Multifunctional casting method and device

Abstract

The invention belongs to the technical field of casting, and provides a multifunctional casting method and device, on one hand, protective atmosphere is added in the casting process, oxidation of a liquid aluminum alloy and a solid iron matrix is avoided, on the other hand, in-situ heat treatment is achieved, stress relief annealing is achieved, and interface stress concentration is reduced. And interface cracking caused by rapid temperature reduction in the casting transferring process is avoided, and the problem of cracking of a bimetallic interface is avoided. And meanwhile, by adjusting the atmosphere of the casting chamber during casting, the defect of the oxidation film of the entrainment structure can be marked in the casting process.

Description

Technical Field

[0001] The present invention belongs to the field of casting technology, and particularly relates to a multi-functional casting method and device, and more specifically, to a casting method and device integrating functions of casting atmosphere protection, in-situ heat treatment, and defect marking. Background Art

[0002] With the rapid development of the aerospace and weapon fields, increasingly stringent requirements are put forward for the metallurgical quality and service performance of complex aluminum alloy castings. Aluminum alloy castings urgently need to transform towards the direction of structural-functional integration. Therefore, bimetallic materials emerge as the times require, such as aluminum / iron bimetals, which not only maintain the lightweight advantage of aluminum alloys but also absorb the high-life characteristics of ferroalloys, thus solving the different performance requirements of different parts in complex aluminum alloy casting.

[0003] The traditional production method of complex aluminum / iron bimetallic castings is liquid-solid casting, that is, the molten aluminum alloy is poured onto the surface of the solid iron matrix to achieve effective connection of two heterogeneous metals. However, under the existing technical conditions, many problems are still faced. First, interface oxidation. Whether it is the liquid aluminum alloy or the solid iron matrix, different degrees of oxidation will occur in the high-temperature environment of casting, and their oxidation products directly isolate the heterogeneous metals, resulting in cracking at the aluminum / iron bimetal interface. Among many casting defects, the defect of entrained structural oxide film is difficult to be accurately detected in actual castings due to its concealment characteristics, which means that such defects become potential hidden dangers during the service of castings. Second, stress concentration. Due to the difference in thermal expansion coefficients between aluminum and iron, during the cooling and solidification process of aluminum / iron bimetallic castings, the deformation amplitudes on both sides of the interface are different, so the stress concentration generated intensifies the interface cracking. Therefore, if qualified structural-functional integrated aluminum / iron bimetallic complex castings are to be produced, the cracking problem at the bimetal interface must be effectively controlled.

[0004] The existing liquid-solid casting technology for complex aluminum / iron bimetallic castings has always faced difficult problems, that is, the interface cracking problem. The traditional technical idea to solve this problem is to add an intermediate layer on the surface of the solid iron matrix. Although the addition of an intermediate layer that is not easily oxidized (such as Cr) alleviates the interface oxidation problem to a certain extent, it does not regulate from the root cause, especially the oxidation of liquid aluminum alloy has never been controlled. In addition, although the addition of the intermediate layer isolates aluminum and iron and avoids interface cracking caused by the large difference in thermal expansion coefficients of the two materials to a certain extent. However, the stress concentration has not been effectively alleviated, but only transfers the position of stress concentration from the aluminum-iron interface to the intermediate layer. And a large amount of concentrated stress will cause the casting to crack under subsequent service conditions.

[0005] In summary, the two major problems of interface oxidation and stress concentration faced by the liquid-solid casting forming technology of aluminum / iron bimetallic complex castings have not been fundamentally solved under the existing technical conditions, and the existing technology has not yet found a good way to study the oxide film defects with entrainment structure. Based on this, the present invention is proposed. Summary of the Invention

[0006] To solve the problems existing in the prior art, the main object of the present invention is to provide a multi-functional casting method and device.

