Journal of the Japan Society for Technology of Plasticity
Online ISSN : 1882-0166
Print ISSN : 0038-1586
ISSN-L : 0038-1586
Volume 48 , Issue 557
Showing 1-9 articles out of 9 articles from the selected issue
  • Yoshihiro KUBOTA, Tamotsu NAKAMURA, Shigekazu TANAKA, Kunio HAYAKAWA, ...
    2007 Volume 48 Issue 557 Pages 561-565
    Published: 2007
    Released: July 03, 2007
    Titanium metal has been used as a dental prosthesis material because of its good biocompatibility. Most of the dental prostheses made of titanium metal have been manufactured by precision lost-wax casting. However, this is not always the best manufacturing process for low-strength products or a long processing time. The authors have developed a net shape forming process for fabricating a precision thin-walled cylindrical can made of titanium powder using a DC pulse resistance sintering apparatus. In the present paper, the DC pulse resistance sintering process of pure titanium powder has been introduced to develop a net shaped dental prosthetic crown. As a result, it has been confirmed that the titanium dental prosthetic crown developed by the process has high density, sufficient hardness and adequate dimensional accuracy.
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  • Masaharu TAKAHASHI, Tomonori SASAKI, Zhen YANG, Ryutaro MAEDA
    2007 Volume 48 Issue 557 Pages 566-570
    Published: 2007
    Released: July 03, 2007
    Micro-nanoimprinting or hot embossing is a target of interest for the industrial production of micro-nano devices because of it's of low cost. In fluidic micro electromechanical system (MEMS) applications, polymer materials have been employed to fabricate economical products owing to their low cost. However, glass is much more suitable for high-temperature applications or adverse chemical environments. Moreover, the UV absorption level of glass materials is much lower than that of polymers, which is advantageous for bioanalysis. In optical MEMSs as well, glass is a good candidate material for achieving good optical properties, such as a high refractive index and a low UV absorption level. In our previous study, micro/nanoimprinting was developed for glass using a glassy carbon (GC) mold prepared by focused-ion-beam (FIB) machining. The disadvantages of FIB machining are the limited area in which etching can be carried out and the long machining time. The typical machining area in FIB is limited to within less than 0.25mm2. Therefore, we used laser machining for GC mold fabrication. The laser is a Q-switched Nd: YAG laser. This method shows great potential for fabricating bio-MEMS devices efficiently and at a very low cost. The main target is to fabricate devices for highly sensitive fluorescence detection applications; this fabrication is very difficult to realize using plastic substrates. A multichannel pattern (with 70μm line and 400μm space) was generated on a 20-mm square glassy carbon what using a YAG laser machine. Replication of the pattern on glass chips was demonstrated. Micro-hot-embossed test structures were successfully developed with high fidelity. These fabricated microstructures can be applied to the fabrication of fluidic channels.
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