Sintered ceramic filter structure having body compressively stressed by sintered ceramic material having different sintering shrinkage ratio

A sintered ceramic filter structure for cleaning exhaust gases emitted by an internal combustion engine, comprising:

• a first body of ceramic material having an inlet end and an outlet end and an outer perimetrical sidewall extending longitudinally between said inlet end and said outlet end;
• a first plurality of longitudinal bores in said first body, opening through said inlet end of said first body and extending towards but terminating short of said outlet end of said first body;
• a second plurality of longitudinal bores in said first body, opening through said outlet end of said first body and extending towards but terminating short of said inlet end of said first body;
• said first and second pluralities of longitudinal bores being longitudinally coextensive with one another within a longitudinally intermediate region of said first body;
• said first body being so porous that a gas introduced into said first body through said first plurality of bores at said inlet end, may flow transversally of said first body, through pores thereof in said longitudinally intermediate section, into said second plurality of bores, and out of said outlet end of said first body, all while being cleaned in said first body;
• a second body of ceramic material extending between said inlet and outlet ends of said first body as an integral wrapper of said outer perimetrical sidewall of said first body, which wrapper is at least partially infiltrated to a desired depth in said pores of said first body, which depth is laterally short of said first and second pluralities of longitudinal bores;
• said first body of ceramic body being made of a first ceramic material having a first sintering shrinkage ratio;
• said second body of ceramic body being made of a second ceramic material having a second sintering shrinkage ratio;
• said second sintering shrinkage ratio being smaller than said first sintering shrinkage ratio;
• said first and second bodies of ceramic material being sintered;
• and
• said first body of ceramic material compressively stressing said second body of ceramic material due to said smaller sintering shrinkage ratio of said second ceramic material.

A sintered ceramic filter structure for cleaning exhaust gases emitted by an internal combustion engine, comprising:

• a first body of ceramic material having an inlet end and an outlet end, and an outer perimetrical sidewall extending longitudinally between said inlet end and said outlet end;
• a plurality of longitudinal bores in said first body, communicating within said first body between said inlet end and said outlet end;
• said first body being characterized by an open porous structure;
• a second body of ceramic material extending between said inlet and outlet ends of said first body as an integral wrapper of said outer perimetrical sidewall of said first body, which wrapper is at least partially infiltrated to a desired depth in said pores of said first body, which depth is laterally short of said plurality of longitidinal bores;
• said first body of ceramic body being made of a first ceramic material having a first sintering shrinkage ratio;
• said second body of ceramic body being made of a second ceramic material having a second sintering shrinkage ratio;
• said second sintering shrinkage ratio being smaller than said first sintering shrinkage ratio;
• said first and second bodies of ceramic material being sintered;
• and
• said first body of ceramic material compressively stressing said second body of ceramic material due to said smaller sintering shrinkage ratio of said second ceramic material.