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Patent
Title
Sinterkoerper auf der Basis von Korund mit einer geschlossenen Zellstruktur, dessen Herstellung und Verwendung
Other Title
Sintered corundum body of closed cell structure used as e.g. grinding disc.
Abstract
NOVELTY - The sintered corundum body has a closed cell structure, specified macroporosity, cell size, structural porosity and sintered crystallite size values and low glass-forming impurity and dopant contents. DETAILED DESCRIPTION - A sintered corundum body has a closed cell structure, a macroporosity of 5-50 vol.%, a cell size of less than 250 mu m, a structural porosity of less than 2.5%, a sintered structure mean crystallite size of less than 5 mu m and a glass-forming impurity and dopant content of less than 3 wt.%. An INDEPENDENT CLAIM is also included for the production of the above sintered body by: (a) preparing a ceramic slip of 35-50 vol.% solids content and 0.1-0.5 Pas viscosity (measured by a rotary viscometer with a shear rate of 100 second-1); (b) impregnating the slip into an open porous pyrolyzable organic body of 30-300 pores/cm pore frequency to fill all the macropores; (c) removing 0-50 vol.% of the impregnated slip for achieving the desired macroporosity in the sin tered body; (d) drying at 60-80 deg. C; and (e) firing in flowing air at 1000-1200 deg. C; and sintering the resulting ceramic skeleton. USE - As a grinding body (claimed), e.g. a grinding disc. ADVANTAGE - The binder-free sintered body has a high strength (e.g. a mean compressive strength of greater than or equal to 100 MPa at less than 35 % macroporosity or greater than or equal to 20 MPa at 50 % macroporosity) and a high hardness of greater than or equal to 1700 HV1.
Inventor(s)
Krell, A.
Blank, P.
Patent Number
1998-19805889
Publication Date
2001
Language
German