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Volume 53, Issue 1
January
Displaying 1-19 of 19 articles from this issue
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Paper
Memorial Lecture of JSPM Award
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Yasuro Ikuma2006 Volume 53 Issue 1 Pages 3-10
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSThe methods to determine oxygen diffusion coefficients in powder, sintered body, and single crystal of metal oxides were summarized and their characteristics were also described. In particular, it was demonstrated that if powder specimens were used, near-surface diffusion coefficient could be obtained in addition to lattice diffusion coefficient. Typical results of diffusion experiments were presented. Finally the summaries of diffusion coefficients in yttrium oxide, nickel oxide, cerium oxide, indium oxide, and mullite were shown.View full abstractDownload PDF (781K) -
Hajime Haneda, Isao Sakaguchi, Naoki Ohashi, Haruki Ryoken, Junichi It ...2006 Volume 53 Issue 1 Pages 11-20
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSDiffusion phenomena and lattice defects in ceramics are discussed. The properties of ceramics are classified broadly into tow groups, one is that the properties are controlled by crystal structure and composition, called "intrinsic" properties. The other is that properties are affected by lattice defects and/or impurities, called "extrinsic". We commonly used the later properties of functional ceramics such as electorceramics. Electrical conductivities and optical emission properties are typical examples. We characterized impurities and diffusion properties in oxides ceramics, using a secondary ion mass spectroscopy (SIMS). By comparing diffusion coefficients and some properties, we identified the original defects governing the properties. The oxygen diffusion coefficients of thin films were also evaluated, and the concerned defects was shown to be in metastable.View full abstractDownload PDF (1932K)
Paper
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Pei Bian, Dong-Ying Ju2006 Volume 53 Issue 1 Pages 21-25
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSRecently, the ultrafine magnetic particles are applied in many fields, such as magnetic record materials, magnetic fluid, catalysts, biologic medicine materials and so on. In order to fabricate the magnetite nanoparticle with uniform size, liquid phase precipitation method with lower cost is used in this research work. Here, Iron (II) Chloride Tetrahydrate [FeCl2·4H2O], Iron(III) Chloride Hexahydrate [FeCl3·6H2O] mixture solution and NaOH solution were added into the reaction solution by titration method step by step according to the change of pH value, and the solution was being stirred during the reaction process. In this paper, the optimum fabrication condition and the magnetism of composed nanoparticles are investigated. Through evaluation of magnetic property of the fabricated nanoparticle, at room temperature and pH value 7.0, 8nm uniform magnetic particles were synthesized with saturation magnetization value of 48 emu/g and Curie point 471°C.View full abstractDownload PDF (1614K) -
Kazuharu Iwasaki2006 Volume 53 Issue 1 Pages 26-30
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSAmorphous BaTiO3 fine particles containing La and Mn were synthesized by the sol-gel method starting from an aqueous solution. The morphology and the phase change by thermal treatment of the formed particles and magnetic properties of the thermal-treated particles have been investigated by TEM, SAED, DSC and XRD.
BaTiO3 fine particles containing La were amorphous, monodispersely spherical and they crystallized at 800°C. La was doped into BaTiO3 crystal. Crystalline BaTiO3 fine particles doped La and Mn could be produced by firing particles of the La doped BaTiO3 coated with manganese(III) acetylacetonate at 1100°C. The magnetic properties of the La and Mn doped BaTiO3 fine particles exhibited a paramagnetic behavior.View full abstractDownload PDF (676K) -
Norimitsu Hirose, Shin-ichi Tanaka, Akira Fujiki, Junichi Asami2006 Volume 53 Issue 1 Pages 31-35
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSThe differences in Young's moduli (E) and Poisson's ratios (ν), calculated by the stress-strain diagrams from tensile testing (TT) and the sound velocities from an acoustic pulse method (APM), of sintered steels were compared. The values of ETT and νTT were smaller than those of EAPM and νAPM, respectively, because not only the elastic strain, but also the plastic strain are included in the stress-strain diagram of the sintered steels. Furthermore, by using the longitudinal and transverse elastic strains calculated from the values of EAPM and νAPM, the longitudinal and transverse plastic strains were separated from the stress-longitudinal and transverse strain diagrams. Consequently, the elastic limit or 0.2% yield strength was simply defined from the stress-longitudinal plastic strain diagram, in the case of the sintered steels which does not show a linearity of stress-strain diagram at the lower stresses. The differences in the elastic and plastic strains versus stress of each sample were explained on the basis of the pore characteristics, such as size, shape, and interconnection, and microstructures.View full abstractDownload PDF (1050K) -
