Magnesium alloy smelting device and preparation method

Abstract

The invention relates to the technical field of magnesium alloy, in particular to a magnesium alloy smelting device and a preparation method. Magnesium ingots are loaded into a smelting crucible and are melted to form a molten pool, a vacuum generation device is started to reduce the air content in the sealed crucible to form vacuum, and a liquid guide pipe extends to the center of the smelting crucible; pure magnesium liquid in the middle of the smelting crucible is sucked into the sealed crucible through the liquid guide pipe, the inert gas pipeline is opened to introduce inert gas to increase the air pressure in the sealed crucible, the magnesium liquid is guided to flow into the crystallizer, and the magnesium liquid is filtered, cooled and formed through a double-layer funnel structure on the crystallizer; pure magnesium liquid in the middle of the smelting crucible is sucked into the sealed crucible, inert gas is injected into the sealed crucible, impurities in the pure magnesium liquid are removed again in a gas refining mode of the inert gas, then the pure magnesium liquid is guided into the crystallizer from the sealed crucible to be filtered and then cooled and formed, and therefore the impurities in the magnesium liquid can be removed and then shaped. And the machining performance of the magnesium alloy workpiece is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of magnesium alloys, and in particular to a magnesium alloy smelting device and a preparation method. Background Art

[0002] Traditional magnesium alloy smelting equipment is relatively simple and usually directly fired at high temperature. However, during the high-temperature and long-term smelting process, some chemical reactions are likely to occur with the magnesium alloy, thereby affecting the quality of the magnesium alloy.

[0003] In the preparation of existing magnesium alloys, a magnesium ingot is first placed in a melting crucible, usually at the bottom of the crucible. The furnace is started to heat, and the magnesium ingot gradually melts to form a molten pool. After melting is completed, the magnesium liquid is transferred from the melting crucible to a suitable casting mold. According to the shape and design of the mold, the magnesium liquid will gradually solidify and form in the mold, thereby forming the desired magnesium alloy casting, reducing the impact of other factors on the quality of the magnesium alloy.

[0004] However, during the smelting preparation of existing magnesium alloys, a large amount of impurities are doped in the magnesium liquid after the magnesium ingot is melted, and the existing preparation method is unable to remove the impurities in the magnesium liquid, which can easily affect the processing performance of the magnesium alloy. Summary of the Invention

[0005] The purpose of the present invention is to provide a magnesium alloy smelting device and preparation method, aiming to solve the problem that during the smelting preparation of existing magnesium alloys, a large amount of impurities are doped in the magnesium liquid after the magnesium ingot is melted, and the existing preparation method is unable to remove the impurities in the magnesium liquid, which easily affects the processing performance of the magnesium alloy.

[0006] To achieve the above object, the present invention provides a method for smelting and preparing a magnesium alloy, comprising the following steps:

[0007] The magnesium ingot is placed in a smelting crucible, and the magnesium ingot is melted to form a molten pool;

[0008] Start the vacuum generating device to reduce the air content inside the sealed crucible to form a vacuum;

[0009] Extending the liquid guide tube to the center of the smelting crucible, and sucking the pure magnesium liquid in the middle of the smelting crucible into the sealed crucible through the liquid guide tube;

[0010] Open the inert gas pipeline to introduce inert gas to increase the internal pressure of the sealed crucible and guide the magnesium liquid into the crystallizer;

[0011] The magnesium liquid is filtered through the double-layer funnel structure on the crystallizer and cooled to form.

[0012] The liquid guide tube is extended to the center of the smelting crucible, and the pure magnesium liquid in the middle of the smelting crucible is sucked into the sealed crucible through the liquid guide tube. The step further includes:

[0013] The liquid guide pipe is a split structure, the straight pipe of the liquid guide pipe is 150 mm away from the bottom of the smelting crucible, and the curved pipe of the liquid guide pipe has a bending angle of 85°.

[0014] The vacuum generating device is started to reduce the air content inside the sealed crucible, and the step further includes:

[0015] Observe whether the pressure vacuum gauge in the vacuum generating device exceeds the corresponding value to ensure that the pressure in the sealed crucible is lower than 0.008 MPa after smelting.

[0016] The inert gas pipeline is opened to introduce inert gas to increase the internal pressure of the sealed crucible and guide the magnesium liquid to flow into the crystallizer. The step further includes:

[0017] The inert gas is argon.

[0018] The inert gas pipeline is opened to introduce inert gas to increase the internal pressure of the sealed crucible and guide the magnesium liquid to flow into the crystallizer. The step further includes:

[0019] Opening the elevator to move the crystallizer to just below the liquid guide tube;

[0020] An argon bottle was connected to the crystallizer via a pipe.

