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Volume 40, Issue 10
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[in Japanese]1993 Volume 40 Issue 10 Pages 938
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSDownload PDF (84K) -
Osamu Kohmoto, Norishige Yamaguchi, Teruo Mori1993 Volume 40 Issue 10 Pages 939-942
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSMechanical alloying process of 6.5 wt. % Si-Fe powder mixtures has been studied using X-ray diffraction, DSC and vibrating sample magnetometer. The alloying process is divided into three stages. In the first stage, Curie temperature (Tc) is the same as that of pure Fe, indicating that the particles are not alloyed yet. In the second stage, both a large calorific value and a large coercive force (Hc) are observed; Tc is not clearly observed. These results indicates that the particles have fine lamellar structure and contain large internal stress. In the third stage, the calorific value decreases and Hc decreases. At the same time, lower Tc is observed. These results indicate the uniformity of the powders have increased.View full abstractDownload PDF (205K) -
Tohru Yamasaki, Yoshikiyo Ogino, Kazuhiko Morishita, Kiyoto Fukuoka, T ...1993 Volume 40 Issue 10 Pages 943-946
Published: October 15, 1993
Released on J-STAGE: December 04, 2009
JOURNAL OPEN ACCESSTi-Si powder mixtures were milled in a low energy rotational ball mill under Ar atmosphere, and the milled powders were dynamically compacted by using a propellant gun. During milling of Ti100-XSiX powder mixtures containing 20-50 at.%Si, the α-Ti and Si phases were progressively refined to average grain sizes of 20-30 nm in diameter and subsequently, the structure was amorphized. By dynamically compacting the amorphous Ti50Si50 powder at a shock pressure of 32.6 GPa, a partially crystallized amorphous alloy having an extremely high hardness (Hv??1300) was obtained. By annealing the materials at 1023K for 1h, crystallization and grain growth occurred to about 15-20 nm, and the hardness was increased to a maximum value (Hv??1700).View full abstractDownload PDF (1805K) -
Nobushige Hiraishi, Kazutaka Asabe1993 Volume 40 Issue 10 Pages 947-950
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSNi3Si intermetallic compounds have an excellent corrosion resistance in sulphuricacid solution. However, production of these compounds was difficult because of poor ductility caused by formation of a very brittle phase. In order to suppress formation of the brittle phase, process conditions involving a mechanical alloying(MA) method have been investigated for the production of Ni3Si intermetallic compounds. First, fine Ni-Si composite powders prepared by the MA method were hot extruded. Then Ni3Si intermetallic compounds were obtained by a particular heat treatment. Influence of the constituents and the MA conditions on mechanical properties of the Ni3Si intermetallic compounds were investigated. As a result, in 13.1 mass%Si- 86.9 mass%Ni materials, tensile strength improved as MA time became longer, although the material had poor ductility. When the Si content was reduced below 13.1 mass%, the tensile strength improved and ductility increased. The critical Si content for achieving of ductility was 12.2 mass%Si.View full abstractDownload PDF (5869K) -
Tsunehiro Takeuchi, Yuh Yamada, Toshiharu Fukunaga, Uichiro Mizutani1993 Volume 40 Issue 10 Pages 951-954
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSMg-based quasicrystals possessing the rhombic triacontahedron (RT) cluster as a structural unit have been prepared through the mechanical alloying (MA) process. The MA process is efficient in searching for the formation area of the icosahedral quasicrystalline phase of the RT type (IRT-phase), because it forms directly from the crystalline elemental powders within a few hours through the solid state reaction. In the previous study, the formation area of the thermally stable IRT-phase and related approximant phases had been determined in the Mg-Al-Zn system. In this study, we have determined the formation area of the IRT-and 1/1 approximant phase in the Mg-Al-Pd system as in the Mg-Al-Zn system. The formation areas and the thermal stability of the IRT-and the 1/1 approximant phases in the Mg-Al-Pd system have been compared to those in the Mg-Al-Zn system. We concluded that both Mg concentration and an average number of sp-valence electron per atom play a critical role in determining the formation area of the thermally stable IRT-and 1/1-phases both in the Mg-Al-Pd and the Mg-Al-Zn systems.View full abstractDownload PDF (279K) -
Keizo Kobayashi, Kenji Miwa, Takeshi Takayanagi, Itsuo Ohnaka1993 Volume 40 Issue 10 Pages 955-958
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSMechanical alloying(MA) for the mixture of Ti-34mass%Al powder, dried zirconia sol powder and stearic acid was performed by a vibrational ball mill for 720ksec in Ar gas atmosphere under pressure of 35kPa.
