A method for self-removal quantitative pouring of magnesium alloy melt

Abstract

The application discloses a magnesium alloy melt self-moving quantitative pouring method, which realizes die casting forming by pouring the smelted magnesium alloy melt into a die casting machine, characterized in that the smelted magnesium alloy melt is first introduced into a first containing body at a first fixed point to realize metering and obtain a fixed volume of magnesium alloy melt; then the metered magnesium alloy melt is transferred to a second containing body, the second containing body is kept closed, ultrasonic vibration is applied to the magnesium alloy melt in the second containing body, and the second containing body is moved to a second fixed point; and the magnesium alloy melt in the second containing body is introduced into the die casting machine at the second fixed point to realize die casting forming. The application can realize rapid pouring with accurate metering, reduce product defects, improve production efficiency, and is particularly suitable for laboratory magnesium alloy test pieces and small-scale trial production of enterprises.

Description

A method for self-moving quantitative casting of magnesium alloy melt Technical Field

[0001] This invention relates to the field of magnesium alloy material production, preparation and forming technology, and in particular to a self-moving quantitative casting method for magnesium alloy melt. Background Technology

[0002] Magnesium alloys are lightweight, have high specific strength, excellent functional properties, and are abundant in resources. They are widely used in aerospace, transportation, electronics, medical devices, and military fields. They have become a global focus, and their widespread application can help alleviate the metal mineral resource crisis, reduce energy consumption and pollution, and contribute to the greening, intelligentization, and lightweighting of manufacturing and key equipment.

[0003] Currently, magnesium alloy product manufacturing typically involves quantitatively pouring molten magnesium alloy into a die-casting machine to achieve die casting. Common methods for conveying molten magnesium alloy include pneumatic conveying, pump delivery, and manual scooping. However, all of these methods have some inherent problems.

[0004] Pneumatic conveying involves introducing a dry protective gas into the crucible for melting magnesium alloy. Under pressure, the molten magnesium alloy is forced through a pipette into the casting ladle of the die-casting machine. Stopping the casting process is achieved by releasing the gas pressure. However, delayed pressure release can lead to significant measurement errors. Furthermore, the molten magnesium alloy may solidify in the pipette, causing blockages and increasing subsequent cleaning work, posing certain risks.

[0005] The pumping process involves using a mechanical pump to deliver molten magnesium alloy through a pipette into the casting ladle of the die-casting machine. The high temperature of the molten magnesium alloy places high demands on the pump's heat resistance, resulting in a short lifespan and high maintenance costs for the mechanical pump. The impeller movement of the mechanical pump increases the amount of air entrapped in the molten magnesium alloy, reducing its density and mechanical properties. Furthermore, the mechanical pump requires preheating before use and cleaning afterward, increasing manual labor and demanding higher skill levels from operators.

[0006] Manual scooping involves manually pouring molten magnesium alloy into the die-casting machine using a ladle. Magnesium alloy is highly flammable upon contact with air, posing a significant risk and requiring operation by qualified personnel. Ladle pouring is inefficient and cannot provide precise metering; furthermore, repeated scooping damages the oxide film on the magnesium alloy surface, increasing burn-off.

[0007] To address the issue of pipetting blockage during pneumatic conveying and pump extraction, patent CN112846119A discloses a crude magnesium molten metal purification and casting system. This system comprises three chambers. A back-suction pump and pipetting system sequentially transfer the magnesium alloy molten metal from the first chamber to the third chamber, purifying the crude magnesium molten metal before it is poured into the die-casting machine through a pipe connected to the third chamber. This device reduces agitation of the magnesium molten metal during casting, significantly lowering its oxidation level. By integrating smelting and casting into a single process, it achieves full automation of crude magnesium smelting and molten metal transfer, improving ingot quality. However, its complex structure and high maintenance costs persist, and issues such as inaccurate molten magnesium casting metering and the inability to perform large-scale casting remain.

[0008] Currently, when developing magnesium alloy properties in the laboratory, it is often necessary to use die-casting machines to prepare magnesium alloy specimens. However, the existing industrial method of transferring molten magnesium alloy to the die-casting machine is not suitable for laboratory preparation of magnesium alloy specimens. Therefore, there is an urgent need to develop a melting and casting device that is both suitable for laboratory magnesium alloy research and closely aligned with industrial applications for small-batch melting and preparation of magnesium alloy samples.

[0009] To address the above issues, providing a high-efficiency, low-cost, and precise magnesium alloy die-casting technology suitable for laboratory and small-scale enterprise pilot production is crucial for promoting the vigorous development of the magnesium alloy industry. Summary of the Invention

[0010] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is: how to provide a rapid casting method for magnesium alloy melt self-moving quantitative casting that can achieve accurate metering, reduce product defects, and improve production efficiency; making it particularly suitable for the trial production of magnesium alloy specimens in the laboratory and small-scale pilot production in enterprises.

[0011] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0012] A self-moving quantitative casting method for magnesium alloy melt involves pouring molten magnesium alloy into a die-casting machine to achieve die casting. The method is characterized by first introducing the molten magnesium alloy into a first container at a first fixed point for metering to obtain a fixed volume of molten magnesium alloy; then transferring the metered molten magnesium alloy to a second container, keeping the second container closed, and simultaneously applying ultrasonic vibration to the molten magnesium alloy within it while moving it to a second fixed point; finally, introducing the molten magnesium alloy from the second container into the die-casting machine at the second fixed point to achieve die casting.

[0013] In this method, a first container is used for measurement to accurately obtain the volume of molten liquid required for die casting. Then, a second container is used to keep the molten liquid moving and apply ultrasonic vibration to it. The ultrasonic vibration eliminates air bubbles and breaks up grains in the molten liquid, preventing premature crystallization. When the second container moves to the second fixed position of the die casting machine and introduces the molten liquid into the die casting machine, the molten liquid can maintain good fluidity, improve the die casting effect of the die casting parts, and reduce product defects.

