Abstract: Porous aluminum-containing ceramic bodies are treated to form acicular mullite crystals onto the surfaces of their pores. The crystals are formed by contacting the body with a fluorine-containing gas or a source of both fluorine and silicon atoms to form fluorotopaz at the surface of the pores, and then decomposing the fluorotopaz to form acicular mullite crystals. This process allows the surface area of the ceramic body to be increased significantly while retaining the geometry (size, shape, general pore structure) of the starting body. The higher surface area makes the body more efficient as a particulate filter and also allows for easier introduction of catalytic materials.

Abstract: A porous ceramic composition having improved thermal stability is comprised of ceramic grains bonded together by grain boundary phase comprised of silica, yttrium and oxygen wherein the amount of alkali metals, alkaline earth metals and other transition metals not including rare earth metals is at most 2% by weight of the grain boundary phase.

Abstract: A porous ceramic composition having improved thermal stability is comprised of ceramic grains bonded together by a grain boundary phase comprised of silica, rare earth element that is Eu, Gd, Nd or mixture thereof and oxygen and optionally yttrium, wherein the grain boundary phase has a amount of an alkali, an alkaline earth metal and a transition metal other than yttrium that is at most 2% by weight of the grain boundary phase.

Abstract: An improved ceramic honeycomb structure is comprised of at least two separate smaller ceramic honeycombs that have been adhered together by a cement layer comprised of a cement layer has at least two regions of differing porosity or cement layer where the ratio of toughness/Young's modulus is at least about 0.1 MPa·m1/2/GPa.

Abstract: A porous ceramic composition having improved thermal stability is comprised of ceramic grains bonded together by grain boundary phase comprised of silica, yttrium and oxygen wherein the amount of alkali metals, alkaline earth metals and other transition metals not including rare earth metals is at most 2% by weight of the grain boundary phase.

Abstract: A porous ceramic composition having improved thermal stability is comprised of ceramic grains bonded together by a grain boundary phase comprised of silica, rare earth element that is Eu, Gd, Nd or mixture thereof and oxygen and optionally yttrium, wherein the grain boundary phase has a amount of an alkali, an alkaline earth metal and a transition metal other than yttrium that is at most 2% by weight of the grain boundary phase.

Abstract: A mullite body comprising: a plurality of crystals, wherein about 70 percent or greater of the crystals have a crystal diameter that is within about 3 microns or less of an average diameter of the plurality of crystals, and a porosity of 55 percent or greater; and made using a process comprising: mixing precursor materials together with an average aggregate particle size of about 3 microns or smaller measured using a particle size analyzer; heating greenware in air to a first temperature such that the greenware is dried and forms calcineware, heating the calcineware in a silicon tetrafiouride atmosphere to form flurotopaz, and heating to a second temperature so that a mullite structure is formed.

Abstract: Densified composites of a metal such as copper or aluminum with a titanium-silicon-carbide or titanium-aluminum-carbide ceramic material are prepared by forming the ceramic material into a body, and infiltrating the body with the molten metal. The metal is able to rapidly penetrate into void spaces, between grain boundaries and even into the crystal structure of the ceramic grains to form a composite. The starting ceramic material may be previously densified, in which case various types of gradient structures can be produced easily. The process can be operated at low pressures, and so the hot pressing methods that normally must be used to densify these ceramic materials can be avoided.

Abstract: A mullite body comprising: a plurality of crystals, wherein about 70 percent or greater of the crystals have a crystal diameter that is within about 3 microns or less of an average diameter of the plurality of crystals, and a porosity of 55 percent or greater; and made using a process comprising: mixing precursor materials together with an average aggregate particle size of about 3 microns or smaller measured using a particle size analyzer; heating greenware in air to a first temperature such that the greenware is dried and forms calcineware, heating the calcineware in a silicon tetrafiouride atmosphere to form flurotopaz, and heating to a second temperature so that a mullite structure is formed.

Abstract: An improved ceramic honeycomb structure is comprised of at least two separate smaller ceramic honeycombs that have been adhered together by a cement layer comprised of a cement layer has at least two regions of differing porosity or cement layer where the ratio of toughness/Young's modulus is at least about 0.1 MPa·m1/2/GPa.

