CN116967468A - An integrated forming processing method for active metal melt stirring paddles - Google Patents

Abstract

The invention relates to an integrated molding processing method for an active metal melt stirring paddle, which includes constructing a basic three-dimensional model of a refractory metal stirring paddle; adding a bottom support structure to obtain a molded three-dimensional model; the bottom support structure includes mutually nested solid support structures and grid support structure; perform slicing processing on the formed three-dimensional model to obtain slice data, perform scan path planning on the slice data, and obtain scan path data; use a laser beam to carry out selective melting scanning and printing of refractory metal powder, and pass through the layers The crude metal stirring paddle is obtained through stacking processing and forming; after post-processing and sandblasting, the finished product of the active metal melt stirring paddle is obtained. Compared with the existing technology, the present invention selectively melts metal powder according to the workpiece model, and manufactures three-dimensional solid parts by spreading powder layer by layer and melting, solidifying and accumulating layer by layer. The impeller and stirring shaft can be integrally formed to achieve The entire part has good high temperature corrosion resistance and extends service life.

Description

An integrated forming processing method for active metal melt stirring paddles

Technical field

The invention relates to the field of nuclear metallurgy, and in particular to an integrated forming processing method for an active metal melt stirring paddle.

Background technique

In the field of nuclear metallurgy, the stirring paddle materials used in the smelting process of active metals and alloys are made of the refractory metal tantalum (Ta) or tungsten and molybdenum. Due to their good high-temperature strength and resistance to active metals and molten alkali, Metals and vapors have good corrosion resistance. The stirring paddle consists of an impeller and a stirring shaft. The connection between the impeller and the stirring shaft should have good stability and reliability. At present, in order to simplify the small impeller, the impeller is often welded to the hub to form a whole, and then the hub is connected to the stirring shaft with keys and stop screws, or the impeller is directly welded to the stirring shaft. Under high temperature conditions, During long-term contact with molten metal, the welding joint of the stirring paddle is prone to severe corrosion, causing contamination of the smelted metal solution. Therefore, if the high-temperature corrosion-resistant material can be integrally formed into a stirring paddle, corrosion failure of the welding joint on the stirring paddle can be avoided and contamination of the smelting metal can be avoided.

Chinese invention patent CN201610877949.9 uses a stirring paddle when stirring metal powder. The structure is: the blade is fixed on the rotating shaft through screws or welded to the rotating shaft. Powder is easy to accumulate at the screw fixing point, or the welding point rubs against the powder for a long time during stirring. Warming affects performance. Chinese patent CN202020738844.7 designs an aluminum alloy melt stirring paddle, which adopts a structure in which the blades are welded to the stirring shaft. Chinese patent CN201520143662.4 designs a stirring paddle suitable for iron powder reduction. The blades are clamped to the rotating shaft or welded to the rotating shaft. Since this patent is aimed at active metal melts, the stirring paddle material is required to have good corrosion resistance at high temperatures above 600°C. The refractory metals tantalum, tungsten, and molybdenum have shown great advantages. However, due to the poor processing performance of these materials, Therefore, it is necessary to study its integrated forming method to obtain the entire high-temperature corrosion-resistant part and extend its service life.

Contents of the invention

The present invention aims at the problem that during long-term contact with high-temperature molten metal, the welding point of the stirring paddle is prone to severe corrosion, causing contamination to the smelted metal solution, and provides a processing method for integrally forming high-temperature corrosion-resistant material metal; The invention uses the laser selective melting method to selectively melt metal powder according to the workpiece model. Through layer-by-layer powder spreading and layer-by-layer melting and solidification accumulation, a three-dimensional solid part can be manufactured. The impeller and stirring shaft can be integrally formed to realize the entire part. It has good high temperature corrosion resistance and extends service life.

The object of the present invention can be achieved through the following technical solutions:

The invention provides an integrated forming processing method for an active metal melt stirring paddle, which includes the following steps:

S1: Construct a basic three-dimensional model of the refractory metal stirring paddle;

S2: Based on the basic three-dimensional model, add a bottom support structure to it to obtain a formed three-dimensional model. The bottom support structure includes a mutually nested solid support structure and a grid support structure;

S3: Perform slicing processing on the molded three-dimensional model to obtain slice data, perform scan path planning on the slice data, and obtain scan path data;

S4: Based on the scanning path data, the laser beam is used to perform selective melting scanning printing on the refractory metal powder, and the crude metal stirring paddle is obtained through layer-by-layer stacking processing;

S5: Post-process and sandblast the obtained crude metal stirring paddle to obtain the finished product of the active metal melt stirring paddle.

