Vacuum melting and pouring device and forming method for aluminum alloy material

Abstract

The invention provides a vacuum melting and pouring device and a forming method for an aluminum alloy material. According to the device and the method, rapid vacuum uniform melting can be ensured, a melt has sufficient standing time before pouring, gas floats upwards, impurities settle, the temperature of the melt is stable, the pouring temperature is prevented from being too low, and casting defects are reduced. The device is internally provided with the split type crucible clamp and the control rod, so that crucibles with different sizes can be quickly, safely and accurately clamped and tilted, and a melt can stably and uniformly flow into a mold along a pouring gate. The device is flexible and changeable, the smelting crucible and the induction heating coil are mutually independent, and the size and the shape of the crucible can be regulated and controlled according to the alloy content needed by an actual casting; the shape, the size and the position of the induction coil can be regulated and controlled according to the actual smelting technology requirements; and the pouring mold can be flexibly replaced to prepare castings with different shapes and sizes. The forming method is simple, high in efficiency, low in cost and high in yield and safety.

Description

Technical Field

[0001] The invention relates to the technical field of smelting and casting of aluminum alloys, and in particular to a vacuum melting and pouring device and a forming method for aluminum alloy materials. Background Art

[0002] Aluminum alloy is a widely used metal material, and its melting and casting process has a vital impact on product quality and production efficiency. In the current technical field, there are two main methods for melting and casting aluminum alloys: atmospheric melting and vacuum induction melting. However, these two traditional methods have many defects, which restrict the further development of aluminum alloy material manufacturing technology.

[0003] Existing aluminum alloys are often melted in the atmosphere. The aluminum alloy melt is easily in direct contact with oxygen, water vapor, nitrogen and other gases in the air, resulting in various casting defects: ① The melt reacts with oxygen to generate inclusions such as aluminum oxide; ② The melt reacts with water vapor to generate hydrogen, forming pinhole defects and microcracks; ③ Nitrogen is involved during pouring to form holes, etc. Therefore, when melting and casting aluminum alloys in the atmosphere, refining technology must be used to remove gases and inclusions in the melt, but the process is complicated and inefficient.

[0004] Vacuum induction melting is another commonly used aluminum alloy casting technology. Although it avoids the reaction between the melt and the gas, there are still technical deficiencies: ① The melting crucible and the induction coil are integrated, the equipment structure is complex and heavy, and a graphite crucible is often placed inside the melting crucible during melting. During pouring, the tilting of the melting crucible and the coil drives the graphite crucible to move. Since the built-in graphite crucible is difficult to fix, the pouring speed and flow rate cannot be accurately controlled, affecting the pouring effect and product quality; or, the upper wall of the graphite crucible is clamped with a crucible tongs, and then poured after it is taken out, but it is easy to cause accidents such as the crucible overturning or rupture, causing safety hazards. ② The integrated structure of the melting crucible and the induction coil fixes the shape and position of the melting crucible and the coil, thereby limiting the shape and size of the internal graphite crucible, which cannot be arbitrarily adjusted. ③ In order to avoid the influence of electromagnetic stirring of the melt, the heating power supply needs to be turned off before pouring to allow the melt to stand, gas to float, and impurities to settle. However, the melt is prone to rapid cooling and cannot reach the pouring temperature, causing problems such as poor filling of the casting and uneven internal structure. Therefore, the above technical methods have obvious shortcomings, and it is urgent to design a vacuum melting and pouring device and forming method for aluminum alloy materials to achieve vacuum melting and pouring of aluminum alloys, reduce casting defects such as pores and inclusions, accurately control temperature and speed for pouring, improve manufacturing efficiency, and reduce costs. Summary of the invention

[0005] The purpose of the present invention is to design a vacuum melting and pouring device for aluminum alloy materials, so as to realize vacuum rapid and uniform melting, precise temperature and speed control pouring, improve efficiency, and reduce casting defects such as insufficient pouring, cold shut, pores and inclusions. The melting chamber and the pouring chamber are independent, so as to ensure that the melt is not affected by electromagnetic stirring after the melting is completed, and the melt has sufficient standing time before pouring, so that the gas floats and the impurities settle, and the melt temperature is stable, so as to avoid the pouring temperature being too low and reduce casting defects. The double-petal crucible clamp and the control rod can realize the rapid, safe and precise clamping and tilting of crucibles of different sizes, so that the melt can flow into the mold stably and evenly along the pouring gate. The device is flexible and changeable, and the melting crucible and the induction heating coil are independent of each other. The size and shape of the crucible can be adjusted according to the alloy content required for the actual casting; the shape, size and position of the induction coil can also be adjusted according to the actual melting technology requirements; the pouring mold can also be flexibly replaced to prepare castings of different shapes and sizes. The technical method is simple, efficient, low cost, high yield and safety.

[0006] On one hand, the present invention provides a vacuum melting and pouring device for aluminum alloy materials, which consists of a melting chamber and a pouring chamber, wherein the melting chamber and the pouring chamber are separated by a fixed partition and a movable partition, and an electric lifting device controls the movable partition to move up and down to connect or close the melting chamber and the pouring chamber. The melting chamber and the pouring chamber are independent, and the alloy is quickly vacuum melted in the melting chamber, and then enters the pouring chamber. The melt is not affected by electromagnetic effects, and there is sufficient standing time before pouring, so that the gas floats and the impurities settle, so as to achieve precise temperature and speed control pouring and reduce casting defects.

[0007] The smelting chamber includes: a smelting chamber furnace body, an air inlet valve, an air exhaust valve, an observation port, a retractable thermocouple, an induction copper coil, an induction copper coil water inlet, an induction copper coil water outlet, a coaxial power supply system, a graphite crucible, and a heat insulation pad.

[0008] The pouring chamber includes: a pouring chamber furnace body, a furnace body bracket, an electric lifting device, a control rod, a sliding device, a petal-type crucible clamp, a thermal insulation resistor, a pouring mold, a preheating resistor, and a thermocouple.

[0009] Furthermore, the graphite crucible is placed on an insulating pad, the insulating pad is placed on a movable partition, and an electric lifting device controls the movable partition to move up and down, driving the graphite crucible in and out of the smelting chamber and the pouring chamber.

[0010] Furthermore, the movable partition moves down, the smelting chamber is connected with the pouring chamber, and the exhaust valve is opened to exhaust the air in the smelting chamber and the pouring chamber, and the gas pressure is less than 1×10 -2 Pa, close the exhaust valve, open the air inlet valve, introduce Ar protection, the gas pressure is 0.01 ~ 0.1MPa, the melting chamber and the pouring chamber reach vacuum conditions.

[0011] Furthermore, the graphite crucible and the induction copper coil move independently, and graphite crucibles of different sizes and shapes can be selected according to the alloy content required for the actual casting; induction copper coils of different shapes and sizes can also be selected according to actual smelting technology requirements; the upper and lower positions of the water inlet and outlet of the induction copper coil can also be adjusted to control the position of the induction copper coil.

[0012] Furthermore, after the smelting is completed, the electric lifting device drives the graphite crucible to move down and enter the heating area of ​​the insulation resistor in the pouring chamber. The melt is kept at a temperature of 680-740°C and poured after standing for 10-15 minutes.

