Manufacturing method and device of gradient metal cast ingot

Abstract

The invention relates to a gradient metal cast ingot manufacturing method and device, and the method comprises the steps: 1) filling a metal powder bin with B metal powder, and painting a heat insulation coating on the inner wall of a cooler; (2) the metal material A is added into a crucible and heated to form molten metal A; (3) casting is conducted, specifically, the molten metal A is injected into a cooler, a movable bottom plate moves downwards, and the movable bottom plate and the solidified cast ingot move downwards together; the metal powder B is continuously added into the crucible, and the metal powder B and the metal liquid A are melted to form mixed metal liquid A and mixed metal liquid B; and the molten metal B is completely cast. The gradient metal cast ingot has the advantages that the gradient metal cast ingot has gradient change on the whole cross section, and compared with an existing gradient metal material, the impurity amount is low. The adopted equipment is simple and reasonable, the investment is low, the operation method is simple and convenient, maintenance is easy, the use cost is low, and the prepared gradient metal blank is gradient metal with continuously-changed components.

Description

Technical Field

[0001] The present invention relates to the field of manufacturing gradient materials, and particularly to a method and device for manufacturing a gradient metal ingot. Background Art

[0002] Strictly speaking, gradient materials should be called "functionally gradient composites" (abbreviated as FGM), also known as functionally graded materials. In general materials, the dispersed phase is uniformly distributed and the properties of the whole material are the same. However, in some cases, people often hope that both sides of the same piece of material have different properties or functions, and also hope that the two sides with different properties are perfectly combined so as not to be damaged due to property mismatch under harsh usage conditions. Taking the most representative scramjet engine in the propulsion system of a space shuttle as an example, the temperature of the combustion gas usually exceeds 2000°C, which will cause a strong thermal shock to the combustion chamber wall; on the other side of the combustion chamber wall, it has to withstand the cooling effect of liquid hydrogen as fuel, usually at a temperature of about -200°C. In this way, one side of the combustion chamber wall in contact with the combustion gas has to bear extremely high temperatures, and the side in contact with liquid hydrogen has to bear extremely low temperatures. Ordinary materials obviously cannot meet this requirement. Therefore, people thought of using metals and ceramics together, using ceramics to deal with high temperatures and metals to deal with low temperatures. However, when combining metals and ceramics using traditional techniques, due to the poor matching of the interfacial thermodynamic properties of the two, it will still be damaged under extremely large thermal stresses.

[0003] In response to this situation, in 1984, Japanese scientist Toshio Hirai first proposed a new idea and concept of functionally gradient materials and carried out research. The basic idea of this brand-new material design concept is: according to specific requirements, select two materials with different properties, and by continuously changing the composition and structure of the two materials, make their internal interfaces disappear, so as to obtain a heterogeneous material whose function changes gradually corresponding to the changes in composition and structure, in order to reduce and overcome the property mismatch factors at the joint. For example, for the above-mentioned combustion chamber wall, by continuously controlling the changes in internal composition and microstructure between ceramics and metals, no interface appears between the two materials, so that the overall material has both good thermal stress resistance and mechanical strength.

[0004] At present, the mainly developed methods for preparing gradient materials include: chemical vapor deposition method, physical evaporation method, plasma spraying method, particle gradient arrangement method, self-propagating high-temperature synthesis method, liquid film direct forming method, thin film infiltration forming method, etc. Their applications have been extended to fields such as nuclear energy, electronics, chemistry, biomedical engineering, etc. Their compositions have also developed from metal-ceramics to various combinations such as metal-alloy, non-metal-non-metal, non-metal-ceramics, polymer film-polymer film, etc. There are a wide variety, and the application prospects are very broad. However, the technology for manufacturing composite metal billets is only mastered by a few countries such as Japan.