[0007] According to one aspect of the present invention, the following technical solution is provided: A multi-functional casting method, comprising the following steps: S1. Pre-place the iron matrix in the mold, then place the mold in the casting chamber, close and seal the cover, position and assemble the casting crucible with the cover, block the gate with a plug, and seal it; S2. Turn on the heater and heat it at a heating rate of 5 °C / min until the mold temperature reaches 200 - 400 °C; S3. Keep the casting chamber connected to the first gas source and the external environment for gas washing. After gas washing for a period of time, cut off the connection between the casting chamber and the external environment; S4. Inject aluminum alloy liquid into the casting crucible, connect the first gas source and the casting crucible for gas supply, start the hydraulic cylinder to drive the plug rod to move to open the gate, and the aluminum alloy liquid enters the mold to start casting and filling. After all the aluminum alloy liquid enters the mold, cut off the connection between the casting chamber and the first gas source, and the connection between the casting crucible and the first gas source; Keep the mold insulated for 2 - 8 h for stress relief annealing to obtain an aluminum / iron bimetallic casting; Or cut off the connection between the casting chamber and the first gas source, connect the second gas source and the casting chamber for gas supply, inject aluminum alloy liquid into the casting crucible, connect the first gas source and the casting crucible for gas supply, start the hydraulic cylinder to drive the plug rod to move to open the gate, and the aluminum alloy liquid enters the mold to start casting and filling. After all the aluminum alloy liquid enters the mold, cut off the connection between the casting chamber and the second gas source, and the connection between the casting crucible and the first gas source; Keep the mold insulated for 2 - 8 h for stress relief annealing to obtain an aluminum / iron bimetallic casting with oxide film defects having an entrainment structure.

[0008] According to another aspect of the present invention, the following technical solution is provided: A multifunctional casting device, the device includes a first gas source, a casting chamber and a casting crucible. The first gas source is filled with an atmosphere gas. One side of the casting chamber is connected to the first gas source, and the other side of the casting chamber is connected to the external environment. A mold is provided inside the casting chamber. A heater is provided between the casting chamber and the mold. A cover is provided at the upper end of the casting chamber. The casting crucible is arranged on the cover through a spacer block. A pouring gate is provided at the bottom of the casting crucible and is connected to the casting chamber. The pouring gate is connected to the mold through a conveying pipeline. The casting crucible is connected to the first gas source. A liquid level control device is provided inside the casting crucible. The liquid level control device includes a hydraulic cylinder, a plug rod and a plug head connected in sequence. The plug head blocks or opens the pouring gate under the drive of the plug rod; The casting chamber is also connected to a second gas source through a fifth valve, and the second gas source is filled with an oxygen isotope gas.

[0009] The beneficial effects of the present invention are as follows: The present invention provides a multifunctional casting method and device. On the one hand, a protective atmosphere is added during the casting process to avoid the oxidation of liquid aluminum alloy and solid iron matrix. On the other hand, in-situ heat treatment is realized to achieve stress relief annealing and reduce the interfacial stress concentration. This method integrates the casting and heat treatment operations, avoiding the interfacial cracking caused by the rapid temperature drop during the transportation of the casting and the cracking problem of the bimetallic interface. At the same time, through the adjustment of the atmosphere in the casting chamber during casting, the marking of the oxide film defect with an entrained structure can be realized during the casting process. Description of the Drawings

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0011] Figure 1 It is a schematic structural diagram of the casting device of the present invention.

[0012] Figure 2 It is a schematic diagram of the interface of the aluminum / iron bimetal prepared in Example 1 of the present invention.

[0013] Figure 3 It is a schematic diagram of the interface of the aluminum / iron bimetal prepared in Comparative Example 1 of the present invention.

[0014] Figure 4 It is a schematic diagram of the interface of the aluminum / iron bimetal prepared in Comparative Example 2 of the present invention.

[0015] In the figure: 1 - First gas source, 2 - Casting chamber, 3 - First valve, 4 - Second valve, 5 - Casting crucible, 6 - Third valve, 7 - Mold, 8 - Fourth valve, 9 - Cover, 10 - Sealing gasket, 11 - Lock, 12 - Spacer block, 13 - Heater, 14 - Hydraulic cylinder, 15 - Plug rod, 16 - Plug, 17 - Nozzle, 18 - Delivery pipeline, 19 - Second gas source, 20 - Fifth valve.