[0013] Furthermore, the petal-type crucible clamp is connected to the control rod. When the control rod is extended, the petal-type crucible clamp is in a closed state to clamp the crucible; when the control rod is retracted, the petal-type crucible clamp is in an open state to release the crucible.

[0014] Furthermore, according to the height of the casting mold, the upper and lower positions of the graphite crucible are adjusted by using an electric lifting device so that the middle position of the graphite crucible is flush with the mold gate.

[0015] Furthermore, the sliding device includes a slider and a slide rail. When the slider moves up and down on the slide rail, it drives the control rod to move up and down, and adjusts the up and down position of the slider so that the double-petal crucible clamp clamps the middle and upper part of the graphite crucible.

[0016] Furthermore, when the control rod rotates, the petal-type crucible clamp is driven to tilt, so that the melt in the graphite crucible flows out. The tilting angle of the control rod is continuously adjusted so that after the graphite crucible is tilted, the melt flows into the mold evenly along the mold gate.

[0017] Furthermore, the pouring mold includes a gate, a runner system, and a casting cavity. The runner is generally cylindrical, wedge-shaped, or S-shaped. The casting cavity is selected according to actual needs to pour castings of different shapes and sizes.

[0018] Furthermore, the preheating mold includes a preheating resistor and a thermocouple. The casting mold is preheated before casting, and the casting mold is preheated at 200-300°C for 1 hour to avoid casting defects such as insufficient casting, cracks, holes, etc. caused by too fast solidification.

[0019] Another aspect of the present invention provides a vacuum melting and pouring forming method of an aluminum alloy material, the forming method comprising:

[0020] (1) Charging: Open the melting chamber and the pouring chamber, place the graphite crucible filled with aluminum alloy raw materials on the movable partition in the melting chamber, and insert a heat insulating pad between the graphite crucible and the movable partition; place the pouring mold in the pouring chamber, and close the melting chamber and the pouring chamber.

[0021] (2) Vacuuming and introducing protective gas: Turn on the electric lifting device to move the movable partition downward, open the vacuum valve, and vacuum the melting chamber and casting chamber to 1×10 -2 Pa, close the exhaust valve, open the air inlet valve, and introduce argon into the melting chamber and pouring chamber to 0.01-0.1MPa; turn on the electric lifting device to raise the movable partition to be parallel to the fixed partition, adjust the upper and lower positions of the inlet and outlet of the induction copper coil, and allow the graphite crucible to enter the heating area of ​​the induction copper coil.

[0022] (3) Alloy smelting and mold preheating: Turn on the cooling water of the induction copper coil, turn on the coaxial power supply system, slowly increase the power to 15-30kW to melt the alloy, and smelt for 5-15 minutes. After the smelting is completed, slowly reduce the power and turn off the coaxial power supply system; turn on the preheating resistor in the casting chamber and preheat the mold at 200-300℃ for 1 hour.

[0023] (4) Insulation and standing: After the smelting is completed, the electric lifting device is turned on to lower the graphite crucible to the heating area of ​​the insulation resistor in the casting chamber, and the melt is kept at 680-740°C for 10-15 minutes.

[0024] (5) Pouring: According to the height of the pouring mold, use the electric lifting device to adjust the upper and lower positions of the graphite crucible so that the middle position of the graphite crucible is flush with the mold gate; adjust the upper and lower positions of the slider so that the petal-type crucible clamp is flush with the middle and upper part of the graphite crucible; extend the control rod to close the petal-type crucible clamp to clamp the graphite crucible; continuously adjust the tilting angle of the control rod so that after the graphite crucible is tilted, the melt flows evenly into the mold along the mold gate; after the pouring is completed, restore the tilting control rod, and the control rod retracts to release the graphite crucible.

[0025] (6) Sampling: After cooling for 30 minutes, open the exhaust valve to exhaust the exhaust gas in the melting chamber and the pouring chamber, close the exhaust valve, open the air inlet valve to allow air to enter the melting chamber and the pouring chamber, disassemble the casting mold to take out the aluminum alloy casting, clean the graphite crucible and the pouring mold, and turn off the cooling water.

[0026] The beneficial effects of the present invention are:

[0027] 1. The aluminum alloy vacuum melting and pouring device of the present invention realizes rapid and uniform vacuum melting, precise temperature and speed control for pouring, improves efficiency, and reduces defects such as insufficient pouring, cold shut, pores and inclusions in castings.

[0028] 2. The device is flexible and changeable. The melting crucible and the induction heating coil are independent of each other. The size and shape of the crucible can be adjusted according to the alloy content required for the actual casting; the shape, size and position of the induction coil can also be adjusted according to the actual melting technology requirements; the casting mold can also be flexibly replaced to prepare castings of different shapes and sizes.

[0029] 3. The independent melting chamber and pouring chamber structure ensures that the melt is not affected by electromagnetic stirring after melting, and the melt has sufficient standing time before pouring to allow the gas to float and impurities to settle. The melt temperature is stable, avoiding excessively low pouring temperature and reducing casting defects.

[0030] 4. The double-petal crucible clamp and control rod can quickly, safely and accurately clamp and tilt crucibles of different sizes, so that the melt can flow into the mold along the gate stably and evenly.

[0031] 5. The aluminum alloy material forming method using this device is simple, efficient, low cost, high yield and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of the vacuum melting and pouring device provided by the present invention.

[0033] Figure 2 It is a schematic diagram of the automatic lifting device before and after it descends.

[0034] Figure 3 It is a schematic diagram of the descent of a graphite crucible in a vacuum melting and pouring apparatus.

[0035] Figure 4 It is a schematic diagram of the split-type crucible clamps for gripping a graphite crucible.

[0036] Figure 5 It is a schematic diagram of a graphite crucible clamped with a pair of petal-type crucible clamps and then tilted for pouring.

[0037] Figure 6 is a schematic diagram of a casting mold.

[0038] Figure 7 This is a diagram of the casting mold in Example 1.

[0039] Figure 8 This is a macroscopic image of the casting in Example 1.

[0040] Fig. 9 is the microstructure diagram of the casting in Example 1.

[0041] Fig.10 This is a diagram of the shape of the induction copper coil in Example 2.

[0042] Fig.11 These are the macroscopic and microstructural images of the casting in Example 2.

[0043] Fig.12 These are the macroscopic and microstructural images of the casting in Example 3.

[0044] Fig.13 These are the macroscopic and microstructural images of the casting in Example 4.

[0045] Fig.14 These are the macroscopic and microstructural images of the casting in Example 5.

[0046] Fig.15 This is a macroscopic image of the casting in Comparative Example 1.

[0047] Fig.16 This is a macroscopic image of the casting in Comparative Example 2.

[0048] Fig.17 This is a macroscopic image of the casting in Comparative Example 3.

[0049] Table 1 shows the reference numerals of the various parts of the vacuum melting and pouring device for aluminum alloy materials.

[0050] Table 1 Composition of the various parts of the vacuum melting and pouring device.

[0051]

[0052] DETAILED DESCRIPTION

[0053] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any combination of the specific implementation modes.

[0054] A vacuum melting and pouring device for aluminum alloy materials,

[0055] The device comprises a smelting chamber 1 and a pouring chamber 2.