The Ti-Al-ZrO2 film was obtained on the surface of a stainless steel ball after MA and this coating film was 8μm thickness. The surface of this ball was smoothed by polishing with fine ceramic particles. The formation of this film occured in the stable adhesion of MA powder on the surface of MA balls during MA process and was promoted by stearic acid and crystal water of the dried zirconia sol.View full abstractDownload PDF (3041K) -
Toshimasa Morooka, Eiji Yuasa, Osamu Matsumoto, Makoto Tsunoda1993 Volume 40 Issue 10 Pages 959-962
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSMechanical alloying teratment of mixtures of elemental copper, titanium and boron powders containing various amounts of boron was carried out by using high energy ball mill. For comparisons, the treatment of mixture of alloy powder prepared from Cu-8mass%Ti cast and the boron powder was also carried out. Influence of boron content on the formation of boride titanium during the mechanical alloying and subsequent heat treatment was examined. In the powder prepared from the mixture of elemental powders, a-solid solution and nonequilibrium Cu-Ti phase are formed during the mechanical alloying. When the powder was heat-treated at 1173K, the noncruilibrium phase disappears, and equilibrium Cu3Ti phase and ultrafine spherical boride titanium particles are formed. Ti3B4 and TiB2 particles are formed in the case of mixture with low contents of boron, but only TiB2 is formed from the mixture with high boron contents. The nonequilibrium Cu-Ti phase is also formed by the mechanical alloying in the powder prepared from the Cu-Ti cast, but the quantity of that phase is less than that of the powder prepared from the mixture of elemental powders.View full abstractDownload PDF (1672K) -
Toshimasa Morooka, Eiji Yuasa, Matsuru Kushida, You Morikawa1993 Volume 40 Issue 10 Pages 963-966
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSMechanical alloying teratment of mixtures of elemental copper, titanium and boron powders containing various amounts of boron was carried out by using high energy ball mill. For comparisons, the treatment of mixture of alloy powder prepared from Cu-8mass%Ti cast and the boron powder was also carried out. Influence of boron content on the formation of boride titanium during the mechanical alloying and subsequent heat treatment was examined. In the powder prepared from the mixture of elemental powders, a-solid solution and nonequilibrium Cu-Ti phase are formed during the mechanical alloying. When the powder was heat-treated at 1173K, the noncruilibrium phase disappears, and equilibrium Cu3Ti phase and ultrafine spherical boride titanium particles are formed. Ti3B4 and TiB2 particles are formed in the case of mixture with low contents of boron, but only TiB2 is formed from the mixture with high boron contents. The nonequilibrium Cu-Ti phase is also formed by the mechanical alloying in the powder prepared from the Cu-Ti cast, but the quantity of that phase is less than that of the powder prepared from the mixture of elemental powders.View full abstractDownload PDF (1551K) -
Ken Tagashira, Keiichi Ishihara, Hideo Shingu1993 Volume 40 Issue 10 Pages 967-970
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSAn Electro Discharge Compaction (EDC) process was used to sinter iron powders mechanically ground (MG) by low energy ball milling. The sintered specimen preserved the grain size of MG powders. In the case of MG powders ground for 10hours, the grain size of the sintered specimen was about 50nm. This specimen exhibited, in the bend test, an yield strength about 1.4times larger than that of sintered non-ground powder.View full abstractDownload PDF (2328K) -
[in Japanese]1993 Volume 40 Issue 10 Pages 972
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSDownload PDF (66K) -
Woo-Seok Cho, Masato Kakihana, Masatomo Yashima, Masao Kumagai, Masahi ...1993 Volume 40 Issue 10 Pages 973-977
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSWell-crystallized polycrystalline films of tetragonal PbTiO3 were successfully synthesized on Ti metal substrate using a hydrothermal method at a low temperature 200°C at 18 kgf/cm2 in aqueous solutions of Pb(OH)2 and a mineralizer such as NaOH and KOH, but PbTiO3 did not form using LiOH as the mineralizer. At 0.07M Pb(OH)2, the grain size became larger and the crystallinity became better with an increase of KOH concentration from 1 to 4M.View full abstractDownload PDF (1166K) -
Toshio Kimura, Kazuhiro Kumakura, Takashi Yamaguchi, David A. Payne1993 Volume 40 Issue 10 Pages 978-981
