A high-performance molybdenum pipe preparation method based on a semi-solid method

Abstract

The application discloses a kind of high-performance molybdenum pipe preparation methods based on semi-solid method, comprising the following steps: high-purity molybdenum powder is mixed with appropriate sintering aid, and mixed powder is obtained;Mixed powder is transported to spiral injection forming machine, and mixed powder becomes liquid slurry at the temperature of 1300 DEG C-1400 DEG C and the pressure of 30MPa, while forming solid-liquid two-phase mixture, i.e., semi-solid slurry, under the action of screw rod stirring shear in spiral injection forming machine;Spiral injection forming machine makes semi-solid slurry be injected into mould under the pressure of 40-60Mpa to prepare molybdenum pipe.The application adopts semi-solid method and new mould to prepare molybdenum pipe, and high-performance dense molybdenum pipe can be obtained at lower temperature, while maintaining high purity and excellent performance of molybdenum, which can not only reduce energy consumption, but also reduce oxidation and volatilization of molybdenum, so as to improve the quality of product.

Description

Technical Field

[0001] This invention relates to the field of molybdenum product preparation technology, specifically to a method for preparing high-performance molybdenum pipes based on a semi-solid method. Background Technology

[0002] Molybdenum is a high-melting-point, high-strength, and high-toughness metallic material with excellent electrical and thermal conductivity. Even at high temperatures, molybdenum maintains high strength and hardness. Therefore, molybdenum is widely used in various high-temperature, high-pressure, and high-intensity working environments, such as in aerospace and nuclear applications. However, traditional methods for manufacturing molybdenum tubing typically require high temperatures and long sintering times, which not only increases energy consumption but may also cause molybdenum oxidation and volatilization, affecting product quality. Therefore, developing a novel, efficient, and environmentally friendly method for manufacturing molybdenum tubing is of great significance. Summary of the Invention

[0003] The technical problem to be solved by this invention is to overcome the existing defects and provide a high-performance molybdenum tube preparation method based on a semi-solid method. By using a semi-solid method and a new mold to prepare molybdenum tubes, high-performance dense molybdenum tubes can be obtained at a lower temperature, while maintaining the high purity and excellent properties of molybdenum. This preparation method can not only reduce energy consumption, but also reduce the oxidation and volatilization of molybdenum, thereby improving the quality of the product and effectively solving the problems in the background technology.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing high-performance molybdenum tubing based on a semi-solid method, comprising the following steps:

[0005] S1. Mix high-purity molybdenum powder with an appropriate amount of sintering aid to obtain a mixed powder;

[0006] S2. The mixed powder is fed into a spiral injection molding machine, and the mixture is made into a liquid slurry at a temperature of 1300℃-1400℃ and a pressure of 30MPa. At the same time, a solid-liquid two-phase mixture, i.e. a semi-solid slurry, is formed under the stirring and shearing action of the screw in the spiral injection molding machine.

[0007] S3. The spiral injection molding machine sprays semi-solid slurry into the mold under a pressure of 40-60 MPa to produce molybdenum tubes.

[0008] S4. Cool the mold and then demold the molybdenum tube to obtain the formed molybdenum tube;

[0009] S5. Cut off the ends of the formed molybdenum tube and straighten and machine it.

[0010] As a preferred embodiment of the present invention, the purity of the high-purity molybdenum powder is not less than 99.9%.

[0011] As a preferred embodiment of the present invention, the sintering aid is any one of Y2O3, La2O3 or CeO2.

[0012] In a preferred embodiment of the present invention, the sintering aid has a mass fraction of 0.1%.

[0013] As a preferred embodiment of the present invention, the mold in S3 includes a mold sleeve and a mold core. The mold sleeve has a connecting groove on its open side for connecting the nozzle of a spiral injection molding machine, and the mold core has spiral blades on its side near the connecting groove.