[0056] The smelting chamber 1 and the pouring chamber 2 are separated by a fixed partition 3 and a movable partition 4 .

[0057] In a specific embodiment, the smelting chamber 1 includes: a smelting chamber furnace body 5, an air inlet valve 6, an air extraction valve 7, an observation port 8, a retractable thermocouple 9, an induction copper coil 10, a coaxial power supply system 11, a graphite crucible 12, and a heat insulation pad 13;

[0058] An observation port 8 and a retractable thermocouple 9 are arranged on the top of the smelting chamber furnace body 5, and an air inlet valve 6 and an air extraction valve 7 are arranged in the side wall of the smelting chamber furnace body 5;

[0059] The induction copper coil 10 is provided with a water inlet 101 and a water outlet 102, and the induction copper coil 10 is connected to a coaxial power supply system 11;

[0060] The graphite crucible 12 is inside the smelting chamber 1 and is placed on the heat-insulating pad 13;

[0061] The heat insulating pad 13 is placed on the movable partition plate 4 .

[0062] The electric lifting device 16 controls the movable partition 4 to move up and down, driving the graphite crucible 12 to enter and exit the smelting chamber 1 and the pouring chamber 2;

[0063] The movable partition 4 moves downward, the smelting chamber 1 and the pouring chamber 2 are connected, the exhaust valve 7 is opened to exhaust the air in the smelting chamber 1 and the pouring chamber 2, and the air inlet valve 6 is opened to introduce protective gas into the smelting chamber 1 and the pouring chamber 2;

[0064] When the movable partition 4 moves up and is parallel to the fixed partition 3, the graphite crucible 12 enters the smelting chamber 1, which meets the vacuum heating conditions; after the smelting is completed, the movable partition 4 moves down, and the graphite crucible 12 enters the pouring chamber 2, which meets the vacuum pouring conditions.

[0065] In a specific embodiment, when the graphite crucible 12 moves up and down, the position of the induction copper coil 10 does not change. The size and shape of the graphite crucible 12 can be replaced according to the alloy content required for the actual casting; the shape and size of the induction coil can also be adjusted according to the actual smelting technology requirements; the upper and lower positions of the water inlet 101 and the water outlet 102 of the induction copper coil can also be adjusted to control the position of the induction copper coil 10.

[0066] In a specific embodiment, the pouring chamber 2 includes: a pouring chamber furnace body 14, a furnace body support 15, an electric lifting device 16, a control rod 17, a sliding device 18, a petal-type crucible clamp 19, a thermal insulation resistor 20, a pouring mold 21, a preheating resistor 22, and a thermocouple 23;

[0067] The pouring chamber furnace body 14 and the electric lifting device 16 are arranged on the furnace body support 15;

[0068] The electric lifting device 16 is composed of a lifting bracket 161 and a motor 162;

[0069] A heat preservation resistor 20 is arranged in the casting chamber furnace body 14, and the heat preservation resistor 20 is arranged at the upper part of the casting chamber 14;

[0070] A pouring mold 21 is provided at the bottom of the pouring chamber furnace body 14;

[0071] Preheating resistors 22 are arranged around the casting mold 21;

[0072] A control rod 17, a sliding device 18 and a thermocouple 23 are arranged on the side of the casting chamber furnace body 14;

[0073] The sliding device 18 is composed of a slider 181 and a slide rail 182;

[0074] When the slider 181 moves up and down on the slide rail 182, it drives the control rod 17 to move up and down;

[0075] The petal-type crucible clamp 19 is connected to the control rod 17. When the control rod 17 is extended or retracted, the petal-type crucible clamp 19 is in a closed or open state, so as to clamp or release the graphite crucible 12. When the control rod 17 is rotated, the petal-type crucible clamp 19 is driven to tilt, and the melt in the graphite crucible 12 flows out.

[0076] In a specific embodiment, the casting mold 21 includes a gate 211, a runner system 212, and a casting cavity 213 arranged from top to bottom. The casting cavity 213 can be modified and replaced according to actual needs, and castings of different shapes and sizes can be cast.

[0077] In a specific embodiment, after smelting is completed, the electric lifting device 16 drives the graphite crucible 12 to move downward and enter the heating area of ​​the insulation resistor 20 in the pouring chamber 2. The melt is kept at a temperature of 680-740°C and poured after standing for 10-15 minutes. According to the height of the pouring mold 21, the electric lifting device 16 is used to adjust the upper and lower positions of the graphite crucible 12 so that the middle position of the graphite crucible 12 is flush with the mold gate 211. The upper and lower positions of the slider 181 are adjusted so that the petal-type crucible clamp 19 clamps the middle and upper part of the graphite crucible 12. The tilting angle of the control rod 17 is continuously adjusted so that after the graphite crucible 12 is tilted, the melt flows evenly into the mold along the mold gate 211.

[0078] In a specific embodiment, the retractable thermocouple 9 measures the melting temperature, the static holding temperature and the pouring temperature of the aluminum alloy in the graphite crucible 12, and the thermocouple 23 measures the mold temperature.

[0079] A vacuum melting and casting method for aluminum alloy material, the forming method comprising:

[0080] (1) Charging: Open the smelting chamber 1 and the pouring chamber 2, load the aluminum alloy raw material to be smelted into the graphite crucible 12, place the graphite crucible 12 on the movable partition 4 in the smelting chamber 1, and insert the heat insulating pad 13 between the graphite crucible 12 and the movable partition 4; place the pouring mold 21 into the pouring chamber 2, and close the smelting chamber 1 and the pouring chamber 2.

[0081] (2) Evacuate and introduce protective gas: Turn on the electric lifting device 16 to move the movable partition 4 downward, open the exhaust valve 7, and evacuate the smelting chamber 1 and the pouring chamber 2 to 1×10 -2 Pa, close the exhaust valve 7, open the air inlet valve 6, and pass argon gas to 0.01-0.1MPa in the smelting chamber 1 and the pouring chamber 2; turn on the electric lifting device 16 to raise the movable partition 4 to be parallel to the fixed partition 3, adjust the upper and lower positions of the water inlet 101 and the water outlet 102 of the induction copper coil, and allow the graphite crucible to enter the heating zone of the induction copper coil 10.

[0082] (3) Alloy smelting and mold preheating: Cooling water is input to the induction copper coil 10, the coaxial power supply system 11 is turned on, and the power is slowly increased to 15-30 kW to melt the alloy. The smelting is carried out for 5-15 minutes. After the smelting is completed, the power is slowly reduced and the coaxial power supply system 11 is turned off; the mold preheating resistor 22 in the casting chamber is turned on, and the mold 21 is preheated at 200-300°C for 1 hour.

[0083] (4) Insulation and standing: After the smelting is completed, the electric lifting device 16 is turned on to lower the graphite crucible 12 to the heating area of ​​the insulation resistor 20 in the casting chamber 2, and the melt is kept at 680-740°C and stood for 10-15 minutes.

[0084] (5) Pouring: According to the height of the pouring mold 21, the upper and lower positions of the graphite crucible 12 are adjusted by the electric lifting device 16 so that the middle position of the graphite crucible 12 is flush with the mold gate 211; the upper and lower positions of the slider 181 are adjusted so that the petal-type crucible clamp 19 is flush with the middle and upper part of the graphite crucible 12; the control rod 17 is extended, and the petal-type crucible clamp 19 is closed to clamp the graphite crucible 12; the tilting angle of the control rod 17 is continuously adjusted so that after the graphite crucible 12 is tilted, the melt flows evenly into the mold along the mold gate 211; after the pouring is completed, the tilted control rod 17 is restored, and the control rod 17 is retracted to release the graphite crucible 12.