[0016] The realization, functional features and advantages of the object of the present invention will be further described with reference to the accompanying drawings in combination with the embodiments. Specific embodiments

[0017] The technical solutions in the embodiments will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] According to one aspect of the present invention, the present invention provides the following technical solution: A multifunctional casting method, comprising the following steps: S1. Pre-place the iron matrix in the mold, then place the mold in the casting chamber, close the cover for sealing, position and assemble the casting crucible with the cover, block the gate with the plug, and perform sealing; S2. Turn on the heater and heat up at a heating rate of 5 °C / min until the mold temperature reaches 200 - 400 °C; S3. Keep the casting chamber connected to the first gas source and the external environment for gas washing. After gas washing for a period of time, cut off the connection between the casting chamber and the external environment; S4. Inject aluminum alloy liquid into the casting crucible, connect the first gas source and the casting crucible for ventilation, start the hydraulic cylinder to drive the plug rod to move to open the gate, the aluminum alloy liquid enters the mold to start casting and filling. After all the aluminum alloy liquid enters the mold, cut off the connection between the casting chamber and the first gas source, and the connection between the casting crucible and the first gas source; Keep the mold insulated for 2 - 8 h for stress relief annealing to obtain an aluminum / iron bimetallic casting; Or cut off the connection between the casting chamber and the first gas source, connect the second gas source and the casting chamber for ventilation, inject aluminum alloy liquid into the casting crucible, connect the first gas source and the casting crucible for ventilation, start the hydraulic cylinder to drive the plug rod to move to open the gate, the aluminum alloy liquid enters the mold to start casting and filling. After all the aluminum alloy liquid enters the mold, cut off the connection between the casting chamber and the second gas source, and the connection between the casting crucible and the first gas source; Keep the mold insulated for 2 - 8 h for stress relief annealing to obtain an aluminum / iron bimetallic casting with oxide film defects of entrainment structure.

[0019] The present invention realizes the integration of casting, heat treatment, and defect marking operations. First, based on the atmosphere protection during the casting process, the surface oxidation of the liquid aluminum alloy and the solid iron matrix is avoided, thereby avoiding the influence of oxidation products on the bonding of the bimetal. Secondly, by means of in-situ heat treatment, stress relief annealing of the aluminum-iron bimetal is carried out, which can eliminate interface cracks. When casting, oxygen isotope gases such as oxygen-18 or oxygen-17 are introduced into the casting chamber. During the casting process of the aluminum alloy liquid, an alumina film will be generated. Marking with isotopes can be used to study and analyze the entrainment structure oxide film defects of the casting and their formation mechanism.

[0020] Preferably, in the step S1, before the iron matrix is pre-placed in the mold, it is pretreated as follows: First, pickling and rust removal are carried out with hydrochloric acid with a concentration of 5wt% and then ultrasonic cleaning with alcohol for 5 minutes; secondly, pickling and rust removal are carried out with a NaOH aqueous solution with a concentration of 5wt% and then ultrasonic cleaning with alcohol for 5 minutes; finally, it is soaked in an aqueous solution of ZnCl2 with a concentration of 8-15wt% for 8-12 minutes and then dried at 200-270°C for 3-5 minutes. Through the above operations, the surface oxide layer of the iron matrix can be removed, and at the same time, a layer of ZnCl2 is retained on the surface of the iron matrix. While achieving isolation from secondary oxidation, ZnCl2 can quickly melt during the subsequent casting process, and the melted ZnCl2 will be carried away along with the liquid flow front and will not stay at the bimetal interface position. Therefore, it will not affect the performance of the bimetal interface.

[0021] Preferably, in the step S3, the gas washing time is 2-3 minutes.