[0005] In the prior art, patent application number: CN202111267557.8 discloses a method for preparing a tungsten-copper functional gradient material, wherein a series of tungsten-copper alloy powders with gradient tungsten powder mass content are sealed in a sleeve and then pressed by cold isostatic pressing to obtain a multilayer tungsten-copper gradient material compact, and the end with the lowest tungsten powder content in the compact is spliced ​​with a copper block and then subjected to infiltration-welding, and then hot isostatic pressing. This method mainly uses metal powder to be achieved through isostatic pressing, but the resulting metal material has a high impurity content and low structural strength, and it is impossible to obtain an ideal gradient metal blank. Patent application number: CN202110773738.1, discloses a method for preparing a structural functional gradient material, using additive manufacturing technology to prepare a structural functional gradient material "skeleton", installing a molding substrate, and filling it with protective gas; importing a "skeleton" three-dimensional digital model, forming a "skeleton" structure, and vacuum heat treating the cleaned "skeleton"; using a chemical corrosion solution to treat the "skeleton" surface and supporting structure, and putting the treated "skeleton" and filling materials into a mold package, and performing hot isostatic pressing to prepare a structural functional gradient material. However, this gradient material is not a gradient change on the entire cross section of the material. Summary of the invention

[0006] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a method and apparatus for manufacturing a gradient metal ingot, so as to obtain a gradient metal ingot having a gradient composition change on the overall cross section, while reducing the impurity content of the gradient metal ingot.

[0007] To achieve the above object, the present invention is implemented through the following technical solutions:

[0008] A method for manufacturing a gradient metal ingot comprises the following steps:

[0009] 1) Fill the metal powder bin with B metal powder and apply insulation paint on the inner wall of the cooler;

[0010] 2) adding metal material A into a crucible, blowing argon gas into the crucible, heating and melting the metal material A to form liquid metal A;

[0011] 3) Start casting, open the slide plate and the water inlet of the crucible, and inject the A metal liquid into the cooler. The A metal liquid solidifies under the cooling effect of the movable bottom plate and the cooler; at the same time, the movable bottom plate moves downward, and the movable bottom plate moves downward together with the solidified ingot;

[0012] At the beginning of casting, the metal powder bin is opened, and the B metal powder is continuously added into the crucible, and the B metal powder and the A metal liquid are melted to form the AB mixed metal liquid; with the continuous addition of the B metal powder and the continuous outflow of the AB mixed metal liquid, the B metal content in the metal liquid in the crucible gradually increases, until it is finally completely replaced by the B metal liquid formed by the melting of the B metal powder by induction heating;

[0013] 4) Continuously cast until the chemical composition of the molten metal in the crucible is all metal B;

[0014] 5) Stop adding metal B powder, and cast all the remaining molten metal in the crucible to obtain a gradient metal ingot of AB metal.

[0015] In step 3), the feeding flow rate of metal B powder is less than the flow rate of the cast molten metal.

[0016] The chemical composition of the head of the gradient metal ingot obtained in step 5) is metal A, the chemical composition of the tail is metal B, and the gradient composition gradually changes between the head and the tail.

[0017] A device for a gradient metal ingot includes a metal powder bin, a crucible, an induction coil, a slide plate and a nozzle, a cooler, a movable bottom plate, a lifting column, and an argon blowing pipe. The metal powder bin is arranged directly above the crucible, the cooler is arranged directly below the crucible, the outside of the crucible is connected with an induction coil, the bottom of the crucible is connected with a slide plate and a nozzle, the argon blowing pipe is used to blow argon gas into the crucible, the top of the lifting column is fixedly connected with a movable bottom plate, and the movable bottom plate is slidably connected with the inner wall of the cooler.

[0018] A permanent temperature measuring probe is fixedly connected to the inner wall of the crucible.

[0019] The cooler is a water-cooled cooler.

[0020] An adiabatic coating layer is covered on the inner wall of the cooler.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] The present invention provides a manufacturing method and device for a gradient metal ingot. Using this method and device, a gradient metal ingot is obtained, and the gradient metal ingot has a gradient change in the overall cross-section, and has a lower impurity content compared with the existing gradient metal materials. The equipment adopted by the present invention is simple and reasonable, with less investment, simple operation method, easy to maintain, low use cost, and the obtained gradient metal blank is a gradient metal with continuously changing composition. Description of the Drawings

[0023] Figure 1 It is a schematic structural diagram of a manufacturing device for a gradient metal ingot.

