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Volume 43, Issue 3
Displaying 1-26 of 26 articles from this issue
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[in Japanese]1996 Volume 43 Issue 3 Pages 266
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSDownload PDF (91K) -
Microstructures and Mechanical Properties of the Composites in the Wsi2 Rich RegionYoshiyuki Muraoka, Masaru Yoshinaka, Ken Hirota, Osamu Yamaguchi1996 Volume 43 Issue 3 Pages 267-271
Published: March 15, 1996
Released on J-STAGE: December 04, 2009
JOURNAL OPEN ACCESSDense sintered composites of ZrO2(2 mol% Y2O3) and WSi2 have been fabricated by hot isostatic pressing for 2 h at 1500°C under 196 MPa. They contain a small amount of W5Si3; during sintering, WSi2 decomposes into W5Si3 and amorphous Si. The ZrO2 particles in the composites consist of only t-ZrO2. Microstructures and mechanical properties are examined, in connection with ZrO2 content. The fracture toughness and bending strength of the composite with 40 mol% ZrO2 addition are 7.1 MPa⋅m1/2 and 1010 MPa, respectively.View full abstractDownload PDF (2669K) -
Yoshikazu Suzuki, Atsushi Nakahira, Tohru Sekino, Koichi Niihara1996 Volume 43 Issue 3 Pages 272-277
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSMo-Si-Al alloy and Mo-Si-Al/SiC composite were fabricated by the powder metallurgical process from a novel Mo-Si-Al prealloyed powder, and their microstructure and mechanical properties were evaluated. The Mo-Si-Al and Mo-Si-Al/15 vol%SiC mixed powders were hot-pressed in an argon atmosphere. XRD analyses revealed that Mo-Si-Al/SiC composites were composed of MoSi2 (tetragonal, Cllσ structure), Mo(Si, Al)2 (hexagonal, C40 structure), a-Al2O3, Mo ?? 5Si3C ?? 1 and β-SiC. Almost no glassy SiO2 phase was found in Mo-Si-Al and Mo-Si-Al/SiC systems contrary to MoSi2 and MoSi2/SiC. The formation of α-Al2O3 was attributed to the predominant oxidation of aluminum at the surface of the Mo-Si-Al prealloyed powder. Mo-Si-Al based systems showed the better high-temperature strength mainly due to the elimination of glassy SiO2 and the crystallographical change from t-MoSi2 to h-Mo(Si, Al)2. Incorporation of fine SiC particles enabled to control microstructure and then to enhance mechanical properties.View full abstractDownload PDF (1855K) -
Lian-meng Zhang, Mamoru Omori, Jian-hui Li, Takashi Goto, Toshio Hirai1996 Volume 43 Issue 3 Pages 278-282
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSTiC and TiC-Ni3Al composites were prepared by hot-pressing at 1573K. Cr3C2 was added as a sintering aid. Fully dense (more than 97% theoretical density) bodies were obtained by 3 vol% Cr3C2 addition. The thermal conductivity(k) of TiC-Ni3Al composites decreased with increasing Ni3Al content in general, however, the maximum of k values was observed at 40 vol% Ni3Al. The microstructure of 40vol% Ni3Al composite (i. e., network structure) was different from that of other compositions (i. e., Ni3Al or TiC particles dispersed).View full abstractDownload PDF (2496K) -
Hiroshi Tsuda, Tomoyoshi Nishimura, Hiroshi Mabuchi, Yutaka Nakayama1996 Volume 43 Issue 3 Pages 283-288
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSIn order to enhance the negligible low-temperature ductility and low high-temperature strength of nickel aluminides, NiAl/TiC composites were fabricated by the combustion reaction process from elemental powders. In this study, the effects of Fe on the combustion reaction of Ni-Al-Ti-C system were studied and mechanical properties of NiAl/TiC composites prepared by the combustion reaction process, following arc-melting were also estimated. The matrix compositions of the alloys included Ni50Fe10Al40, Ni50Fe20Al30 and Ni25Fe50Al25, with TiC of 0-50 at%, respectively.