[0085] (6) Sampling: After cooling for 30 min, open the exhaust valve 7 to exhaust the exhaust gas in the smelting chamber 1 and the pouring chamber 2, close the exhaust valve 7, open the air inlet valve 6 to introduce air into the smelting chamber 1 and the pouring chamber 2, disassemble the casting mold 21 to take out the aluminum alloy casting, clean the graphite crucible 12 and the pouring mold 21, and turn off the cooling water.

[0086] Embodiment 1:

[0087] (1) Charging: Open the smelting chamber 1 and the pouring chamber 2, and put 1 kg of Al-5Cu-1Mn alloy raw material (weight percentage) to be smelted into a graphite crucible 12 (upper diameter 121 mm, upper wall thickness 11 mm, bottom outer diameter 83 mm, bottom thickness 15 mm, height 141 mm). Place the graphite crucible 12 on the movable partition 4 in the smelting chamber 1, and insert the heat insulation pad 13 between the graphite crucible 12 and the movable partition 4; Place the pouring mold 21 ( Figure 7 ) is placed into the pouring chamber 2, and the smelting chamber 1 and the pouring chamber 2 are closed.

[0088] (2) Evacuate and introduce protective gas: Turn on the electric lifting device 16 to move the movable partition 4 downward, open the exhaust valve 7, and evacuate the smelting chamber 1 and the pouring chamber 2 to 5×10 -3 Pa, close the exhaust valve 7, open the air inlet valve 6, and pass argon gas to 0.05MPa in the smelting chamber 1 and the pouring chamber 2; turn on the electric lifting device 16 to raise the movable partition 4 to be parallel to the fixed partition 3; use a cylindrical induction copper coil, adjust the upper and lower positions of the inlet 101 and the outlet 102 of the induction copper coil, and make the graphite crucible enter the heating zone of the induction copper coil 10.

[0089] (3) Alloy smelting and mold preheating: Cooling water is input to the induction copper coil 10, the coaxial power supply system 11 is turned on, and the power is slowly increased to 20 kW to melt the alloy. The smelting is continued for 10 minutes. After the smelting is completed, the power is slowly reduced and the coaxial power supply system 11 is turned off; the mold preheating resistor 22 in the casting chamber is turned on, and the mold 21 is preheated at 300°C for 1 hour.

[0090] (4) Insulation and Standing: After the smelting is completed, the electric lifting device 16 is turned on to lower the graphite crucible 12 to the heating area of ​​the insulation resistor 20 in the casting chamber 2, and the melt is kept at 720° C. and stood for 10 minutes.

[0091] (5) Pouring: According to the height of the pouring mold 21, the upper and lower positions of the graphite crucible 12 are adjusted by the electric lifting device 16 so that the middle position of the graphite crucible 12 (1 / 2 of the crucible height, about 70 mm) is flush with the mold gate 211; the upper and lower positions of the slider 181 are adjusted so that the petal-type crucible clamp 19 is flush with the middle and upper part of the graphite crucible 12 (2 / 3 of the crucible height, about 95 mm); the control rod 17 is extended, and the petal-type crucible clamp 19 is closed to clamp the graphite crucible 12; the tilting angle of the control rod 17 is continuously adjusted so that after the graphite crucible 12 is tilted, the melt flows evenly into the mold along the mold gate 211; when the pouring is completed, the tilted control rod 17 is restored, and the control rod 17 is retracted to release the graphite crucible 12.

[0092] (6) Sampling: After cooling for 30 minutes, open the exhaust valve 7 to exhaust the exhaust gas in the smelting chamber 1 and the pouring chamber 2, close the exhaust valve 7, open the air inlet valve 6 to introduce air into the smelting chamber 1 and the pouring chamber 2, disassemble the casting mold 21 to take out the aluminum alloy casting, clean the graphite crucible 12 and the casting mold 21, and turn off the cooling water. An Al-5Cu-1Mn alloy casting with a plum blossom-shaped cross section and a height of about 300 mm was prepared ( Figure 8 ), the casting is complete, the surface is smooth, and there is no obvious macroscopic casting defect. Fig. 9 ) No defects such as holes and microcracks were found in the steel, the structure was uniform and the quality was good.

[0093] Embodiment 2:

[0094] (1) Charging: Open the melting chamber 1 and the pouring chamber 2, and put 2 kg of Al-14Cu-7Ce alloy raw material (weight percentage) to be melted into a graphite crucible 12 (upper diameter 137 mm, upper wall thickness 13 mm, bottom outer diameter 94 mm, bottom thickness 17 mm, height 169 mm), place the graphite crucible 12 on the movable partition 4 in the melting chamber 1, and insert the heat insulating pad 13 between the graphite crucible 12 and the movable partition 4; put the pouring mold 21 into the pouring chamber 2, and close the melting chamber 1 and the pouring chamber 2.

[0095] (2) Vacuuming and introducing protective gas: Turn on the electric lifting device 16 to move the movable partition 4 downward, open the exhaust valve 7, and vacuumize the melting chamber 1 and the pouring chamber 2 to 3×10 -3 Pa, close the exhaust valve 7, open the air inlet valve 6, and pass argon gas to 0.1MPa in the smelting chamber 1 and the pouring chamber 2; turn on the electric lifting device 16 to make the movable partition 4 rise to be parallel to the fixed partition 3; use the "upper large and lower small" truncated cone induction copper coil ( Fig.10 ), adjust the upper and lower positions of the water inlet 101 and the water outlet 102 of the induction copper coil so that the graphite crucible enters the heating area of ​​the induction copper coil 10.

[0096] (3) Alloy smelting and mold preheating: Cooling water is input to the induction copper coil 10, the coaxial power supply system 11 is turned on, and the power is slowly increased to 15 kW to melt the alloy. The smelting is continued for 15 minutes. After the smelting is completed, the power is slowly reduced and the coaxial power supply system 11 is turned off; the mold preheating resistor 22 in the casting chamber is turned on, and the mold 21 is preheated at 300°C for 1 hour.

[0097] (4) Insulation and Standing: After the smelting is completed, the electric lifting device 16 is turned on to lower the graphite crucible 12 to the heating area of ​​the insulation resistor 20 in the casting chamber 2, and the melt is kept at 680° C. and stood for 15 minutes.

[0098] (5) Pouring: According to the height of the pouring mold 21, the upper and lower positions of the graphite crucible 12 are adjusted by the electric lifting device 16 so that the middle position of the graphite crucible 12 (1 / 2 of the crucible height, about 85 mm) is flush with the mold gate 211; the upper and lower positions of the slider 181 are adjusted so that the flap-type crucible clamp 19 is flush with the middle and upper part of the graphite crucible 12 (2 / 3 of the crucible height, about 114 mm); the control rod 17 is extended, and the flap-type crucible clamp 19 is closed to clamp the graphite crucible 12; the tilting angle of the control rod 17 is continuously adjusted so that after the graphite crucible 12 is tilted, the melt flows evenly into the mold along the mold gate 211; when the pouring is completed, the tilted control rod 17 is restored, and the control rod 17 is retracted to release the graphite crucible 12.

