Patent classifications
C04B41/4558
Fibers fabricated to incorporate metals for high temperature applications
A fiber comprises a bulk material comprising one or more materials selected from the group consisting of carbon, silicon, boron, silicon carbide, and boron nitride; and a metal whose affinity for oxygen is greater than the affinity for oxygen of any of the one or more materials. The metal may be selected from the group consisting of beryllium, titanium, hafnium and zirconium. At least a first portion of the metal may be present in un-oxidized form at the entrance to and/or within grain boundaries within the fiber. A method of improving at least one of the strength, creep resistance, and toughness of a fiber comprises adding to a fiber, initially comprising a bulk material having a first affinity for oxygen, a metal that has a second affinity for oxygen higher than the first affinity. The metal may be selected from the group consisting of beryllium, titanium, hafnium and zirconium.
Fibers fabricated to incorporate metals for high temperature applications
A fiber comprises a bulk material comprising one or more materials selected from the group consisting of carbon, silicon, boron, silicon carbide, and boron nitride; and a metal whose affinity for oxygen is greater than the affinity for oxygen of any of the one or more materials. The metal may be selected from the group consisting of beryllium, titanium, hafnium and zirconium. At least a first portion of the metal may be present in un-oxidized form at the entrance to and/or within grain boundaries within the fiber. A method of improving at least one of the strength, creep resistance, and toughness of a fiber comprises adding to a fiber, initially comprising a bulk material having a first affinity for oxygen, a metal that has a second affinity for oxygen higher than the first affinity. The metal may be selected from the group consisting of beryllium, titanium, hafnium and zirconium.
Perovskite relaxor-PBTI0.SUB.3 .based ferroelectric ceramics with ultrahigh dielectric and piezoelectric properties through polar nanoregions engineering
Embodiments of the invention can be directed to controlling and/or engineering the size and/or volume of polar nanoregions (PNRs) of ferroelectric polycrystalline material systems. Some embodiments can achieved this via composition modifications to cause changes in the PNRs and/or local structure. Some embodiments can be used to control and/or engineer dielectric, piezoelectric, and/or electromechanical properties of polycrystalline materials. Controlling and/or engineering the PNRs may facilitate improvements to the dielectric, piezoelectric, and/or electromechanical properties of materials. Controlling and/or engineering the PNRs may further facilitate generating a piezoelectric material that may be useful for many different piezoelectric applications.
METHOD FOR FABRICATING A CERAMIC HEATING BODY WITH POROUS HEATING FILM
The present application discloses a method for fabricating a ceramic heating body with a porous heating film, which relates to technical field of fabricating method of heating body; the method including mixing, ball-milling, defoaming, molding and drying, sintering, paraffin filling, machining, coating, metalizing sintering, and electrode leading; the beneficial effects of the present application is simple in whole fabricating method, and by using a box furnace to sinter the green body under an oxidizing atmosphere and normal pressure, the fabricated ceramic heating body is heated uniformly and the heating efficiency is high.
Silicon-based materials containing boron
A ceramic component is provided that includes a silicon-based layer comprising a silicon-containing material (e.g., a silicon metal and/or a silicide) and a boron-doped refractory compound, such as about 0.001% to about 85% by volume of the boron-doped refractory compound (e.g., about 1% to about 60% by volume of the boron-doped refractory compound). A coated component is also provided that includes a CMC component defining a surface; a bond coating directly on the surface of the CMC component, with the bond coating comprises a silicon-containing material and a boron-doped refractory compound (e.g., about 0.1% to about 25% of the boron-doped refractory compound); a thermally grown oxide layer on the bond coating; and an environmental barrier coating on the thermally grown oxide layer.
Silicon-based materials containing boron
A ceramic component is provided that includes a silicon-based layer comprising a silicon-containing material (e.g., a silicon metal and/or a silicide) and a boron-doped refractory compound, such as about 0.001% to about 85% by volume of the boron-doped refractory compound (e.g., about 1% to about 60% by volume of the boron-doped refractory compound). A coated component is also provided that includes a CMC component defining a surface; a bond coating directly on the surface of the CMC component, with the bond coating comprises a silicon-containing material and a boron-doped refractory compound (e.g., about 0.1% to about 25% of the boron-doped refractory compound); a thermally grown oxide layer on the bond coating; and an environmental barrier coating on the thermally grown oxide layer.
Method of controllably coating a fiber preform during ceramic matrix composite (CMC) fabrication
A method of controllably coating a fiber preform has been developed. The method includes infiltrating a fiber preform with a first solvent to form a solvent-filled preform. After the infiltration, a slurry is applied to one or more outer surfaces of the solvent-filled preform to form a slurry coating thereon. The slurry coating comprises particulate solids dispersed in a second solvent having a vapor pressure higher than that of the first solvent. The slurry coating and the solvent-filled preform are dried. During drying, the second solvent evaporates from the slurry coating before the first solvent evaporates from the solvent-filled preform. The slurry coating dries to form a porous surface coating comprising the particulate solids on the one or more outer surfaces of the solvent-filled preform. The drying of the solvent-filled preform continues after formation of the porous surface coating to remove the first solvent.
Method of controllably coating a fiber preform during ceramic matrix composite (CMC) fabrication
A method of controllably coating a fiber preform has been developed. The method includes infiltrating a fiber preform with a first solvent to form a solvent-filled preform. After the infiltration, a slurry is applied to one or more outer surfaces of the solvent-filled preform to form a slurry coating thereon. The slurry coating comprises particulate solids dispersed in a second solvent having a vapor pressure higher than that of the first solvent. The slurry coating and the solvent-filled preform are dried. During drying, the second solvent evaporates from the slurry coating before the first solvent evaporates from the solvent-filled preform. The slurry coating dries to form a porous surface coating comprising the particulate solids on the one or more outer surfaces of the solvent-filled preform. The drying of the solvent-filled preform continues after formation of the porous surface coating to remove the first solvent.
REACTION BARRIER LAYER FOR ENVIRONMENTAL BARRIER COATING
A method may include applying a layer comprising a carbon source on a surface of a substrate including silicon; applying a layer comprising silicon on the layer comprising elemental carbon; and heat treating at least the layer comprising the carbon source to cause carbon from the layer comprising the carbon source to react with at least one of silicon from the substrate or silicon from the layer comprising silicon to form silicon carbide.
REACTION BARRIER LAYER FOR ENVIRONMENTAL BARRIER COATING
A method may include applying a layer comprising a carbon source on a surface of a substrate including silicon; applying a layer comprising silicon on the layer comprising elemental carbon; and heat treating at least the layer comprising the carbon source to cause carbon from the layer comprising the carbon source to react with at least one of silicon from the substrate or silicon from the layer comprising silicon to form silicon carbide.