Toru Shimizu, Kunio Matsuzaki, Yoshinobu Ohara2006 Volume 53 Issue 1 Pages 36-41
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSThe process of preparing porous metal foam titanium powder has been developed In this process, polystyrene foam powder is used as a space holder, and a water solution of polymer is used as a binder. The slurry of the titanium powder, space holder and binder is added to the gelatinizing agent to increase its viscosity. It can then be formed by hand like clay. The slurry is dried, sintered and porous titanium is obtained. The binder and space holder are decomposed in a heating process before sintering. Using this process, porous titanium with porosity in the range of 17-77% is produced, and the mechanical properties are evaluated. From these results, porous titanium that has a porosity of 50 to 60% has a strength of about 30-100 MPa and Young's modulus about 10-30GPa. These mechanical properties arc appropriate for use as implant bone.View full abstractDownload PDF (1067K)
Special Issue: Mechanical Alloying and Mechanochemistry
Summarization
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Keiichi Ishihara2006 Volume 53 Issue 1 Pages 44
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSDownload PDF (74K)
Paper
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—Wear and Corrosion Resistances—Eiji Yuasa, Naoki Saitoh, Yoshinari Oki2006 Volume 53 Issue 1 Pages 45-50
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSMechanically alloyed (MA) powder with Mg-30, 40 and 61.5 mol%Al compositions (30AlMA, 40AlMA and 61.5AlMA) were compressively bonded to a surface of magnesium alloy (AZ31B) rod, and then wear and corrosion properties of the bonded MA alloy layer were investigated. The wear resistance was examined by sliding of hardened steel on the surface of the bonded MA alloy layer using disk-on-ring type wear tester and the corrosion resistance of that was estimated by salt-water spray test. Wear loss of the bonded MA alloy layer surface by the sliding of hardened steel is remarkably smaller than that of AZ31 alloy. This shows the wear resistance of magnesium alloy can be improved by the compressive bonding of MA powder with high aluminum content because of high hardness of the MA alloy layer. Corrosion has not practically progressed on surfaces of the 40AlMA and 61.5AlMA alloy layers when they were salt-water sprayed for over 28.8ks, whereas the surfaces of AZ31 alloy and 30AlMA alloy layer were remarkably corroded.View full abstractDownload PDF (1419K) -
Masaru Nakayama, Tetsuya Okuyama, Takaaki Tanaka, Shogo Izumi2006 Volume 53 Issue 1 Pages 51-57
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSTi-1mass%Sc mixed powder was milled up to 240h in argon gas atmosphere in a stainless pot with stainless steel balls. Pure Ti powder and Ti-20mass%Sc mixed powder were used as comparing materials. Mean particle sizes of MA powders increased with increasing MA time up to 72h and decreased with increasing MA time in the time more than 72h. The mean particle size of pure Ti powder milled for 240h was approximately 30μm to 30μm before milling. On the other hand that of Ti-1mass%Sc powder was approximately 10μm to 20μm before milling. In both pure Ti and Ti-1mass%Sc powder, the particles were hardened gradually with increasing MA time. The hardness of particles of pure Ti and Ti-1mass%Sc powders was approximately HV500 at the time of 240h to HV150 before milling. It was clarified that Sc was distributed uniformly in the particles after milled at 120h in Ti-20mass%Sc mixed powder. The particles of powders milled were maintained very high hardness even after heated for 1h at 1273K. The hardness of sintered body was very high and approximately HV500.View full abstractDownload PDF (2169K) -
Keizo Kobayashi, Akihiro Matsumoto, Kimihiro Ozaki, Toshiyuki Nishio, ...2006 Volume 53 Issue 1 Pages 58-61
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSTiB2-30mass%Fe3Al powder was prepared by mechanical alloying of TiB2 powder, Fe powder and Al powder as starting materials for a short time. After a mechanical alloying, the recovery rate of 90% or more of the start materials by weight was shown from 7.2ks to 72ks. All mechanically alloyed powders were composed of TiB2, Fe and Al. The obtained MA powders were consolidated using by a pulsed current sintering equipment. When the MA powder milling for 72ks was consolidated at 1373K under a pressure of 80MPa, it reached 96.4% of the theoretical density. Fe-Al intermetallic compound were synthesized during sintering of the MA powder by a self-propagating high temperature synthesis. This MA powder was consolidated by a pulsed current of 100Hz for 300s without cracks.View full abstractDownload PDF (593K) -
Tomoaki Satoh, Koichi Tanno, Kaku Asada, Mitsuhiro Takeda2006 Volume 53 Issue 1 Pages 62-67
