnetic field, we have developed the magneto-Cosserat continuum theory. In this theory, the Maxwell stress that is related to the distribution of magnetic flux density in the powder and particles' easy axes for magnetization are taken into account. By implementing the magneto-Cosserat continuum theory in FEM scheme, it is possible to simulate magnetic alignment in powders with magnetic anisotropy during compaction in an applied magnetic field. In the present paper, we analyze the relationship between the direction of magnetic field and compaction process, such as cross compaction, transverse compaction and isostatic compaction. In the calculation, the directions of the easy axes are given by a set of random numbers. The rotation of the axes is thus calculated at various conditions of applied magnetic field. The results are discussed comparing with those by particle dynamics simulation.View full abstractDownload PDF (473K) -
Nobuhiro Sadatomi, Masami Ueda, Masakazu Umeda, Osamu Yamashita1998 Volume 45 Issue 9 Pages 866-871
Published: September 15, 1998
Released on J-STAGE: November 19, 2010
JOURNAL FREE ACCESSFeSi2 alloys doped with Mn or Co (p-type Fe0.92Mn0.08Si2, n-type Fe0.98Co0.02Si2) were prepared by vacuum induction melting. The ingots were pulverized in a jet mill, and the powders were granulated by spray drying method using aqueous polyvinylalcohol (PVA) binder, in order to investigate the possibility of production on a large scale. The powders granulated exhibited excellent characteristics of fluidity, leading to smoothly feed it into a die cavity. To remove the binder from a compacted body, it was debindered at 723K for lh in H2, and then sintered at 1423K for 5h in H2, so that the residual carbon and oxygen contents in a sintered body approached those of the starting powder. Subsequently it was annealed at 1113K for 100h in Ar, so that it was almost composed of β-FeSi2. The thermoelectric figures of merit (Z) for optimal p- and n-type FeSi2 thermoelectric are 1.75×10-4(K-1) and 2.0×10-4(K-1), respectively, which are slightly higher than those obtained by H. Nagai on a laboratory scale.View full abstractDownload PDF (3754K) -
Keijio Terashita, Kazuhiko Miyauchi, Kei Miyanami1998 Volume 45 Issue 9 Pages 872-876
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSMany coin-shaped lithium batteries have anodes of manganese dioxide and carbon (graphite). Manganese dioxide and graphite differ so much in particle size distribution and apparent density that further granulation is needed to standardize them. The powder is then compressed and shaped into anode pellets. Methods of granulating and shaping anode material, however, are industrial secrets that have not yet been disclosed.
In this study, manganese dioxide, and graphite (carbon)-based material were stirred and further granulated under various conditions. Average particle size and fine grain yield of the obtained powder were examined. The powder was shaped into pellets, whose hardness and electric resistance were measured. This elucidated the granulating time, binder liquid additive percentage, and binder concentration that produced small anode-pellet particles of high yield. The optimal conditions were found for shaping the powder into anode pellets of greater hardness and electric resistance.View full abstractDownload PDF (1873K) -
Keijio Terashita, Tatsuya Hashimoto, Kei Miyanami1998 Volume 45 Issue 9 Pages 877-881
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSFor wide-scale use in small electronic devices and other equipment, manganese dioxide lithium batteries are produced by the process of mixing, granulating, shaping, and drying (the wet process). This process, however, uses binder liquid and other substances. High costs, environmental pollution, and imperfect drying of such substances are problems. To eliminate the need for binder liquid in the anode pellet-shaping process, this study attempted to use a high-speed shear mill to produce a composite of manganese dioxide and graphite (carbon black)-based particles. The particle fluidity and size distribution were measured. Composite particles were shaped into anode pellets, whose electric resistance and density were examined. The following was concluded:
The dry coating method can design composite particles for anode pellets without binder liquid. The present results show clarify the optimal operating conditions of a mixer for designing composite particles that have excellent design parameters, such as high fluidity and improved electric resistance. The dry method can shape anode pellets of greater electric resistance than the wet process.View full abstractDownload PDF (338K) -