The addition of Fe significantly reduced the heat of formation during the combustion reaction in Ni-Al-Ti-C system. Resulting compacts consisted of small TiC particles of about 0.5μm and the matrix NiAl. In the arc-melted and annealed specimens, TEM observation revealed that γ-Ni phase appeared on the grain boundaries in Ni50Fe10Al40 alloys, and α -Fe phase precipitated in the matrix in Ni25Fe50Al25 alloys. For Ni50Fe10Al40 alloys, ductility in bending increased because of the γ-Ni phase. The other hand, for Ni25Fe50Al25 alloys, compressive strength pronouncedly increased at ambient and elevated temperatures, caused to the presence of α-Fe phase and TiC particles in the matrix.View full abstractDownload PDF (4201K) -
Hitoshi Hashimoto, Hiraku Sato, Toshihiko Abe1996 Volume 43 Issue 3 Pages 289-294
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSPowder metallurgy is expected to be processing technology of titanium aluminides with high strength, which are candidates for lightweight high-temperature materials in near future, because more uniform materials having finer microstructures can be synthesized through powder metallurgical processes than through casting processes. However, the fine microstructures become coarser due to grain growth and therefore the materials become weak during exposure to high temperatures. Reinforcement of titanium aluminides by dispersion of ceramic particles and/or fibers into titanium aluminides matrix is expected to restrain the grain growth by their pinning effect. In this study, a blend of Ti, Al and B powders was mechanically alloyed and sintered by spark plasma activated sintering technique to synthesize TiAl intermetallic material with TiB2 particulate dispersion. As a result, Ti-Al intermetallic powder of non-equilibrium phase was made by mechanical alloying of Ti-Al-B powder mixture and fully dense TiAl-TiB2 composite material was synthesized by sintering the powder at 1223K, 49MPa for 300s.View full abstractDownload PDF (2504K) -
Akira Kawasaki, Chien-Hung Yeh, Ryuzo Watanabe1996 Volume 43 Issue 3 Pages 295-299
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSThe thermal shock fracture mechanism of metal/ceramic functionally graded materials was studied by burner heating test. Dependence of thermal shock crack initiation and propagation on controlled compositional gradients was virtually shown and discussions were made on the basis of fracture mechanics with special reference to the effect of compositional profile on crack extension behavior. Three types of FGMs, having the same thickness of graded layer with different compositional profiles, were fabricated by powder metallurgical process. The fracture toughness of each composition was determined by newly devised repeated vickers indentation method directly on FGM specimens. The fracture toughness increased with, increase in the metal phase content, owing to toughening mechanisms of thermal-strain-misfit and crack deflection. The FGMs were joined on cooling substrates and used for burner heating test. The crack formation was always observed on the ceramic surface during cooling due to large residual tensile stresses. By comparison between the fracture toughness and mode I stress intensity factor, vertical cracks in convex-profile FGMs were deflected toward the direction parallel to the surface. The depth of the parallel cracks beneath the surface may correspond well to a location of mode II stress intensity being equal to zero. On the other hand, initiated vertical cracks in concave-profile FGMs were considered to arrest without deflection.View full abstractDownload PDF (1652K) -
Hiroshi Okamura, Masafumi Miyajima, Yasutoshi Noda, Akira Kawasaki, Ry ...1996 Volume 43 Issue 3 Pages 300-305
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSTo improve the conversion efficiency of thermoelectric device, segment type combination of different thermoelectric materials is very effective. However, it is necessary to consider the thermal stress when different materials are joined. So it has been suggested to join SiGe(high performance at 900-1200K) to PbTe(high performance at 600-900K) through the SiGe/PbTe FGM layers. We studied thermoelectric properties of each of SiGe/PbTe composites of the SiGe/PbTe FGM layers. The result is as follows. Electrical resistivity of the SiGe/PbTe composites in the present study was about 1000 times greater than that of SiGe or PbTe single phase. Therefore, the figure of merits of the SiGe/PbTe composites rather degraded compared to those for each single phase. This undesirable results were interpreted to be caused by the change of electronic structure at the interface of SiGe and PbTe with slight interdiffusion into each components.View full abstractDownload PDF (304K) -