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSMechano-chemical (MC) synthesis of photocatalyst compound powders in ZnO-TiO2 system was carried out by a new high energy ball mill with functions of the powder layer formation onto inner wall of revolving vessel and the intensive impact of medium ball on the layer. Crystal grown of compound zinc titanate in MC treatment, shown in XRD patterns, was different with inner diameter of revolving vessel and inclined angle of "guide vane". Higher diffraction peaks and narrower half width of compound ZnTiO3 powders synthesized in MC treatment were obtained over 20 h of treatment time, compared to that by a planetary ball mill. Furthermore, the high intensive mill is capable to obtain higher yield of MC treated powders.View full abstractDownload PDF (2671K) -
Koichi Tanno, Tomoaki Satoh, Akiyuki Maruyama, Yuuichi Yanbe, Yuuji Fu ...2006 Volume 53 Issue 1 Pages 68-75
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSThe milling and mechanical alloying (MA) performances of a new high energy ball mill with functions of the powder layer formation onto inner wall of revolving vessel and the intensive impact of medium ball on the layer were studied. The high intensive mill is capable to decrease of powder size under 5 μm at 1.8 ks of treatment time for glass, bottom ash and tourmaline, and at 7.2 ks for Japanese cedar powder. In Ni-Al system, crystallite size of Ni (111) was dramatically decreased under 18 nm within 14.4 ks of milling, and further milling led to the formation of Ni3Al at 180 ks of treatment time. In this study, we develop the performance of this high intensive mill for milling, mechanical alloying and mechanochemical synthesis, which permit us to obtain higher rate of collection and lower impurity concentration of treated powders.View full abstractDownload PDF (1738K)
Special Issue: Science and Technology of Glassy and Nanocrystalline Materials
Summarization
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Akihisa Inoue2006 Volume 53 Issue 1 Pages 78
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSDownload PDF (143K)
Review
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Hisamichi Kimura, Akihisa Inoue2006 Volume 53 Issue 1 Pages 79-84
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSIn this report, structures and mechanical properties were studies for rapidly solidified Ni-Nb-Zr alloys and glassy Fe-based alloys shots with high strength and long life time for shot peening. The results obtained are summarized as follows.
Rapidly solidified Ni-Nb-Zr alloys were formed in a wide composition range of 20 to 75at%Ni, 0 to 60 at%Nb and 0 to 80 at%Zr for formation of amorphous phase, 50 to 70at%Ni, 5 to 35 at%Nb and 5 to 45 at%Zr for formation of glass phase, respectively. The largest value of the supercooled liquid region was 51 K for Ni60Nb20Zr20 alloy. The crystallization temperature (Tx), Vickers hardness (Hv) and fracture strength (σf) of the amorphous (Ni0.5Nb0.5)100-xZrx (x=10, 20, 30 40) alloys were in the rang from 770 to 870 K, 540 to 760 and 1530 to 2300 MPa, respectively. The σf and Hv of the glassy Ni60Nb20Zr20 alloy with the largest supercoold liquid region are 2160 MPa and 700, respectively. The hydrogen permeability of the amorphous (Ni0.6Nb0.4)70Zr30 alloy ribbon was 1.3×10-8 mol/m-1/s-1/Pa-1/2 at 673 K which is slightly larger than that of thin pure Pd metal. Wide ribbons of 50 mm in wide were prepared for the amorphous Ni42Nb28Zr30 and glassy Ni60Nb20Zr20 alloys.
Amorphous/glassy phases with volume fraction exceeding 98% in (Fe, Co, Ni)75B14Si8Mo3 alloy powder with spherical form of about 500μm in diameter were formed with wide composition ranges of 45 to 100at%Fe, 0 to 50at%Co and 5 to 55at%Ni, respectively. Glass transition temperature (Tg), Tx and supercoold liquid region (ΔTx=Tx-Tg) of Fe46Co5Ni24B14Si8Mo3 alloy were 789 K, 833 K and 44 K, respectively. The endurance life time of the glassy Fe-based alloy shots was 4 to 10 times longer than those for the conventional cast steel and high speed steel shots in the same shot peening condition. The maximum value of compressive residual stress in the tool (SKD11) steel shotted were 1600 MPa for the glassy Fe-based alloy shot and 1470 MPa for high speed steel shot, respectively.View full abstractDownload PDF (1237K)
Paper
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Seijiro Higashi, Kazuki Murooka, Shinji Nagata, Tatsuo Shikama, Kentar ...2006 Volume 53 Issue 1 Pages 85-89
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSIrradiation effect on transition of local structure in Zr-based metallic glasses was examined to stabilize metallic glasses and to transform crystalline structure to amorphous structure. To clarify the radiation effect on transition of local structure, we investigated primary phases formed in the metallic glasses during heat treatment. It is found that γ-ray and electron irradiation obstructed precipitation of fcc-Zr2Ni even though little exposure, indicating that electronic excitation was effective as well as atomic collision. Atomic collision plays an important role in the transition of primary phase by irradiating ions like N and noble metals. On the other hand, Cu ion irradiation accelerated precipitation of fcc-Zr2Ni. This is due to increase of concentration of Cu that is one of the elements of Zr55Ni5Al10Cu30 metallic glass. Crystalline structure was amorphized by irradiation of Au ion and amorphous phase was stabilized against the heat treatment.View full abstractDownload PDF (493K)
