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Volume 63, Issue 5
May
Displaying 1-14 of 14 articles from this issue
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Paper
Rapid Communication
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Tomohiro SATO, Takehiro MURAOKA, Ken-ichi SAITOH, Masanori TAKUMA, Yos ...2016 Volume 63 Issue 5 Pages 255-260
Published: May 15, 2016
Released on J-STAGE: June 07, 2016
JOURNAL OPEN ACCESSCopper (Cu) alloys are used as sliding materials. Especially, bronze (Cu-Sn alloy) is popular material for sintered bearings. In the sintering process, the reductive atmosphere is generally adopted on an industrial field to reduce the oxide which exists on the surface of Cu-Sn alloy powders as atomized. However, sintering in the vacuum atmosphere is useful because of disusing any kinds of gases. It was reported that sintering in the vacuum atmosphere gives better properties unless the alloy powder is heavily oxidized. In this report, the radial crushing strengths was investigated for the sintered Cu-Sn alloys which were the bronze and the sulfide dispersed bronze (Sulfide bronze). Especially tin powder and fine tin powder were used as the additives mixed for the Cu-Sn alloys to compare the radial crushing strengths. With increasing compacting pressure and sintering temperature, the pores in the sintered specimen were decreasing, and the sintered specimen which had lower porosity indicated high radial crushing strength. And on the sulfide bronze the feature of the fracture surface depended on tin content. In the specimen with lower tin content the interface between the bronze matrix and sulfide particle became the origin of the fracture, while in the one with higher tin content the Cu-Sn intermetallic compound which was so hard and brittle became the origin of the fracture.View full abstractDownload PDF (1994K)
Paper
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Isao FUKUMOTO, Yasuyuki KANDA2016 Volume 63 Issue 5 Pages 261-268
Published: May 15, 2016
Released on J-STAGE: June 07, 2016
JOURNAL OPEN ACCESSBagasse is obtained from squeezing sugar cane. In sugar factories, bagasse is burned as fuel for boiler machines. Therefore, large amounts of bagasse ash remain every year. Bagasse ash can be considered as a ceramics material because it mainly contains silica component (SiO2). As the carbonized bagasse has electrical conductivity, the composites using the carbonized bagasse and bagasse ash were applied for the spark plasma sintering (SPS). From X-ray diffraction of composite material of composition ratio of 1(bagasse ash) : 3(carbonized bagasse), the synthesis of β-SiC was recognized over the firing temperature of 1673 K. The laminated structure by 3 and 5 layers which means bagasse ash was sandwiched by carbonized bagasse is extremely effective for promoting the synthesis of β-SiC. The morphology of crystalline of β-SiC was observed by SEM. The qualitative chemical analysis and quantitative analysis of β-SiC were performed by X-ray diffraction and EDX. And purity of the SiO2 in bagasse ash could be heightened by hydrochloric acid treatment. As the result, the formation and crystallization of β-SiC are accomplished more than the case of raw bagasse ash. As a conclusion, the composite used bagasse ash and carbonized bagasse could fabricate to synthesize β-SiC by SPS.View full abstractDownload PDF (2680K) -
Toshiyuki UENO, Takashi YOSHIOKA, Atsushi MINODA2016 Volume 63 Issue 5 Pages 269-276
Published: May 15, 2016
Released on J-STAGE: June 07, 2016
JOURNAL OPEN ACCESSThough anti-lightning receptor was important to avoid lightning damage to wind turbine, the conventional receptor made by typical copper or stainless steel was often melted down. A new developed material for the receptor had very high thermal conductivity. The high thermal conductive material was fabricated with compositing copper and graphite. The composite was sintered by pulsed electric current sintering (PECS) method. The highest thermal conductivity of the composites showed up to 600 Wm−1K−1. The receptor made from the high thermal conductive composite improved satisfactory lightning resistance compared with copper one. The high lightning resistance should be achieved from temperature suppression by thermal diffusion.View full abstractDownload PDF (1557K) -
Toshitake MIYAKE, Nobuhiko MATSUMOTO, Mikio KONDOH2016 Volume 63 Issue 5 Pages 277-281
Published: May 15, 2016
Released on J-STAGE: June 07, 2016
JOURNAL OPEN ACCESSIn this study, we selected the Mn and Si as strengthening elements for high strength sintered steels to eliminate the Cu and Ni. Improvement of the tensile strength as well as the toughness was investigated in Fe-Mo-Mn-Si-C sintered steels using a Fe-Mn-Si-C master alloyed powder as additives. Developed sintered steels have the dual phase microstructure composed of lower bainite and island shaped martensite, and this microstructure realizes the high tensile strength and impact value more than 950 MPa and 48 J/cm2 respectively at the density of 7.4 g/cm3.View full abstractDownload PDF (2264K)
Short Note
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Masakazu KAWAHARA, Takuya YASUNO, Yuki KAIYAMA, Mikio ITO, Yukio MAKIN ...2016 Volume 63 Issue 5 Pages 282-288