[0014] Furthermore, this method relies on a self-moving quantitative casting production system for magnesium alloy melt. This system includes a magnesium alloy melting and casting furnace located at a first fixed position and a magnesium alloy die-casting machine located at a second fixed position. A crucible is installed inside the magnesium alloy melting and casting furnace, with an outwardly protruding outlet nozzle on one side of the upper end. The outlet nozzle is rotatably mounted on the outlet ports at the upper end of the magnesium alloy melting and casting furnace via a furnace body rotation shaft. The magnesium alloy melting and casting furnace also includes a crucible tilting and discharging control mechanism to control the crucible's tilting and discharging around the furnace body rotation shaft. A horizontally arranged guide rail connects the magnesium alloy melting and casting furnace and the magnesium alloy die-casting machine. A self-moving quantitative casting device for magnesium alloy melt is also installed on the guide rail. This device includes an obliquely oriented elongated holding groove, which is entirely enclosed. A fixed cover is fixedly installed on the oblique groove opening. The device has a cover plate with an ultrasonic vibration device installed on it. A lower end cover, which can be opened, is installed at the lower port of the holding tank via a pneumatic switch. The upper end of the holding tank has a vertically upward-facing bend section, and an upper end cover, which can be opened, is installed at the upper port of the bend section via an upper pneumatic switch. A metering liquid receiving tank is installed inside the bend section. The metering liquid receiving tank is rotatably mounted on the side walls of the bend section's inner cavity at the middle positions on both sides via a tank body rotating shaft. One end of the tank body rotating shaft extends outside the bend section and is connected to a receiving tank motor. A liquid level sensor is also installed inside the metering liquid receiving tank. Both the liquid level sensor and the receiving tank motor are connected to a control center. When the magnesium alloy melt self-moving metering pouring device is located at one end of the first fixed point on the guide rail, the upper port of the holding tank is positioned directly below the crucible's outlet. When the magnesium alloy melt self-moving metering pouring device is located at one end of the second fixed point on the guide rail, the lower port of the holding tank is positioned directly above the pouring port of the magnesium alloy die-casting machine.

[0015] In this casting production system, the magnesium alloy molten metal is first melted in a crucible within the magnesium alloy melting and casting furnace. Then, during die casting, the self-propelled quantitative casting device for the magnesium alloy molten metal is moved to the first fixed position and the upper cover is opened. The crucible is tilted and the molten metal is poured into a quantitative receiving tank via a crucible tilting and discharging control mechanism. The volume of molten metal poured in is controlled by a level sensor, and once the required volume is reached, the pouring stops, and the upper cover is closed. The receiving tank motor then controls the tilting of the quantitative receiving tank, pouring the metered molten metal into a holding tank. An ultrasonic vibration device on the holding tank applies ultrasonic vibration to the solution, squeezing out air bubbles and breaking up grains. This prevents premature crystallization and solidification, refining the crystal nuclei. Simultaneously, ultrasonic vibration prevents heavier materials from settling to the bottom, thus avoiding gravity segregation. While undergoing ultrasonic vibration, the magnesium alloy molten material is moved along the guide rail by a self-propelled quantitative pouring device to the magnesium alloy die-casting machine at the second fixed position. The lower end cover is then controlled to flip open outwards, allowing the molten material in the holding tank to flow into the pouring port of the magnesium alloy die-casting machine, completing the die-casting process. Therefore, this equipment enables precise metering and rapid pouring of magnesium alloy molten material. During the molten material transfer process, the ultrasonic vibration effect squeezes out air bubbles and breaks up crystal nuclei, better ensuring the fluidity of the molten material during die-casting, reducing product defects, and improving production quality and efficiency. This production equipment is particularly suitable for laboratory magnesium alloy specimen production and small-scale trial production in enterprises.

[0016] The magnesium alloy melting and casting furnace is a mature, existing piece of equipment. It includes a rotatable, tiltable crucible for discharging molten magnesium. An electric heating module is installed inside the crucible for heating during melting. A discharge trough cover is located at the discharge nozzle at the top of the crucible, and a melting operation cover is positioned at the center of the top of the crucible. Additionally, protective gas pipelines and other accessories are installed at the top of the crucible; the specific structure is not detailed here. The magnesium alloy die-casting machine is also a mature, existing piece of equipment, and its specific structure is not detailed here. In practice, the crucible is preferably an inert crucible (made of imported 310s coated low-carbon steel plate) to avoid chemical reactions with the molten magnesium, which could reduce the performance of the magnesium alloy. The holding tank and the metering receiving tank can be made of the same material as the crucible. In practice, the level sensor can be a mass level sensor, a laser level sensor, a float level sensor, a dual-line level sensor, or other level sensors. Furthermore, the level sensor can be used individually or in combination to improve metering accuracy.

[0017] Furthermore, the cover plate is secured to the retaining groove with bolts. The entire partition can be removed when needed for easy maintenance of the device.

[0018] Furthermore, the magnesium alloy melt self-moving quantitative casting device is also equipped with an atmosphere protection mechanism. The atmosphere protection mechanism includes an upper protective gas pipe connected to the upper end cover and a lower protective gas pipe connected to the upper part of the retaining tank cover plate. The outer ends of the upper and lower protective gas pipes are each connected to a protective gas source.

[0019] This design allows for the injection of protective gas into the magnesium alloy melt self-propelled quantitative casting device before use, creating a protective atmosphere. Furthermore, the unique dual protective gas pipeline configuration enables dynamic atmosphere protection of the molten metal during the pouring process from the crucible to the quantitative receiving tank. The protective gas supplied through the upper pipeline, while the upper cover is open, prevents oxidation from contact with air during pouring. The lower protective gas pipeline applies pressure to the molten metal as it is introduced into the die-casting machine's pouring port after the lower cover of the holding tank is opened, ensuring faster and more complete entry into the machine. In practice, the preferred protective gas type is CO2+R-134a with a maximum flow rate of 50 L / min, providing effective flame-retardant protection for melting and casting.

[0020] Furthermore, a retaining tank heating module is also installed inside the lower side wall of the retaining tank, and the retaining tank heating module is connected to the control center.

