■化学食品部 豊田丈紫 佐々木直哉 北川賀津一 中村静夫


Development of Synthesis Technology for Ceramic Materials by Means of the Hot Isocratic Press Method
―Microstructure Control of Machinable Glass Ceramics―

Takeshi TOYODA, Naoya SASAKI, Kaduichi KITAGAWA and Shizuo NAKAMURA

In order to meet requests for synthetic technology for fine micro-machining of ceramic materials, we developed an innovative heat treatment method for machinable glass ceramics with fine mica crystals by means of the Hot Isostatic Press (HIP) method. A complex structure including fine mica crystal of 5μm or less in longitudinal grain size was fabricated through the crystallization process under a high pressure of over 50 MPa. Two-dimensional Zr composition analysis showed that HIP treatment was effective for improving the nucleation of fine ZrO2 particles, and fine microstructure in mica and zirconia enhanced the bending strength of the glass matrix. Measurement of the thermal expansion rate showed that the glass matrix had residual stress. In addition, it was confirmed that HIP treatment was effective in reducing crystallization time.

Keywords:machinable ceramics, Hot Isostatic Press, mica, zirconia, microstructure, grain size