[0024] In the figure: 1 - metal powder bin, 2 - metal B powder, 3 - crucible, 4 - induction coil, 5 - permanent temperature measuring probe, 6 - AB mixed molten metal, 7 - slide plate and nozzle, 8 - cooler, 9 - gradient metal ingot, 10 - movable bottom plate, 11 - adiabatic coating layer, 12 - lifting column, 13 - cooler wall, 14 - argon blowing pipe. Detailed Embodiments

[0025] The present invention will be described in detail below in conjunction with the accompanying drawings of the specification. However, it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0026] See Figure 1 , a manufacturing device for a gradient metal ingot, comprising a metal powder bin 1, a crucible 3, an induction coil 4, a slide plate and a nozzle 7, a cooler 8, a movable bottom plate 10, a lifting column 12, and an argon blowing pipe 14. The metal powder bin 1 is arranged directly above the crucible 3 and is filled with B metal powder 2 inside. The outside of the crucible 3 is connected with an induction coil 4. The induction coil 4 and the crucible 3 are used to melt A metal. The B metal is added in the form of metal powder into the A metal liquid in the crucible 3. The A metal and the B metal have different compositions. The bottom of the crucible 3 is connected with a slide plate and a nozzle 7. The argon blowing pipe 14 is used to blow argon gas into the crucible 3. A permanent temperature probe 5 is fixedly connected to the inner wall of the crucible 3 for measuring the temperature of the metal liquid in the crucible 3. The cooler 8 is arranged directly below the crucible 3 for receiving the AB mixed metal liquid 6 flowing out of the crucible 3 and forming a gradient metal ingot 9. The top end of the lifting column 12 is fixedly connected with a movable bottom plate 10. The movable bottom plate 10 is slidably connected with the inner wall of the cooler 8. The lifting column 12 can be powered by a motor. The lifting column 12 is longitudinally fixed with a rack, and the rack meshes with a gear. The motor drives the gear to rotate, and the lifting column 12 is driven to lift smoothly through gear transmission. The lifting column 12 can also be driven to lift in other ways. The cooler 8 is a water-cooled cooler 8. The inner wall of the cooler 8 is coated with an adiabatic coating layer 11, and the adiabatic coating 11 can be a metal mold release casting coating.

[0027] A manufacturing method for a gradient metal ingot comprises the following steps:

[0028] 1) Fill the B metal powder 2 into the metal powder bin 1 and apply the adiabatic coating 11 on the inner wall of the cooler 8;

[0029] 2) Add the A metal material into the crucible 3 and blow argon gas into the crucible 3 to form a protective atmosphere, and heat and melt the A metal material to form A metal liquid;

[0030] 3) Start casting, open the slide plate and the nozzle 7 of the crucible 3, and inject the A metal liquid into the cooler 8. The A metal liquid solidifies under the cooling action of the movable bottom plate 10 and the cooler 8. At the same time, under the downward pulling action of the lifting column 12, the movable bottom plate 10 moves downward, and the movable bottom plate 10 and the solidified ingot move downward together. The adiabatic coating 11 plays a certain adiabatic role, making the heat conduction heat flow of the metal liquid or the ingot to the cooler wall 13 weaker. Most of the heat of the metal liquid is conducted out by the movable bottom plate 10, so the liquid-solid front of the ingot is generally a horizontal plane;

[0031] At the same time as starting the casting, open the metal powder bin 1, and continuously add the B metal powder 2 into the crucible 3. The feeding rate of the B metal powder 2 is less than the feeding rate of the casting metal liquid. The difference between the two feeding rates and the total addition amount of the two metals A and B determine the casting duration and the weight of the gradient metal ingot. The B metal powder 2 and the A metal liquid melt to form the AB mixed metal liquid 6; as the B metal powder 2 is continuously added and the AB mixed metal liquid 6 continuously flows out, the B metal content in the metal liquid in the crucible 3 gradually increases until it is finally completely replaced by the B metal liquid formed by the induction heating and melting of the B metal powder 2;

[0032] 4) Continuously cast until the chemical composition of the metal liquid in the crucible 3 is all B metal;

[0033] 5) Stop adding the B metal powder 2, and cast all the remaining metal liquid in the crucible 3 to obtain the gradient metal ingot of the AB metal. The chemical composition of the head of this gradient metal ingot is A metal, the chemical composition of the tail is B metal, and the composition between the head and the tail is a gradually changing gradient composition.