Further, in S1, Solidworks software was used to build a basic three-dimensional model of the refractory metal stirring paddle. The modeling dimensions were: the height of the stirring paddle was 50-100mm, the ratio of the height of the stirring paddle to the diameter of the blade was 4-6, and the peripheral speed was 20 -30cm/s, the blades rotate 35°-45° in opposite direction.

Further, in S2, Materialize Magics software was used to add a support structure to the bottom of the basic three-dimensional model of the refractory metal stirring paddle.

Further, in S3, Build Planner software is used to slice the molded three-dimensional model to obtain slice data, and scan path planning is performed on the slice data to form scan path data.

Further, in S4, the refractory metal powder used is selected from one or more of tantalum metal powder, tungsten powder, and molybdenum powder.

Further, in S4, the refractory metal powder is prepared through a plasma rotating electrode atomization process, with a powder particle size of 10-53 μm and an oxygen content of less than 200 ppm.

Further, in S4, before performing selective melting scanning printing, argon gas with a purity of 99.999% is introduced into the forming chamber, the argon gas flow rate is 4-5L/min, and the oxygen concentration in the forming chamber is controlled to be no higher than 10 ppm.

Further, in S4, the selected melting scanning and printing process specifically includes:

Load the refractory metal powder into the forming chamber of the laser selective melting equipment;

Evenly spread refractory metal powder on the titanium alloy substrate of the forming chamber;

According to the imported scan path data, the laser beam is used to perform selective melting scanning and printing of the refractory metal powder;

The melt scan printing parameters include:

The powder coating thickness is 20-60μm, the scanning method adopts strip mode, the scanning spacing is 0.04-0.11mm, the spot diameter is 100μm, the laser power is 150-250W, and the scanning rate is 200-800mm/s.

Further, in S4, the post-processing includes: placing the crude metal molybdenum stirring blade into a vacuum heat treatment furnace, holding it at 1350°C for 120 minutes, with a vacuum degree of 5×10 ^-3 Pa, and eliminating its internal residual stress through heat treatment to prevent cracking and deformation, the heat-treated metal molybdenum stirring paddle will then be cut from the base plate.

Further, in S5, the process parameters of the sandblasting treatment include: sandblasting sand particles are Al ₂ O ₃ with a diameter of 0.3-0.85mm, sandblasting speed is 0.8-1m/min, air pressure is 0.2-0.4MPa, sandblasting The time is 0.01-0.03m ² /min.

Compared with the existing technology, the present invention has the following technical advantages:

(1) The present invention adopts an integrated molding processing method and uses 3D printing technology to stack metal stirring paddles layer by layer. Compared with traditional processing methods, it can reduce material waste and processing procedures and improve production efficiency; by using laser selective melting method , no mold is required in the entire manufacturing process of the mixing paddle, which reduces the manufacturing process, shortens the manufacturing cycle of parts, and reduces costs;

(2) The present invention adds a bottom support structure to the basic three-dimensional model of the mixing paddle, including a solid support structure and a grid support structure, which can provide stable support and fixation and ensure the shape and structural integrity of the mixing paddle during the printing process.

(3) The present invention uses spherical powder to form and stack layer by layer to obtain a refractory metal stirring blade with a dense microstructure. Since the stirring blade is integrally formed, the entire part can have good high-temperature corrosion resistance and extend its service life.

(4) The present invention uses refractory metal powder for selective melting scanning printing, which improves the high temperature resistance and corrosion resistance of the stirring paddle. The refractory metal powder is prepared through a plasma rotating electrode atomization process and has a smaller particle size and low oxygen content, which improves printing quality and material performance.

(5) The present invention performs post-processing on the printed crude stirring paddle, including vacuum heat treatment and sand blasting. Vacuum heat treatment can eliminate internal residual stress, prevent cracking and deformation, and improve the strength and stability of the stirring paddle. Sandblasting can improve the surface finish and roughness of the mixing paddle, increasing its service life and performance.

