A device and method for preparing foamed aluminum special-shaped parts

Abstract

The present invention belongs to the technical field of porous material preparation, and relates to a device and method for preparing foamed aluminum special-shaped parts. The device comprises a metal melting and extrusion system, a melt and additive mixing system, and a mixed melt filling and foaming system. First, pure aluminum or an aluminum alloy is placed in a melting chamber and melted; then, the original melt in the melting chamber is pressurized, and a spiral nozzle is used to achieve uniform dispersion and mixing of the original melt and additives in the mixing chamber at a lower temperature; after the mixed melt reaches a certain amount, the mixed melt is pressurized and then heated to a certain temperature; finally, the mixed melt is injected into a mold cavity, and foamed in the mold cavity for a certain period of time to obtain the foamed aluminum special-shaped part.

Description

Technical Field

[0001] The invention belongs to the technical field of foam metal materials and relates to a device and method for preparing foam aluminum special-shaped parts. Background Art

[0002] As a gas-solid composite material, foam aluminum combines structural and functional properties. Thanks to its light weight, high specific strength, energy absorption and shock absorption, sound absorption and noise reduction, electromagnetic shielding, thermal insulation and heat preservation, it has broad application prospects in transportation, shipbuilding, national defense and military industry, aerospace and other fields.

[0003] Commonly produced aluminum foams are often in regular shapes, such as flat plates, cubes, and cylinders, and contain varying degrees of solid aluminum layers at the bottom. Therefore, during use, the desired shape and size must be cut at a good point in the structure, avoiding the solid aluminum layer. This not only reduces production efficiency but also reduces material utilization, increasing production costs.

[0004] At present, the preparation method of aluminum foam special-shaped parts mainly relies on secondary foaming. Its main process is: obtain a foamable precursor containing a certain proportion of foaming agent by powder metallurgy or melting casting, cut the foamable precursor into pieces, and foam it in a mold at a certain temperature to obtain aluminum foam special-shaped parts. This method has the following problems: (1) The foaming precursor needs to be mechanically processed before foaming to obtain a basic shape that is compatible with the foaming mold, which increases the production cost; (2) The temperature field of the solid foaming precursor is uneven when heated, and the foaming filling ability is weak. In addition, the powder metallurgy method uses metal powder as raw material, which has the disadvantages of high cost and complex process. Therefore, the future research direction of preparing aluminum foam special-shaped parts is to realize the continuous pouring and foaming based on the melt foaming method.

[0005] Invention patent CN 112427622 A discloses a foamed aluminum casting method using a pouring and foaming process. First, titanium hydride particles are heat-treated to achieve surface modification. Then, an aluminum-silicon-magnesium near-eutectic alloy is heated and melted, followed by stirring to increase viscosity. Pretreated titanium hydride particles are added within a certain melt temperature range and stirred to disperse to produce a prefabricated melt. Finally, the prefabricated melt is poured into a mold, insulated, and foamed to produce a foamed aluminum alloy part. This invention achieves the goals of a short process and low cost, but titanium hydride decomposes after stirring and during pouring, affecting the melt's mold filling and subsequent foaming performance. Furthermore, ensuring the continuity of the production process remains to be determined.

[0006] Invention patent CN 115627377 A discloses a device and method for producing special-shaped metal foams. The device comprises a metal foam forming module, an additive rotary injection module, and an air pressure control and conversion system. The additive rotary injection module primarily includes a tank for the additive and a hydraulic lifting and stirring device. However, the mechanical stirring device employed in this device suffers from long stirring times and the nozzle holes, which are immersed in the melt, are prone to clogging. Summary of the Invention

[0007] In response to the aforementioned issues, the present invention provides an apparatus and method for producing foamed aluminum special-shaped parts. Unlike existing production devices that rely on mechanical stirring, this invention utilizes the principle of spiral spraying to evenly disperse and mix the raw melt with additives (foaming agent and stabilizer) before performing mold filling and foaming. A melt extrusion device provides power for the extrusion and spraying process.

