Device and method for improving refining stability of magnesium alloy

Abstract

The invention belongs to the technical field of metal smelting, and particularly relates to a device and method for improving magnesium alloy refining stability. According to a traditional refining agent refining method, the spreading uniformity of a refining agent is difficult to control, industrialization, standardization and process are difficult to achieve, and meanwhile potential safety hazards exist. A main body frame of the refining stirring device comprises a horizontal supporting structure and a vertical rail extending into a crucible, and a first motor controls a stirrer to move up and down through a rocker arm connecting rod mechanism; according to the refining agent feeding device, a gas cylinder and a supporting frame are installed on a bottom plate, a feeding channel, a refining agent tank and a second motor are installed at the upper end of the supporting frame, the feeding channel comprises a horizontal pipeline and a spiral pipeline which are communicated, and an impeller is installed in the spiral pipeline and driven by the second motor. The lower outlet of the refining agent tank is communicated with the horizontal pipeline, and the gas cylinder is filled with protective gas. The magnesium and magnesium alloy refining device can eliminate instability caused by human factors in magnesium and magnesium alloy refining operation, meanwhile, the safety production goals of strengthening labor protection and improving labor conditions are achieved, and finally the purposes of industrialization, standardization and process of magnesium and magnesium alloy refining operation are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of metal smelting, and in particular relates to a device and a method for improving the refining stability of a magnesium alloy. Background Art

[0002] With the continuous development of green manufacturing awareness, traditional manufacturing has gradually transformed into green manufacturing. As the time nodes for achieving "carbon peak" and "carbon neutrality" are gradually approaching, magnesium and magnesium alloys, as a green and environmentally friendly metal material, are favored by researchers and manufacturers. Magnesium and magnesium alloys have broad application prospects in aerospace, automobiles, 3C digital devices, wearable electronic devices and other fields due to their low density, high specific strength, good shock absorption performance, and excellent electromagnetic shielding capabilities. They are indispensable materials in today's production industry.

[0003] The preparation of magnesium and magnesium alloys usually adopts the smelting method, among which the refining process is a crucial link in the smelting of magnesium and magnesium alloys, which determines the purity of the molten metal and directly affects the quality of castings. The existing refining methods are divided into refining agent refining method and protective gas refining method. Among them, the protective gas refining method has high cost, which has certain limitations on its application. The refining agent refining method is one of the most commonly used methods for smelting and refining magnesium and magnesium alloys in industrial production due to its simple operation and low cost.

[0004] However, the traditional refining method of refining agents usually adopts the method of manually spreading the refining agent for refining. This method is not only difficult to control the uniformity of the spreading of the refining agent, but also difficult to achieve industrialization, standardization and process. At the same time, on-site operators also need to face safety hazards such as splashing of high-temperature molten metal.

[0005] In the existing refining schemes for magnesium and magnesium alloy melts, the method of changing the crucible structure and refining medium is usually used to improve the refining quality of the molten metal. For example, in Chinese patent CN201711337654.3, a method for refining magnesium and magnesium alloys is shown. By changing the crucible structure, the bottom of the crucible is designed with a boss. After the metal refining is completed, a ceramic filter plate with a diameter smaller than the inner diameter of the crucible and larger than the inner diameter of the boss is precipitated into the molten metal. The filter holes are evenly distributed on the filter plate. Through the action of gravity, the impurities in the alloy liquid are filtered to the bottom of the crucible during the sedimentation of the ceramic filter plate to purify the molten metal. However, the method of settling the ceramic filter plate can only ensure that some solid impurities in the molten metal are filtered to the bottom of the crucible, and it has almost no effect on the gas mixed in the molten metal. At the same time, it cannot ensure that the ceramic filter plate and the boss structure are in a parallel position relationship and sink stably, and the stability of magnesium and magnesium alloy refining cannot be guaranteed. In China's CN202010005243.X, a magnesium alloy refining crucible with improved purity is shown. By designing a feed port, a stirring and diverting device, and a cryogenic treatment chamber on a refining crucible with an elliptical cross-section, the material is subjected to a hot rolling-like treatment through the stirring and diverting device, and the circumferential force generated by the inner ring rotor forms a cyclone with the introduced argon gas to achieve material refining. At the same time, the cryogenic treatment chamber performs a chilling treatment on the refined material. However, in the smelting process of magnesium and magnesium alloys, the crucible is a consumable. An overly complex crucible structure design will lead to an increase in smelting costs. At the same time, the patent directly chills the material, which is not conducive to the subsequent casting of castings.