[0034] Example 1:

[0035] For the gradient metal ingot of Mn13 high manganese steel and heavy rail steel U71Mn, the cross-sectional size of the ingot is: 600×200mm, the length is 2600mm, and the total weight is 1800kg. See Figure 1 , the manufacturing method of this gradient metal ingot includes the following steps:

[0036] 1. The capacity of the crucible 3 is 1 ton, and 900 kg of Mn13 high manganese steel waste (A metal waste) and U71Mn steel powder (B metal powder 2) are prepared respectively;

[0037] 2. Fill the B metal powder 2 into the metal powder bin 1; coat the cooler wall 13 with the heat-insulating coating 11;

[0038] 3. Add the A metal waste into the crucible 3, blow argon into the crucible 3 through the argon blowing pipe 14 to form a protective atmosphere, heat and melt the A metal waste to form the A metal liquid, and the superheat degree is 90°C;

[0039] 4. Start casting, open the slide plate and the nozzle 7, inject the A metal liquid into the cooler 8, and solidify under the cooling action of the movable bottom plate 10 and the cooler wall 13. At the same time, under the downward pulling action of the lifting column 12, the movable bottom plate 10 moves downward together with the solidified ingot;

[0040] 5. While starting the casting, turn on the feeding system of the metal powder bin 1, continuously add the B metal powder 2 into the molten metal in the crucible 3, and melt it to form the AB mixed molten metal 6. As the B metal powder 2 is continuously added and the AB mixed molten metal 6 continuously flows out, the content of the B metal in the molten metal in the crucible 3 gradually increases until it is finally completely replaced by the B molten metal formed by the induction heating and melting of the B metal powder 2;

[0041] 6. By adjusting the opening degrees of the slide plate and the nozzle 7 and the metal powder bin 1, make the flow rate of adding the B metal powder 2 lower than the flow rate of the casting molten metal, and the difference between the two flow rates is 100 kg / min;

[0042] 7. Continuously cast until the chemical composition of the molten metal in the crucible 3 is 100% B metal;

[0043] 8. Stop adding the B metal powder 2, and cast all the remaining molten metal in the crucible 3 to obtain a gradient metal ingot of AB metal, and the length of the ingot is 2630 mm.

[0044] After testing, the chemical composition of the head of the ingot is Mn13 high manganese steel, the chemical composition of its tail is heavy rail steel U71Mn, and the composition between the head and the tail is a gradient composition with a uniform gradual change from Mn13 high manganese steel to the composition of heavy rail steel U71Mn.

[0045] Example 2:

[0046] A gradient metal ingot of plain carbon steel Q235B and 304 stainless steel, the cross-sectional size of the ingot is: 300×200 mm, the length is 2550 mm, and the total weight is 900 kg. See Figure 1 , the manufacturing method of this gradient metal ingot includes the following steps:

[0047] 1. The capacity of the crucible 3 is 1 ton, and 450 kg of Q235B steel scrap (A metal scrap) and 304 stainless steel powder (B metal powder 2) are prepared respectively;

[0048] 2. Fill the B metal powder 2 into the metal powder bin 1; coat the cooler wall 13 with the heat-insulating coating 11;

[0049] 3. Add the A metal scrap into the crucible 3, blow argon into the crucible 3 through the argon blowing pipe 14 to form a protective atmosphere, heat and melt the A metal scrap to form the A molten metal, and the superheat degree is 90°C;

[0050] 4. Start casting, open the slide plate and the nozzle 7, inject the A molten metal into the cooler 8, and solidify under the cooling action of the movable bottom plate 10 and the cooler wall 13. At the same time, under the downward pulling action of the lifting column 12, the movable bottom plate 10 moves downward together with the solidified ingot;