[0008] In order to achieve the above-mentioned purpose of the invention, the present invention adopts the following technical solutions.

[0009] A device for preparing foamed aluminum special-shaped parts includes a metal melting and extrusion system, the metal melting and extrusion system is connected to a melt and additive mixing system, and the melt and additive mixing system is connected to a melt filling and foaming system, wherein:

[0010] The metal melting and extrusion system includes a resistance furnace A7, which has openings at its upper and lower portions. A melting chamber 11 is provided within the resistance furnace A7, and the melting chamber 11 has openings at its upper and lower portions. The upper opening of the melting chamber 11 corresponds to the upper opening of the resistance furnace A7, and the lower opening of the melting chamber 11 corresponds to the lower opening of the resistance furnace A7. The upper opening of the melting chamber 11 and the upper opening of the resistance furnace A7 are connected to a melt extrusion device. The lower opening of the melting chamber 11 and the lower opening of the resistance furnace A7 are connected to a melt and additive mixing system via a melt channel A12. A shutoff baffle A13 is provided on the melt channel A12.

[0011] The melt and additive mixing system includes a resistance furnace B16, which is provided with openings at the upper and lower parts respectively; a mixing chamber 17 is provided in the resistance furnace B16, and the mixing chamber 17 is provided with openings at the upper and lower parts respectively; the upper opening of the mixing chamber 17 corresponds to the upper opening of the resistance furnace B16, and the lower opening of the mixing chamber 17 corresponds to the lower opening of the resistance furnace B16; the upper opening of the mixing chamber 17 and the upper opening of the resistance furnace B16 are connected to the melt channel A12, and the outlet of the melt channel A12 is provided with a spiral nozzle 15; the lower opening of the mixing chamber 17 and the lower opening of the resistance furnace B16 are connected to the mixed melt filling and foaming system through the melt channel B19; a cut-off baffle B is provided on the melt channel B19. 18; A hole is opened on the side of the mixing chamber 17, and the opening is connected to the feeding tank 24 through the feeding channel 3. The outlet of the feeding channel 3 in the mixing chamber 17 is provided with a rotary nozzle 15; a resistance furnace D 23 is provided outside the feeding tank 24, and the feeding tank 24 is connected to the gas booster pump B 27 through the gas channel C 26;

[0012] The melt filling and foaming system includes a resistance furnace C 22, which has an opening on its upper portion. A mold cavity 21 is provided in the resistance furnace C 22, and an opening is provided on its upper portion. The opening on the upper portion of the mold cavity 21 corresponds to the opening on the upper portion of the resistance furnace C 22, and the opening on the upper portion of the mold cavity 21 and the opening on the upper portion of the resistance furnace C 22 are connected to the melt channel B 19.

[0013] Furthermore, the melt extrusion device includes a gas booster pump A1, which is connected to the upper opening of the melting chamber 11 and the upper opening of the resistance furnace A7 through a gas channel A8; the gas booster pump A1 is connected to the mixing chamber 17 through a gas channel B14.

[0014] Furthermore, the melt extrusion device includes a hydraulic or pneumatic system 6, which is connected to the upper opening of the melting chamber 11 and the upper opening of the resistance furnace A1 through a lifting rod 5; a pressing plate 10 is provided on the lifting rod 5 in the melting chamber 11.

[0015] Furthermore, the melting chamber 11 is provided with a detachable top cover, and the melting chamber 11 and the top cover are fixed by bolts 9 .

[0016] Furthermore, a valve A 4 is provided on the gas channel A 8; a three-way valve 2 is provided on the gas channel B 14; and a valve B 25 is provided on the gas channel C 26.

[0017] Furthermore, the angle α between the two spiral nozzles 15 on the side of the mixing chamber 17 and the vertical direction is 30-60°.

[0018] Furthermore, an air hole 20 is provided on the top of the mold cavity 21 .