Description of the drawings

Figure 1 is a flow chart of the steps of the metal stirring paddle preparation method in the present invention;

Figure 2 is a model diagram of a stirring paddle prepared by selective laser melting in the present invention;

Figure 3 is a physical diagram of the stirring paddle prepared by selective laser melting in the present invention;

Figure 4 is a microstructure diagram of a stirring paddle prepared by selective laser melting in the present invention.

Detailed ways

The invention uses high-purity tantalum, high-purity tungsten and high-purity molybdenum metal powders as raw materials, and uses laser selective melting equipment to stir the paddle. The process flow of the invention (as shown in Figure 1) is: building a three-dimensional model → building a support structure → slicing processing → Data import → powder preparation → argon gas filling → powder spreading → laser selective melting → heat treatment → wire cutting → surface treatment (sandblasting), including the following steps:

(1) Use Solidworks software to establish a three-dimensional model of the mixing paddle to be processed. The modeling size is that the height of the mixing paddle is 50-100mm, the ratio of the height to the diameter of the blade is 4-6, the peripheral speed is 20-30cm/s, and the blades turn inversely 35 °-45°, the model diagram is shown in Figure 2;

(2) In order to prevent the stirring paddle from cracking, the Materialize Magics software is used to add a support structure to the bottom of the three-dimensional model of the refractory metal stirring paddle constructed in step (1). The support structure includes a solid support and a grid support, both of which are nested in each other;

(3) Use Build Planner software to slice the three-dimensional model and support structure constructed in steps (1) and (2) to obtain slice data, and perform scan path planning on the slice data to form scan path data;

(4) Import the scan path data planned in step (3) into the laser selective melting equipment;

(5) Load 12 kilograms of spherical refractory metal powder into the laser selective melting equipment;

(6) Pour inert gas argon (purity 99.999%) into the forming chamber, with an argon flow rate of 4-5L/min, and control the oxygen concentration in the forming chamber to not be higher than 10ppm;

(7) Evenly spread spherical refractory metal powder with an area of 105mm×105mm on the titanium alloy substrate of the forming chamber;

(8) According to the scan path data imported in step (4), use a laser beam to perform selective melting scanning printing on the refractory metal powder. The printing process is printed one by one in the order of the support, lower surface, main body and upper surface. Control the scanning method, laser Power, scanning rate and scanning spacing process parameters, powder coating thickness 20-60μm, scanning method adopts strip mode, scanning spacing 0.04-0.11mm, spot diameter 100μm, laser power 150-250W, scanning rate 200-800mm/s; after The metal stirring paddle is obtained by stacking and processing layer by layer;

(9) Put the metal stirring blade obtained in step (8) into a vacuum heat treatment furnace and keep it at 900-1500°C for 60-150 minutes with a vacuum degree of 2×10 ^-3 -6×10 ^-3 Pa. Eliminate it through heat treatment. Internal residual stress to prevent cracking and deformation;

(10) Cut the metal stirring blade heat-treated in step (9) from the substrate,

(11) Sandblast the stirring paddle printed in step (10). The sandblasting process conditions are: the sandblasting sand particles are Al ₂ O ₃ with a diameter of 0.3-0.85mm, and the sandblasting speed is 0.8-1m/min. The air pressure is 0.2-0.4MPa and the sandblasting time is 0.01-0.03m ² /min to obtain a metal stirring paddle that ultimately meets industrial applications.

This process can rapidly heat and rapidly cool spherical refractory metal powder by adjusting the scanning mode, laser power, scanning rate and scanning spacing, and stack the layers layer by layer to form a three-dimensional entity.

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Features such as structure/module name, control mode, algorithm, process or composition ratio that are not clearly stated in this technical solution are regarded as common technical features disclosed in the prior art.

Example 1

Raw materials and requirements: high-purity tantalum metal powder (tantalum content greater than 99.95wt.%)

(1) Use Solidworks software to construct a three-dimensional model of the metal tantalum stirring blade to be processed. The modeling size is the height of the stirring blade 100mm, the ratio of blade diameter to height is 4, the peripheral speed is 20cm/s, and the blades are reversely turned at 45°;

(2) In order to prevent cracking at the connection between the stirring paddle and the substrate, Materialize Magics software is used to add a support structure to the bottom of the three-dimensional model of the metal tantalum stirring paddle constructed in step (1). The support structure includes a solid support and a grid support, and the two are mutually exclusive. Nesting, see Figure 2;