[0021] In this way, the holding tank can be heated before and after the molten liquid is poured in, which facilitates heat preservation during the transfer process after the molten liquid enters.

[0022] Furthermore, a temperature probe connected to the control center is installed inside the tank. This facilitates real-time temperature monitoring and feedback control during molten metal transfer.

[0023] Furthermore, the lower pneumatic switch is a rotary switch and is installed at the upper end of the lower cover. This facilitates the lower cover to open outward and upward to allow the molten liquid to flow out.

[0024] Furthermore, the upper pneumatic switch is a rotary switch and is installed on the side of the upper cover away from the magnesium alloy melting and casting furnace.

[0025] This design allows the upper cover to open upwards on the side facing the magnesium alloy melting and casting furnace, facilitating the pouring of molten magnesium and the ejection of protective gas from the upper protective gas pipe to maintain an atmosphere of protection during the pouring process. In practice, both the lower and upper pneumatic switches are connected to the control center for automatic control. As an optimization, the upper pneumatic switch controls the upper cover to open at a 90-degree rotation angle. This ensures that the protective gas forms a protective layer on the molten surface perpendicular to the liquid surface, and also prevents excessive flow velocity of the molten magnesium from splashing outside the track-type self-propelled insulating casting system, which could cause combustion and safety accidents.

[0026] Furthermore, a bracket is fixedly installed on the lower side of the groove, and rollers are spaced apart at the lower end of the bracket, with the rollers engaging with the guide rail. This facilitates the movement of the groove.

[0027] Furthermore, a telescopic cylinder is mounted upwards on the rollers near the magnesium alloy melting and casting furnace, with the upper end of the telescopic cylinder fixed to the lower side of the upper end of the retaining groove. This facilitates the control and adjustment of the tilt angle of the retaining groove as needed. In practice, the telescopic cylinder can be an electric cylinder, a pneumatic cylinder, or a hydraulic cylinder.

[0028] Furthermore, lifting lugs are installed on the upper surface of the cover plate. This facilitates the transportation and lifting of the device.

[0029] Furthermore, ultrasonic vibration devices are installed on both side walls of the holding tank. This ultrasonic vibration from two mutually perpendicular directions creates a more effective three-dimensional oscillation effect within the holding tank, intensifying the internal disturbance of the magnesium melt, breaking down dendrites, refining grains, and improving fluidity. Simultaneously, the ultrasonic vibration devices on the cover plate prevent the magnesium melt from solidifying on the surface of the holding tank cover due to the large temperature difference when in contact with it, thus preventing inaccurate measurement. The ultrasonic vibration devices located on both sides of the holding tank also prevent heavier substances from settling to the bottom, thus avoiding gravity segregation.

[0030] Furthermore, the ultrasonic vibration device includes a push rod, the rear end of which is telescopically (vertically) mounted on a base (the base corresponding to the ultrasonic vibration device mounted on the cover plate is the cover plate, and the base corresponding to the ultrasonic vibration device mounted on the side wall of the retaining groove is the side wall of the retaining groove). The front end of the push rod extends forward into the inner cavity of the retaining groove. An air cavity surrounding the rear end of the push rod is provided on the base where the rear end of the push rod is located. A piston is also vertically fixed at the rear end of the push rod. A helical spring sleeved on the push rod is abutted between the front side of the piston and the front end of the air cavity. An air inlet channel is provided outwardly on the air cavity behind the piston, and an air outlet channel is provided outwardly on the air cavity in front of the piston.

[0031] In this way, the ultrasonic vibration device is used by connecting the air inlet channel to an external air compressor. Air from the compressor enters the air chamber behind the piston, compressing the piston and causing it to move forward. After passing the return air channel, the piston releases air through the outlet channel. After releasing air, the piston returns to its original position, blocking the outlet channel, and then continues to move forward under pressure. This repetitive motion achieves ultrasonic vibration. In this way, the tip of the ultrasonic vibration device's push rod is immersed in the molten magnesium alloy, directly contacting the molten magnesium. This avoids ultrasonic wave loss at the interface and within the medium, improving the efficiency of mechanical property enhancement. Therefore, it has the advantages of simple structure, convenient control, and easy adjustment. During implementation, after the ultrasonic vibration device is started, it should be stopped only after the molten metal has been completely discharged from the holding tank to prevent residual molten metal from solidifying at the push rod installation gap, which would affect the flexibility of the push rod's extension and retraction.

[0032] Furthermore, the ultrasonic vibration devices are multiple and arranged in an array on the corresponding substrates. This better ensures the vibration effect on the molten liquid throughout the entire holding tank cavity.

[0033] Furthermore, a pressure control valve is installed in the air intake channel, and a flow control valve is installed in the air outlet channel. The pressure control valve can adjust the intake air pressure, thereby controlling the vibration intensity. The flow control valve can adjust the output air flow, thereby adjusting the vibration amplitude.

[0034] Furthermore, a vibrating head is provided at the front end of the push rod. The vibrating head includes an elastic vibrating ring coaxially sleeved at the front end of the push rod. The vibrating ring and the vibrating head are fixedly connected by multiple springs arranged radially and evenly distributed along the ring. Multiple obliquely arranged vibrating plates are evenly distributed and fixedly installed on the vibrating ring.

[0035] In this way, the push rod transmits its own back-and-forth vibration to the elastic vibrating ring through the radial spring. This integrates the push rod's reciprocating vibration, the spring's oscillating vibration, and its own torsional vibration into a single unit. This creates a multi-angle and multi-directional composite vibration effect between the vibrating ring and the vibrating plates on it. The vibration is transmitted outward in a three-dimensional manner around the center of the push rod's front end, greatly improving the vibration effect on the molten metal. This makes the internal disturbance of the molten metal more intense, better achieving the effects of breaking dendrites, refining grains, and improving fluidity.

[0036] Thus, the ultrasonic vibration device is a pneumatic ultrasonic device. During implementation, the top rod and its upper structure are made of tungsten or tungsten alloy to avoid reaction with the magnesium alloy melt. The unique structure of the vibrating head can generate a three-dimensional spatial vibration effect outward and propagate radially inside the melt. The amplitude can be adjusted according to the actual measurement volume by adjusting the air pressure. Its vibration effect is far greater than that of traditional piezoelectric ceramic ultrasonic vibration.