Published: May 15, 2016
Released on J-STAGE: June 07, 2016
JOURNAL OPEN ACCESSAlumina ceramics were fabricated by spark plasma sintering (SPS) at a temperature range between 1473 K and 1773 K from an ultrafine alumina powder of 120 nm in diameter. Microstructural observation and EDS analyses were carried out for the alumina sintered. When the alumina powder sintered at a temperature range between 1473 K and 1673 K, the grain size of the peripheral parts in the alumina was larger than that of the central part in the alumina. The pore morphology in the peripheral parts of alumina was different from those in the central parts of alumina. The densification behavior of alumina powder during SPS changed according to the position in the alumina powder compact. From above results, the existence of temperature distribution in alumina powder compact during SPS consolidation was suggested. Chemical compositions in the vicinity of the pores on the triple grain boundary in the alumina sintered were different from the stoichiometric composition of alumina, indicating the possibility of reduction of alumina powder during SPS consolidation.View full abstractDownload PDF (901K)
Special Issue: High-performance Electronic Components and Materials for Supporting the Society in the 21st Century
Paper
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Yuki HAMATAKA, Masahiko HATAKEYAMA, Toshiko OSADA, Hideshi MIURA, Osam ...2016 Volume 63 Issue 5 Pages 291-297
Published: May 15, 2016
Released on J-STAGE: June 07, 2016
JOURNAL OPEN ACCESSFe-Cr based soft magnetic alloys have high corrosion resistance and magnetic property. Therefore they are widely used for the solenoid valves and electronic devices. In this situation, economic Fe-Cr based soft magnetic alloy, which has excellent soft magnetic properties and practical corrosion resistance is required. SUS430 is one of the candidate alloy with soft magnetic property in stainless steels. To achieve the economic aim, sintering process is useful to make low Cr alloy by adding the pure iron powder to SUS430 powder. While, reduction of Cr content deteriorate corrosion resistance. Sintered SUS430 based alloys with different Cr content were prepared using metal injection molding process. We carried out slow strain rate tensile (SSRT) test and open circuit potential (OCP) to evaluate their mechanical properties and electrochemical properties.View full abstractDownload PDF (2335K)
Review
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Hiroyuki SAITOH, Shigeyuki TAKAGI, Shin-ichi ORIMO, Katsutoshi AOKI2016 Volume 63 Issue 5 Pages 298-305
Published: May 15, 2016
Released on J-STAGE: June 07, 2016
JOURNAL OPEN ACCESSNovel hydrides are synthesized under high pressure and high temperature, where novel hydrogenation reactions are expected to be realized owing to high reactivity of hydrogen fluid. Theoretical calculations predict stabilities of hydrides before experiments, of which results are effectively used for the synthetic studies. In situ synchrotron radiation x-ray diffraction measurement enables us to explore reaction conditions and to reveal the reaction mechanism. In the present paper, synthetic studies of Al2CuH and Li4FeH6 will be presented along with the experimental details.View full abstractDownload PDF (1720K) -
Teruhisa HORITA2016 Volume 63 Issue 5 Pages 306-310
Published: May 15, 2016
Released on J-STAGE: June 07, 2016
JOURNAL OPEN ACCESSThis review paper introduces recent national projects in relation to hydrogen and fuel cell technologies, current status of the R&D for high temperature Solid Oxide Fuel Cells (SOFCs) technologies, and related research with powder metallurgy. From 2014, a new national research program, cross-ministerial Strategic Innovation Promotion Program (SIP) has been started with 10 projects. Among them, “Energy Carrier Project” has been started which includes the study of hydrogen carrier synthesis and hydrogen carrier combustion with gas turbine. In the SOFC R&D, some technological issues were introduced: degradation and reliability were the main issues to commercialize the SOFC-type “Ene-farm system”. To increase the life-time of SOFC cell-stacks, degradation mechanism have been clarified especially with relation to impurities. By the impurity analysis at SOFC reaction sites, degradation mechanism and life time estimation have been clarified, which enabled us to increase the life time of SOFCs up to 10 years.View full abstractDownload PDF (991K) -
Shinya ODA, Atsushi YOKOI, Hiroyuki MUTO2016 Volume 63 Issue 5 Pages 311-316
Published: May 15, 2016
Released on J-STAGE: June 07, 2016
JOURNAL OPEN ACCESSNano-assembly technique to fabricate the novel functional nano-composite materials has developed in this study. The integrated composite particles, i.e. functional nano materials are adsorbed on matrix powder, were obtained by proposed nano-assembly technique. The electrostatic attractive force induced by layering the two kinds of polyelectrolytes was utilized to assemble nano materials. The fabrication process of integrated composite particle involves the sequential adsorption of oppositely charged polyelectrolytes, i.e., PSS (poly (sodium 4-styrene sulfonate)) and PDDA (poly (diallyl dimethyl ammoniumchloride)) on surface of matrix and additive grains, respectively. The novel nanocomposite with well-dispersed and/or percolation structure of nano materials were successfully fabricated via integrated composite particles.View full abstractDownload PDF (1099K) -