[0019] A method for preparing a foam aluminum special-shaped part comprises the following steps:

[0020] Step 1: Place pure aluminum or aluminum alloy in a melting chamber 11 and melt it. The heating temperature is set at 620-750° C. and the temperature is kept at this temperature for 15-25 minutes after melting.

[0021] Step 2: Lower the temperature of the above-mentioned pure aluminum or aluminum alloy original melt to 580-660°C, open the three-way valve 2 to connect the mixing chamber 17 to the air, press the melt surface with pressure, open the interception baffle A13 to control the flow of the pure aluminum or aluminum alloy melt, and at the same time open the three spiral nozzles 15. Use the spiral nozzle 15 at the outlet of the melt channel A12 to spray the original melt from the melting chamber 11 to the mixing chamber 17, and use the spiral nozzle 15 on the side of the mixing chamber to spray the additive preheated at 200-400°C for 10-30 minutes into the mixing chamber, so that the original melt and the additive are dispersed and evenly mixed to form a mixed melt. The temperature inside the mixing chamber 17 is controlled at 400-480°C;

[0022] Step 3: After the volume of the mixed melt reaches 1 / 4-1 / 2 of the internal volume of the mixing chamber, close the interception baffle A13 and the spiral nozzle; adjust the three-way valve 2 to isolate the mixing chamber 17 from the outside air, turn on the gas booster pump A1 to charge the mixing chamber 17 with positive pressure, and then heat the mixed melt to keep it at 600-680°C;

[0023] Step 4: Remove the intercepting baffle B18, and fill the mixed melt under positive pressure into the mold cavity 21 with air holes 20, then keep it warm and foam it in the mold cavity 21, and finally cool it and remove it from the mold to obtain the foam aluminum special-shaped part.

[0024] Furthermore, in step 1, the composition of the aluminum alloy is an Al-Si-Mg-Ca alloy, wherein Si accounts for 6% to 13% by mass of the aluminum alloy used, Mg accounts for 1% to 4% by mass of the aluminum alloy used, Ca accounts for 1% to 3% by mass of the aluminum alloy used, and the balance is Al.

[0025] Furthermore, in step 2, the surface pressure of the original melt is pressed to 1-3 MPa.

[0026] Furthermore, in step 2, the original melt is sprayed from the spiral nozzle 15 at the outlet of the melt channel A12 at a rate of 60-200 ml / min, and the additive is sprayed from the spiral nozzle 15 at the side of the mixing chamber 17 at a rate of 3-50 ml / min.

[0027] Furthermore, in step 3 and step 4, the positive pressure in the mixing chamber 17 is 1.5-5 MPa.

[0028] Furthermore, in step 4, a release agent is applied to the inner surface of the mold cavity, and the release agent is one of an oil-based, powder-based or water-based release agent.

[0029] Furthermore, in step 4, the mixed melt in the mold cavity 21 is kept at 650-720° C. for foaming for 3-10 minutes.

[0030] Furthermore, the cooling method in step 4 is water cooling or air cooling.

[0031] Compared with the prior art, the present invention has the following beneficial effects.

[0032] (1) Different from the mechanical stirring method used in the existing preparation device, the present invention uses the spiral blowing principle for the first time to disperse and evenly mix the original melt and the foaming agent before filling and foaming.

[0033] (2) The spiral blowing process of the present invention can reduce the blowing temperature of the original melt as much as possible to achieve no decomposition or very little decomposition of the foaming agent while ensuring that the mixed melt has the ability to fill the mold, thereby greatly improving the utilization rate of the foaming agent.

[0034] (3) The present invention innovatively uses lifting and lowering pressure plates or gas pressure to suppress the melt surface, thereby achieving stable and quantitative blowing of the original melt.

[0035] (4) The present invention reduces the temperature of the mixing chamber so that the mixed melt after spraying settles quickly, thereby avoiding further decomposition of the foaming agent; at the same time, it increases the pressure and temperature of the mixing chamber to inhibit the decomposition of the foaming agent and meet the requirements of mold filling. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the preparation device of foam aluminum special-shaped parts of the present invention.