[0037] Therefore, the above-mentioned magnesium alloy melt self-moving quantitative casting production system can transfer the molten magnesium in the casting furnace to the magnesium alloy melt self-moving quantitative casting device by hydraulic tilting, and then move it to the magnesium alloy die casting part by track to pour the molten liquid into the die casting machine to obtain magnesium alloy parts. The specific process includes the following steps.

[0038] Before the melting in the magnesium alloy melting and casting furnace is completed, the self-moving quantitative casting device for the magnesium alloy melt is moved to the first fixed position and connected to the magnesium alloy melting and casting furnace, and the holding tank heating module is turned on to preheat the holding tank; after melting is completed, the upper cover of the holding tank is opened, and the lower protective gas pipeline is turned on to introduce protective gas into the inner cavity of the holding tank, forcing the air out of the upper port and forming an atmosphere protection in the inner cavity of the holding tank. Then, the upper gas pipeline is turned on to introduce protective gas to form an atmosphere protection in the upper port of the holding tank; then the magnesium alloy melting and casting furnace is opened, the upper discharge chute cover of the crucible is opened, and the furnace body shaft around the liquid outlet of the crucible is rotated. Under the protective atmosphere, the molten metal is poured into a metering tank. The level sensor in the metering tank detects the level in real time and measures the amount of molten metal poured in. When the molten metal level reaches the set value, the crucible is controlled to return to its original position, the upper cover of the holding tank is controlled to close, and then the metering tank is controlled to flip over to pour the metered molten metal into the holding tank. The ultrasonic vibration device is activated to apply ultrasonic vibration to the molten metal entering the holding tank. At the same time, the magnesium alloy melt self-moving metering pouring device is moved to the second fixed position and connected to the magnesium alloy die casting machine. The lower cover of the holding tank is opened to guide the molten metal into the pouring port of the magnesium alloy die casting. The magnesium alloy die casting machine is used to achieve die casting.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] 1. Solvent-free purification avoids harmful gases generated during solvent purification, improves the smelting working environment, protects the health of employees, and reduces the risk of spontaneous combustion of magnesium alloys.

[0041] 2. The self-moving insulated casting system moves along the track, allowing the magnesium melt to be transferred quickly, avoiding combustion, improving efficiency, and eliminating the need for post-processing cleaning. It is suitable for laboratory and small-scale trial production in enterprises.

[0042] 3. The liquid level sensor in the quantitative casting tank accurately measures the magnesium melt, improves the utilization rate of magnesium melt, avoids secondary remelting, and improves production efficiency.

[0043] 4. By using an ultrasonic vibration device, the solidification structure of magnesium alloy melt is improved, the grains are refined, and the mechanical properties of magnesium alloy are enhanced.

[0044] 5. By using a heating and heat preservation device, the fluidity of magnesium melt is improved, the filling performance of magnesium melt is enhanced, and the solidification structure is improved.

[0045] 6. The self-moving heat-insulating casting system has full-condition gas protection, preventing oxidation and burn-off of the magnesium alloy melt. During the casting process, no oxygen inclusions enter the interior of the melt, resulting in high mechanical properties of the casting.

[0046] 7. The entire process is controlled by an intelligent integrated control system, which has a high degree of automation, ensures continuous and good quality of magnesium melt, reduces labor intensity, and results in high uniformity of die-cast parts. Attached Figure Description

[0047] Figure 1 is a schematic diagram of the structure of the magnesium alloy melt self-moving quantitative casting production system used in the embodiment of the present invention.

[0048] Figure 2 is a schematic diagram of the structure of the single ultrasonic vibration device in Figure 1.

[0049] Figure 3 is a cross-sectional view of Figure 2.

[0050] Figure 4 is a schematic diagram of the structure of a single vibrating head in Figure 2. Detailed Implementation

[0051] The present invention will now be described in further detail with reference to specific embodiments.

[0052] Example: A self-moving quantitative casting method for magnesium alloy melt, wherein the molten magnesium alloy is poured into a die-casting machine to achieve die casting. The method is characterized by first introducing the molten magnesium alloy into a first container at a first fixed point for metering to obtain a fixed volume of molten magnesium alloy; then transferring the metered molten magnesium alloy to a second container, keeping the second container closed and applying ultrasonic vibration to the molten magnesium alloy inside while moving it to a second fixed point, where the molten magnesium alloy inside the second container is introduced into the die-casting machine to achieve die casting.

[0053] In this method, a first container is used for measurement to accurately obtain the volume of molten liquid required for die casting. Then, a second container is used to keep the molten liquid moving and apply ultrasonic vibration to it. The ultrasonic vibration eliminates air bubbles and breaks up grains in the molten liquid, preventing premature crystallization. When the second container moves to the second fixed position of the die casting machine and introduces the molten liquid into the die casting machine, the molten liquid can maintain good fluidity, improve the die casting effect of the die casting parts, and reduce product defects.