Takashi Goto, Jianhui Li, Toshio Hirai1996 Volume 43 Issue 3 Pages 306-310
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSB-C system compounds were prepared by arc melting in argon atmosphere using B4C, B and C powders. The non-stoichiometric composition of the B-C compounds ranged between 10 and 20at%C. The maxima of the Seebeck coefficient values were observed at 20at%C (B4C), and the greatest value was 270 μV/K at 1100K. The electrical conductivity increased with increasing carbon content in general, but had minimum at 17at%C (B5C). The thermal conductivity increased with increasing carbon content. The thermoelectric figure of merit values (Z) decreased with increasing carbon content, but the Z values showed maximum at 20at%C (B4C). The greatest ZT value of B4C at 1100K was 0.15.View full abstractDownload PDF (273K) -
Takashi Goto, Eiji Ito, Masakazu Mukaida, Toshio Hirai1996 Volume 43 Issue 3 Pages 311-315
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSB4C-SiC quasi-binary and B-C-Si ternary composites were prepared by arc melting in argon atmosphere using B4C, SiC, Si, B and C powders. Uniform lamella texture indicating eutectic reaction was observed at SiC molar content of 45 to 50mol% in the quasi-binary system. Free C and free Si co-precipitated at the C-rich and Si-rich side of the quasi-binary compositions, respectively. The thermoelectric figure of merit values (Z) of the B4C-SiC composites were generally greater than those of the C-rich and Si-rich composites. The SiC-B4C composites near the eutectic composition (40mol%SiC) showed the greatest Seebeck coefficient, electrical conductivity and Z values. The greatest ZT value of the B4C-SiC composites (40mol%SiC) at T=1100K was about 0.2.View full abstractDownload PDF (1719K) -
Hirooki Yanagisawa, Hiroshi Tsuda, Hiroshi Mabuchi, Kenji Morii1996 Volume 43 Issue 3 Pages 316-320
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSThe ceramic composites were prepared from elemental powders, i.e., titanium powders, aluminum powders and graphite powders. The powder mixtures, with a composition Ti50Al25C25 (in atomic% ) were cold pressed, and combustion reaction was carried out to form ceramic composites in Ti-Al-C system. However, the reaction products had extensive pores. Then the products densified by hot pressing for 1.8ks at 1473K under 70MPa in Ar gas atmosphere. It was found that the matrix phase (Ti2AlC) had good properties, e.g., microhardness and thermal expansion coefficient, as a composite phase for TiAl alloys. The processing technique in the present investigation is of interest as a new combustion reaction process to synthesize in-situ ceramics and ceramic composites.View full abstractDownload PDF (3454K) -
Shigemi Sato, Min-Cheol Chu, Jong-Hoon Kim, Yasuyoshi Kobayashi, Kotoj ...1996 Volume 43 Issue 3 Pages 321-326
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSSi3N4/SiC composite ceramics which contained 20wt% dispersed SiC particles (0.03-1.20μm) and 8wt% Y2O3 as the sintering additive were fabricated by hot-pressing at 2073K under 35MPa for 2h.The influence ofpowder preparation on the microstructure and mechanical properties was investigated. The sintering materials which were prepared by mixing with distilled water and burning in air (W series) contained larger amounts of oxygen than those which were prepared by mixing with ethanol and without burning (E series). In comparing W and E of equal SiC particle size, in the Si3N4 matrix grain diameter of W was larger than that of E. Accordingly, the fracture toughness and the bending strength at room temperature of W increased and decreased, respectively. Furthermore, the observed grain boundary phases of E were Y20N4Si12O48 and Y2Si3N4O3, but W was Y20N4Si12O48 Only. It is estimated that Y20N4Si12O48 is lower softening temperature than Y2Si3N4O3. Therefore, compared to E, the strength of W which contained larger amounts of Y20N4Si12O48 decreased at high temperatures. In 2W and 2E which contained 0.03μm SiC particles, the bending strength showed a maximum value of 882MPa and 950MPa at 1673K, respectively. It is considered that the remarkable improvement in the strength of 2W and 2E are attributed to the fine grains of the Si3N4 matrix.View full abstractDownload PDF (1662K) -