[0014] As a preferred technical solution of the present invention, the method of using the mold includes the following steps: the mold core drives the spiral blades to rotate at high speed and slowly moves towards the connecting groove. When the nozzle of the spiral injection molding machine sprays the semi-solid slurry into the mold sleeve, the high-speed rotating spiral blades transport the semi-solid slurry between the mold sleeve and the mold core, and extrude the semi-solid slurry to form a high-pressure dense molybdenum tube.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] The present invention provides a method for preparing high-performance molybdenum tubing based on a semi-solid method. This method uses a semi-solid method and a novel mold to prepare molybdenum tubing, which can obtain high-performance, dense molybdenum tubing at a lower temperature while maintaining the high purity and excellent properties of molybdenum. This preparation method can not only reduce energy consumption but also reduce the oxidation and volatilization of molybdenum, thereby improving product quality. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the mold structure in this invention.

[0018] In the diagram: 1. Mold sleeve, 2. Connecting groove, 3. Mold core, 31. Spiral blade. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1 The present invention provides a technical solution: Example 1:

[0021] A method for preparing high-performance molybdenum tubing based on a semi-solid method includes the following steps:

[0022] S1. Molybdenum powder with a purity of not less than 99.9% is mixed with Y2O3 with a mass fraction of 0.1% to obtain a mixed powder. Rare earth elements can improve the sintering performance of molybdenum and increase its density and strength.

[0023] S2. The mixed powder is fed into a spiral injection molding machine, and the mixed powder is turned into a liquid slurry at a temperature of 1300℃ and a pressure of 30MPa. At the same time, a solid-liquid two-phase mixture, i.e. a semi-solid slurry, is formed under the stirring and shearing action of the screw in the spiral injection molding machine. The semi-solid slurry can obtain a blank with better density, avoiding problems such as holes and cracks that occur in traditional powder sintering methods.

[0024] S3. The spiral injection molding machine sprays semi-solid slurry into the mold under a pressure of 40 MPa to produce molybdenum tubes.

[0025] S4. Cool the mold and then demold the molybdenum tube to obtain the formed molybdenum tube;

[0026] S5. Cut off the ends of the formed molybdenum tube and straighten and machine it.

[0027] Furthermore, the mold in S3 includes a mold sleeve and a mold core. The mold sleeve has a connecting groove on its open side for connecting the nozzle of the spiral injection molding machine, and the mold core has spiral blades on its side near the connecting groove.

[0028] Furthermore, the method of using the mold includes the following steps: the mold core drives the spiral blades to rotate at high speed and slowly moves towards the connecting groove. When the nozzle of the spiral injection molding machine sprays the semi-solid slurry into the mold sleeve, the high-speed rotating spiral blades transport the semi-solid slurry between the mold sleeve and the mold core, and extrude the semi-solid slurry to form a high-pressure dense molybdenum tube. Example 2:

[0029] A method for preparing high-performance molybdenum tubing based on a semi-solid method includes the following steps:

[0030] S1. Molybdenum powder with a purity of not less than 99.9% is mixed with La2O3 with a mass fraction of 0.1% to obtain a mixed powder. Rare earth elements can improve the sintering performance of molybdenum and increase its density and strength.

[0031] S2. The mixed powder is fed into a spiral injection molding machine, and the mixture is made into a liquid slurry at a temperature of 1350℃ and a pressure of 30MPa. At the same time, a solid-liquid two-phase mixture, i.e. a semi-solid slurry, is formed under the stirring and shearing action of the screw in the spiral injection molding machine.

[0032] S3. The spiral injection molding machine sprays semi-solid slurry into the mold under a pressure of 50 MPa to produce molybdenum tubes.

[0033] S4. Cool the mold and then demold the molybdenum tube to obtain the formed molybdenum tube;

[0034] S5. Cut off the ends of the formed molybdenum tube and straighten and machine it.

[0035] Furthermore, the mold in S3 includes a mold sleeve and a mold core. The mold sleeve has a connecting groove on its open side for connecting the nozzle of the spiral injection molding machine, and the mold core has spiral blades on its side near the connecting groove.