[0054] In this embodiment, the method relies on a self-moving quantitative casting production system for magnesium alloy melt, as shown in Figures 1-4. The system includes a magnesium alloy melting and casting furnace (not shown) located at a first fixed position and a magnesium alloy die-casting machine (not shown) located at a second fixed position. A crucible 1 is installed inside the magnesium alloy melting and casting furnace. A protruding outlet nozzle 2 is provided on one side of the upper end of the crucible 1. The outlet nozzle 2 is rotatably mounted on both sides of the magnesium alloy melt via the furnace body's rotating shaft. At the outlet of the upper end of the melting and casting furnace, a crucible tilting and discharging control mechanism (not shown in the figure) is also installed inside the magnesium alloy melting and casting furnace to control the crucible to tilt and discharge liquid around the furnace body axis; a horizontally arranged guide rail 3 is also provided between the magnesium alloy melting and casting furnace and the magnesium alloy die casting machine, and a magnesium alloy melt self-moving quantitative casting device is also installed on the guide rail 3. The magnesium alloy melt self-moving quantitative casting device includes an obliquely arranged elongated holding groove 4, the holding groove 4 is completely closed, and a cover is fixed on the oblique groove opening of the holding groove 4. The cover is equipped with a cover plate 5, on which an ultrasonic vibration device 6 is installed. A lower end cover 7, which can be opened, is installed at the lower port of the retaining tank via a lower pneumatic switch. The upper end of the retaining tank 4 has a vertically upward-facing bend section, at which an upper end cover 8, which can be opened, is installed at the upper port of the bend section via an upper pneumatic switch. A metering liquid receiving tank 9 is installed inside the bend section. The metering liquid receiving tank 9 is rotatably mounted on the side walls of the bend section's inner cavity at the middle positions on both sides via a tank body rotating shaft 10. One end of the tank body rotating shaft 10 extends outside the bend section and connects to a receiving... The liquid tank motor (not shown in the figure) is connected to the liquid level sensor (not shown in the figure) in the quantitative liquid receiving tank 9. Both the liquid level sensor and the liquid receiving tank motor are connected to the control center (not shown in the figure). When the magnesium alloy melt self-moving quantitative pouring device is located at one end of the first fixed position of the guide rail 3, the upper port of the tank is positioned directly below the liquid outlet of the crucible. When the magnesium alloy melt self-moving quantitative pouring device is located at one end of the second fixed position of the guide rail, the lower port of the tank is positioned directly above the pouring port of the magnesium alloy die casting machine.

[0055] In this casting production system, the magnesium alloy molten metal is first melted in a crucible within the magnesium alloy melting and casting furnace. Then, during die casting, the self-propelled quantitative casting device for the magnesium alloy molten metal is moved to the first fixed position and the upper cover is opened. The crucible is tilted and the molten metal is poured into a quantitative receiving tank via a crucible tilting and discharging control mechanism. The volume of molten metal poured in is controlled by a level sensor, and once the required volume is reached, the pouring stops, and the upper cover is closed. The receiving tank motor then controls the tilting of the quantitative receiving tank, pouring the metered molten metal into a holding tank. An ultrasonic vibration device on the holding tank applies ultrasonic vibration to the solution, squeezing out air bubbles and breaking up grains. This prevents premature crystallization and solidification, refining the crystal nuclei. Simultaneously, ultrasonic vibration prevents heavier materials from settling to the bottom, thus avoiding gravity segregation. While undergoing ultrasonic vibration, the magnesium alloy molten material is moved along the guide rail by a self-propelled quantitative pouring device to the magnesium alloy die-casting machine at the second fixed position. The lower end cover is then controlled to flip open outwards, allowing the molten material in the holding tank to flow into the pouring port of the magnesium alloy die-casting machine, completing the die-casting process. Therefore, this equipment enables precise metering and rapid pouring of magnesium alloy molten material. During the molten material transfer process, the ultrasonic vibration effect squeezes out air bubbles and breaks up crystal nuclei, better ensuring the fluidity of the molten material during die-casting, reducing product defects, and improving production quality and efficiency. This production equipment is particularly suitable for laboratory magnesium alloy specimen production and small-scale trial production in enterprises.

[0056] The magnesium alloy melting and casting furnace is a mature, existing piece of equipment. Within the furnace, a rotatable, tiltable crucible 1 is installed, containing a crucible heating module 11 for heating during melting. A discharge trough cover 12 is located at the discharge nozzle at the top of the crucible, and a melting operation cover 13 is positioned at the center of the top of the crucible. Additionally, a protective gas pipeline 14 and other accessories are provided at the top of the crucible. Specific structural details are not described here. The magnesium alloy die-casting machine is also a mature, existing piece of equipment, and its specific structure is not detailed here. In practice, the crucible is preferably an inert crucible (made of imported 310s coated low-carbon steel plate) to avoid chemical reactions with the molten magnesium, which could reduce the performance of the magnesium alloy. The holding tank and the metering receiving tank can be made of the same material as the crucible. In practice, the level sensor can be a mass level sensor, a laser level sensor, a float level sensor, a dual-line level sensor, or other level sensors. In addition, the liquid level sensor can be used alone or in combination to improve measurement accuracy.

[0057] The cover plate 5 is fixed to the retaining groove 4 with bolts. When needed, the entire partition can be removed for easy maintenance of the device.

[0058] The magnesium alloy melt self-moving quantitative casting device is also equipped with an atmosphere protection mechanism. The atmosphere protection mechanism includes an upper protective gas pipe 16 connected to the upper end cover and a lower protective gas pipe 17 connected to the upper part of the retaining tank cover plate. The outer ends of the upper and lower protective gas pipes are each connected to a protective gas source.

[0059] This design allows for the injection of protective gas into the magnesium alloy melt self-propelled quantitative casting device before use, creating a protective atmosphere. Furthermore, the unique dual protective gas pipeline configuration enables dynamic atmosphere protection of the molten metal during the pouring process from the crucible to the quantitative receiving tank. The protective gas supplied through the upper pipeline, while the upper cover is open, prevents oxidation from contact with air during pouring. The lower protective gas pipeline applies pressure to the molten metal as it is introduced into the die-casting machine's pouring port after the lower cover of the holding tank is opened, ensuring faster and more complete entry into the machine. In practice, the preferred protective gas type is CO2+R-134a with a maximum flow rate of 50 L / min, providing effective flame-retardant protection for melting and casting.

[0060] The retaining groove 4 is also equipped with a retaining groove electric heating module 18 inside the lower side wall, and the retaining groove electric heating module 18 is connected to the control center.

[0061] In this way, the holding tank can be heated before and after the molten liquid is poured in, which facilitates heat preservation during the transfer process after the molten liquid enters.

[0062] The inner cavity of the holding tank 4 is also equipped with a temperature probe connected to a control center (not shown in the figure). This facilitates real-time temperature monitoring and feedback control during the molten metal transfer process.

[0063] The lower pneumatic switch is a rotary switch and is installed at the upper end of the lower cover. This allows the lower cover to be opened outwards and upwards to allow the molten liquid to flow out.

