METHOD FOR FORMING 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 Nb 3 ‰¤ 0.06 and an as-fired E 500°C /E 25°C ratio ‰¤ 0.99. The article exhibits a coated microcrack parameter Nb 3 ‰¤ 0.14 and a coated E 500°C /E 25°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 Nb 3 ‰¥ 0.18, and a first treated mean coefficient of thermal expansion of not more than 12x10 -7 /°C over a temperature range of 25°C to 800°C. Methods of forming the porous ceramic honeycomb article are also disclosed.