[0099] (6) Sampling: After cooling for 30 min, open the exhaust valve 7 to exhaust the exhaust gas in the smelting chamber 1 and the pouring chamber 2, close the exhaust valve 7, open the air inlet valve 6 to introduce air into the smelting chamber 1 and the pouring chamber 2, disassemble the casting mold 21 to take out the aluminum alloy casting, clean the graphite crucible 12 and the pouring mold 21, and turn off the cooling water. Fig.11 It shows that the prepared Al-14Cu-7Ce alloy castings are complete, with a smooth surface, no obvious macroscopic casting defects, and no microscopic defects such as holes and microcracks. The structure is uniform and the quality is good.

[0100] Embodiment 3:

[0101] (1) Charging: Open the smelting chamber 1 and the pouring chamber 2, and put 2 kg of ZL205A (Al-5Cu-0.4Mn-0.2Cd-0.2Ti-0.1Zr-0.15V-0.03B) alloy raw material (weight ratio) to be smelted into a graphite crucible 12 (upper diameter 137 mm, upper wall thickness 13 mm, bottom outer diameter 94 mm, bottom thickness 17 mm, height 169 mm), place the graphite crucible 12 on the movable partition 4 in the smelting chamber 1, and insert the heat insulating pad 13 between the graphite crucible 12 and the movable partition 4; put the pouring mold 21 into the pouring chamber 2, and close the smelting chamber 1 and the pouring chamber 2.

[0102] (2) Evacuate and introduce protective gas: Turn on the electric lifting device 16 to move the movable partition 4 downward, open the exhaust valve 7, and evacuate the smelting chamber 1 and the pouring chamber 2 to 5×10 -3 Pa, close the exhaust valve 7, open the air inlet valve 6, and pass argon gas to 0.01MPa in the smelting chamber 1 and the pouring chamber 2; turn on the electric lifting device 16 to make the movable partition 4 rise to be parallel to the fixed partition 3; use a cylindrical induction copper coil, adjust the upper and lower positions of the induction copper coil water inlet 101 and the water outlet 102, so that the graphite crucible enters the heating zone of the induction copper coil 10.

[0103] (3) Alloy smelting and mold preheating: Cooling water is input to the induction copper coil 10, the coaxial power supply system 11 is turned on, and the power is slowly increased to 30 kW to melt the alloy. The smelting is continued for 5 minutes. After the smelting is completed, the power is slowly reduced and the coaxial power supply system 11 is turned off; the mold preheating resistor 22 in the casting chamber is turned on, and the mold 21 is preheated at 300°C for 1 hour.

[0104] (4) Insulation and Standing: After the smelting is completed, the electric lifting device 16 is turned on to lower the graphite crucible 12 to the heating area of ​​the insulation resistor 20 in the casting chamber 2, and the melt is kept at 740° C. and stood for 10 minutes.

[0105] (5) Pouring: According to the height of the pouring mold 21, the upper and lower positions of the graphite crucible 12 are adjusted by the electric lifting device 16 so that the middle position of the graphite crucible 12 (1 / 2 of the crucible height, about 85 mm) is flush with the mold gate 211; the upper and lower positions of the slider 181 are adjusted so that the flap-type crucible clamp 19 is flush with the middle and upper part of the graphite crucible 12 (2 / 3 of the crucible height, about 114 mm); the control rod 17 is extended, and the flap-type crucible clamp 19 is closed to clamp the graphite crucible 12; the tilting angle of the control rod 17 is continuously adjusted so that after the graphite crucible 12 is tilted, the melt flows evenly into the mold along the mold gate 211; when the pouring is completed, the tilted control rod 17 is restored, and the control rod 17 is retracted to release the graphite crucible 12.

[0106] (6) Sampling: After cooling for 30 min, open the exhaust valve 7 to exhaust the exhaust gas in the smelting chamber 1 and the pouring chamber 2, close the exhaust valve 7, open the air inlet valve 6 to introduce air into the smelting chamber 1 and the pouring chamber 2, disassemble the casting mold 21 to take out the aluminum alloy casting, clean the graphite crucible 12 and the pouring mold 21, and turn off the cooling water.

[0107] Fig.12 It shows that the prepared ZL205A alloy castings are complete, with a smooth surface, no obvious macroscopic casting defects, and no microscopic defects such as holes and microcracks. The structure is uniform and the quality is good.

[0108] Example 4

[0109] (1) Charging: Open the smelting chamber 1 and the pouring chamber 2, and put 2 kg of ZL206 (Al-8Cu-1.8RE-0.9Mn-0.2Zr) alloy raw material (weight ratio) to be smelted into a graphite crucible 12 (upper diameter 137 mm, upper wall thickness 13 mm, bottom outer diameter 94 mm, bottom thickness 17 mm, height 169 mm). Place the graphite crucible 12 on the movable partition 4 in the smelting chamber 1, and insert the heat insulating pad 13 between the graphite crucible 12 and the movable partition 4; place the pouring mold 21 into the pouring chamber 2, and close the smelting chamber 1 and the pouring chamber 2.

[0110] (2) Evacuate and introduce protective gas: Turn on the electric lifting device 16 to move the movable partition 4 downward, open the exhaust valve 7, and evacuate the smelting chamber 1 and the pouring chamber 2 to 5×10 -3 Pa, close the exhaust valve 7, open the air inlet valve 6, and pass argon gas to 0.05MPa in the smelting chamber 1 and the pouring chamber 2; turn on the electric lifting device 16 to raise the movable partition 4 to be parallel to the fixed partition 3; use a cylindrical induction copper coil, adjust the upper and lower positions of the inlet 101 and the outlet 102 of the induction copper coil, and make the graphite crucible enter the heating zone of the induction copper coil 10.

[0111] (3) Alloy smelting and mold preheating: Cooling water is input to the induction copper coil 10, the coaxial power supply system 11 is turned on, and the power is slowly increased to 25 kW to melt the alloy. The smelting is continued for 10 minutes. After the smelting is completed, the power is slowly reduced and the coaxial power supply system 11 is turned off; the mold preheating resistor 22 in the casting chamber is turned on, and the mold 21 is preheated at 300°C for 1 hour.

[0112] (4) Insulation and Standing: After the smelting is completed, the electric lifting device 16 is turned on to lower the graphite crucible 12 to the heating area of ​​the insulation resistor 20 in the casting chamber 2, and the melt is kept at 720° C. and stood for 5 minutes.

[0113] (5) Pouring: According to the height of the pouring mold 21, the upper and lower positions of the graphite crucible 12 are adjusted by the electric lifting device 16 so that the middle position of the graphite crucible 12 (1 / 2 of the crucible height, about 85 mm) is flush with the mold gate 211; the upper and lower positions of the slider 181 are adjusted so that the flap-type crucible clamp 19 is flush with the middle and upper part of the graphite crucible 12 (2 / 3 of the crucible height, about 114 mm); the control rod 17 is extended, and the flap-type crucible clamp 19 is closed to clamp the graphite crucible 12; the tilting angle of the control rod 17 is continuously adjusted so that after the graphite crucible 12 is tilted, the melt flows evenly into the mold along the mold gate 211; when the pouring is completed, the tilted control rod 17 is restored, and the control rod 17 is retracted to release the graphite crucible 12.