Abstract: Densified composites of a metal such as copper or aluminum with a titanium-silicon-carbide or titanium-aluminum-carbide ceramic material are prepared by forming the ceramic material into a body, and infiltrating the body with the molten metal. The metal is able to rapidly penetrate into void spaces, between grain boundaries and even into the crystal structure of the ceramic grains to form a composite. The starting ceramic material may be previously densified, in which case various types of gradient structures can be produced easily. The process can be operated at low pressures, and so the hot pressing methods that normally must be used to densify these ceramic materials can be avoided.

Abstract: An improved particulate filtration system has an inlet, for the fluid to be filtered, connected to a housing containing a filter medium such that the fluid passes through the filter medium, and an outlet for the filtered fluid to exit. The filtration system's improvement is the filter medium being comprised of a porous ceramic of fused platelet grains. In a particular embodiment, the porous ceramic is a celsian porous ceramic, where the celsian grains have a hexagonal morphology and display a continuous volume thermal expansion coefficient from 100° C. to 1000° C.

Abstract: An improved particulate filtration system has an inlet, for the fluid to be filtered, connected to a housing containing a filter medium such that the fluid passes through the filter medium, and an outlet for the filtered fluid to exit. The filtration system's improvement is the filter medium being comprised of a porous ceramic of fused platelet grains. In a particular embodiment, the porous ceramic is a celsian porous ceramic, where the celsian grains have a hexagonal morphology and display a continuous volume thermal expansion coefficient from 100° C. to 1000° C.

Abstract: A boron containing ceramic-aluminum metal composite is formed by mixing a boron containing ceramic with a metal powder comprised of aluminum or alloy thereof, shaping the mixture into a porous preform, contacting the preform with an infiltrating metal comprised of aluminum or alloy thereof that melts at a lower temperature than the metal powder and heating to a temperature sufficient to melt the infiltrating metal, but insufficient to melt the metal powder, such that the infiltrating metal infiltrates the porous preform to form the composite. The composite that is formed may be used for vehicular parts.

Abstract: A concrete article comprised of concrete having therein a reinforcing polymer that has a surface comprised of a thermoplastic hydroxy-functionalized polyether or polyester. The concrete article is made by mixing concrete, water and a reinforcing polymer that has a surface comprised of a thermoplastic hydroxy-functionalized polyether or polyester and curing said concrete mixture forming the concrete article.

Abstract: A monofilament plastic fiber useful in reducing plastic shrinkage cracking of concrete articles has been discovered. The fiber has a core that is a polyolefin that is at least partially enveloped by a sheath that is a copolymer of an olefin and at least one olefinically unsaturated comonomer selected from the group consisting of an unsaturated carboxylic acid, alkyl acrylate, alkyl methacrylate and vinyl ester.

Abstract: A boron containing ceramic-aluminum metal composite is formed by mixing a boron containing ceramic with a metal powder comprised of aluminum or alloy thereof, shaping the mixture into a porous preform, contacting the preform with an infiltrating metal comprised of aluminum or alloy thereof that melts at a lower temperature than the metal powder and heating to a temperature sufficient to melt the infiltrating metal, but insufficient to melt the metal powder, such that the infiltrating metal infiltrates the porous preform to form the composite. The composite that is formed may be used for vehicular parts.

Abstract: A concrete article comprised of concrete having therein a reinforcing polymer that has a surface comprised of a thermoplastic hydroxy-functionalized polyether or polyester. The concrete article is made by mixing concrete, water and a reinforcing polymer that has a surface comprised of a thermoplastic hydroxy-functionalized polyether or polyester and curing said concrete mixture forming the concrete article.

Abstract: A monofilament plastic fiber useful in reducing plastic shrinkage cracking of concrete articles has been discovered. The fiber is comprised of a core that is a polyolefin that is at least partially enveloped by a sheath that is a copolymer of an olefin and at least one olefinically unsaturated comonomer selected from the group consisting of an unsaturated carboxylic acid, alkyl acrylate, alkyl methacrylate and vinyl ester.

Abstract: A boron containing ceramic-aluminum metal composite is formed by mixing a boron containing ceramic with a metal powder comprised of aluminum or alloy thereof, shaping the mixture into a porous preform, contacting the preform with an infiltrating metal comprised of aluminum or alloy thereof that melts at a lower temperature than the metal powder and heating to a temperature sufficient to melt the infiltrating metal, but insufficient to melt the metal powder, such that the infiltrating metal infiltrates the porous preform to form the composite. The composite that is formed may be used for vehicular parts.