[0036] Furthermore, the method of using the mold includes the following steps: the mold core drives the spiral blades to rotate at high speed and slowly moves towards the connecting groove. When the nozzle of the spiral injection molding machine sprays the semi-solid slurry into the mold sleeve, the high-speed rotating spiral blades transport the semi-solid slurry between the mold sleeve and the mold core, and extrude the semi-solid slurry to form a high-pressure dense molybdenum tube. Example 3:

[0037] A method for preparing high-performance molybdenum tubing based on a semi-solid method includes the following steps:

[0038] S1. Molybdenum powder with a purity of not less than 99.9% is mixed with CeO2 with a mass fraction of 0.1% to obtain a mixed powder. Rare earth elements can improve the sintering performance of molybdenum and increase its density and strength.

[0039] S2. The mixed powder is fed into a spiral injection molding machine, and the mixture is made into a liquid slurry at a temperature of 1400℃ and a pressure of 30MPa. At the same time, a solid-liquid two-phase mixture, i.e. a semi-solid slurry, is formed under the stirring and shearing action of the screw in the spiral injection molding machine.

[0040] S3. The spiral injection molding machine sprays semi-solid slurry into the mold under a pressure of 60 MPa to produce molybdenum tubes.

[0041] S4. Cool the mold and then demold the molybdenum tube to obtain the formed molybdenum tube;

[0042] S5. Cut off the ends of the formed molybdenum tube and straighten and machine it.

[0043] Furthermore, the mold in S3 includes a mold sleeve and a mold core. The mold sleeve has a connecting groove on its open side for connecting the nozzle of the spiral injection molding machine, and the mold core has spiral blades on its side near the connecting groove.

[0044] Furthermore, the method of using the mold includes the following steps: the mold core drives the spiral blades to rotate at high speed and slowly moves towards the connecting groove. When the nozzle of the spiral injection molding machine sprays the semi-solid slurry into the mold sleeve, the high-speed rotating spiral blades transport the semi-solid slurry between the mold sleeve and the mold core, and extrude the semi-solid slurry to form a high-pressure dense molybdenum tube.

[0045] This invention employs a semi-solid method and a novel mold to prepare molybdenum tubing, which can obtain high-performance, dense molybdenum tubing at lower temperatures while maintaining the high purity and excellent properties of molybdenum. This preparation method not only reduces energy consumption but also minimizes the oxidation and volatilization of molybdenum, thereby improving product quality.

[0046] All parts not disclosed in this invention are prior art, and their specific structures, materials, and working principles will not be described in detail. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing high-performance molybdenum tubing based on a semi-solid method, characterized in that: Includes the following steps: S1. High-purity molybdenum powder is mixed with an appropriate amount of sintering aid to obtain a mixed powder. The purity of the high-purity molybdenum powder is not less than 99.9%, and the sintering aid is any one of Y2O3, La2O3, or CeO2, with a mass fraction of 0.1%. S2. The mixed powder is fed into a spiral injection molding machine, and the mixture is made into a liquid slurry at a temperature of 1300℃-1400℃ and a pressure of 30MPa. At the same time, a solid-liquid two-phase mixture, i.e. a semi-solid slurry, is formed under the stirring and shearing action of the screw in the spiral injection molding machine. S3. The spiral injection molding machine sprays semi-solid slurry into a mold under a pressure of 40-60 MPa to form a molybdenum tube. The mold includes a mold sleeve and a mold core. The mold sleeve has a connecting groove on its open side for connecting the nozzle of the spiral injection molding machine. The mold core has spiral blades on its side near the connecting groove. The method of using the mold includes the following steps: the mold core drives the spiral blades to rotate at high speed and slowly moves towards the connecting groove. When the nozzle of the spiral injection molding machine sprays semi-solid slurry into the mold sleeve, the high-speed rotating spiral blades transport the semi-solid slurry between the mold sleeve and the mold core and extrude the semi-solid slurry to form a high-pressure and dense molybdenum tube. S4. Cool the mold and then demold the molybdenum tube to obtain the formed molybdenum tube; S5. Cut off the ends of the formed molybdenum tube and straighten and machine it.

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