[0114] (6) Sampling: After cooling for 30 min, open the exhaust valve 7 to exhaust the exhaust gas in the smelting chamber 1 and the pouring chamber 2, close the exhaust valve 7, open the air inlet valve 6 to introduce air into the smelting chamber 1 and the pouring chamber 2, disassemble the casting mold 21 to take out the aluminum alloy casting, clean the graphite crucible 12 and the pouring mold 21, and turn off the cooling water.

[0115] Fig.13 The results show that the prepared ZL206 alloy castings are complete, with a smooth surface, no obvious casting defects, and no microscopic defects such as holes and microcracks. The structure is uniform and the quality is good.

[0116] Embodiment 5:

[0117] (1) Charging: Open the melting chamber 1 and the pouring chamber 2, and put 5 kg of A356 (Al-7Si-3Mg) alloy raw material (weight ratio) to be melted into a graphite crucible 20 (upper diameter 183 mm, upper wall thickness 18 mm, bottom outer diameter 120 mm, bottom thickness 18 mm, height 232 mm). Place the graphite crucible 12 on the movable partition 4 in the melting chamber 1, and insert the heat insulating pad 13 between the graphite crucible 12 and the movable partition 4; Place the pouring mold 21 in the pouring chamber 2, and close the melting chamber 1 and the pouring chamber 2.

[0118] (2) Evacuate and introduce protective gas: Turn on the electric lifting device 16 to move the movable partition 4 downward, open the exhaust valve 7, and evacuate the smelting chamber 1 and the pouring chamber 2 to 5×10 -3 Pa, close the exhaust valve 7, open the air inlet valve 6, and pass argon gas to 0.05MPa in the smelting chamber 1 and the pouring chamber 2; turn on the electric lifting device 16 to raise the movable partition 4 to be parallel to the fixed partition 3; use a cylindrical induction copper coil, adjust the upper and lower positions of the inlet 101 and the outlet 102 of the induction copper coil, and make the graphite crucible enter the heating zone of the induction copper coil 10.

[0119] (3) Alloy smelting and mold preheating: Cooling water is input to the induction copper coil 10, the coaxial power supply system 11 is turned on, and the power is slowly increased to 20 kW to melt the alloy. The smelting is continued for 15 minutes. After the smelting is completed, the power is slowly reduced and the coaxial power supply system 11 is turned off; the mold preheating resistor 22 in the casting chamber is turned on, and the mold 21 is preheated at 200°C for 1 hour.

[0120] (4) Insulation and Standing: After the smelting is completed, the electric lifting device 16 is turned on to lower the graphite crucible 12 to the heating area of ​​the insulation resistor 20 in the casting chamber 2, and the melt is kept at 700° C. and stood for 10 minutes.

[0121] (5) Pouring: According to the height of the pouring mold 21, the upper and lower positions of the graphite crucible 12 are adjusted by the electric lifting device 16 so that the middle position of the graphite crucible 12 (1 / 2 of the crucible height, about 115 mm) is flush with the mold gate 211; the upper and lower positions of the slider 181 are adjusted so that the flap-type crucible clamp 19 is flush with the middle and upper part of the graphite crucible 12 (2 / 3 of the crucible height, about 155 mm); the control rod 17 is extended, and the flap-type crucible clamp 19 is closed to clamp the graphite crucible 12; the tilting angle of the control rod 17 is continuously adjusted so that after the graphite crucible 12 is tilted, the melt flows evenly into the mold along the mold gate 211; after the pouring is completed, the tilted control rod 17 is restored, and the control rod 17 is retracted to release the graphite crucible 12.

[0122] (6) Sampling: After cooling for 30 min, open the exhaust valve 7 to exhaust the exhaust gas in the smelting chamber 1 and the pouring chamber 2, close the exhaust valve 7, open the air inlet valve 6 to introduce air into the smelting chamber 1 and the pouring chamber 2, disassemble the casting mold 21 to take out the aluminum alloy casting, clean the graphite crucible 12 and the pouring mold 21, and turn off the cooling water.

[0123] Fig.14 The A356 alloy casting obtained by pouring is displayed. It can be seen that the casting is complete, the surface is smooth, there are no obvious casting defects, no defects such as holes and microcracks are found, the structure is uniform and the quality is good.

[0124] Comparative Example 1:

[0125] Al-5Cu-1Mn alloy was prepared according to vacuum induction melting + static casting technology.

[0126] (1) Charging: Open the smelting chamber 1 and the pouring chamber 2, and put 1 kg of Al-5Cu-1Mn alloy raw material (weight percentage) to be smelted into a graphite crucible 12 (upper diameter 121 mm, upper wall thickness 11 mm, bottom outer diameter 83 mm, bottom thickness 15 mm, height 141 mm), place the graphite crucible 12 on the movable partition 4 in the smelting chamber 1, and insert the heat insulating pad 13 between the graphite crucible 12 and the movable partition 4; put the pouring mold 21 into the pouring chamber 2, and close the smelting chamber 1 and the pouring chamber 2.

[0127] (2) Evacuate and introduce protective gas: Turn on the electric lifting device 16 to move the movable partition 4 downward, open the exhaust valve 7, and evacuate the smelting chamber 1 and the pouring chamber 2 to 5×10 -3 Pa, close the exhaust valve 7, open the air inlet valve 6, and pass argon gas to 0.05MPa in the smelting chamber 1 and the pouring chamber 2; turn on the electric lifting device 16 to raise the movable partition 4 to be parallel to the fixed partition 3, adjust the upper and lower positions of the inlet 101 and the outlet 102 of the induction copper coil, and allow the graphite crucible to enter the heating zone of the induction copper coil 10.

[0128] (3) Alloy smelting and mold preheating: Cooling water is input to the induction copper coil 10, the coaxial power supply system 11 is turned on, and the power is slowly increased to 20 kW to melt the alloy. The smelting is continued for 10 minutes. After the smelting is completed, the power is slowly reduced and the coaxial power supply system 11 is turned off; the mold preheating resistor 22 in the casting chamber is turned on, and the mold 21 is preheated at 300°C for 1 hour.

[0129] (4) Standing: After the smelting is completed, the melt is not allowed to enter the insulation area of ​​the pouring chamber. In order to avoid electromagnetic stirring of the melt, the induction copper coil is no longer heated and the melt is allowed to stand for 10 minutes.

[0130] (5) Pouring: After the standing period is over, the upper and lower positions of the graphite crucible 12 are adjusted by the electric lifting device 16 according to the height of the casting mold 21, so that the middle position of the graphite crucible 12 (1 / 2 of the crucible height, about 70 mm) is flush with the mold gate 211; the upper and lower positions of the slider 181 are adjusted so that the petal-type crucible clamp 19 is flush with the middle and upper part of the graphite crucible 12 (2 / 3 of the crucible height, about 95 mm); the control rod 17 is extended, and the petal-type crucible clamp 19 is closed to clamp the graphite crucible 12; the tilting angle of the control rod 17 is continuously adjusted so that after the graphite crucible 12 is tilted, the melt flows evenly into the mold along the mold gate 211; after the pouring is completed, the tilted control rod 17 is restored, and the control rod 17 is retracted to release the graphite crucible 12.