Hideki Nakayama, Hideki Kyogoku, Shinichiro Komatsu1998 Volume 45 Issue 9 Pages 882-886
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSThe effect of heat treatment conditions on the microstructure and mechanical properties of SUS630 compacts made by metal injection molding were investigated. The compacts were made by injecting the mixtures of gasatomized SUS630 powder and polyamide binder into a metallic mold. The compacts were debound in air at 593K for 7.2ks, and sintered in vacuum at 1573K for 7.2ks. The specimens were aged at various temperatures between 753K and 893K after solution treatment. The microstructures of the heat treated compacts consisted of martensite and δ-ferrite. Both proof stress and tensile strength tended to become smaller with raising the aging temperature. The maximum values of proof stress and tensile strength of the heat treated compacts were as high as 1190MPa and 1330MPa respectively, and these values were equivalent to those of wrought steels. Charpy impact value increased with increasing the aging temperature. Charpy impact value of the compacts was smaller than that of wrought steel.View full abstractDownload PDF (3388K) -
Hideshi Miura, Yoshiaki Sakajiri, Shigeya Sakaguchi, Kei Tokumoto, Yas ...1998 Volume 45 Issue 9 Pages 887-891
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSMetal injection molding (MIM) process has an advantage of fabricating three dimensional complex shaped components, which alleviates the need for secondary working operations. Therefore, MIM process is hoped to be a suitable production route for the hard materials such as cemented carbides. This study has been performed to determine the production feasibility of sintered Co-Cr-W-C alloys by MIM process, and the mechanical propertie microstructures. The results obtained were as follows:
(1) An adequate carbon level of the alloy was achieved by solvent debinding followed by final thermal debinding in H2 and N2 gas mixtures atmosphere.
(2) Injection molded alloys showed the same microstructure and mechanical properties as those of conventional P/M alloys.View full abstractDownload PDF (3725K) -
Hideshi Miura, Toshihiro Yokomizo, Shigeya Sakaguchi, Kei Tokumoto, Ke ...1998 Volume 45 Issue 9 Pages 892-895
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSTi-Mo alloys have difficulties in manufacturing by melting-casting process because of its heavy gravitational segregation. On the other hand, several types of sintered titanium base hard alloys such as Ti-Mo and Ti-Mo-TiC have been developed by the powder metallurgy (P/M) process. However, there are still problems in fabricating three dimensional complex shaped components by conventional P/M process. Metal injection molding (MIM) process may solve those P/M processing problems because of the near net shape forming with high density and high performance properties.
In this study, the effects of MIM processing conditions (debinding, sintering) on the mechanical properties and microstructures of sintered titanium base hard alloys were investigated. Injection molded Ti-Mo-TiC alloys showed the same microstructures and mechanical properties as those of conventional P/M alloys. This indicates that MIM process has enormous potential to produce several types of high performance sintered titanium base hard alloys.View full abstractDownload PDF (4543K) -
Hao-Nien Huang, Jian Yang, Masaki Goto, Teruhisa Watanabe1998 Volume 45 Issue 9 Pages 896-900
Published: September 15, 1998
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSMethod for determination of Young's modulus of sintered metal materials is dynamic testing method by the longitudinal oscillations of the specimens, which has been provided in the standard of Japan Powder Metallurgy Association JPMA M 10 in March 1997. This paper shows the testing results of Young's modulus of various sintered metal materials for machine parts of the iron base, the stainless steel base and the bronze base materials, which are introduced in Japanese Industrial Standard JIS Z 2550. For example, the specimens of the iron base (6×8×60mm) were made from reduced iron powder, atomized iron powder, electrolytic copper powder, natural graphite powder and carbonyl nickel powder, by compressing with 300-600 MPa and sintering at 1423K for 1.8ks in cracked ammonia atmosphere. Consequently, the values of Young's modulus and relations between the values of Young's modulus and the sintered densities of various sintered metal materials could be obtained.View full abstractDownload PDF (373K)
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