Yuichi Nishimura, Makoto Sasaki, Ken-ichi Mukaida1996 Volume 43 Issue 3 Pages 327-330
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSBoron-containing Si-C-N-H polymers were fabricated. Amorphous ceramics were derived from the poly(silazane) and other organic polymer precursors. The precursor routes in this paper showed high ceramic yields in the range of 60 to 80%. Crystallization behavior of the boron-containing Si-C-N ceramics was investigated. The main crystalline phase was β-SiC. Crystalline size of the β-SiC decreased with increasing boron contents in the ceramics. And the X-ray intensity of the β-SiC also decreased with them. Heat treatment at 2373K in N2 atmosphere introduced both β-SiC and free silicon, in the boron free Si-C-N ceramics and 1.6wt% boron-containing Si-C-N ceramics. 5.5wt% boron-containing Si-C-N ceramics showed crystalline phase of β-SiC and Si3N4. Boron may act as an inhibitant of both crystallization and decomposition of silicon nitride at high temperatures.View full abstractDownload PDF (196K) -
Wei Yan Lin, Shigetoshi Okada, Jun Takada, Hideyuki Kuwahara, Susumu N ...1996 Volume 43 Issue 3 Pages 331-335
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSFe-Cr alloys with 3.0 to 18.6wt%Cr were plasma-nitrided at 650°C for 16h in a mixed gas of N2:H2=1:3. A nitriding layer, which is so called "internal nitriding layer", was formed parallel to the specimen surface, but the formation of a surface nitriding layer of γ'-Fe4N was not observed. The Cr nitride formed in the nitriding layer was determined by XRD experiments to be CrN, not Cr2N. The hardness Hv of the nitriding layer increased as the Cr content increased. The hardness increase is due to the dispersion of fine CrN particles in α-Fe matrix. The thickness of the nitriding layer decreased linearly as the Cr content increased.View full abstractDownload PDF (1617K) -
Masanobu Uno, Hiroshi Tsuda, Hiroshi Mabuchi, Kenji Morii1996 Volume 43 Issue 3 Pages 336-340
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSIn this work, high-temperature reaction process with gaseous nitrogen led Si and Ti powders, Si and titanium silicide powders or titanium silicide powders to two phase ceramic composites consisting of Si3N4 (α-Si3N4 and β-Si3N4) and TiN. The results of X-ray diffraction analysis showed there are remarkable differences in the ratio of α-Si3N4/β-Si3N4 between the specimen used elemental powders and that used intermetalic powders. That is mainly caused by a difference in the starting temperature and reactivity of silicon nitridation. Thus, it is promising for synthesis of Si3N4-TiN composite powders to use intermetalic powders.View full abstractDownload PDF (280K) -
Hiroshi Mabuchi, Takeshi Ohtsuka, Hiroshi Tsuda, Kenji Morii1996 Volume 43 Issue 3 Pages 341-345
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSUsing elemental powders, high-temperature reaction was carried out to form ceramics and ceramic-ceramic composites in the Si-N-C system. Si and C powders reacted in gaseous nitrogen and formed a Si3N4 (α-Si3N4 and β-Si3N4) - SiC (β-SiC) mixture product, that is, the reaction, 4Si+C+2N2→Si3N4+SiC, was complete. In the reaction pass, it is noted that the equilibrium reaction, Si3N4+3C=3SiC+2N2, progress under a nitrogen gas, and suppress the decomposition of the Si3N4. Therefore, the processing technique in the present work is of interest as a new high-temperature reaction process to make Si3N4-SiC composite materials.View full abstractDownload PDF (2734K) -
Toshio Shimoo, Ari Sandjaja, Kiyohito Okamura1996 Volume 43 Issue 3 Pages 346-350