[0131] (6) Sampling: After cooling for 30 min, open the exhaust valve 7 to exhaust the exhaust gas in the smelting chamber 1 and the pouring chamber 2, close the exhaust valve 7, open the air inlet valve 6 to introduce air into the smelting chamber 1 and the pouring chamber 2, disassemble the casting mold 21 to take out the aluminum alloy casting, clean the graphite crucible 12 and the pouring mold 21, and turn off the cooling water.

[0132] Fig.15 The Al-5Cu-1Mn alloy casting with a plum blossom-shaped cross-section and a height of about 300 mm was shown. Due to the low pouring temperature, the casting had defects such as holes and insufficient pouring.

[0133] Comparative Example 2:

[0134] (1) Charging: Open the melting chamber 1 and the pouring chamber 2, and put 5 kg of A356 (Al-7Si-3Mg) alloy raw material (weight ratio) to be melted into a graphite crucible 20 (upper diameter 183 mm, upper wall thickness 18 mm, bottom outer diameter 120 mm, bottom thickness 18 mm, height 232 mm). Place the graphite crucible 12 on the movable partition 4 in the melting chamber 1, and insert the heat insulating pad 13 between the graphite crucible 12 and the movable partition 4; Place the pouring mold 21 in the pouring chamber 2, and close the melting chamber 1 and the pouring chamber 2.

[0135] (2) Evacuate and introduce protective gas: Turn on the electric lifting device 16 to move the movable partition 4 downward, open the exhaust valve 7, and evacuate the smelting chamber 1 and the pouring chamber 2 to 5×10 -3 Pa, close the exhaust valve 7, open the air inlet valve 6, and pass argon gas to 0.05MPa in the smelting chamber 1 and the pouring chamber 2; turn on the electric lifting device 16 to raise the movable partition 4 to be parallel to the fixed partition 3; use a cylindrical induction copper coil, adjust the upper and lower positions of the inlet 101 and the outlet 102 of the induction copper coil, and make the graphite crucible enter the heating zone of the induction copper coil 10.

[0136] (3) Alloy smelting and mold preheating: Cooling water is input to the induction copper coil 10, the coaxial power supply system 11 is turned on, and the power is slowly increased to 20 kW to melt the alloy. The smelting is continued for 15 minutes. After the smelting is completed, the power is slowly reduced and the coaxial power supply system 11 is turned off; the mold preheating resistor 22 in the casting chamber is turned on, and the mold 21 is preheated at 100°C for 1 hour.

[0137] (4) Insulation and Standing: After the smelting is completed, the electric lifting device 16 is turned on to lower the graphite crucible 12 to the heating area of ​​the insulation resistor 20 in the casting chamber 2, and the melt is kept at 670° C. and stood for 5 minutes.

[0138] (5) Pouring: According to the height of the pouring mold 21, the upper and lower positions of the graphite crucible 12 are adjusted by the electric lifting device 16 so that the middle position of the graphite crucible 12 (1 / 2 of the crucible height, about 115 mm) is flush with the mold gate 211; the upper and lower positions of the slider 181 are adjusted so that the flap-type crucible clamp 19 is flush with the middle and upper part of the graphite crucible 12 (2 / 3 of the crucible height, about 155 mm); the control rod 17 is extended, and the flap-type crucible clamp 19 is closed to clamp the graphite crucible 12; the tilting angle of the control rod 17 is continuously adjusted so that after the graphite crucible 12 is tilted, the melt flows evenly into the mold along the mold gate 211; after the pouring is completed, the tilted control rod 17 is restored, and the control rod 17 is retracted to release the graphite crucible 12.

[0139] (6) Sampling: After cooling for 30 min, open the exhaust valve 7 to exhaust the exhaust gas in the smelting chamber 1 and the pouring chamber 2, close the exhaust valve 7, open the air inlet valve 6 to introduce air into the smelting chamber 1 and the pouring chamber 2, disassemble the casting mold 21 to take out the aluminum alloy casting, clean the graphite crucible 12 and the pouring mold 21, and turn off the cooling water.

[0140] Fig.16 The A356 alloy casting obtained by pouring is shown. It can be seen that the casting is relatively complete, but due to the low holding temperature, pouring temperature and mold temperature, the shrinkage compensation is incomplete and micro-crack defects appear in the casting.

[0141] Comparative Example 3:

[0142] (1) Charging: Open the melting chamber 1 and the pouring chamber 2, and put 5 kg of A356 (Al-7Si-3Mg) alloy raw material (weight ratio) to be melted into a graphite crucible 20 (upper diameter 183 mm, upper wall thickness 18 mm, bottom outer diameter 120 mm, bottom thickness 18 mm, height 232 mm). Place the graphite crucible 12 on the movable partition 4 in the melting chamber 1, and insert the heat insulating pad 13 between the graphite crucible 12 and the movable partition 4; Place the pouring mold 21 in the pouring chamber 2, and close the melting chamber 1 and the pouring chamber 2.

[0143] (2) Evacuate and introduce protective gas: Turn on the electric lifting device 16 to move the movable partition 4 downward, open the exhaust valve 7, and evacuate the smelting chamber 1 and the pouring chamber 2 to 5×10 -3 Pa, close the exhaust valve 7, open the air inlet valve 6, and pass argon gas to 0.05MPa in the smelting chamber 1 and the pouring chamber 2; turn on the electric lifting device 16 to raise the movable partition 4 to be parallel to the fixed partition 3; use a cylindrical induction copper coil, adjust the upper and lower positions of the inlet 101 and the outlet 102 of the induction copper coil, and make the graphite crucible enter the heating zone of the induction copper coil 10.

[0144] (3) Alloy smelting and mold preheating: Cooling water is input to the induction copper coil 10, the coaxial power supply system 11 is turned on, and the power is slowly increased to 20 kW to melt the alloy. The smelting is continued for 15 minutes. After the smelting is completed, the power is slowly reduced and the coaxial power supply system 11 is turned off; the mold preheating resistor 22 in the casting chamber is turned on, and the mold 21 is preheated at 200°C for 1 hour.

[0145] (4) Insulation and Standing: After the smelting is completed, the electric lifting device 16 is turned on to lower the graphite crucible 12 to the heating area of ​​the insulation resistor 20 in the casting chamber 2, and the melt is kept at 700° C. and stood for 10 minutes.

[0146] (5) Pouring: Use a double-petal crucible clamp to directly clamp the graphite crucible 12 at any position, and quickly tilt the control rod 17 to allow the melt in the graphite crucible 12 to flow into the mold quickly and concentratedly; when the pouring is completed, restore the tilted control rod 17, the control rod 17 contracts, and the graphite crucible 12 is released.

[0147] (6) Sampling: After cooling for 30 min, open the exhaust valve 7 to exhaust the exhaust gas in the smelting chamber 1 and the pouring chamber 2, close the exhaust valve 7, open the air inlet valve 6 to introduce air into the smelting chamber 1 and the pouring chamber 2, disassemble the casting mold 21 to take out the aluminum alloy casting, clean the graphite crucible 12 and the pouring mold 21, and turn off the cooling water.

