Composite cordierite filters

The honeycomb of claim 6 wherein the non-oxide polycrystalline phase is polycrystalline silicon carbide.

The honeycomb of claim 6 wherein the non-oxide phase is polycrystalline silicon nitride.

The honeycomb of claim 8 wherein the ceramic material has an open porosity of at least 30% and a median pore size of at least 5 micrometers.

A filter for trapping and combusting diesel exhaust particulates comprising a wall-flow honeycomb body composed of a porous ceramic material and having a plurality of parallel end-plugged cell channels traversing the body from a frontal inlet end to an outlet end thereof, wherein the ceramic material comprises a non-oxide polycrystalline phase constituting 10-70% by weight, with the remainder of the ceramic material constituting a cordierite phase, the non-oxide polycrystalline phase being selected from the group consisting of carbides, nitrides, and borides, wherein the filter has an open porosity of at least 30% and a median pore size of at least 5 micrometers.

A diesel exhaust particulate filter comprising a plugged, wall-flow honeycomb filter body composed of porous ceramic material and comprising a plurality of parallel end-plugged cell channels traversing the body from a frontal inlet end to an outlet end thereof, wherein:

• the honeycomb body is composed of a composite ceramic having a non-oxide polycrystalline phase selected from the group consisting of carbide, nitrides and borides, the non-oxide polycrystalline phase constituting 10-70% by weight of the ceramic, the remainder being an oxide phase selected from the group consisting of alkali aluminum silicates and alkaline earth aluminum silicates,
• the diesel exhaust particulate filter being characterized by an open porosity of at least 30%, a median pore size of at least 5 micrometers, a mean coefficient of thermal expansion of between 20-45×10−7/° C., and a modulus of rupture as measured on a cellular bar of at least about 300 pounds per square inch (psi).