[0022] Preferably, in the step S4, after stress relief annealing, it is cooled in the furnace, and the cooling rate is 20-50°C / h.

[0023] Preferably, the iron matrix is QT500, and the aluminum alloy liquid is ZL114A, ZL702A, or ZL205A alloy liquid.

[0024] Preferably, the first gas source provides an atmosphere gas, and the atmosphere gas is argon, sulfur dioxide, or sulfur hexafluoride.

[0025] Preferably, the second gas source provides an oxygen isotope gas (oxygen-18 or oxygen-17 isotope gas).

[0026] According to another aspect of the present invention, the present invention provides the following technical solution: See Figure 1, a multifunctional casting device, which includes a first gas source 1, a casting chamber 2 and a casting crucible 5. The first gas source 1 contains an atmosphere gas. One side of the casting chamber 2 is connected to the first gas source 1, and the other side of the casting chamber 2 is connected to the external environment. A mold 7 is provided inside the casting chamber 2. A heater 13 is provided between the casting chamber 2 and the mold 7 for providing heat to the mold and the castings solidifying inside. A cover 9 is provided at the upper end of the casting chamber 2. The casting crucible 5 is arranged on the cover 9 through a spacer 12. The bottom of the casting crucible 5 is provided with a gate and is connected to the casting chamber 2. The gate is connected to the mold 7 through a conveying pipeline 18. The casting crucible 5 is connected to the first gas source 1. A liquid level control device is provided inside the casting crucible 5. The liquid level control device includes a hydraulic cylinder 14, a plug rod 15 and a plug 16 connected in sequence. The plug 16 blocks or opens the gate under the drive of the plug rod 15; The casting chamber is also connected to a second gas source 19 through a fifth valve. The second gas source 19 contains oxygen isotope gas (oxygen-18 or oxygen-17 isotope gas).

[0027] Preferably, the casting chamber 2 and the cover 9 are connected by a buckle 11, and a gasket 10 is also provided between the casting chamber 2 and the cover 9.

[0028] Preferably, the first gas source 1 is connected to the casting chamber 2 through a pipeline. The pipeline includes a first pipeline and a second pipeline arranged up and down. The first pipeline faces the casting chamber 2 and supplies gas with a large flow rate to achieve the atmosphere control during the casting process. A first valve 3 is provided on the first pipeline; The second pipeline faces the mold 7 and supplies gas with a small flow rate to ensure that the residual air inside the mold is exhausted. A second valve 4 is provided on the second pipeline.

[0029] Preferably, the first gas source 1 is connected to the casting crucible 5 through a third pipeline. A third valve 6 is provided on the third pipeline, and a nozzle 17 is provided at the end of the third pipeline inside the casting crucible 5.

[0030] Preferably, the casting chamber 2 is connected to the external environment through a fourth pipeline. A fourth valve 8 is provided on the fourth pipeline.

[0031] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0032] In the following examples and comparative examples, the iron matrix is QT500. The iron matrix is pretreated before being placed in the mold. Specifically: First, it is pickled and rust-removed with hydrochloric acid with a concentration of 5wt% and then ultrasonically cleaned with alcohol for 5 minutes; Secondly, it is pickled and rust-removed with an aqueous NaOH solution with a concentration of 5wt% and then ultrasonically cleaned with alcohol for 5 minutes; Finally, it is soaked in an aqueous ZnCl2 solution with a concentration of 10wt% for 10 minutes and then dried at 230°C for 3 minutes.

