The present disclosure relates to porous ceramic articles and a method of making the same. The porous ceramic articles have a porosity (P) as a fraction in a range of about 0.3 to about 0.7; a permeability factor PQ>0.025, wherein PQ is (K.sub.bulk)/(P.Math.d.sub.50.sup.2), K.sub.bulk being bulk permeability in Darcy, and d.sub.50 being the mean pore size in micrometers (m); a tortuosity in a range of about 1.8 to 3; and a median pore size diameter d.sub.50 in a range of about 10 m to about 35 m. The porous ceramic articles can have an interconnected bead microstructure comprising beads and bead connections, PQ is directly proportional to bead size, and wherein in a random cross section through the body, the beads appear as globular portions.

The present disclosure relates to porous ceramic articles and a method of making the same. The porous ceramic articles have a porosity (P) as a fraction in a range of about 0.3 to about 0.7; a permeability factor PQ>0.025, wherein PQ is (K.sub.bulk)/(P.Math.d.sub.50.sup.2), K.sub.bulk being bulk permeability in Darcy, and d.sub.50 being the mean pore size in micrometers (m); a tortuosity in a range of about 1.8 to 3; and a median pore size diameter d.sub.50 in a range of about 10 m to about 35 m. The porous ceramic articles can have an interconnected bead microstructure comprising beads and bead connections, PQ is directly proportional to bead size, and wherein in a random cross section through the body, the beads appear as globular portions.

A method for indirect additive manufacturing of an object constructed of boron carbide, silicon carbide, and free silicon, comprising: (i) producing a porous preform constructed of boron carbide and silicon carbide by an indirect ceramic additive manufacturing (ICAM) process in which particles of a powder mixture become bonded together with an organic binder, wherein the powder mixture comprises: a) boron carbide particles, and b) silicon carbide particles, wherein at least 80 vol % of the silicon carbide particles are larger than the boron carbide particles; and wherein the boron carbide and silicon carbide particles are each included in an amount of 40-60 wt. % of the powder mixture, provided that the foregoing amounts sum to at least 95 wt. %; (ii) subjecting the porous preform to a temperature of 500-900 C. to volatilize the organic binder; and (iii) infiltrating molten silicon into pores of the porous preform to produce the object.

Systems and corresponding methods are provided for separation of support structures from near net shape manufactured parts. The system can include a support structure and a non-adhering material. The non-adhering material can be positioned on one or more predetermined exterior-facing surfaces of the support structure. The support system can be dimensioned for receipt within a void space of a porous green body defined by an overhang region of the porous green body. After receipt within a void space of a porous green body that undergoes a thermally-induced volumetric change, the support system can be configured to support the overhang region and the non-adhering material can be configured to inhibit adherence of the exterior-facing surfaces of the support structure to opposed surfaces of the void space.

A porous refractory cast material contains a closed refractory aggregate fraction having a minimum particle size and a maximum particle size; the ratio of maximum particle size to minimum particle size is 10:1 or less. This closed refractory aggregate fraction comprises all of the porous refractory cast material having a particle diameter greater than 0.1 mm. The porous refractory cast material also contains a binder phase containing refractory selected from calcium aluminate cement, alumina phosphate, hydratable alumina, colloidal silica and combinations thereof. Also disclosed is a metallurgical vessel with an interior lining incorporating the porous refractory cast material.

A porous refractory cast material contains a closed refractory aggregate fraction having a minimum particle size and a maximum particle size; the ratio of maximum particle size to minimum particle size is 10:1 or less. This closed refractory aggregate fraction comprises all of the porous refractory cast material having a particle diameter greater than 0.1 mm. The porous refractory cast material also contains a binder phase containing refractory selected from calcium aluminate cement, alumina phosphate, hydratable alumina, colloidal silica and combinations thereof. Also disclosed is a metallurgical vessel with an interior lining incorporating the porous refractory cast material.

Articles comprising carbon composites are disclosed. The carbon composites contain carbon microstructures having interstitial spaces among the carbon microstructures; and a binder disposed in at least some of the interstitial spaces; wherein the carbon microstructures comprise unfilled voids within the carbon microstructures. Alternatively, the carbon composites contain: at least two carbon microstructures; and a binding phase disposed between the at least two carbon microstructures; wherein the binding phase comprises a binder comprising one or more of the following: SiO.sub.2; Si; B; B.sub.2O.sub.3; a metal; or an alloy of the metal; and wherein the metal is at least one of aluminum; copper; titanium; nickel; tungsten; chromium; iron; manganese; zirconium; hafnium; vanadium; niobium; molybdenum; tin; bismuth; antimony; lead; cadmium; or selenium.

Articles comprising carbon composites are disclosed. The carbon composites contain carbon microstructures having interstitial spaces among the carbon microstructures; and a binder disposed in at least some of the interstitial spaces; wherein the carbon microstructures comprise unfilled voids within the carbon microstructures. Alternatively, the carbon composites contain: at least two carbon microstructures; and a binding phase disposed between the at least two carbon microstructures; wherein the binding phase comprises a binder comprising one or more of the following: SiO.sub.2; Si; B; B.sub.2O.sub.3; a metal; or an alloy of the metal; and wherein the metal is at least one of aluminum; copper; titanium; nickel; tungsten; chromium; iron; manganese; zirconium; hafnium; vanadium; niobium; molybdenum; tin; bismuth; antimony; lead; cadmium; or selenium.

A fluorescent member includes: a plurality of fluorescent particles; an inorganic binder; and a plurality of pores. An upper surface of the fluorescent member is a light extraction surface of the fluorescent member. The plurality of pores are localized in a vicinity of at least one of the plurality of fluorescent particles in a cross section that is parallel to the upper surface of the fluorescent member and extends through the fluorescent particles and the pores.

A silicon carbide porous body includes a skeletal structure formed by a plurality of silicon carbide particles bonded to each other, a plurality of pores formed by the skeletal structure, neck parts formed by surface-contacting of adjacent silicon carbide particles, and an average pore size is larger than 3 m and equal to or smaller than 9 m, and a porosity ranges from 35% to 55%. A break filter using the silicon carbide porous body enables high performance of collection of particles, prevention of soaring up of particles, and shortening of a restoration time from the depressurized state of the chamber to the atmospheric state.