Managed pore size distribution in honeycomb substrates

摘要

The invention is directed to a method for managing pore size distribution in honeycomb substrates by using two or more pore forming agents in the batch ingredients. In particular, the invention is particularly useful in managing pore size distribution in cordierite and aluminum titanate honeycomb substrates in the face of particle size variations in the pore forming agents and other materials used to make such substrates.

主权项

1. A method of manufacturing porous ceramic articles and controlling the pore size distribution of the articles to meet a targeted pore size distribution, the method comprising:
(a) introducing a first mixture of a plurality of ceramic-forming materials into an extruder, the first mixture comprising:
a first amount of a first pore forming powder (in wt % A) with a first pore former particle size distribution,a first amount of a second pore forming powder (in wt % B) with a second pore former particle size distribution, anda first amount of a first type of inorganic ceramic-forming powder (in wt % C) having a powder particle size distribution,wherein the first and second pore forming powders are present in a first weight ratio (wt % A/wt % B) in the first mixture, andfurther wherein the first and second pore former particle size distributions differ from each other; (b) extruding at least a portion of the first mixture into a first extrudate, (c) firing at least a portion of the first extrudate to form a first porous ceramic body, and (d) measuring a pore size distribution of the first porous ceramic body and adjusting a pore size distribution of a second porous ceramic body to meet a targeted pore size distribution,
wherein adjusting the pore size distribution is done by:
(i) modifying the first mixture by providing the first and second pore forming powders in respective amounts (wt % D, wt % E) to result in a second weight ratio (wt % D/wt % E) which is different from the first weight ratio, and adding and mixing the first and second pore forming powders in the ratio wt % D/wt % E to the first type of inorganic ceramic forming powder to form a second mixture,(ii) introducing the second mixture into the extruder,(iii) extruding at least a portion of the second mixture into a second extrudate,(iv) firing at least a portion of the second extrudate to form the second porous ceramic body, and(v) measuring a pore size distribution of the second porous ceramic body to determine the adjusted pore size distribution; wherein the first and second porous ceramic bodies have a CTE, an MOR, D-Factor and an EMOD, and the CTE, MOR, D-Factor and EMOD of the first and second porous ceramic bodies is substantially the same.