(3) Use the Build Planner software to convert the three-dimensional model into a printing model that can contain printing information, perform slicing and stratification to obtain slicing data, and perform scan path planning on the slicing data to form scan path data;

(4) Import the scan path data planned in step (3) into the laser selective melting equipment;

(5) Load 12 kilograms of spherical tantalum metal powder into the forming bin of the laser selective melting equipment;

(6) Pour in the inert gas high-purity argon (purity 99.99%) into the forming chamber, the argon gas flow rate is 4-5L/min, and control the oxygen concentration in the forming chamber to not be higher than 10ppm;

(7) Evenly spread spherical tantalum metal powder with an area of 105mm×105mm on the titanium alloy substrate of the forming chamber;

(8) According to the scan path data imported in step (4), use a laser beam to perform selective melting scanning printing on the refractory metal powder. The printing process is printed one by one in the order of the support, lower surface, main body and upper surface. Control the scanning method, laser Power, scanning rate and scanning spacing process parameters, the powder coating thickness is 20μm, the scanning method adopts strip mode, the scanning spacing is 0.04mm, the spot diameter is 100μm, the laser power is 200W, the scanning rate is 300mm/s; after layer-by-layer stacking processing, metal tantalum is obtained impeller;

(9) Put the metal stirring blade obtained in step (8) into a vacuum heat treatment furnace and keep it at 900°C for 60 minutes with a vacuum degree of 5×10 ^-3 Pa. Eliminate its internal residual stress through heat treatment to prevent cracking and deformation;

(10) Cut the metal stirring blade heat-treated in step (9) from the substrate,

(11) Sandblast the stirring paddle printed in step (10). The sandblasting process conditions are: the sandblasting sand particles are Al ₂ O ₃ with a diameter of 0.3-0.85mm, and the sandblasting speed is 0.8-1m/min. The air pressure is 0.2-0.4MPa and the sandblasting time is 0.01-0.03m ² /min to obtain a metal stirring paddle that ultimately meets industrial application, see Figure 3.

The microstructure of the stirring paddle prepared by laser selective melting is shown in Figure 4. It can be seen from Figure 4 that the microstructure of tantalum presents typical equiaxed crystal structure characteristics, with good grain size consistency (average about 50 microns), no holes and Inclusions indicate that the laser selective melting process has better molding quality.

Example 2

Raw materials and requirements: high-purity tantalum metal powder (tantalum content greater than 99.95wt.%)

(1) Use Solidworks software to construct a three-dimensional model of the metal tantalum stirring blade to be processed. The modeling size is the height of the stirring blade 100mm, the ratio of blade diameter to height is 5, the peripheral speed is 25cm/s, and the blades are reversely turned at 45°;

(2) In order to prevent cracking at the connection between the stirring paddle and the substrate, Materialize Magics software is used to add a support structure to the bottom of the three-dimensional model of the metal tantalum stirring paddle constructed in step (1). The support structure includes a solid support and a grid support, and the two are mutually exclusive. Nesting;

(3) Use the Build Planner software to convert the three-dimensional model into a printing model that can contain printing information, perform slicing and stratification to obtain slicing data, and perform scan path planning on the slicing data to form scan path data;

(4) Import the scan path data planned in step (3) into the laser selective melting equipment;

(5) Load 12 kilograms of spherical tantalum metal powder into the forming bin of the laser selective melting equipment;

(6) Pour in the inert gas high-purity argon (purity 99.99%) into the forming chamber, the argon gas flow rate is 4-5L/min, and control the oxygen concentration in the forming chamber to not be higher than 10ppm;

(7) Evenly spread spherical tantalum metal powder with an area of 105mm×105mm on the titanium alloy substrate of the forming chamber;

(8) According to the scan path data imported in step (4), use a laser beam to perform selective melting scanning printing on the refractory metal powder. The printing process is printed one by one in the order of the support, lower surface, main body and upper surface. Control the scanning method, laser Power, scanning rate and scanning spacing process parameters, the powder coating thickness is 30μm, the scanning method adopts strip mode, the scanning spacing is 0.04mm, the spot diameter is 100μm, the laser power is 200W, the scanning rate is 300mm/s; after layer-by-layer stacking processing, metal tantalum is obtained impeller;