[0033] Example 1 A casting method for an aluminum / iron bimetallic casting, the specific steps are as follows: S1. Pre-place the iron matrix in the mold, then place the mold in the casting chamber, close the cover, and use a gasket for sealing to prevent air leakage. The locking buckle locks the casting chamber and the cover; use a spacer to position and assemble the casting crucible and the casting chamber cover; block the gate with a plug. S2. Turn on the heater, and the temperature in the casting chamber rises at a rate of 5 °C / min until the temperature in the mold reaches 300 °C. S3. Open the first valve, the second valve, and the fourth valve simultaneously, and introduce argon for gas washing to remove the initial atmosphere. After 2 minutes of gas washing, first close the fourth valve, then close the second valve, and the first valve remains open. S4. Pour ZL114A aluminum alloy liquid into the casting crucible until the liquid level is 5 cm below the nozzle. Open the third valve to introduce argon from the first gas source through the nozzle into the casting crucible for liquid level protection. Start the hydraulic cylinder to drive the piston rod to move vertically upward, and the plug leaves the gate of the casting crucible. The aluminum alloy liquid in the casting crucible enters the mold in the casting chamber through the gate. After all the aluminum alloy liquid has entered, close the first valve and the third valve; then, keep the mold at 300 °C for 3 hours for stress relief annealing through the heater, and then cool it in the furnace (the cooling rate is 50 °C / h) to obtain an aluminum / iron bimetallic casting.

[0034] After casting is completed, take out the mold from the casting chamber to obtain an aluminum / iron bimetallic casting. As Figure 1 shown, it can be seen that there are no defects at the interface of the aluminum / iron bimetallic casting, and its bonding strength is tested to be 62 MPa.

[0035] Example 2 A casting method for an aluminum / iron bimetallic casting, the specific steps are as follows: S1. Pre-place the iron matrix in the mold, then place the mold in the casting chamber, and use a gasket for sealing to prevent air leakage. The locking buckle locks the casting chamber and the cover; use a spacer to position and assemble the casting crucible and the casting chamber cover; block the gate with a plug. S2. Turn on the heater, and the temperature in the casting chamber rises at a rate of 5 °C / min until the temperature in the mold reaches 200 °C. S3. Open the first valve, the second valve, and the fourth valve simultaneously, and introduce sulfur dioxide for gas washing to remove the initial atmosphere. After 3 minutes of gas washing, first close the fourth valve, then close the second valve, and the first valve remains open. S4. Inject ZL702A aluminum alloy liquid into the casting crucible until the liquid level is 5 cm lower than the nozzle, open the third valve to pass sulfur dioxide in the first gas source into the casting crucible through the nozzle to protect the liquid level, start the hydraulic cylinder to drive the plug rod to move vertically upward, the plug leaves the pouring mouth of the casting crucible, and the aluminum alloy liquid in the casting crucible enters the mold in the casting chamber through the pouring mouth. After all the aluminum alloy liquid enters, close the first valve and the third valve; then keep the mold at 200°C for 8h for stress relief annealing through a heater, and then cool it with the furnace (cooling rate is 20°C / h) to obtain an aluminum / iron bimetallic casting.

[0036] Example 3 A casting method for aluminum / iron bimetallic castings, the specific steps are as follows: S1. Pre-place the iron matrix in the casting mold, then place the casting mold in the casting chamber, seal it with a sealing gasket to prevent air leakage, and lock the casting chamber and the cover with a lock; use a pad to position and assemble the casting crucible and the casting chamber cover; and plug the pouring port with a plug; S2, turn on the heater, and heat the casting chamber at a heating rate of 5°C / min until the temperature in the mold reaches 400°C; S3, open the first valve, the second valve and the fourth valve at the same time, introduce sulfur hexafluoride for gas washing to remove the initial atmosphere, and after gas washing for 2 minutes, close the fourth valve first and then the second valve, and keep the first valve normally open; S4. Inject ZL705A aluminum alloy liquid into the casting crucible until the liquid level is 5 cm lower than the nozzle, open the third valve to pass sulfur hexafluoride in the first gas source into the casting crucible through the nozzle to protect the liquid level, start the hydraulic cylinder to drive the plug rod to move vertically upward, the plug leaves the pouring mouth of the casting crucible, and the aluminum alloy liquid in the casting crucible enters the mold in the casting chamber through the pouring mouth. After all the aluminum alloy liquid enters, close the first valve and the third valve; then keep the mold at 400°C for 2h for stress relief annealing through a heater, and then cool it with the furnace (cooling rate is 30°C / h) to obtain an aluminum / iron bimetallic casting.