[0051] 5. While starting casting, turn on the feeding system of the metal powder bin 1, continuously add the B metal powder 2 into the molten metal in the crucible 3, and melt it to form the AB mixed molten metal 6. As the B metal powder 2 is continuously added and the AB mixed molten metal 6 continuously flows out, the content of the B metal in the molten metal in the crucible 3 gradually increases until it is finally completely replaced by the B molten metal formed by the induction heating and melting of the B metal powder 2;

[0052] 6. By adjusting the opening degrees of the slide plate and the nozzle 7 and the metal powder bin 1, make the flow rate of adding the B metal powder 2 lower than the flow rate of the casting molten metal, and the difference between the two flow rates is 80 kg / min;

[0053] 7. Continuously cast until the chemical composition of the molten metal in the crucible 3 is 100% B metal;

[0054] 8. Stop adding the B metal powder 2, and cast all the remaining molten metal in the crucible 3 to obtain a gradient metal ingot of AB metal, and the length of the ingot is 2560 mm.

[0055] After testing, the chemical composition of the head of the ingot is A metal, the chemical composition of its tail is B metal, and the gradient composition from the head to the tail is a uniform gradual change from Q235B to 304 stainless steel composition.

Claims

1. A method for manufacturing a gradient metal ingot, characterized in that: The following steps are involved: 1) Fill the metal powder bin with B metal powder and apply insulation paint on the inner wall of the cooler; 2) adding metal material A into a crucible, blowing argon gas into the crucible, heating and melting the metal material A to form liquid metal A; 3) Start casting, open the slide plate and the water inlet of the crucible, and inject the A metal liquid into the cooler. The A metal liquid solidifies under the cooling effect of the movable bottom plate and the cooler; at the same time, the movable bottom plate moves downward, and the movable bottom plate moves downward together with the solidified ingot; At the beginning of casting, the metal powder bin is opened, and the B metal powder is continuously added into the crucible, and the B metal powder and the A metal liquid are melted to form the AB mixed metal liquid; with the continuous addition of the B metal powder and the continuous outflow of the AB mixed metal liquid, the B metal content in the metal liquid in the crucible gradually increases, until it is finally completely replaced by the B metal liquid formed by the melting of the B metal powder by induction heating; 4) Continue casting until the chemical composition of the molten metal in the crucible is all B metal; 5) Stop adding B metal powder and cast all the remaining molten metal in the crucible to obtain a gradient metal ingot of AB metal.

2. The method for manufacturing a gradient metal ingot according to claim 1, characterized in that: In step 3), the addition flow rate of B metal powder is less than the flow rate of casting molten metal.

3. The method for manufacturing a gradient metal ingot according to claim 1, characterized in that: The chemical composition of the gradient metal ingot obtained in step 5) is metal A at the head, metal B at the tail, and the gradient composition changes gradually from the head to the tail.

4. A device used in the method for manufacturing a gradient metal ingot as claimed in any one of claims 1 to 3, characterized in that: It includes a metal powder bin, a crucible, an induction coil, a slide plate and a nozzle, a cooler, a movable bottom plate, a lifting column, and an argon blowing tube. The metal powder bin is arranged directly above the crucible, and the cooler is arranged directly below the crucible. The outside of the crucible is connected to the induction coil, the bottom of the crucible is connected to the slide plate and the nozzle, the argon blowing tube is used to blow argon into the crucible, and the top of the lifting column is fixedly connected to the movable bottom plate, and the movable bottom plate is slidably connected to the inner wall of the cooler.

5. The manufacturing device of a gradient metal ingot according to claim 4, characterized in that: The inner wall of the crucible is fixedly connected with a permanent temperature measuring probe.

6. The manufacturing device of a gradient metal ingot according to claim 4, characterized in that: The cooler is a water-cooled cooler.

7. The manufacturing device of a gradient metal ingot according to claim 4, characterized in that: The inner wall of the cooler is covered with a heat-insulating coating layer.

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