(9) Put the metal stirring blade obtained in step (8) into a vacuum heat treatment furnace and keep it at 900°C for 120 minutes with a vacuum degree of 5×10 ^-3 Pa. Eliminate its internal residual stress through heat treatment to prevent cracking and deformation;

(10) Cut the metal stirring paddle heat-treated in step (9) from the substrate;

(11) Sandblast the stirring paddle printed in step (10). The sandblasting process conditions are: the sandblasting sand particles are Al ₂ O ₃ with a diameter of 0.3-0.85mm, and the sandblasting speed is 0.8-1m/min. The air pressure is 0.2-0.4MPa and the sandblasting time is 0.01-0.03m ² /min to obtain a metal stirring paddle that ultimately meets industrial applications.

Example 3

Raw materials and requirements: high-purity tantalum metal powder (tantalum content greater than 99.95wt.%)

(1) Use Solidworks software to construct a three-dimensional model of the metal tantalum stirring blade to be processed. The modeling size is the height of the stirring blade 100mm, the ratio of blade diameter to height is 6, the peripheral speed is 30cm/s, and the blades are reversely turned at 45°;

(2) In order to prevent cracking at the connection between the stirring paddle and the substrate, Materialize Magics software is used to add a support structure to the bottom of the three-dimensional model of the metal tantalum stirring paddle constructed in step (1). The support structure includes a solid support and a grid support, and the two are mutually exclusive. Nesting;

(3) Use the Build Planner software to convert the three-dimensional model into a printing model that can contain printing information, perform slicing and stratification to obtain slicing data, and perform scan path planning on the slicing data to form scan path data;

(4) Import the scan path data planned in step (3) into the laser selective melting equipment;

(5) Load 12 kilograms of spherical tantalum metal powder into the forming bin of the laser selective melting equipment;

(6) Pour in the inert gas high-purity argon (purity 99.99%) into the forming chamber, the argon gas flow rate is 4-5L/min, and control the oxygen concentration in the forming chamber to not be higher than 10ppm;

(7) Evenly spread spherical tantalum metal powder with an area of 105mm×105mm on the titanium alloy substrate of the forming chamber;

(8) According to the scan path data imported in step (4), use a laser beam to perform selective melting scanning printing on the refractory metal powder. The printing process is printed one by one in the order of the support, lower surface, main body and upper surface. Control the scanning method, laser Power, scanning rate and scanning spacing process parameters, the powder coating thickness is 30μm, the scanning method adopts strip mode, the scanning spacing is 0.04mm, the spot diameter is 100μm, the laser power is 220W, the scanning rate is 300mm/s; after layer-by-layer stacking processing, metal tantalum is obtained impeller;

(9) Put the metal tantalum stirring blade obtained in step (8) into a vacuum heat treatment furnace and keep it at 900°C for 120 minutes with a vacuum degree of 5×10 ^-3 Pa. Eliminate its internal residual stress through heat treatment to prevent cracking and deformation;

(10) Cut the metal tantalum stirring blade heat-treated in step (9) from the substrate;

(11) Sandblast the stirring paddle printed in step (10). The sandblasting process conditions are: the sandblasting sand particles are Al ₂ O ₃ with a diameter of 0.3-0.85mm, and the sandblasting speed is 0.8-1m/min. The air pressure is 0.2-0.4MPa and the sandblasting time is 0.01-0.03m ² /min to obtain a metal tantalum stirring impeller that ultimately meets industrial applications.

Example 4

Raw materials and requirements: high purity tungsten (tungsten content greater than 99.95wt.%)

(1) Use Solidworks software to construct a three-dimensional model of the metal tungsten stirring blade to be processed. The modeling size is the height of the stirring blade 100mm, the ratio of blade diameter to height is 6, the peripheral speed is 30cm/s, and the blades are reversely turned 45°;

(2) In order to prevent cracking at the connection between the stirring paddle and the substrate, Materialize Magics software is used to add a support structure to the bottom of the three-dimensional model of the metal tungsten stirring paddle constructed in step (1). The support structure includes a solid support and a grid support, and the two are mutually exclusive. Nesting;

(3) Use the Build Planner software to convert the three-dimensional model into a printing model that can contain printing information, perform slicing and stratification to obtain slicing data, and perform scan path planning on the slicing data to form scan path data;

(4) Import the scan path data planned in step (3) into the laser selective melting equipment;