[0037] Example 4 A casting method for aluminum / iron bimetallic castings, the specific steps are as follows: S1. Pre-place the iron matrix in the casting mold, then place the casting mold in the casting chamber, seal it with a sealing gasket to prevent air leakage, and lock the casting chamber and the cover with a lock; use a pad to position and assemble the casting crucible and the casting chamber cover; and plug the pouring port with a plug; S2, turn on the heater, and heat the casting chamber at a heating rate of 5°C / min until the temperature in the mold reaches 300°C; S3. Open the first valve, the second valve, and the fourth valve simultaneously, introduce argon gas for gas washing to remove the initial atmosphere. After 3 minutes of gas washing, first close the fourth valve, and then close the second valve and the first valve; S4. Inject ZL702A aluminum alloy liquid into the casting crucible until the liquid level is 5 cm lower than the nozzle. Open the third valve to introduce argon gas from the first gas source into the casting crucible through the nozzle for liquid level protection. Open the fifth valve to introduce oxygen-18 isotope gas. Start the hydraulic cylinder to drive the plug rod to move vertically upward, and the plug leaves the gate of the casting crucible. The aluminum alloy liquid in the casting crucible enters the mold in the casting chamber through the gate. After all the aluminum alloy liquid has entered, close the third valve and the fifth valve; Then, use a heater to keep the mold at 300 °C for 3 hours for stress relief annealing, and then cool it in the furnace (the cooling rate is 40 °C / h) to obtain an aluminum / iron bimetallic casting with an oxygen-18 isotope-labeled oxide film defect.

[0038] After casting is completed, take the mold out of the casting chamber to obtain an aluminum alloy casting labeled with oxygen-18 isotope. Dissect this casting to find the entrained structure oxide film defect for isotope analysis, which is convenient for studying the oxide film defect and its formation mechanism.

[0039] Comparative Example 1 Use the device of the present invention for casting, but do not open the first gas source for atmosphere protection and do not open the heater for in-situ heating during the casting process. The other steps are the same as in Example 1. The obtained aluminum / iron bimetallic casting is as Figure 3 shown. It can be seen that obvious cracking occurs at its interface, and the measured bonding strength < 10 MPa.

[0040] Comparative Example 2 Use the device of the present invention for casting, but do not open the first gas source for atmosphere protection during the casting process. The other steps are the same as in Example 1. The obtained aluminum / iron bimetallic casting is as Figure 4 shown. Elemental analysis of its interface reveals the presence of alumina. It can be seen that when only in-situ heating is carried out without atmosphere protection, the interface of the obtained casting will also crack due to the incorporation of oxide film defects during the casting process.

[0041] It can be seen from the above examples and comparative examples that when using the present invention for casting, on the one hand, a protective atmosphere is added during the casting process to avoid the oxidation of liquid aluminum alloy and solid iron matrix, and on the other hand, in-situ heat treatment is realized to achieve stress relief annealing and reduce the interfacial stress concentration, which can solve the problem of interface cracking of aluminum / iron bimetallic castings. At the same time, the present invention can also introduce oxygen isotope gas for oxide film defect marking, and analyze the entrained structure oxide film defect and its formation mechanism.

[0042] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made by using the content of the specification of the present invention under the inventive concept of the present invention, or direct / indirect application in other related technical fields shall be included within the patent protection scope of the present invention.