[0064] The upper pneumatic switch is a rotary switch and is installed on the side of the upper cover away from the magnesium alloy melting and casting furnace.

[0065] This design allows the upper cover to open upwards on the side facing the magnesium alloy melting and casting furnace, facilitating the pouring of molten magnesium and the ejection of protective gas from the upper protective gas pipe to maintain an atmosphere of protection during the pouring process. In practice, both the lower and upper pneumatic switches are connected to the control center for automatic control. As an optimization, the upper pneumatic switch controls the upper cover to open at a 90-degree rotation angle. This ensures that the protective gas forms a protective layer on the molten surface perpendicular to the liquid surface, and also prevents excessive flow velocity of the molten magnesium from splashing outside the track-type self-propelled insulating casting system, which could cause combustion and safety accidents.

[0066] The retaining groove 4 has a bracket 19 fixedly mounted on its lower side facing downwards. Rollers 20 are spaced apart at the lower end of the bracket, and the rollers are fitted onto the guide rail 3. This facilitates the movement of the retaining groove.

[0067] A telescopic cylinder 21 is mounted upwards on the roller closest to the magnesium alloy melting and casting furnace. The upper end of the telescopic cylinder is fixed to the lower side of the upper end of the holding groove. This facilitates the control and adjustment of the tilt angle of the holding groove as needed. In practice, the telescopic cylinder can be an electric cylinder, a pneumatic cylinder, or a hydraulic cylinder.

[0068] The cover plate 5 also has lifting lugs 22 mounted on its upper surface. This facilitates the transportation and lifting of the device.

[0069] Ultrasonic vibration devices are installed on both side walls of the holding tank 4. This ultrasonic vibration from two mutually perpendicular directions creates a more effective three-dimensional oscillation effect within the holding tank, intensifying the internal disturbance of the magnesium melt, breaking down dendrites, refining grains, and improving fluidity. Simultaneously, the ultrasonic vibration devices on the cover plate prevent the magnesium melt from solidifying on the surface of the holding tank cover due to the large temperature difference when in contact with it, thus avoiding inaccurate measurement. Furthermore, the ultrasonic vibration devices located on both sides of the holding tank prevent heavier substances from settling to the bottom, thus preventing gravity segregation.

[0070] The ultrasonic vibration device 6 includes a push rod 61. The rear end of the push rod 61 is telescopically (vertically) mounted on a base 62 (the base corresponding to the ultrasonic vibration device mounted on the cover plate is the cover plate, and the base corresponding to the ultrasonic vibration device mounted on the side wall of the retaining groove is the side wall of the retaining groove). The front end of the push rod 61 extends forward into the inner cavity of the retaining groove. An air cavity 63 surrounding the rear end of the push rod is provided on the base where the rear end of the push rod 61 is located. A piston 64 is also vertically fixed at the rear end of the push rod. A helical spring 65 sleeved on the push rod is abutted between the front side of the piston and the front end of the air cavity. An air inlet channel 66 is provided outwardly on the air cavity behind the piston, and an air outlet channel 67 is provided outwardly on the air cavity in front of the piston.

[0071] In this way, the ultrasonic vibration device is used by connecting the air inlet channel to an external air compressor. Air from the compressor enters the air chamber behind the piston, compressing the piston and causing it to move forward. After passing the return air channel, the piston releases air through the outlet channel. After releasing air, the piston returns to its original position, blocking the outlet channel, and then continues to move forward under pressure. This repetitive motion achieves ultrasonic vibration. In this way, the tip of the ultrasonic vibration device's push rod is immersed in the molten magnesium alloy, directly contacting the molten magnesium. This avoids ultrasonic wave loss at the interface and within the medium, improving the efficiency of mechanical property enhancement. Therefore, it has the advantages of simple structure, convenient control, and easy adjustment. During implementation, after the ultrasonic vibration device is started, it should be stopped only after the molten metal has been completely discharged from the holding tank to prevent residual molten metal from solidifying at the push rod installation gap, which would affect the flexibility of the push rod's extension and retraction.

[0072] The ultrasonic vibration devices are multiple and arranged in an array on the corresponding substrates. This ensures a better vibration effect on the molten liquid throughout the entire holding tank cavity.

[0073] The intake channel is equipped with a pressure control valve (not shown in the diagram), and the outlet channel is equipped with a flow control valve (not shown in the diagram). The pressure control valve can adjust the intake air pressure, thereby controlling the vibration intensity. The flow control valve can adjust the outlet air flow, thereby adjusting the vibration amplitude.

[0074] The top rod 61 is provided with a vibrating head at its front end. The vibrating head includes an elastic vibrating ring 68 coaxially sleeved on the front end of the top rod. The vibrating ring 68 and the vibrating head are fixedly connected by a plurality of springs 69 arranged radially and evenly distributed in a ring. A plurality of obliquely arranged vibrating plates 70 are evenly distributed and fixed on the vibrating ring.

[0075] In this way, the push rod transmits its own back-and-forth vibration to the elastic vibrating ring through the radial spring. This integrates the push rod's reciprocating vibration, the spring's oscillating vibration, and its own torsional vibration into a single unit. This creates a multi-angle and multi-directional composite vibration effect between the vibrating ring and the vibrating plates on it. The vibration is transmitted outward in a three-dimensional manner around the center of the push rod's front end, greatly improving the vibration effect on the molten metal. This makes the internal disturbance of the molten metal more intense, better achieving the effects of breaking dendrites, refining grains, and improving fluidity.

[0076] Thus, the ultrasonic vibration device is a pneumatic ultrasonic device. During implementation, the top rod and its upper structure are made of tungsten or tungsten alloy to avoid reaction with the magnesium alloy melt. The unique structure of the vibrating head can generate a three-dimensional spatial vibration effect outward and propagate radially inside the melt. The amplitude can be adjusted according to the actual measurement volume by adjusting the air pressure. Its vibration effect is far greater than that of traditional piezoelectric ceramic ultrasonic vibration.