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSThe products of reaction between lead acetate and tetraethoxysilane (TEOS) in 2-methoxyethanol (CH3OC2H4OH) at 100°C were identified by kinematic viscosity measurement and IR and 1H-NMR spectroscopic techniques. Two reaction methods were used: Lead acetate and TEOS were directly reacted in Method I, whereas they were reacted with 2-methoxyethanol prior to the reaction in Method II. The reaction product in Method I is identified as (CH3COO)-Pb-O-Si-(OC2H4OCH3)3, which polymerized during prolonged heating. In Method II, lead acetate and TEOS changed to (CH3COO)-Pb-(OC2H4OCH3) and Si(OC2H4OCH3)4, respectively, by the reaction with 2-methoxyethanol. The reaction product in Method II was identified as (CH3OC2H4O)-Pb-O-Si-(OC2H4OCH3)3. No polymerization reaction occurred, because there was no acetyl group in the reaction product.View full abstractDownload PDF (239K) -
Masato Kakihana, Hirotaka Fujimori, Masatomo Yashima, Masahiro Yoshimu ...1993 Volume 40 Issue 10 Pages 982-986
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSHigh-purity ceramic samples of the superconducting YBa2Cu3O7-d (123) phase have been prepared by the polymerized complex method starting either from metal carbonates dissolved into ethyleneglycol (EG) with large excess of citric acid (CA) or from metal nitrates dissolved into a mixed solvent of water and EG with an approximately equivalent amount of CA. The method is based on the formation of a polymeric gel which is obtained through polyesterification between metal citrate complexes and EG. It has turned out that the large excess of citric acid facilitates direct gelation without passing through formation of colloid or sol, whereas coagulation of a colloid (sol) has occurred when the amount of citric acid is insufficient. X-ray diffraction, Raman scattering and complex magnetic susceptibility measurements have shown better aspects with regard to purity and superconducting properties in samples prepared via the direct gelation than those prepared via the colloid (sol) coagulation. The onset temperature of superconducting transition for the best 123 sample was 91.5 K and the transition width (10-90%) of full diamagnetism was 0.5 K for a measuring field of 10 mOe.View full abstractDownload PDF (364K) -
Satoko Nagashima, Takeshi Yoshida, Hiroyuki Nakamura, Akio Kato1993 Volume 40 Issue 10 Pages 987-992
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSSynthesis and sinterability of SiC-YSZ composite powders prepared by the homogeneous precipitation technique were studied. YSZ-coated SiC composite particles were obtained from the solutions consisting of [ZrO(NO3)2] = 0.092M, [Y(NO3)3] = 0.016M, [SiC] = 0.067-1.9M, [(NH2)2CO] = 3.6 - 7.2M, [H2SO4] = 0.18M. When H2SO4 concentration was higher or urea concentration was lower than these conditions, YSZ precipitate deposited separately from SiC particles. Mixture of SiC-YSZ composite powders and YSZ commercial powder containing 5-20mol%SiC was sintered at 1500-1650°C. They showed a higher sinterability than the mechanical mixture of SiC powder and YSZ powder. When SiC-YSZ composite powder (95mol%SiC) was used as the raw material, sintered bodies with 96 (SiC:20mol%) - 99% (SiC:5mol%) of theoretical density was obtained by sintering at 1550°C for 1h.View full abstractDownload PDF (4447K) -
Yousuke Matsumoto, Ken Hirota, Osamu Yamaguchi, Souichi Fujii, Masahir ...1993 Volume 40 Issue 10 Pages 993-997
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSIn the Al2O3-TiO2 system, solid solutions of AIO(OH) gel are formed between 5 and 20 mol% TiO2 by the simultaneous hydrolysis of aluminium and titanium alkoxides, followed by washing and drying. After dehydration γ-Al2O3 solid solutions crystallize slowly from amorphous materials. At higher temperatures, rutile (TiO2) is formed directly with the transformation of γ-Al2O3 phases into corundum. Corundum-rutile composite ceramics with dispersed fine pores generated from the decomposition of Al2TiO5 have been fabricated as follows:(1) hot pressing for 2 h at 1350°C under 35 MPa using γ-Al2O3 solid solutions, (2) heating for 1 h at 1500°C to achieve the complete formation of Al2TiO5, and (3) annealing for 7 h at 1000°C to decompose of Al2TiO5 into corundum and rutile. Their mechanical properties have been examined. The bending strength yields the maximum value of 365 MPa with 15 mol% TiO2 content whereas the fracture toughness increases from 4.7 to 6.2 MPam1/2 with increasing TiO2 content.View full abstractDownload PDF (2736K) -
Nobuyuki Hiratsuka, Katsumi Saito, Hidehiko Kobayashi, Takashi Mitamur ...1993 Volume 40 Issue 10 Pages 998-1001
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSThe composite fine powders of nickel zinc ferrite and nickel-iron alloy were synthesized from α-hematite, nickel chloride and zinc by using the thermite method. These starting materials were arranged to mixtures having α-Fe2O3:NiCl2:Zn of 1.0:0.5:X(X=0.5, 1.0, 1.5) and were sufficiently mixed. These samples were heated over the temperature range from 400°C to 600°C for 2 hours under argon gas flow and their crystal phases and magnetic properties of the products were investigated by X-ray diffraction and vibrating sample magnetometer respectively.