[0006] Therefore, a device and method are needed to improve the refining stability of magnesium alloys. Summary of the invention

[0007] The purpose of the present invention is to provide a device and method for improving the refining stability of magnesium and magnesium alloys in view of the problems of unstable refining and splashing of high-temperature molten metal in the refining agent refining method during the smelting process of magnesium and magnesium alloys in industrial production.

[0008] The present invention proposes a device for improving the refining stability of magnesium alloy, which comprises a refining stirring device, a refining agent feeding device and a refining agent quality control device, wherein

[0009] The main frame of the refining and stirring device includes a horizontal support structure and a vertical track extending into the crucible, a first motor is provided on the horizontal support structure, and a stirrer is provided on the vertical track, and the first motor controls the stirrer to move up and down through a rocker arm connecting rod mechanism;

[0010] The refining agent feeding device is provided with a gas cylinder and a support frame on the bottom plate, a feeding channel, a refining agent tank and a second motor are provided on the upper end of the support frame, the feeding channel comprises a horizontal pipe and a spiral pipe communicating with each other, an impeller is provided in the spiral pipe and driven by the second motor; the lower outlet of the refining agent tank is connected with the horizontal pipe, the gas cylinder contains protective gas, and the outlet of the gas cylinder is connected to the outer end of the horizontal pipe;

[0011] The refining agent quality control device comprises a refining agent quality sensor, an alarm element and a control system in a refining agent tank, and is used for setting, monitoring and alarming the quality of the refining agent.

[0012] Advantageously, the output end of the first motor is connected to one end of the first connecting rod through a first rotating pair, the other end of the first connecting rod is connected to one end of the second connecting rod through a second rotating pair, and the other end of the second connecting rod is connected to the agitator through a third rotating pair.

[0013] Advantageously, the second motor is connected to the impeller via a rotating shaft.

[0014] Advantageously, a plurality of lifting ears are provided at the upper end of the horizontal supporting structure.

[0015] Advantageously, universal wheels are also provided on the bottom side of the base plate.

[0016] Advantageously, the gas cylinder is connected to the outer end of the horizontal pipe through a gas supply pipe.

[0017] Advantageously, the outlet of the spiral pipe is aligned with the metal liquid level of the crucible 7 .

[0018] The present invention also proposes a method for improving the refining stability of magnesium alloy using the above device, the method comprising the following steps:

[0019] S1, turning on the first motor to make the stirrer stably reciprocate up and down in the crucible until the metal liquid surface shows a stable rolling phenomenon;

[0020] S2. Input the quality range of the refining agent through the control panel of the control system. After the control system determines that it is successful, turn on the switches of the second motor, the gas cylinder and the refining agent tank, and spray the protective gas and the refining agent onto the wave crest of the molten metal in the crucible through the gas pressure and the centrifugal force generated by the blades; and monitor the quality of the refining agent in the refining agent tank through the control system, and alarm if it is abnormal.

[0021] Advantageously, the control system receives the refining agent quality signal M1, and when the refining agent quality signal M1 and the minimum working quality M2 of the refining agent satisfy the following relationship, the alarm element issues an alarm: M1≤0 or M2-M1>0.

[0022] Advantageously, the control system comprises an operation panel for setting a lower limit mass M3 and an upper limit mass M4 of the refining agent before refining.

[0023] Beneficial effects: The present invention can eliminate the instability caused by human factors in the refining operation of magnesium and magnesium alloys, while achieving the safe production goal of "strengthening labor protection and improving working conditions", and ultimately achieving the purpose of industrialization, standardization and process-based refining operations of magnesium and magnesium alloys. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the refining and stirring device of the present invention;

[0025] Figure 2 and Figure 3 It is a structural schematic diagram of a refining agent feeding device;

[0026] Figure 4 This is a schematic diagram of alarm determination of the refining agent quality control system;

[0027] Figure 5 Schematic diagram for determining the input values ​​of the refining agent control system.

[0028] Among them: 1-lifting ear, 2-first rotating pair, 3-first connecting rod, 4-first motor, 5-second connecting rod, 6-main frame, 7-crucible, 8-second rotating pair, 9-third rotating pair, 10-agitator, 11-feeding channel, 12-impeller, 13-air supply pipeline, 14-gas cylinder, 15-support frame, 16-universal wheel, 17-refining agent tank, 18-rotating shaft, 19-second motor, 20-refining agent quality control device DETAILED DESCRIPTION

[0029] In order to more clearly describe the shape, structure and effect of the present invention, the specific implementation of the present invention will be described with reference to the accompanying drawings.