[0077] Therefore, the above-mentioned magnesium alloy melt self-moving quantitative casting production system can transfer the molten magnesium in the casting furnace to the magnesium alloy melt self-moving quantitative casting device by hydraulic tilting, and then move it to the magnesium alloy die casting part by track to pour the molten liquid into the die casting machine to obtain magnesium alloy parts. The specific process includes the following steps.

[0078] Before the melting in the magnesium alloy melting and casting furnace is completed, the self-moving quantitative casting device for the magnesium alloy melt is moved to the first fixed position and connected to the magnesium alloy melting and casting furnace, and the holding tank heating module is turned on to preheat the holding tank; after melting is completed, the upper cover of the holding tank is opened, and the lower protective gas pipeline is turned on to introduce protective gas into the inner cavity of the holding tank, forcing the air out of the upper port and forming an atmosphere protection in the inner cavity of the holding tank. Then, the upper gas pipeline is turned on to introduce protective gas to form an atmosphere protection in the upper port of the holding tank; then the magnesium alloy melting and casting furnace is opened, the upper discharge chute cover of the crucible is opened, and the furnace body shaft around the liquid outlet of the crucible is rotated. Under the protective atmosphere, the molten metal is poured into a metering tank. The level sensor in the metering tank detects the level in real time and measures the amount of molten metal poured in. When the molten metal level reaches the set value, the crucible is controlled to return to its original position, the upper cover of the holding tank is controlled to close, and then the metering tank is controlled to flip over to pour the metered molten metal into the holding tank. The ultrasonic vibration device is activated to apply ultrasonic vibration to the molten metal entering the holding tank. At the same time, the magnesium alloy melt self-moving metering pouring device is moved to the second fixed position and connected to the magnesium alloy die casting machine. The lower cover of the holding tank is opened to guide the molten metal into the pouring port of the magnesium alloy die casting. The magnesium alloy die casting machine is used to achieve die casting.

[0079] During implementation, the molten metal is kept in a protective gas atmosphere during the smelting, pouring, and transfer processes described above. The temperature fluctuation range of the molten metal at the outlet is ≤±3℃. The preheating temperature of the holding tank is within the range of 400±20℃, and the holding temperature after the molten metal is poured in is within the range of 750±10℃. The ultrasonic vibration device begins vibrating when the magnesium molten metal enters the holding tank and stops vibrating when the magnesium molten metal is completely poured into the die-casting machine, maximizing the effect of the ultrasound on the magnesium molten metal.

[0080] To further verify the effectiveness of the present invention, the applicant conducted the following verification through examples based on the requirements of the above-described embodiments.

[0081] To verify the accuracy of the quantitative measuring device of the present invention under high-temperature conditions, the applicant used a density of 1.8 g / cm³. 3AZ91 magnesium alloy was used for casting. Specifically, 20 kg of AZ91 magnesium alloy was used as the raw material. The AZ91 magnesium alloy was placed into the crucible of the casting furnace through the operating cover on top of the casting furnace. The gas protection of the casting furnace was activated, and then the electric heating module of the crucible was activated to heat it to 800°C. After solvent-free melting, the discharge trough cover was opened. Under the control of the intelligent integrated control system control center, the pneumatic casting tank cover and the protective gas mixing supply system connected to the protective gas pipeline were opened. The moving magnesium alloy melt self-moving quantitative casting device was connected directly below the discharge port of the casting furnace. The entire casting furnace body was hydraulically tilted, and the magnesium melt was poured into the quantitative receiving tank. The liquid level sensor sent the liquid level information to the control center. When the magnesium melt reached 2.78L, the casting furnace body was controlled to return to the upright position, and the quantitative receiving tank was tilted. The magnesium melt entered the preheated holding tank, which was preheated to 300°C and the holding temperature was 730°C. At the same time, the ultrasonic vibration device was activated. The mobile magnesium alloy melt self-moving quantitative pouring device is connected to the pouring port of the die casting machine. The pneumatically operated opening and closing retaining tank end cover is opened, and the magnesium melt flows into the die casting machine along the retaining tank.

[0082] Magnesium alloy castings with volumes of 2.78L, 5.56L, and 8.33L were poured using the method described above, with a volume ratio of 1:2:3. The castings were then weighed, yielding masses of 4.95kg, 9.8kg, and 14.9kg respectively, with a mass ratio of approximately 1:2:3. This demonstrates the high accuracy of the measuring device. Using the formula m=ρ×v, the actual masses of the 2.78L, 5.56L, and 8.33L magnesium alloy castings should be 5kg, 10kg, and 15kg respectively. The actual masses are slightly lower due to the high reactivity of magnesium alloy, leading to oxidation and burn-off. The die-cast magnesium alloy was cut, ground, and polished. Under an optical microscope, the grains were found to be fine and uniform, without inclusions. The internal pores were small and evenly distributed, with fewer pores than other casting methods, resulting in minimal impact on the mechanical properties of the magnesium alloy. The burn loss rate obtained by weighing using the present invention is only 2%, which is much higher than that of manual scooping and also higher than the industrial production standard, and can be directly used in industrial production.

[0083] In industrial production, the burn-off rate of magnesium melt delivered by pneumatic conveying and pumping is 5%-10%, while in the laboratory and enterprise pilot production, the burn-off rate of magnesium melt manually scooped is ≥30%, which seriously affects the quality of magnesium alloys. The magnesium alloy samples obtained in the laboratory are seriously deviated from the actual industrial production, which means that in the process of transferring the laboratory research results to industrial application, it is necessary to repeatedly verify them under process conditions.

