Cordierite porous ceramic honeycomb articles with delayed microcrack evolution

摘要

A porous ceramic honeycomb article includes a primary cordierite phase and an intercrystalline glass phase. In an as-fired condition, the porous ceramic honeycomb article exhibits microcrack parameter Nb3≦0.06 and an as-fired E500° C./E25° C. ratio ≦0.99. The article exhibits a coated microcrack parameter Nb3≦0.14 and a coated E500° C./E25° C. ratio ≦1.06 after the porous ceramic honeycomb article has been washcoated and calcined at a temperature of 550° C. After the article is exposed to a thermal treatment at a temperature ≧800° C. following washcoating and calcining, at least a first portion of the porous ceramic honeycomb article has a first treated microcrack parameter Nb3≧0.18, and a first treated mean coefficient of thermal expansion of not more than 12×10−7/° C. over a temperature range of 25° C. to 800° C. Methods of forming the porous ceramic honeycomb article are also disclosed.

主权项

1. A porous ceramic honeycomb article comprising:
a primary cordierite phase; an intercrystalline glass phase; an as-fired microcrack parameter Nb3≦0.06; a coated microcrack parameter Nb3≦0.14 and a coated E500° C./E25° C. ratio ≦1.06 after the porous ceramic honeycomb article has been washcoated and calcined at a temperature of 550° C.; and after the porous ceramic honeycomb article is exposed to a thermal treatment at a temperature ≧800° C. following washcoating and calcining, at least a first portion of the porous ceramic honeycomb article has a first treated microcrack parameter Nb3≧0.18, and a first treated mean coefficient of thermal expansion of not more than 12×10−7/° C. over a temperature range of 25° C. to 800° C., wherein the primary cordierite phase comprises domains of cordierite crystallites having an average domain length parameter ≧40 microns, wherein the cordierite crystallites within the domains have a sub-parallel orientation with one another, and an orientation of the cordierite crystallites within the domains differs between adjacent domains.