Fumio UCHIKOBA, Minami TAKATO, Ken SAITO2016 Volume 63 Issue 5 Pages 317-322
Published: May 15, 2016
Released on J-STAGE: June 07, 2016
JOURNAL OPEN ACCESSPattern formation technology by powder paste and photo resist is reported. Fine pattern formation as well as pattern formation with plural materials are discussed respectively. In the fine pattern, the photo resist pattern was formed on a glass substrate by photo process and silver paste was filled in the pattern by a metal blade. After peeling the photo resist, the silver pattern was obtained. The minimum pattern width was 10 μm. In the plural materials formation, ferrite as a magnetic, LTCC (Low Temperature Cofired Ceramic) as a nonmagnetic and silver as a conducting material were applied. A dry film of photo resist was formed on a base film and patterned. The ferrite pattern was formed on the base film in the same manner. Preparing the patterned dry film beforehand, it was laminated on the ferrite pattern. Filling LTCC and silver paste successively, the pattern composed of plural materials of ferrite, LTCC and silver was formed. In the formed LTCC pattern, the thickness of center was thinner than that of peripheral part. In order to achieve further fine patterning and precise structure, it is considered that less adhesion of the paste and the photo resist material is important.View full abstractDownload PDF (1191K) -
Akihiko HAPPOYA, Kunio MORI2016 Volume 63 Issue 5 Pages 323-327
Published: May 15, 2016
Released on J-STAGE: June 07, 2016
JOURNAL OPEN ACCESSWe have developed a molecular bonding technology that forms a layer of molecules on the surface of the adherends and provides a smooth surface with strong joining force for the manufacturing of structures composed of different materials. We have applied this technology to the process of direct copper plating on a polyimide film with a smooth surface in order to manufacture flexible printed circuits (FPCs) with high performance.View full abstractDownload PDF (901K) -
Tsuyoshi FUNAKI2016 Volume 63 Issue 5 Pages 328-332
Published: May 15, 2016
Released on J-STAGE: June 07, 2016
JOURNAL OPEN ACCESSPower electronics have been attracting attention as an energy saving technology. The rated voltage and the operating frequency of the power conversion circuit have been increasing to attain higher efficiency, higher power density, and superior functionality. To this end, the conventional Si power semiconductor device have been developing, but the improvement approaches the theoretical limitation. Then, novel power semiconductor devices, which are essentially different from conventional Si power devices, have been researching and developing enthusiastically. They are unchartered territory for the conventional power electronics. Therefore, there are many difficult problems to solve. Power electronics is not an independent academic discipline, but it consist of number of engineering aspects; e.g. electronics engineering, electrical engineering, and control engineering. The recent progress of power electronics is led by the development of power device, but it cannot be realized without cooperation of peripheral components and fabrication technologies. This paper explains the precious technology, which is indispensable to fully utilize the performance of newly developed novel wide band gap power semiconductor device from the view point of peripheral component.View full abstractDownload PDF (899K) -
Michiya OKADA2016 Volume 63 Issue 5 Pages 333-339
Published: May 15, 2016
Released on J-STAGE: June 07, 2016
JOURNAL OPEN ACCESSThe environment surrounding power electronics has been undergoing tremendous changes due to the rapid expansion of demand for highly efficient utilization of energy, as can be seen in the increased global efforts toward creation of a low-carbon society and the shift toward utilization of renewable energy. The Tsukuba Power Electronics Constellations (TPEC) was started on April 2012, with celebrating the 4th anniversary on FY2016. More than a hundred researchers have joined together from 30 industrial companies, 8 universities, and 4 public research institutions. Research and development of the next-generation Wide Band Gap (WBG) semiconductor materials for power electronics with an emphasis on silicon carbide (SiC) is being conducted here. AIST has been the world leader in research and development of SiC for over 30 years. The TPEC is a perfect example of our challenge toward a radical innovation for power electronics based on Japan’s advanced WBG semiconductor technologies.View full abstractDownload PDF (1265K)
JSPM Announcements
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2016 Volume 63 Issue 5 Pages Pref5_1-
Published: May 15, 2016
Released on J-STAGE: June 07, 2016
JOURNAL OPEN ACCESSDownload PDF (198K)
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