[0084] To further verify that the ultrasonic vibration device of this invention improves the solidification structure of magnesium alloy melt, refines grains, and enhances the mechanical properties of magnesium alloy, the applicant again conducted a control experiment. All processes and equipment in the experimental group were the same as in the previous examples, but the ultrasonic vibration device was not activated during the casting process in the control group. The die-cast magnesium alloy was cut, ground, and polished. Grain information was obtained using EBSD, and the mechanical properties of the obtained magnesium alloy tensile parts were tested using a tensile testing machine. The density of the magnesium alloy casting was determined using an electronic densitometer. The performance parameters are shown in the table below:

[0085] Magnesium alloy tensile strength; magnesium alloy density (without ultrasonic treatment): 253 MPa; 1.78 g / cm³ 3 After ultrasonic treatment, the pressure was 280 MPa and the pressure was 1.81 g / cm³. 3 surface

[0086] Comparing magnesium alloys that have not undergone ultrasonic treatment with those that have, it can be seen that the magnesium alloy castings treated by ultrasonic treatment have a grain refinement of 36%, a tensile strength increase of 10%, and a density increase of 1.7%, thus optimizing the overall performance of the magnesium alloy.

Claims

1. A self-moving quantitative casting method for magnesium alloy melt, wherein the molten magnesium alloy is poured into a die-casting machine to achieve die casting, characterized in that, First, molten magnesium alloy is introduced into a first container at a first fixed point for metering, obtaining a fixed volume of molten magnesium alloy. Then, the metered molten magnesium alloy is transferred to a second container, which is kept sealed while ultrasonic vibration is applied to the molten magnesium alloy inside. Simultaneously, the molten magnesium alloy inside the second container is moved to a second fixed point, where it is introduced into a die-casting machine to achieve die casting. This method relies on a self-moving quantitative casting production system for molten magnesium alloy, which includes a system located at... A magnesium alloy melting and casting furnace is located at the first fixed point, and a magnesium alloy die-casting machine is located at the second fixed point. The magnesium alloy melting and casting furnace contains a crucible with a protruding outlet nozzle on one side of its upper end. The outlet nozzle is rotatably mounted on the outlet at the upper end of the magnesium alloy melting and casting furnace via a furnace body shaft. The magnesium alloy melting and casting furnace also includes a crucible tilting and discharging control mechanism to control the crucible's tilting around the furnace body shaft for discharging liquid. A horizontally arranged guide rail connects the magnesium alloy melting and casting furnace and the magnesium alloy die-casting machine, and a self-moving mechanism for the molten magnesium alloy is installed on the guide rail. The quantitative casting device for magnesium alloy melt includes an obliquely oriented elongated holding groove, which is entirely enclosed. A cover plate is fixedly installed on the oblique opening of the holding groove, and an ultrasonic vibration device is installed on the cover plate. An openable lower end cover is installed at the lower end of the holding groove via a lower pneumatic switch. The upper end of the holding groove has a vertically upward bending section, and an openable upper end cover is installed at the upper end of the bending section via an upper pneumatic switch. A quantitative receiving tank is installed in the inner cavity of the bending section, with the middle positions on both sides of the quantitative receiving tank relying on the tank body. The rotating shaft is rotatably mounted on both sides of the inner cavity of the deflection section. One end of the rotating shaft extends out of the deflection section and is connected to a liquid receiving tank motor. A liquid level sensor is also installed inside the quantitative liquid receiving tank. Both the liquid level sensor and the liquid receiving tank motor are connected to the control center. When the magnesium alloy melt self-moving quantitative pouring device is located at one end of the first fixed position of the guide rail, the upper port of the tank is positioned directly below the liquid outlet of the crucible. When the magnesium alloy melt self-moving quantitative pouring device is located at one end of the second fixed position of the guide rail, the lower port of the tank is positioned directly above the pouring port of the magnesium alloy die-casting machine.

2. The self-moving quantitative casting method for magnesium alloy melt as described in claim 1, characterized in that, The magnesium alloy melt self-moving quantitative casting device is also equipped with an atmosphere protection mechanism. The atmosphere protection mechanism includes an upper protective gas pipe connected to the upper end cover and a lower protective gas pipe connected to the upper part of the retaining tank cover plate. The outer ends of the upper and lower protective gas pipes are each connected to a protective gas source.

3. The self-moving quantitative casting method for magnesium alloy melt as described in claim 1, characterized in that, The lower side wall of the holding tank is also equipped with a holding tank heating module, which is connected to the control center.

4. The self-moving quantitative casting method for magnesium alloy melt as described in claim 1, characterized in that, A temperature probe connected to the control center is also installed inside the tank.

5. The self-moving quantitative casting method for magnesium alloy melt as described in claim 1, characterized in that, The lower pneumatic switch is a rotary switch and is installed at the upper end of the lower cover; the upper pneumatic switch is a rotary switch and is installed on the side of the upper cover away from the magnesium alloy melting and casting furnace.

6. The self-moving quantitative casting method for magnesium alloy melt as described in claim 1, characterized in that, A bracket is fixedly installed on the lower side of the groove, and rollers are arranged at intervals at the lower end of the bracket, with the rollers engaging with the guide rail.

7. The self-moving quantitative casting method for magnesium alloy melt as described in claim 1, characterized in that, Ultrasonic vibration devices are also installed on the side walls of the retainer.

8. The self-moving quantitative casting method for magnesium alloy melt as described in claim 1, characterized in that, The ultrasonic vibration device includes a push rod, the rear end of which is telescopically mounted on the base, and the front end of which extends forward into the inner cavity of the retaining groove. An air cavity surrounding the rear end of the push rod is provided on the base where the rear end of the push rod is located. A piston is also vertically fixed at the rear end of the push rod. A helical spring sleeved on the push rod is abutted between the front side of the piston and the front end of the air cavity. An air inlet channel is provided outwardly on the air cavity behind the piston, and an air outlet channel is provided outwardly on the air cavity in front of the piston.

9. The self-moving quantitative casting method for magnesium alloy melt as described in claim 8, characterized in that, The ultrasonic vibration device has multiple units arranged in an array and installed on corresponding bases; a pressure control valve is installed in the air inlet channel and a flow control valve is installed in the air outlet channel; a vibration head is provided at the front end of the push rod, the vibration head includes an elastic vibrating ring coaxially sleeved on the front end of the push rod, the vibrating ring and the vibration head are fixedly connected by multiple springs arranged radially and evenly distributed in a ring, and multiple obliquely arranged vibrating plates are evenly distributed and fixed on the vibrating ring.

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