Claims

1. A multi-functional casting method, characterized in that, It includes the following steps: S1. Pre-place the iron matrix in the mold, then place the mold in the casting chamber, close the cover for sealing, position and assemble the casting crucible and the cover, block the gate with a plug, and conduct sealing; S2. Turn on the heater to heat the mold; S3. Keep the casting chamber connected to the first gas source and the external environment for gas washing. After gas washing for a period of time, cut off the connection between the casting chamber and the external environment; S4. Inject aluminum alloy liquid into the casting crucible, connect the first gas source and the casting crucible for gas supply, start the hydraulic cylinder to drive the plug rod to move to open the gate, the aluminum alloy liquid enters the mold to start casting and filling. After all the aluminum alloy liquid enters the mold, cut off the connection between the casting chamber and the first gas source, and the connection between the casting crucible and the first gas source; After the mold is heat-insulated for stress relief annealing, an aluminum / iron bimetallic casting is obtained; Or cut off the connection between the casting chamber and the first gas source, connect the second gas source and the casting chamber for gas supply, start the hydraulic cylinder to drive the plug rod to move to open the gate, the aluminum alloy liquid enters the mold to start casting and filling. After all the aluminum alloy liquid enters the mold, cut off the connection between the casting chamber and the second gas source, and the connection between the casting crucible and the first gas source; After the mold is heat-insulated for stress relief annealing, an aluminum / iron bimetallic casting with oxide film defects of the entrainment structure is obtained.

2. The multi-functional casting method according to claim 1, characterized in that, Before the iron matrix is pre-placed in the mold, it undergoes pretreatment, specifically: first, pickling and rust removal with hydrochloric acid and then ultrasonic cleaning with alcohol; second, pickling and rust removal with NaOH aqueous solution and then ultrasonic cleaning with alcohol; finally, soaking in an 8-15wt% ZnCl2 aqueous solution for 8-12 min and then drying at 200-270 °C for 3-5 min.

3. The multi-functional casting method according to claim 1, characterized in that, The gas washing time is 2-3 min.

4. The multi-functional casting method according to claim 1, characterized in that, After stress relief annealing, it is cooled in the furnace, and the cooling rate is 20-50 °C / h.

5. The multi-functional casting method according to claim 1, characterized in that, The iron matrix is QT500, and the aluminum alloy liquid is ZL114A, ZL702A or ZL205A alloy liquid.

6. The multi-functional casting method according to claim 1, characterized in that, The first gas source provides an atmosphere gas, and the atmosphere gas is argon, sulfur dioxide, sulfur hexafluoride; the second gas source provides an oxygen isotope gas.

7. A multi-functional casting device, characterized in that, For implementing the multifunctional casting method according to any one of claims 1-6, the device includes a first gas source, a casting chamber and a casting crucible. The first gas source is filled with an atmosphere gas. One side of the casting chamber is connected to the first gas source, and the other side of the casting chamber is connected to the external environment. A mold is provided in the casting chamber. A heater is provided between the casting chamber and the mold. A cover is provided at the upper end of the casting chamber. The casting crucible is arranged on the cover through a cushion block. A gate is provided at the bottom of the casting crucible and is connected to the casting chamber. The gate is connected to the mold through a conveying pipeline. The casting crucible is connected to the first gas source. A liquid level control device is provided in the casting crucible. The liquid level control device includes a hydraulic cylinder, a plug rod and a plug connected in sequence. The plug blocks or opens the gate driven by the plug rod; The casting chamber is also connected to a second gas source through a fifth valve, and the second gas source is filled with an oxygen isotope gas.

8. The multi-functional casting device according to claim 7, characterized in that, The casting chamber and the cover are connected by a buckle, and a sealing gasket is also provided between the casting chamber and the cover.

9. The multi-functional casting device according to claim 7, characterized in that, The first gas source is connected to the casting chamber through a pipeline. The pipeline includes a first pipeline and a second pipeline arranged vertically. The first pipeline faces the casting chamber, and a first valve is provided on the first pipeline; the second pipeline faces the mold, and a second valve 4 is provided on the second pipeline; the first gas source is connected to the casting crucible through a third pipeline, a third valve is provided on the third pipeline, and a nozzle is provided at the end of the third pipeline inside the casting crucible.

10. The multi-functional casting device according to claim 7, characterized in that, The casting chamber is connected to the external environment through a fourth pipeline, and a fourth valve is provided on the fourth pipeline.

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