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSIn relation to the joining of silicon nitride ceramics to metal, the reaction products between Si3N4 and Co have been investigated under Ar or N2 atmosphere at temperatures from 1423 to 1673K. Using Si3N4-Co powder mixtures, the reaction rate was determined thermogravimetrically and the reaction products were examined by X-ray diffraction. Above 1423K, the reaction proceeded under both atmospheres. The Co-Si solid solution was formed at low temperatures. At higher temperatures and on prolonged heating, the reaction products changed in the following order: Co-Si solid solution, Co2Si, CoSi and CoSi2. Under Ar atmosphere, the formation of cobalt silicides was enhanced, because of low partial pressures of N2.View full abstractDownload PDF (277K) -
Masaki Shibuya, Yasuhiro Shioji, Mitsuhiko Sato, Takemi Yamamura1996 Volume 43 Issue 3 Pages 353-357
Published: March 15, 1996
Released on J-STAGE: December 04, 2009
JOURNAL OPEN ACCESSCeramic matrix composites using three dimensional woven fabric of Si-Ti-C-O fiber were fabricated by infiltration of polytitanocarbosilane solution and pyrolysis, and evaluated. It was possible to fabricate a dence composite even by this convenient method. The composite using Si-Ti-C-O fiber which has both of oxide rich surface layer and carbon rich surface layer, was excellent in mechanical property compared to the composites using Si-Ti-CO fiber with carbon rich surface layer or with no surface layer. The composite using Si-Ti-C-O fiber with two surface layers maintained about 80% of bending strength after heat-treatment at 1200°C for 100 hours in air.View full abstractDownload PDF (1303K) -
Takashi Sakamoto1996 Volume 43 Issue 3 Pages 358-363
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSBonding test of sintered go powder compacts has been done by using Ni, Au, Pt and Pd metal foils. As the result, it was confirmed that sintered Mo powder compacts inserted by Ni, Pt and Pd foils well bonded each other at 1300°C, which may be due to the diffusion of Mo to the metal foils. In the case of using Au foils, the well-bonding was also observed by heating above melting temperature of Au, which indicates that Au diffuses into Mo powder compacts.View full abstractDownload PDF (7968K) -
Takehisa Ohno1996 Volume 43 Issue 3 Pages 364-367
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSAl-In composite nanoparticles were prepared by the condensation of In vapor onto flying Al nanoparticles which were produced in advance by a gas-evaporation technique. The structural and morphological observation of these nanoparticles was carried out by means of a transmission electron microscope. It was found that the particle is composed, of an Al sphere with an In crystallite sticking to the Al surface. It is concluded that the particles grow through three steps; first, Al nanoparticles grow, then, they melt and re-evaporate due to subsequent heating, and last, In vapor condenses onto them.View full abstractDownload PDF (3276K) -
Hideki Nakayama, Takuo Toda, Hideki Kyogoku, Shinichiro Komatsu1996 Volume 43 Issue 3 Pages 368-372
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSEffects of debinding conditions on the carbon content and mechanical properties of sintered 4340 alloy compacts made by injection moldings were studied. Specimens were made of gas-atomized 4340 alloy powder which was blended with binders and injected into a metallic mold. The compacts were debound in air at the temperatures between 513K and 553K for 7.2ks. They were sintered in vacuum at 1623K for 7.2ks. The carbon content of sintered compacts decreased linearly with increasing in debinding temperature. This means that the carbon content of sintered compacts can be controlled accurately by the debinding temperature. In the range of debinding temperature lower than 533K, the density of sintered compacts decreased with increasing in debinding temperature, and in the range of debinding temperature higher than 533K, it became constant. The mechanical properties of sintered compacts changed with the carbon content. The higher the debinding temperature was, the lower the tensile strength of sintered compacts and the higher the elongation became.View full abstractDownload PDF (1711K) -
Kanji Notomi, Hiroshi Hosokawa1996 Volume 43 Issue 3 Pages 373-376
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSP/M heating alloy containing 23%Cr-5%Al was produced by Gas-Atomization and HIP process. The microstructures and the hot strength of this alloy were investigated in comparison with conventionally cast and forged alloy.