[0030] The device for improving the refining stability of magnesium alloys of the present invention comprises a refining stirring device, a refining agent feeding device and a refining agent quality control device.

[0031] See also Figure 1 The refining and stirring device structure includes a lifting ear 1, a first connecting rod 3, a first motor 4, a second connecting rod 5, a main frame 6, a crucible 7 and a stirrer 10. The main function of this structure is to automatically stir the molten metal during the refining process to achieve a bottom-up circulation.

[0032] The lifting lug 1 is fixed on the upper end of the main frame 6, and the lifting lug 1 is on both sides of the upper end of the main frame 6. The lifting lug 1 is used for the transportation of the refining and stirring device structure. The first motor 4 and the central position of the upper end of the main frame 6 can drive one end of the first connecting rod 3 to rotate through the first rotating pair 2. The other end of the first connecting rod 3 is connected to one end of the second connecting rod 5 through the second rotating pair 8. The other end of the second connecting rod 5 is connected to the stirrer 10 through the third rotating pair 9, driving the stirrer 10 to move in the vertical direction. The first motor 4 adopts variable frequency rotation, and the speed is adjusted according to needs to provide power for the operation of the entire refining and stirring device structure. The lower part of the main frame 6 provides a track or channel for the stirrer 10 to move up and down.

[0033] The first motor 4 and the first rotating pair 2 are fixedly connected, for example, by integral connection, pin shaft, welding or the like.

[0034] See also Figure 2-3 The refining agent feeding device includes a second motor 19, a rotating shaft 18, an impeller 12, a feeding channel 11, a refining agent tank 17, a gas cylinder 14, an air delivery pipeline 13, a support frame 15 and a universal wheel 16. The main function of this structure is to realize the automatic feeding and spraying function of the refining agent during the refining process, and to use a mechanical structure instead of manual spreading, which greatly improves the stability during the refining operation and helps to realize the standardization and automation of the refining operation.

[0035] The impeller 12 is installed in the feeding channel 11, and the second motor 19 is connected to the impeller 12 through the rotating shaft 18 to ensure that the impeller 12 can make a circular motion as the second motor 19 rotates. The second motor 19 adopts variable frequency rotation and adjusts the speed as needed. The feeding channel 11 and the rotating shaft 18 are in orthogonal directions. The refining agent tank 17 is located above the feeding channel 11, and the gas cylinder 14 is filled with protective gas, which is connected to one end of the feeding channel 11 through the gas supply pipe 13, and blows the refining agent to the impeller 12. The refining agent and the protective gas are stably spread on the surface of the alloy liquid as the impeller 12 rotates. At the same time, the presence of the protective gas can further avoid the oxidation of the molten metal and help to purify the molten metal melt.

[0036] The second motor 19, the rotating shaft 18, the impeller 12, the feeding channel 11, and the refining agent tank 17 are placed on the support frame 15 and fixed, and the universal wheel 16 is placed on the lower side of the bottom plate below the support frame 15 to achieve free movement.

[0037] See also Figure 4 The refining agent quality control device 20 is composed of a sensor for measuring the quality of the refining agent in the refining agent tank 17, an alarm element and a control system. The main function of this structure is to automatically detect the quality of the refining agent in the refining agent tank 17, and to prompt through the alarm element that the quality of the refining agent in the refining agent tank 17 is insufficient to meet the needs of this refining, and the refining agent needs to be added in time.

[0038] The control system receives the refining agent mass signal M1 in the refining agent tank 17 transmitted by the sensor. When the refining agent mass signal M1 and the minimum working mass M2 of the refining agent satisfy the following relationship, the alarm element sounds an alarm to remind the operator that the refining agent needs to be added to ensure the smooth progress of the refining process: M1≤0 or M2-M1>0, wherein. When the refining agent mass signal M1 and the upper limit mass signal M2 do not satisfy the above relationship, the alarm stops working and the refining device can work normally. In this embodiment, the minimum working mass set in the control system is 20g, and the error range is not greater than ±1g.

[0039] See also Figure 5 The control system includes an operation panel. Before refining, the lower limit mass M3 and the upper limit mass M4 of the refining agent can be set. The operator can select the refining agent mass according to the actual situation during the smelting process and assign the selected refining agent mass to M2.

[0040] The specific working principle of the present invention is as follows: when magnesium and magnesium alloy are fully melted and ready to be refined, a crane is used to place the refining stirring device above the refining crucible through the lifting lug 1, and the first motor 4 is turned on to make the stirrer 10 stably reciprocate up and down in the crucible 7.

