Title:
POROUS CERAMIC MATERIAL, ITS PRODUCTION AND VALVE UNIT
Document Type and Number:
Japanese Patent JP3532641
Kind Code:
B2
Abstract:
PURPOSE: To obtain a porous ceramic material excellent in thermal shock resistance and suitable for use as a sliding member, etc., by mixing ceramic powder with Si-contg. hollow particles, compacting and sintering the resultant mixture.
CONSTITUTION: A binder is added to ceramic powder of 1-20μm average diameter and spherical hollow SiO2-Al2O3, or SiO2 particles of 20-250μm average diameter, and they are mixed, compacted in a prescirbed shape and sintered at a temp. above the melting temp. of the hollow particles to obtain a sintered compact having dispersedly formed pores as the objective porous ceramic material. The Si content of the surfaces of the pores or layers including the surfaces of the pores is higher than that of the nonporous part, the average diameter of the pores is 5-300μm and the volume fraction of the pores is 2-40%. This porous ceramic material is suitable for use as the sliding member of a valve unit, etc., as it is or when it is cut or polished.
Inventors:
Niwa, Michinori
Makino, Tomosuke
Makino, Tomosuke
Application Number:
JP30829494A
Publication Date:
May 31, 2004
Filing Date:
November 16, 1994
Export Citation:
Assignee:
NGK SPARK PLUG CO LTD
International Classes:
F16K11/00; C04B38/04; C04B38/08; C04B41/00; F16C33/04; F16K25/00; (IPC1-7): C04B38/04; F16K11/00