초록 ▼

A method of making heat engine components, such as rocket nozzle throats, includes forming a body having at least one surface, wherein the body is made of a refractory metal, and compressing a ceramic powder between a die and the at least one surface of the body, with sufficient heat and pressure to

A method of making heat engine components, such as rocket nozzle throats, includes forming a body having at least one surface, wherein the body is made of a refractory metal, and compressing a ceramic powder between a die and the at least one surface of the body, with sufficient heat and pressure to densify and thus form a solid ceramic coating on the at least one surface of the body. Nozzle throats made according to the invention have bodies made of refractory metals, such as tantalum, and ceramic coatings on the inner surfaces of the annular bodies, wherein the ceramic coatings are made of ceramic materials such as tantalum carbide.

대표청구항 ▼

1. A method of making a rocket nozzle throat, comprising: forming a body from refractory metallic material, the body having a generally annular shape and a central passageway defined by an inner surface; placing the body inside mold having a mandrel that extends through the central passageway;

1. A method of making a rocket nozzle throat, comprising: forming a body from refractory metallic material, the body having a generally annular shape and a central passageway defined by an inner surface; placing the body inside mold having a mandrel that extends through the central passageway; placing ceramic powders inside the central passageway; and applying pressure and temperature to the ceramic powders at sufficient levels to densify the ceramic powders and form a solid coating made of ceramic material on the surface of the central passageway, whereby the ceramic coating is diffusion bonded to the inner surface of the metal body. 2. A method according to claim 1, further comprising machining the ceramic coating to form a final nozzle throat surface. 3. A method according to claim 1, wherein the ceramic body is made of tantalum carbide and tantalum2carbide, and the metal body is made of tantalum. 4. A method according to claim 1, wherein the step of applying pressure and temperature to the ceramic powders comprises heating the body to a temperature of between about 3,000° F. and about 5,000° F., and applying pressure of between about 1/2 and 15 ksi to the ceramic body using upper and lower forging dies. 5. A method according to claim 1, further comprising selecting a thickness of the ceramic coating which is optimized for a given rate of ablation. 6. A method according to claim 1, wherein the diffusion bond of the ceramic coating to metal body militates against thermal shock. 7. A method according to claim 1, wherein the refractory metal body is made from a material selected from the group consisting of tantalum, tantalum alloys, hafnium alloys, molybdenum alloys, titanium alloys, tungsten alloys, and niobium alloys. 8. A method according to claim 1, wherein the step of placing ceramic powders inside the central passageway includes placing powders selected from the group consisting of TaC, Ta2C, ZrC, HfC, and NbC. 9. A method of making heat engine components, comprising: forming a body having at least one surface, wherein the body is made of a refractory metal; and compressing a ceramic powder between a die and the at least one surface of the body, with sufficient heat and pressure to densify and [thus] form a solid ceramic coating on the at least one surface of the body. 10. A method according to claim 9, wherein the forming step comprises forming the body to have an annular shape with a central passageway defined by an interior surface, and the method further comprising, prior to the compressing step, placing the body in a mold having a mandrel extending at least partially through the central passageway, placing the ceramic powder between the mandrel and the interior surface of the body, and pressing the powder with a die for a time, and at a temperature and pressure sufficient to densify the ceramic powder and form the ceramic coating with the ceramic coating diffusion bonded to the body. 11. A product made by the method of claim 9. 12. A method according to claim 9, wherein the step of forming the body includes a body from a refractor metal material selected from the group consisting of tantalum, tantalum alloys, hafnium alloys, molybdenum alloys, titanium alloys, tungsten alloys, and niobium alloys. 13. A method according to claim 9, wherein the step of forming a refractory metal body includes forming the body from a material made from a material selected from the group consisting of Ta-2.5W, Ta-10W, Ta-40Nb, and an alloy consisting of 89% Nb, 10% Hf and 1% Ti. 14. A method according to claim 9, wherein the step of compressing a ceramic powder includes compressing a ceramic powder selected from the group consisting of TaC, Ta2C, ZrC, HfC, and NbC.