US 12,065,383 B2
Oriented ceramic sintered body production method and flat sheet
Morimichi Watanabe, Nagoya (JP); Kei Sato, Tokai (JP); Kiyoshi Matsushima, Nagoya (JP); Takahiro Maeda, Ichinomiya (JP); Jun Yoshikawa, Nagoya (JP); and Tsutomu Nanataki, Toyoake (JP)
Assigned to NGK INSULATORS, LTD., Nagoya (JP)
Filed by NGK INSULATORS, LTD., Nagoya (JP)
Filed on Mar. 13, 2020, as Appl. No. 16/818,025.
Application 16/818,025 is a continuation of application No. PCT/JP2018/039445, filed on Oct. 24, 2018.
Claims priority of application No. 2017-207783 (JP), filed on Oct. 27, 2017.
Prior Publication US 2020/0216364 A1, Jul. 9, 2020
Int. Cl. C04B 35/00 (2006.01); C04B 35/111 (2006.01); C04B 35/32 (2006.01); C04B 35/638 (2006.01); C04B 35/645 (2006.01)
CPC C04B 35/645 (2013.01) [C04B 35/111 (2013.01); C04B 35/638 (2013.01); C04B 2235/3217 (2013.01)] 7 Claims
OG exemplary drawing
 
1. An oriented ceramic sintered body production method comprising:
(a) a step of preparing a ceramic compact before firing into an oriented ceramic sintered body; and
(b) a step of obtaining an oriented ceramic sintered body by sandwiching the ceramic compact between a pair of releasing sheets, placing the ceramic compact and the releasing sheets in a hot press firing furnace, and hot press firing the ceramic compact while applying a pressure by a pair of punches through the pair of releasing sheets,
wherein the releasing sheet used in step (b) has a total profile height Pt of 0.8 μm or less when the releasing sheet is measured by a predetermined measurement procedure, wherein the predetermined measurement procedure comprises, first, the releasing sheet is sandwiched between PET films having a thickness of 75 μm and an arithmetic mean surface roughness Ra of 0.03 μm to form a three-layer structure, next, a vacuum-packed product is obtained by placing the three-layer structure on a stainless steel sheet having an arithmetic mean surface roughness Ra of 0.29 μm and vacuum-packing, then, the vacuum-packed product is isostatically pressed at 200 kg/cm2, and then, a total profile height Pt of a cross-sectional curve on a surface of the releasing sheet of the vacuum-packed product opposite to the stainless steel sheet side is measured, and,
wherein the releasing sheets have a porosity of 10% to 53%.