A uniform distribution of small precipitates and a fine grained structure were found in an annealed state. It was also found that secondary recrystallization took place after a time at a high temperature, resulting in an extremely large grained structure. Excellent hot strength due to the large grained structure was confirmed by a hot tensile test and a practical test in our HIP furnace.View full abstractDownload PDF (4215K) -
Hirohiko Fujimaki, Tetsuya Takaai, Manabu Kiuchi1996 Volume 43 Issue 3 Pages 377-382
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSAluminum oxide dispersion strengthened copper (ODSC) wire, in which fine Al2O3 dispersed uniformly, was manufactured by mechanical alloying, plasma activated sintering, hot extrusion and cold drawing technologies. The relationships between milling time and wire's mechanical and electrical properties were investigated from a viewpoint of the wire's internal structure by using optical microscope, scanning electron microscope and electron plobe microscope analyzer. Obtained results were as follows, (1) 6h milling time was enough for finishing internal oxidation of Cu-0.35mass%Al alloy. (2) Higher than 590N/mm2 tensile strength, higher than 8% fructure elongation and higher than 85%IACS of electric conductivity were obtained by internal oxidized Cu-0.35mass%Al alloy wire of the present study.View full abstractDownload PDF (4865K) -
Jinsuke Takata, Nobuyasu Kawai1996 Volume 43 Issue 3 Pages 383-389
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSThe effect of graphite properties on the dimensional change of Fe-2mass% Cu-0.8mass%C-0.75mass% zinc stearate was examined by using two kinds of natural graphite, flaky graphite of 0.5-35μm and amorphous graphite of 3-9μm. The compacts were sintered in endogas. Their sintering behaviors were correlated with the properties of graphite.
As the size of graphite decreased, the compacts shrank and the dimensional change varied according to 0.27 log(B/A)% when graphite was replaced from A to Bμm. Finely divided flaky graphite showed a rapid carburization, which led to the acceleration of sintering and the suppression of copper growth. When flaky graphite was divided to 0.5μm, however, the dimensional change did not obey above formula at all. In this case, the compact expanded at the temperature ranging from about 150 to 450°C and the carburizing rate markedly decreased above 970°C, with a large fraction of the graphite remaining after sintering. Amorphous graphite of 9μm also showed a similar expansion in the early sintering stage, but the carburizing rate did not decrease. Such behaviors led to a remarkable shrinkage by liquid generation due to the ternary monotecto-eutectic reaction above the melting point of copper.View full abstractDownload PDF (1687K) -
Eiju Komuro, Tatsuru Namikawa, Yohtaro Yamazaki1996 Volume 43 Issue 3 Pages 390-395
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSStructural, magnetic and magneto-optical properties of polycrystalline bismuth iron garnet Bi3Fe5O12 (p-BIG) films were prepared on Bi1.7Y1.2Fe5.1O12 coated glass. The p-BIG layers were formed on vitreous SiO2 and Coming 0317 glass substrates by rf-sputtering in the wide range of substrate temperature from 475°C to 700°C. BIG single crystal (s-BIG) films were also prepared on gadolinium gallium garnet (GGG) single crystals in the temperature range from 500°C to 600°C. It is found that p-BIG layers could be obtained by sputtering with Ar gas alone as well as mixed gases of Ar and O2, and that they show higher figures of merit than s-BIG layers because of small absorption of light for the wavelength of around 540nm. The effect of glass substrates on the crystallinity, magnetic and magneto-optical properties of the p-BIG films were also investigated.View full abstractDownload PDF (324K) -
Kiyoshi Nogi, Makio Naitoh, Akira Kondoh, Atsushi Nakahira, Kohichi Ni ...1996 Volume 43 Issue 3 Pages 396-401
Published: March 15, 1996
Released on J-STAGE: May 22, 2009
JOURNAL OPEN ACCESSNew method to evaluate temperature at the interface between particles under mechanical stirring was proposed and the temperature was elucidated from a thermodynamical view point. It was found that the interface temperature can be estimated from a reaction between C and O at the interface. The interface temperature is significantly higher than the container temperature and depends on a frictinal force. An increase in the frictinal force increases the temperature of the container and of the whole powder and increases the interface temperature more effectively. It was also found that a small amount of carbon addition is effective to remove oxide layer from metal particle surface.View full abstractDownload PDF (358K)
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