Review
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Yoshihiko Hirotsu2006 Volume 53 Issue 1 Pages 90-99
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSInvestigations of atomic and electronic structures in amorphous solid and liquid states of metallic glasses are important to understand the reason for the stability of metallic glasses. For this purpose, a research division A02 was organized in the program of Grant-in-Aid for Scientific Research on Priority Areas "Materials Science of Bulk Metallic Glasses". This research division consists of four sub-groups to investigate (1) as-formed and annealed structures, (2) liquid and super-cooled liquid atomic structures, (3) liquid-solid phase transformation and (4) electronic structures and physical properties of metallic glasses. Researches of our division achieved in these three years are summarized in the following.View full abstractDownload PDF (1399K)
Paper
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Sakura Nakano, Tsunehiro Takeuchi, Kazuo Soda, Masashi Hasegawa, Uichi ...2006 Volume 53 Issue 1 Pages 100-106
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSStability of the Zr-Ni-Al bulk metallic glass (BMG) was investigated by making full use of its relevant crystals. The local atomic arrangements (characteristic atomic clusters) commonly existing in the BMG and its relevant crystals were identified by the experimentally determined radial distribution functions. We found that the local atomic arrangements of the BMG were characterized by the prism clusters with a transition element, Zr or Ni, in their center and the Kasper polyhedrons about an Al atom. Internal energy of these clusters was investigated by combinational use of the DVXα cluster calculation and the high-resolution photoemission spectroscopy. The prism clusters about the transition metal elements were confirmed to possess a low internal energy. We propose, as a consequence of present analyses, that the Zr-Ni-Al BMG is stabilized by the low internal-energy of the clusters and the large entropy caused by the freedom in the bond-direction between the clusters.View full abstractDownload PDF (735K) -
Takaharu Suzuki, Hidetoshi Miyazaki, Kazuo Soda, Tsunehiro Takeuchi, M ...2006 Volume 53 Issue 1 Pages 107-110
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSThe valence-band electronic structures of Zr-TM-Al (TM=Ni, Cu) bulk metallic glasses have been investigated by means of synchrotron-radiation photoelectron spectroscopy. Their valence-band spectra show Zr 4d-, Ni 3d- and Cu 3d-derived bands at the binding energies of 0.5, 2.0 and 3.6 eV, respectively. The Zr 4d-derived band becomes prominent around the excitation photon energy hν of 40 eV. It is found that the wider the supercooled liquid region ΔTx=Tx-Tg (Tx: the crystallization temperature, Tg: the glass transition temperature), the larger the peak binding energy of the Zr 4d-derived band becomes. For the photoexcitation at hν∼18 eV, where the Zr 4d states less contribute to the spectrum, the spectral intensity reduces towards the Fermi level. This may imply the formation of a pseudogap in the sp bands. It is also found that the width of the pseudogap for the occupied states becomes wider as ΔTx is increased. These spectral findings suggest that both the strength of the chemical bonding around Zr and the reduction in the electronic energy because of the pseudogap formation and the chemical bonding contribute to the large glass formation ability of the Zr-Cu-Al metallic glasses.View full abstractDownload PDF (448K) -
Toshiharu Hoshino, Mituhiro Asato, Nobuhisa Fujima, Ryo Tamura2006 Volume 53 Issue 1 Pages 111-116
Published: 2006
Released on J-STAGE: July 14, 2006
JOURNAL OPEN ACCESSThere are many kinds of exprimenatally-known atomic structures (ASs) for Al-rich AlX (X=Sc-Zn) alloys, depending on X. The ASs for Al3Sc and Al3V are L12 and DO22, respectively, while the local ASs for the quasicrystal Al80Mn20 is Mackay icosahedron. For X=Cu and Zn, the Al1-cXc (c<0.05) alloys have a phase decomposition, but the shapes of Cu- and Zn-precipitations are very different. In order to elucidate the interactions characteristic of the Al-rich AlX alloys and the micromechanism of stability of the above-mentioned ASs, we give systematic ab-initio calculations for the two-body and many-body(MB) interaction energies (IEs) of X atoms in Al. The calculated results for X=3d elements show; (1) the Al-X pairs are very stable because of the strong sp-d interactions (INTs) of X atoms with the neighboring Al atoms; (2) the n th-MB IEs of X atoms rapidly decrease with the increase of n; (3) The X-X INTs in Al show the distance dependence of Friedel-type oscillation because the X-X INTs beyond the 2nd-neighbor distance are mediated by free-electron-like sp electrons of Al. The chemical trend of ASs of the above-mentioned alloys is explained by using the calculated X-X IEs.View full abstractDownload PDF (714K)
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