The sample with X=0.5 contained only two phase: nickel and spinel phases which were ferromagnetic. Saturation magnetization of the sample was around 70 emu/g. Nickel-iron alloy powders, nickel-zinc ferrite powders and non-magnetic zinc oxides were produced with the increase of zinc amounts and heating temperature. The lattice constant of the ferrite was increased by the formation of nickel zinc ferrite. The value of saturation magnetization of the composite powder prepared with X=1.0 was 89.7 emu/g, which was greatest.
The value of saturation magnetization of the sample with X=1.5, however, decreased because of the increase of non-magnetic zinc oxides.View full abstractDownload PDF (1562K) -
Yoshifumi Uchita, Tadashi Endo, Hirotsugu Takizawa, Masahiko Shimada1993 Volume 40 Issue 10 Pages 1002-1006
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSC2H9N2O2+-H2PO4-complex was prepared by adding of 2-metyl-4-nitoroanilinium[MNA(2-4)] and 4-metyl-2-nitoroanilinium[MNA(4-2)] into the 85% H3PO4 solution at 60°C. The large platelet crystals were obtained after maturing for several days at room temperature. The XRD pattern of the newly obtained crystal of MNA(4-2) +-H2PO4-was indexed as orthorhombic unit cell with a=33.14A, b=8.307A, c=8.056A, respectively. Also, the complexes were identified as the layered structure in which the MNA cations were sandwitched between H2PO4- sheets via hydrogen bonds. The results of thermal analysis demonstrated that the thermal stability of complexes was closely related to the basic activities of organic moiety. According to the UV-Vis spectra, the maximum position of absorbance shifted to higher wavenumber, because a change in the molar polarity was occurred by the formation of the complex. The dielectric constants at MHz was almost independent of the temperature in ranging of 15-17. In particular, the conformational discrepancy of MNA(2-4) and MNA(4-2) reflected on the dielectric properties and the apparent distance of hydrogen bonds bridging between MNA cation and H2PO4-. A novel preppration procedure for the material design with dielectric property is suggested.View full abstractDownload PDF (258K) -
Masami Tanahashi, Takeshi Yao, Tadashi Kokubo1993 Volume 40 Issue 10 Pages 1007-1010
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSA dense and uniform layer in any thickness of highly biologically active bone-like apatite layer can be formed on the surfaces of any kind. of solid materials in any shape at the normal temperature and pressure by the following biomimetic method: First, a substrate is placed on or in CaO-Si02 based glass particles soaked in a simulated body fluid(SBF) with ion concentrations nearly equal to those of human blood plasma in order to form a lot of apatite nuclei on the surface of the substrate. Then, the substrate is soaked in another solution highly supersaturated with respect to the apatite e.g. that with ion concentrations 1.5 times those of SBF (1.5SBF) in order to make the apatite nuclei grow on the substrate in situ. Thus obtained apatite-organic polymer composites are expected to be useful as the bone-repairing materials as well as soft tissue-repairing materials. In these applications, adhesive strength of the apatite to the substrate is an important property. In the present study, effect of NaOH treatment of the substrate before the nucleation treatment on the adhesive strength of the apatite layer formed by the biomimetic method was investigated. Polyethyleneterephthalate (PET), polymethylmethacrylate(PMMA) and polyamide 6(Nylon 6) increased the adhesive strengths from 3.5 to 8.6, from 1.1 to 3.4 and from 0.6 to 5.3 MPa, respectively, by the 5N-NaOH pre-treatment for 10 min, whereas polyethylene(PE) polyethersulfone(PESF) and polytetrafluoroethylene(PTFE) did not increase it. The increase in the adhesive strength for the former three kinds of polymers was attributed to the formation of the carboxyl group which has high polarity and forms strong bond to the apatite by hydrolysis of ester group in PET and PMMA and amido group in Nylon 6 with the NaOH treatment.View full abstractDownload PDF (1127K) -
Masashi Wada, Hiroshi Yoshinaga, Osamu Kajita, Tetsuo Sakai, Hiroshi M ...1993 Volume 40 Issue 10 Pages 1013-1017
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSA new composite powder composed of hydrogen storage alloy and electrolytic copper powders was prepared by the use of mechano-fusion system. The composite powder was almost spherical and had porous surface with particle diameters from 10 to 50μm . Discharge capacites of electrodes using this composite powder were larger than those using mixed powders prepared by the conventional process, and increased by the addition of small amounts of cuprous oxide powder and cobalt powder in the preparation process of the powder.