[0148] Fig.17 The A356 alloy casting obtained by pouring is shown. Due to the fast pouring speed of the melt, air entrainment occurs, resulting in obvious porosity defects in the casting. The melt also washes the mold, causing long-term wear of the mold and reducing the casting accuracy.

Claims

1. A vacuum melting and pouring device for aluminum alloy material, comprising a melting chamber and a pouring chamber, wherein the melting chamber and the pouring chamber are separated by a fixed partition and a movable partition, and an electric lifting device controls the movable partition to move up and down to connect or close the melting chamber and the pouring chamber; characterized in that: The graphite crucible is placed on the heat-insulating pad, and the heat-insulating pad is placed on the movable partition. The electric lifting device controls the movable partition to move up and down, driving the graphite crucible in and out of the melting chamber and the pouring chamber; When the movable partition moves up and is parallel to the fixed partition, the graphite crucible enters the melting chamber and meets the vacuum heating conditions; the graphite crucible is in the heating area of ​​the induction copper coil in the melting chamber; The movable partition moves down, and the graphite crucible enters the pouring chamber, which meets the vacuum pouring conditions; the graphite crucible is in the heating area of ​​the insulation resistor in the pouring chamber, and the heating area can ensure sufficient static time before pouring; In addition, a petal-type crucible clamp, a control rod, and a sliding device are arranged in the casting chamber furnace body, and the petal-type crucible clamp is connected to the control rod; When the control rod is extended or retracted, the split-flap crucible clamp is in a closed or open state, and can clamp or release the graphite crucible; When the control rod rotates, the double-petal crucible clamp is driven to tilt, and the melt in the graphite crucible flows out; The electric lifting device can adjust the upper and lower positions of the graphite crucible so that the middle position of the graphite crucible is flush with the mold gate; When the slider of the sliding device moves up and down on the slide rail, it drives the control rod to move up and down, so that the petal-type crucible clamp clamps the middle and upper part of the graphite crucible; the tilting angle of the control rod is continuously adjusted so that after the graphite crucible is tilted, the melt flows into the casting mold evenly along the casting mold gate.

2. The vacuum melting and pouring device for aluminum alloy material according to claim 1, characterized in that: In the smelting chamber, an observation port and a retractable thermocouple are arranged on the top of the smelting chamber furnace; An air inlet valve and an air exhaust valve are arranged in the side wall of the furnace body of the smelting chamber; The induction copper coil of the smelting chamber is provided with a water inlet and a water outlet, and the water inlet and the water outlet are connected with a coaxial power supply system.

3. The vacuum melting and pouring device for aluminum alloy material according to claim 2, characterized in that: The graphite crucible and the induction copper coil move independently. When the graphite crucible moves up and down, the position of the induction copper coil does not change. According to the alloy content required by the actual casting, graphite crucibles of different sizes and shapes can be selected; according to the actual smelting technology requirements, induction copper coils of different shapes and sizes can be selected; the upper and lower positions of the water inlet and outlet of the induction copper coil can also be adjusted to control the position of the induction copper coil.

4. The vacuum melting and pouring device for aluminum alloy material according to claim 1, characterized in that: The thermal insulation resistor of the casting chamber furnace body is arranged at the upper part of the casting chamber; the casting mold is arranged at the bottom of the casting chamber furnace body; Preheating resistors are set around the casting mold; The pouring chamber furnace body and the electric lifting device are arranged on the furnace body support.

5. The vacuum melting and pouring device for aluminum alloy material according to claim 1 or 4, characterized in that: The electric lifting device comprises a lifting bracket and a motor.

6. The vacuum melting and pouring device for aluminum alloy material according to claim 1, characterized in that: A control rod, a sliding device and a thermocouple are arranged on the side of the furnace body of the pouring chamber.

7. The vacuum melting and pouring device for aluminum alloy material according to claim 1, characterized in that: The petal-type crucible clamp is connected to the control rod. When the control rod is extended, the petal-type crucible clamp is in a closed state to clamp the graphite crucible; when the control rod is retracted, the petal-type crucible clamp is in an open state to release the crucible.

8. The vacuum melting and pouring device for aluminum alloy material according to claim 1, characterized in that: The casting mold includes a gate, a runner system, and a casting cavity arranged from top to bottom; The mold cavity can be modified and replaced according to actual needs, and castings of different shapes and sizes can be cast; The runner is cylindrical, wedge-shaped or S-shaped; According to actual needs, select the casting cavity to pour castings of different shapes and sizes.

9. The vacuum melting and pouring device for aluminum alloy material according to claim 2 or 6, characterized in that: The retractable thermocouple measures the melting temperature, static holding temperature and pouring temperature of the aluminum alloy in the graphite crucible, and the thermocouple measures the mold temperature.

10. A vacuum melting and pouring forming method of aluminum alloy material based on the device according to any one of claims 1 to 9, characterized in that: The forming method comprises: Charging: Open the melting chamber and the pouring chamber, place the graphite crucible filled with aluminum alloy raw materials on the movable partition in the melting chamber, insert a heat-insulating pad between the graphite crucible and the movable partition; place the pouring mold in the pouring chamber, and close the melting chamber and the pouring chamber; Vacuuming and introducing protective gas: Turn on the electric lifting device to move the movable partition downward, open the vacuum valve, and vacuum the melting chamber and casting chamber to 1×10 -2 Pa, stop, close the exhaust valve, open the air inlet valve, and introduce argon gas to 0.01-0.1MPa into the melting chamber and the pouring chamber; turn on the electric lifting device to raise the movable partition to be parallel to the fixed partition, adjust the upper and lower positions of the inlet and outlet of the induction copper coil, and allow the graphite crucible to enter the heating area of ​​the induction copper coil; Alloy smelting and mold preheating: Turn on the cooling water of the induction copper coil, turn on the coaxial power supply system, slowly increase the power to 15-30kW to melt the alloy, smelt for 5-15 minutes, and when the smelting is finished, slowly reduce the power and turn off the coaxial power supply system; turn on the preheating resistor in the casting chamber, and preheat the mold at 200-300℃ for 1 hour; Insulation and standing: After the smelting is completed, the electric lifting device is turned on to lower the graphite crucible to the heating area of ​​the insulation resistor in the casting chamber, and the melt is kept at 680-740℃ for 10-15 minutes; Pouring: According to the height of the pouring mold, the upper and lower positions of the graphite crucible are adjusted by the electric lifting device so that the middle position of the graphite crucible is flush with the mold gate; the upper and lower positions of the slider are adjusted so that the petal-type crucible clamp is flush with the middle and upper part of the graphite crucible; the control rod is extended to close the petal-type crucible clamp to clamp the graphite crucible; the tilting angle of the control rod is continuously adjusted so that after the graphite crucible is tilted, the melt flows into the mold evenly along the mold gate; after the pouring is completed, the tilting control rod is restored, and the control rod is retracted to release the graphite crucible; Sampling: After cooling for 30 minutes, open the exhaust valve to exhaust the exhaust gas in the melting chamber and pouring chamber, close the exhaust valve, open the air inlet valve to allow air to enter the melting chamber and pouring chamber, disassemble the casting mold to take out the aluminum alloy casting, clean the graphite crucible and casting mold, and turn off the cooling water.

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