[0041] After the metal liquid surface shows a stable rolling phenomenon, the quality range value of the refining agent is input through the control panel of the refining agent quality control device 20. After the refining agent quality control device determines that it is successful, the second motor 19 of the refining agent feeding device, the switch of the gas cylinder 14 and the switch of the refining agent tank 17 are turned on, and the protective gas and refining agent are sprayed onto the metal liquid wave crest in the crucible through the gas pressure and the centrifugal force generated when the blade 12 rotates to achieve uniform spreading. At the same time, the presence of protective gas can prevent the metal liquid from being oxidized. The refining flux will absorb impurities in the metal liquid during the sedimentation process. At the same time, the dual effects of stirring and refining flux will release or capture the gas in the metal liquid, thereby improving the refining quality of the metal liquid melt. Compared with artificial refining agent refining, the stirring frequency and amplitude are more consistent, the refining flux is spread more evenly, and the entire refining operation process is more stable.

Claims

1. A device for improving the refining stability of magnesium alloy, characterized in that: The device comprises a refining stirring device, a refining agent feeding device and a refining agent quality control device (20), wherein The main frame (6) of the refining and stirring device comprises a horizontal support structure and a vertical track extending into the crucible (7), a first motor (4) is provided on the horizontal support structure, and a stirrer (10) is provided on the vertical track, and the first motor (4) controls the stirrer (10) to move up and down through a rocker arm connecting rod mechanism; The refining agent feeding device is provided with a gas cylinder (14) and a support frame (15) mounted on a bottom plate, a feeding channel (11), a refining agent tank (17) and a second motor (19) mounted on the upper end of the support frame (15), the feeding channel (11) comprising a horizontal pipe and a spiral pipe communicating with each other, an impeller (12) being mounted in the spiral pipe and driven by the second motor (19); the lower outlet of the refining agent tank (17) is connected to the horizontal pipe, the gas cylinder (14) contains protective gas, and the outlet of the gas cylinder (14) is connected to the outer end of the horizontal pipe; The refining agent quality control device (20) comprises a refining agent quality sensor, an alarm element and a control system in the refining agent tank (17), and is used for setting, monitoring and alarming the quality of the refining agent.

2. The device for improving the refining stability of magnesium alloy according to claim 1, characterized in that: The output end of the first motor (4) is connected to one end of a first connecting rod (3) via a first rotating pair (2), the other end of the first connecting rod (3) is connected to one end of a second connecting rod (5) via a second rotating pair (8), and the other end of the second connecting rod (5) is connected to the agitator (10) via a third rotating pair (9).

3. The device for improving the refining stability of magnesium alloy according to claim 1, characterized in that: The second motor (19) is connected to the impeller (12) via a rotating shaft (18).

4. The device for improving the refining stability of magnesium alloy according to claim 1, characterized in that: A plurality of lifting ears (1) are also provided at the upper end of the horizontal supporting structure.

5. The device for improving the refining stability of magnesium alloy according to claim 1, characterized in that: A universal wheel (16) is also provided on the lower side of the base plate.

6. The device for improving the refining stability of magnesium alloy according to claim 1, characterized in that: The gas cylinder (14) is connected to the outer end of the horizontal pipeline through the gas supply pipeline (13).

7. The device for improving the refining stability of magnesium alloy according to claim 1, characterized in that: The outlet of the spiral pipe is aligned with the metal liquid level of the crucible (7).

8. A method for improving the refining stability of magnesium alloy using the device according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: S1, turning on the first motor (4) to make the stirrer (10) stably reciprocate up and down in the crucible (7) until the metal liquid surface shows a stable rolling phenomenon; S2. The quality range of the refining agent is input through the control panel of the control system. After the control system determines that it is successful, the switches of the second motor (19), the gas cylinder (14) and the refining agent tank (17) are turned on, and the protective gas and the refining agent are sprayed onto the wave crest of the molten metal in the crucible through the gas pressure and the centrifugal force generated by the blades (12); and the quality of the refining agent in the refining agent tank (17) is monitored by the control system, and an alarm is issued if it is determined to be abnormal.

9. The method for improving the refining stability of magnesium alloy according to claim 8, characterized in that: The control system receives the refining agent quality signal M1. When the refining agent quality signal M1 and the minimum working quality M2 of the refining agent satisfy the following relationship, the alarm element issues an alarm: M1≤0 or M2-M1>0.

10. The method for improving the refining stability of magnesium alloy according to claim 9, characterized in that: The control system comprises an operation panel, and a lower limit mass M3 and an upper limit mass M4 of the refining agent are set before refining.

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