(5) Load 12 kilograms of spherical metal tungsten powder into the forming bin of the laser selective melting equipment;

(6) Pour in the inert gas high-purity argon (purity 99.99%) into the forming chamber, the argon gas flow rate is 4-5L/min, and control the oxygen concentration in the forming chamber to not be higher than 10ppm;

(7) Evenly spread spherical metal tungsten powder with an area of 105mm×105mm on the titanium alloy substrate of the forming chamber;

(8) According to the scan path data imported in step (4), use a laser beam to perform selective melting scanning printing on the refractory metal powder. The printing process is printed one by one in the order of the support, lower surface, main body and upper surface. Control the scanning method, laser Power, scanning rate and scanning spacing process parameters, the powder coating thickness is 30μm, the scanning method adopts strip mode, the scanning spacing is 0.05mm, the spot diameter is 100μm, the laser power is 180W, the scanning rate is 500mm/s; after layer-by-layer stacking processing, metal tungsten is obtained impeller;

(9) Put the metal tungsten stirring blade obtained in step (8) into a vacuum heat treatment furnace, keep it at 1500°C for 120 minutes, and a vacuum degree of 5×10 ^-3 Pa. Eliminate its internal residual stress through heat treatment to prevent cracking and deformation;

(10) Cut the metal tungsten stirring blade heat-treated in step (9) from the substrate;

(11) Sandblast the stirring paddle printed in step (10). The sandblasting process conditions are: the sandblasting sand particles are Al ₂ O ₃ with a diameter of 0.3-0.85mm, and the sandblasting speed is 0.8-1m/min. The air pressure is 0.2-0.4MPa and the sandblasting time is 0.01-0.03m ² /min to obtain a metal tungsten stirring blade that ultimately meets industrial applications.

Example 5

Raw materials and requirements: high purity molybdenum (molybdenum content greater than 99.95wt.%)

(1) Use Solidworks software to construct a three-dimensional model of the metal molybdenum stirring blade to be processed. The modeling size is the height of the stirring blade 100mm, the ratio of blade diameter to height is 6, the peripheral speed is 30cm/s, and the blades are reversely turned at 45°;

(2) In order to prevent cracking at the connection between the stirring paddle and the substrate, Materialize Magics software is used to add a support structure to the bottom of the three-dimensional model of the metal molybdenum stirring paddle constructed in step (1). The support structure includes a solid support and a grid support, and the two are mutually exclusive. Nesting;

(3) Use the Build Planner software to convert the three-dimensional model into a printing model that can contain printing information, perform slicing and stratification to obtain slicing data, and perform scan path planning on the slicing data to form scan path data;

(4) Import the scan path data planned in step (3) into the laser selective melting equipment;

(5) Load 12 kilograms of spherical metal molybdenum powder into the forming bin of the laser selective melting equipment;

(6) Pour in the inert gas high-purity argon (purity 99.99%) into the forming chamber, the argon gas flow rate is 4-5L/min, and control the oxygen concentration in the forming chamber to not be higher than 10ppm;

(7) Evenly spread spherical metal molybdenum powder with an area of 105mm×105mm on the titanium alloy substrate of the forming chamber;

(8) According to the scan path data imported in step (4), use a laser beam to perform selective melting scanning printing on the refractory metal powder. The printing process is printed one by one in the order of the support, lower surface, main body and upper surface. Control the scanning method, laser Power, scanning rate and scanning spacing process parameters, the powder coating thickness is 30μm, the scanning method adopts strip mode, the scanning spacing is 0.05mm, the spot diameter is 100μm, the laser power is 200W, the scanning rate is 400mm/s; after layer-by-layer stacking processing, metal molybdenum is obtained impeller;

(9) Put the metal molybdenum stirring blade obtained in step (8) into a vacuum heat treatment furnace and keep it at 1350°C for 120 minutes with a vacuum degree of 5×10 ^-3 Pa. Eliminate its internal residual stress through heat treatment to prevent cracking and deformation;

(10) Cut the metal molybdenum stirring blade heat-treated in step (9) from the substrate;

(11) Sandblast the metal molybdenum stirring paddle printed in step (10). The sandblasting process conditions are: the sandblasting sand particles are Al ₂ O ₃ with a diameter of 0.3-0.85mm, and the sandblasting speed is 0.8-1m/ min, the air pressure is 0.2-0.4MPa, and the sandblasting time is 0.01-0.03m ² /min, to obtain a metal molybdenum stirring blade that ultimately meets industrial applications.

