Entity

Time filter

Source Type


Kita H.,Japan National Institute of Advanced Industrial Science and Technology | Himoto I.,Stereo Fabric Research Association
International Journal of Applied Ceramic Technology | Year: 2012

Several technologies were utilized to develop a method for producing a large-sized heat transfer container. Specifically, material development, vessel and sub-component design, fabrication, and assembly were integrated to create a container with superior properties. As a result, the finished vessel proved to be more energy efficient and lighter in weight than the one that is used currently for transferring molten aluminum. © 2012 American Ceramic Society. Source


Sekine K.,Stereo Fabric Research Association | Kumazawa T.,Mino Ceramic Co. | Tian W.-B.,Stereo Fabric Research Association | Hyuga H.,Japan National Institute of Advanced Industrial Science and Technology | Kita H.,Japan National Institute of Advanced Industrial Science and Technology
Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan | Year: 2012

Low-temperature joining of boron carbide (B 4C) ceramics using an Al sheet was investigated in the temperature range of 6001200° for 2 h in vacuum (10 -210 -4 Pa). Successful joining and high bending strength close to that of the B 4C base were achieved in the samples joined at 7001100°. Different techniques including scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and transmission electron microscopy (TEM) were used to characterize the high-strength B 4C joints. SEM observations suggested the dense interlayer and the crack-free interface as well as the penetration of Al into the surface microcracks of B 4C base. Further TEM examinations revealed that B 4C and Al joined directly. EPMA analysis demonstrated the existence of several reaction products within interlayer, including AlB 2 and Al 3BC, which resulted in the development of high-strength composite interlayer. © 2012 The Ceramic Society of Japan. Source


Miyazaki H.,Japan National Institute of Advanced Industrial Science and Technology | Hotta M.,Japan National Institute of Advanced Industrial Science and Technology | Kita H.,Japan National Institute of Advanced Industrial Science and Technology | Izutsu Y.,Stereo Fabric Research Association
Ceramics International | Year: 2012

In the joining of structural ceramics, a porous interlayer is generally believed to deteriorate the mechanical properties of the joint. This paper, however, shows that a porous interlayer can sustain high adhesion strength when cavities or interfacial cracks are eliminated. The characteristic of the new slurry approach, described in this work, is that a pure alumina slurry interlayer is dried between two adjoining dense alumina plates and sintered with a negligible external pressure to form the porous interlayer. The effect of slurry concentration was studied to optimize the microstructure of interlayer. By controlling the interlayer microstructure and nature of the flaws, it was possible to fabricate high-strength bonds. The new slurry approach opens up the possibility of pure diffusion bonding which requires neither high pressure during heat treatments nor flat surfaces. © 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved. Source


Kita K.,Japan National Institute of Advanced Industrial Science and Technology | Kondo N.,Japan National Institute of Advanced Industrial Science and Technology | Hyugh A.,Japan National Institute of Advanced Industrial Science and Technology | Izutsu Y.,Stereo Fabric Research Association | Kita H.,Japan National Institute of Advanced Industrial Science and Technology
Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan | Year: 2011

This paper describes a novel experiment on surface modification for alumina plates. Polycarbosilane (PCS), an organosilicon polymer, was used in this experiment as a precursor. Tiny cracks on an alumina surface caused by grain boundaries and introduced by rough grinding were filled by PCS, and PCS was transformed into silicon oxycarbide (SiCO, silicon carbide including several mass percents of oxygen) by thermal oxidation curing at 453K and pyrolysis at 1273 K. Moreover, Al 6Si 2O 13 (mullite) layer was made from alumina and SiCO and prevented exfoliation of the alumina and SiCO during pyrolysis. In addition, the wettability between samples and molten aluminum was investigated in order to make sure the effect of surface modification. This experiment confirms that surface modification of alumina with a SiCO membrane can be successfully. © 2011 The Ceramic Society of Japan. Source


Kita K.,Japan National Institute of Advanced Industrial Science and Technology | Kondo N.,Japan National Institute of Advanced Industrial Science and Technology | Izutsu Y.,Stereo Fabric Research Association | Kita H.,Japan National Institute of Advanced Industrial Science and Technology
Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan | Year: 2011

This paper describes a novel experiment involving the joining of alumina using polycarbosilane (PCS). PCS filled in the cracks on the surface of alumina, the silicon in PCS oxidized to silicon dioxide (SiO 2), and part of SiO 2 reacted with alumina to form mullite during pyrolysis of PCS at 1673 and 1873 K. The SiO2 and mullite acted as a binder between the alumina boards. 4-point bending tests showed the average flexural strength of the samples pyrolyzed at 1673K was 81.8 MPa, whereas that of the samples that pyrolyzed at 1873K was 109 MPa. The difference in flexural strength was caused by the difference in the thickness and the compounds of the joining area, which was brought by the diffusion of the decomposition products derived from PCS and alumina during pyrolysis. © 2011 The Ceramic Society of Japan. All rights reserved. Source

Discover hidden collaborations