[0021] A magnesium alloy melting device includes a sealed crucible, a sealing cover, a vacuum pipe, a vacuum generating device, an inert gas pipe, an argon gas bottle, a casting tube, a melting device, a casting device, and a pressure vacuum gauge. The sealing cover is mounted on the sealed crucible, the vacuum pipe is mounted on the sealing cover, the vacuum pipe is connected to the vacuum pipe, the inert gas pipe is mounted on the sealing cover, the argon gas bottle is connected to the inert gas pipe, the casting tube is mounted on the sealing cover, the casting device is connected to the casting pipe, and the melting device is connected to the sealing cover. The sealing cover is provided with an opening connected to the pressure vacuum gauge.

[0022] The present invention provides a magnesium alloy smelting device and preparation method. A magnesium ingot is placed in a smelting crucible, and the magnesium ingot is melted to form a molten pool. A vacuum generating device is activated to reduce the air content inside the sealed crucible to form a vacuum. A liquid guide tube is extended to the center of the smelting crucible, and pure magnesium liquid in the middle position of the smelting crucible is sucked into the sealed crucible through the liquid guide tube. An inert gas pipeline is opened to introduce inert gas to increase the air pressure inside the sealed crucible, and the magnesium liquid is guided to flow into a crystallizer. The magnesium liquid is filtered and cooled to form through a double-layer funnel structure on the crystallizer, so that the pure magnesium liquid in the middle position of the smelting crucible can be sucked into the sealed crucible and inert gas is injected. Impurities therein are removed again by refining with inert gas. The pure magnesium liquid is then introduced from the sealed crucible into the crystallizer, filtered, and cooled to form. Impurities in the magnesium liquid can be removed before final processing, thereby improving the processing performance of the magnesium alloy workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art.

[0024] Figure 1 It is a step diagram of the magnesium alloy smelting preparation method according to the first embodiment of the present invention.

[0025] Figure 2 It is a schematic structural diagram of a magnesium alloy smelting device according to a second embodiment of the present invention.

[0026] In the figure: 101-sealed crucible, 102-sealed cover, 103-vacuum pipe, 104-inert gas pipe, 105-argon gas bottle, 106-casting tube, 107-pressure vacuum gauge, 108-two-stage rotary vane vacuum pump, 109-Roots vacuum pump, 1140-low vacuum electromagnetic pressure differential charging valve, 111-vacuum stop valve, 112-connecting pipe, 113-pressure air storage tank, 114-vacuum ball valve, 115-electric contact vacuum gauge, 116-cover plate, 117-melting crucible, 118-liquid guide tube, 119-elevator, 120-crystallizer, 121-protective gas support, 122-funnel. DETAILED DESCRIPTION

[0027] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0028] The first embodiment of this application is:

[0029] See also Figure 1 ,in Figure 1It is a step diagram of the magnesium alloy smelting preparation method according to the first embodiment of the present invention.

[0030] The present invention provides a method for smelting and preparing a magnesium alloy, comprising the following steps:

[0031] S100: placing a magnesium ingot into a smelting crucible 117 and melting the magnesium ingot to form a molten pool;

[0032] S101: starting a vacuum generating device to reduce the air content inside the sealed crucible 101 to form a vacuum;

[0033] S102: Extending the liquid conduit 118 to the center of the smelting crucible 117, and sucking the pure magnesium liquid in the middle of the smelting crucible 117 into the sealed crucible 101 through the liquid conduit 118;

[0034] S103: Open the inert gas pipeline 104 to introduce inert gas to increase the internal pressure of the sealed crucible 101 and guide the magnesium liquid to flow into the crystallizer 120;

[0035] S104: The magnesium liquid is filtered through the double-layer funnel 122 structure on the crystallizer 120 and cooled to form.