Addition of a small quantity of oxidation-protective agents to the powder was effective for preventing the composite powder from oxidation. The powder was produced even in an atmospheric condition when the oxidation-protective agents was added. It has been found that this new copper-alloy composite powder can be used for improving of discharge capacities of hydrogen storage alloy anodes.View full abstractDownload PDF (3879K) -
Shigetoshi Muranaka1993 Volume 40 Issue 10 Pages 1018-1021
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSValence state of tin ions in the reactively deposited SnOx films were analyzed by Mössbauer spectroscopy. Both the amorphous and crystallized films were composed of Sn2+ and Sn4+. With increasing oxygen pressure, the oxidized degree of the amorphous films was increased to be saturated at the film composition of SnO1.5, while it was decreased at the higher substrate temperatures. The crystallized films was markedly oxidized at the higher substrate temperatures. The film composition was nearly SnO2 at 420°C. The values of the isomer shift and quadrupole splitting of Sn2+ and Sn4+ in the amorphous films suggested the oxygen coordinations for Sn2+ and Sn4 similar to those in Sn2O2 crystals, nearly independent of the film composition.View full abstractDownload PDF (209K) -
Shigeru Katsuyama, Hiroshi Ueda, Kazuhiko Majima, Hiroshi Nagai1993 Volume 40 Issue 10 Pages 1022-1026
Published: October 15, 1993
Released on J-STAGE: December 04, 2009
JOURNAL OPEN ACCESSPhase relation and thermoelectric properties of LaSy. (4/35≤y≤93/2) were examined. Three phases (β, γ and LaS) were obtained by the direct reaction of La and S in an evacuated quartz capsule at 1000-C. Single phase 7 -LaSy, which has Th3P4-type structure, was obtained by reaction sintering at 1600-C in a vacuum in the range of 1.33≤y≤51.39.γ-phase easily transforms to 8-phase and the strong reduced atmosphere is necessary for the stabilization of 7-phase. The electrical resistivity (r) and thermoelectric power (a) of 7 -LaS, increase with an increase of sulphur content y. Power factor (α2/r) of LaS1.39 larger than that of laS1.33.View full abstractDownload PDF (1674K) -
Yusaku Sakata, Yasuhiro Etoh, Shigeaki Kasaoka1993 Volume 40 Issue 10 Pages 1027-1031
Published: October 15, 1993
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSGas mixtures simulated a stational exhaust, composed of SO2(1000ppm), 02(5%), H2O (8%), NO(1000ppm) and N2 as balance gas, were applied for the desulfurization carbon sorbents with or without Fe2O3 prepared from impregnation of saw dust powder into water or a ferrous sulfate solution followed by drying and carbonization in a N2 stream at 850°C. Thermogravimetric analyses were carried out on the weight increase by oxidative sorption of SO2 and the weight decrease by carbon gasification in the various gas mixtures at a constant temperature over 150°C to 350°C.
Coexistence of H2O or NO-H2O into the SO2-O2-N2 mixture enhanced both oxidation potential of SO2 and gasification potential of carbon component of the sorbent: the sorption of SO3/H2SO4 predominated to increase sample weight at lower temperature 150°C, but carbon gasification predominated at above 250°C, where no gasification occurred with the SO2-O2-N2 mixture below 250°C.View full abstractDownload PDF (362K)
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