The above description of the embodiments is to facilitate those of ordinary skill in the technical field to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without inventive efforts. Therefore, the present invention is not limited to the above embodiments. Based on the disclosure of the present invention, improvements and modifications made by those skilled in the art without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims (10)

1. An integrated forming processing method of an active metal melt stirring paddle is characterized by comprising the following steps of:

s1: constructing a basic three-dimensional model of the refractory metal stirring paddle;

s2: adding a bottom support structure based on the basic three-dimensional model to obtain a molded three-dimensional model, wherein the bottom support structure comprises a solid support structure and a grid support structure which are mutually nested;

s3: slicing the molded three-dimensional model to obtain slice data, and planning a scanning path of the slice data to obtain scanning path data;

s4: based on the scanning path data, performing zone-selecting melting scanning printing on refractory metal powder by adopting laser beams, and performing layer-by-layer stacking processing to obtain a crude product of the metal stirring paddle;

s5: and (3) carrying out post-treatment and sand blasting on the obtained crude product of the metal stirring paddle to obtain a finished product of the active metal melt stirring paddle.

2. The integrated processing method of an active metal melt stirring paddle according to claim 1, wherein in S1, a basic three-dimensional model of the refractory metal stirring paddle is constructed by using Solidworks software, and the modeling size is as follows: the height of the stirring paddle is 50-100mm, the ratio of the height of the stirring paddle to the diameter of the blade is 4-6, the circumferential speed is 20-30cm/s, and the blades are reversely turned by 35-45 degrees.

3. The method of claim 1, wherein in S2, a support structure is added to the bottom of the base three-dimensional model of the refractory metal stirring paddle by using Materialise Magics software.

4. The integrated forming processing method of the active metal melt stirring paddle according to claim 1, wherein in S3, slicing is performed on the formed three-dimensional model by utilizing Build Planner software to obtain slice data, and scan path planning is performed on the slice data to form scan path data.

5. The method of claim 1, wherein in S4, the refractory metal powder is one or more selected from the group consisting of tantalum powder, tungsten powder, and molybdenum powder.

6. The method for integrally forming an active metal melt stirring paddle according to claim 5, wherein in S4, the refractory metal powder is prepared by a plasma rotary electrode atomization process, the particle size of the powder is 10-53 μm, and the oxygen content is lower than 200ppm.

7. The integrated forming processing method of the active metal melt stirring paddle, according to claim 5, is characterized in that in S4, argon with the purity of 99.999% is introduced into a forming bin before selective melting scanning printing, the flow rate of the argon is 4-5L/min, and the oxygen concentration in the forming bin is controlled to be not higher than 10ppm.

8. The method for integrally forming an active metal melt stirring paddle according to claim 1, wherein in S4, in the process of performing selective melting scanning printing, the method specifically comprises:

loading the refractory metal powder into a forming bin of a laser selective melting device;

uniformly spreading refractory metal powder on a titanium alloy substrate of a forming bin;

according to the imported scanning path data, performing selective melting scanning printing on refractory metal powder by adopting laser beams;

the parameters of the melt scan printing include:

the thickness of the powder is 20-60 mu m, the scanning mode adopts a strip mode, the scanning interval is 0.04-0.11mm, the spot diameter is 100 mu m, the laser power is 150-250W, and the scanning speed is 200-800mm/s.

9. The method of integrally forming an active metal melt paddle according to claim 1, wherein in S4, the post-treatment comprises: placing the crude product of the metal molybdenum stirring paddle into a vacuum heat treatment furnace, preserving heat at 1350 ℃ for 120min, and vacuum degree being 5 multiplied by 10 ^-3 Pa, eliminating the residual stress in the base plate through heat treatment, preventing cracking and deformation, and cutting the heat-treated metal molybdenum stirring paddle from the base plate.

10. The method for integrally forming an active metal melt stirring paddle according to claim 1, wherein in S5, the process parameters of the sand blasting include: the sand grain of the sand blasting is Al with the diameter of 0.3-0.85mm ₂ O ₃ The sand blasting speed is 0.8-1m/min, the air pressure is 0.2-0.4MPa, and the sand blasting time is 0.01-0.03m ² /min。