Porous material and honeycomb structure
There are disclosed a porous material having a high thermal shock resistance and a honeycomb structure. The porous material contains main aggregates and auxiliary aggregates as aggregates, the main aggregates are silicon carbide particles, the auxiliary aggregates are at least either of mullite particles or alumina particles, the aggregates are bound to one another via a binding phase, so as to form pores, and the binding phase is at least one of an amorphous phase and a cordierite phase, and a porosity is from 40 to 90%. Furthermore, the honeycomb structure is constituted of such a porous material, and includes partition walls defining and forming a plurality of cells extending from one end face to the other end face.
1. A porous material containing main aggregates and auxiliary aggregates as aggregates,
wherein the main aggregates are silicon carbide particles, the auxiliary aggregates are at least one of mullite particles and alumina particles,
the aggregates are bound to one another via a binding phase so as to form pores,
the main aggregates are bridged by the binding phase,
the average particle diameter of the main aggregates is greater than the average particle diameter of the auxiliary aggregates,
the binding phase contains at least one of an amorphous phase and a cordierite phase,
a porosity is from 40 to 90%, and
the porous material contains 8.4 to 10.5 mass % of the auxiliary aggregates to a total mass of the main aggregates, the auxiliary aggregates and the binding phase, and 6.8 to 11.7 mass % of the binding phase to the total mass of the main aggregates, the auxiliary aggregates and the binding phase.
2. The porous material according to claim 1 ,
wherein the amorphous phase contains magnesium, aluminum, silicon and oxygen.
3. The porous material according to claim 1 , wherein an average pore diameter is from 10 to 40 μm.
4. The porous material according to claim 1 ,
wherein a percentage of the pores having pore diameters smaller than 10 μm is 20% or less of all the pores, and a percentage of the pores having pore diameters in excess of 40 μm is 10% or less of all the pores.
5. The porous material according to claims 1 ,
wherein an average particle diameter of the silicon carbide particles which are the main aggregates is from 5 to 100 μm, and an average particle diameter of the auxiliary aggregates is from 5 to 100 μm.
6. The porous material according to claim 1 ,
wherein a bending strength is 6.5 MPa or more, and a bending strength/Young's modulus ratio is 1.4×10 −3 or more.
7. A honeycomb structure which is constituted of the porous material according to claim 1 , and which comprises partition walls defining and forming a plurality of cells extending from one end face to the other end face.