[0036] Specifically, after the magnesium ingot is loaded into the crucible, the crucible needs to be heated to achieve the melting of the magnesium ingot. Electric current passes through the heating elements at the bottom or around the crucible, and the electrical energy is converted into thermal energy. The heat is transferred to the magnesium ingot to gradually increase its temperature. As the temperature continues to rise, the solid structure of the magnesium ingot is destroyed, the bond between atoms is weakened, and it begins to change from solid to liquid. When enough magnesium ingots are melted, these liquid magnesium gather at the bottom of the crucible to form a molten pool. The magnesium liquid in the molten pool is in a high-temperature and flowing state. The vacuum generating device is connected to the sealed crucible 101 through a pipeline. After the device is started, the vacuum pump group inside the device starts to work, generating a strong suction force to continuously extract the air originally existing in the sealed crucible 101. As the air is continuously extracted, the air pressure in the sealed crucible 101 gradually decreases until it reaches a relatively low vacuum state. After the liquid guide tube 118 is in place, the sealed crucible 101 is vacuum generated. The suction force is generated by the liquid conduit 118, and the pressure difference between the inside and outside of the liquid conduit 118 is utilized to cause the magnesium liquid in the center of the smelting crucible 117 to flow along the liquid conduit 118 into the sealed crucible 101. After the valve on the inert gas conduit 104 is opened, inert gas continuously flows from the gas source along the conduit into the sealed crucible 101. The operator controls the flow of the inert gas by adjusting the valve opening and coordinating with the pressure and vacuum gauge 107, thereby precisely regulating the pressure change inside the sealed crucible 101, thereby directing the magnesium liquid through the casting tube 106 into the crystallizer 120. The double funnel 122 structure of the crystallizer 120 can filter the magnesium liquid. At the same time, a cooling pipe is usually provided inside or around the wall of the second funnel 122. Low-temperature argon gas circulates in the cooling pipe. When the filtered magnesium liquid flows into the second funnel 122, the cooling gas removes heat from the magnesium liquid through heat transfer, gradually reducing the temperature of the magnesium liquid. As the temperature drops, the fluidity of the magnesium liquid deteriorates and it begins to transform from a liquid to a solid state, and finally completes solidification and forming in the crystallizer 120. Therefore, the pure magnesium liquid in the middle position of the smelting crucible 117 is sucked into the sealed crucible 101 and injected with inert gas. Impurities therein are removed again by inert gas refining. The pure magnesium liquid is then introduced from the sealed crucible 101 into the crystallizer 120, filtered, and then cooled to form. In this way, impurities in the magnesium liquid can be removed before final shaping, thereby improving the processing performance of the magnesium alloy workpiece.

[0037] The second embodiment of the present application is:

[0038] Based on the first embodiment, please refer to Figure 2 , Figure 2 It is a schematic structural diagram of a magnesium alloy smelting device according to a second embodiment of the present invention.

[0039] The present invention provides a magnesium alloy smelting device, comprising a sealed crucible 101, a sealing cover 102, a vacuum pipe 103, a vacuum generating device, an inert gas pipe 104, an argon gas bottle 105, a casting pipe 106, a smelting device, a casting device and a pressure vacuum gauge 107. The vacuum generating device comprises a two-stage rotary vane vacuum pump 108, a Roots vacuum pump 109, a low vacuum electromagnetic pressure differential inflation valve 110, a vacuum shut-off valve 111, a connecting pipe 112, a pressure air storage tank 113, a vacuum ball valve 114 and an electric contact vacuum gauge 115. The smelting device comprises a cover plate 116, a smelting crucible 117 and a liquid guide pipe 118, an elevator 119, a crystallizer 120, a protective gas support 121 and a funnel 122.

[0040] The sealing cover 102 is provided on the sealing crucible 101, the vacuum pipe 103 is provided on the sealing cover 102, the vacuum pipe 103 is connected to the vacuum pipe 103, the inert gas pipe 104 is provided on the sealing cover 102, the argon bottle 105 is connected to the inert gas pipe 104, the casting pipe 106 is provided on the sealing cover 102, the casting device is connected to the casting pipe 106, the smelting device is connected to the sealing cover 102, and the sealing cover 10 2 is provided with an opening, which is connected to a pressure vacuum gauge 107. The air content inside the sealed crucible 101 is reduced by a vacuum generating device, and argon gas in the argon gas bottle 105 is introduced to form normal pressure in the sealed crucible 101. The pure magnesium liquid in the middle of the melting crucible 117 is sucked into the sealed crucible 101 through the liquid guide tube 118, thereby preventing the magnesium liquid from being oxidized while effectively reducing the solvent content. The magnesium liquid in the sealed crucible 101 is then introduced into the casting device through the casting tube 106 to be cooled and formed.

[0041] The low vacuum electromagnetic pressure differential charging valve 110 is connected between the two-stage rotary vane pump and the Roots pinhole pump. The vacuum shut-off valve 111 is connected above the Roots pinhole pump. The top of the vacuum shut-off valve 111 is connected to the connecting pipe 112. The right side of the connecting pipe 112 is connected to the pressurized air storage tank 113. The right side of the pressurized air storage tank 113 is connected to the vacuum ball valve 114. The vacuum ball valve 114 is connected to the vacuum pipe 103. The two-stage rotary vane vacuum pump 108 and the Roots vacuum pump 109 form a vacuum pump group, which can evacuate the sealed crucible 101 through the vacuum pipe 103. At the same time, the pressurized air storage tank 113 provides a stable pressure source while preventing high-temperature magnesium liquid or gas from entering the pump group. The pressure level of the pressurized air storage tank 113 is controlled by the electric contact vacuum gauge 115 located on the side of the pump group.

[0042] The cover plate 116 is connected to the smelting crucible 117 and the liquid conduit 118, respectively. The liquid conduit 118 is connected to the sealing cover 102. The liquid conduit 118 can extend to the center of the smelting crucible 117. The horizontal section of the liquid conduit 118 is inclined at 15°, and the liquid conduit 118 is inclined at 13° to the vertical section inside the sealed crucible 101. The pure magnesium liquid in the smelting crucible 117 can be sucked into the sealed crucible 101 through the liquid conduit 118.

[0043] The crystallizer 120 is disposed on the elevator 119. The shielding gas support 121 is disposed on the crystallizer 120. The funnel 122 is disposed on the shielding gas support 121 and is located on one side of the casting tube 106. The magnesium liquid in the sealed crucible 101 can be introduced into the funnel 122 of the crystallizer 120 through the casting tube 106. The dual structure of the funnel 122 can filter the magnesium liquid, and then the introduced magnesium liquid is cooled and formed in the crystallizer 120. The elevation of the crystallizer 120 can be controlled by the elevator 119.

[0044] The above disclosure is merely one or more preferred embodiments of the present application and is not intended to limit the scope of the present application. A person skilled in the art will understand that all or part of the processes of the above embodiments and equivalent changes made in accordance with the claims of the present application are still within the scope of the present application.

Claims

1. A method for preparing magnesium alloy by smelting, characterized in that: The following steps are involved: The magnesium ingot is placed in a smelting crucible, and the magnesium ingot is melted to form a molten pool; Start the vacuum generating device to reduce the air content inside the sealed crucible to form a vacuum; Extending the liquid guide tube to the center of the smelting crucible, and sucking the pure magnesium liquid in the middle of the smelting crucible into the sealed crucible through the liquid guide tube; Open the inert gas pipeline to introduce inert gas to increase the internal pressure of the sealed crucible and guide the magnesium liquid into the crystallizer; The magnesium liquid is filtered through the double-layer funnel structure on the crystallizer and cooled to form.

2. The magnesium alloy smelting preparation method according to claim 1, characterized in that: Extending the liquid conduit to the center of the smelting crucible, and sucking the pure magnesium liquid in the middle of the smelting crucible into the sealed crucible through the liquid conduit, the step further includes: The liquid guide pipe is a split structure, the straight pipe of the liquid guide pipe is 150 mm away from the bottom of the smelting crucible, and the curved pipe of the liquid guide pipe has a bending angle of 85°.

3. The method for preparing magnesium alloy by smelting according to claim 1, wherein: Starting a vacuum generating device to reduce the air content inside the sealed crucible, the step further includes: Observe whether the pressure vacuum gauge in the vacuum generating device exceeds the corresponding value to ensure that the pressure in the sealed crucible is lower than 0.008 MPa after smelting.

4. The method for preparing magnesium alloy by smelting according to claim 1, wherein: Opening the inert gas pipeline to introduce inert gas to increase the internal pressure of the sealed crucible and guide the magnesium liquid to flow into the crystallizer, the step further includes: The inert gas is argon.

5. The method for preparing magnesium alloy by smelting according to claim 1, wherein: Opening the inert gas pipeline to introduce inert gas to increase the internal pressure of the sealed crucible and guide the magnesium liquid to flow into the crystallizer, the step further includes: Opening the elevator to move the crystallizer to just below the liquid guide tube; An argon bottle was connected to the crystallizer via a pipe.

6. A magnesium alloy smelting device, suitable for the magnesium alloy smelting preparation method according to any one of claims 1 to 5, characterized in that: The invention comprises a sealed crucible, a sealing cover, a vacuum pipe, a vacuum generating device, an inert gas pipe, an argon gas bottle, a casting pipe, a smelting device, a casting device and a pressure vacuum gauge. The sealing cover is arranged on the sealed crucible, the vacuum pipe is arranged on the sealing cover, the vacuum pipe is connected to the vacuum pipe, the inert gas pipe is arranged on the sealing cover, the argon gas bottle is connected to the inert gas pipe, the casting pipe is arranged on the sealing cover, the casting device is connected to the casting pipe, the smelting device is connected to the sealing cover, an opening is provided on the sealing cover, and the opening is connected to the pressure vacuum gauge.

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