[0037] Figure 2 The figure is a flow chart of the preparation process of the foam aluminum special-shaped parts of the present invention.

[0038] Among them, 1: gas booster pump A; 2: three-way valve; 3: feeding channel; 4: valve A; 5: lifting rod; 6: hydraulic or pneumatic system; 7: resistance furnace A; 8: gas channel A; 9: bolt; 10: pressure plate; 11: melting chamber; 12: melt channel A; 13: shut-off baffle A; 14: gas channel B; 15: spiral nozzle; 16: resistance furnace B; 17: mixing chamber; 18: shut-off baffle B; 19: melt channel B; 20: air hole; 21: mold cavity; 22: resistance furnace C; 23: resistance furnace D; 24: feeding tank; 25: valve B; 26: gas channel C; 27: gas booster pump B. DETAILED DESCRIPTION

[0039] The following describes in detail the specific embodiments of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0040] A method for preparing a foam aluminum special-shaped part comprises the following steps:

[0041] Step 1: Place pure aluminum or aluminum alloy in a melting chamber 11 and melt it. The heating temperature is set at 620-750° C. and the temperature is kept at this temperature for 15-25 minutes after melting.

[0042] Step 2: Lower the temperature of the above-mentioned pure aluminum or aluminum alloy original melt to 580-660°C, open the three-way valve 2 to connect the mixing chamber 17 to the air, press the melt surface with pressure, open the interception baffle A13 to control the flow of the pure aluminum or aluminum alloy melt, and at the same time open the three spiral nozzles 15. Use the spiral nozzle 15 at the outlet of the melt channel A12 to spray the original melt from the melting chamber 11 to the mixing chamber 17, and use the spiral nozzle 15 on the side of the mixing chamber to spray the additive preheated at 200-400°C for 10-30 minutes into the mixing chamber, so that the original melt and the additive are dispersed and evenly mixed to form a mixed melt. The temperature inside the mixing chamber 17 is controlled at 400-480°C;

[0043] Step 3: After the volume of the mixed melt reaches 1 / 4-1 / 2 of the internal volume of the mixing chamber, close the interception baffle A13 and the spiral nozzle; adjust the three-way valve 2 to isolate the mixing chamber 17 from the outside air, turn on the gas booster pump A1 to charge the mixing chamber 17 with positive pressure, and then heat the mixed melt to keep it at 600-680°C;

[0044] Step 4: Remove the intercepting baffle B18, and fill the mixed melt under positive pressure into the mold cavity 21 with air holes 20, then keep it warm and foam it in the mold cavity 21, and finally cool it and remove it from the mold to obtain the foam aluminum special-shaped part.

[0045] Furthermore, the composition of the aluminum alloy in step 1 is an Al-Si-Mg-Ca alloy, wherein Si accounts for 6% to 13% by mass of the aluminum alloy used, Mg accounts for 1% to 4% by mass of the aluminum alloy used, Ca accounts for 1% to 3% by mass of the aluminum alloy used, and the balance is Al.

[0046] Furthermore, the additive in step 2 is a foaming agent or a mixture of a foaming agent and a stabilizer, and the mass ratio of the foaming agent to the stabilizer is (1:8)-(1:3).

[0047] Furthermore, the stabilizer is one or a combination of silicon carbide powder, aluminum oxide powder, titanium boride powder, boron carbide powder or zirconium carbide powder, and the particle size is 5-75 μm.

[0048] Furthermore, the foaming agent is one of titanium hydride, magnesium hydride, calcium carbonate or magnesium carbonate, wherein the amount of titanium hydride added is 0.5% to 2.5% by mass of the aluminum alloy used, the particle size is 30μm to 75μm, and the titanium hydride is pre-oxidized in air at 400-450°C for 1-5h; the amount of magnesium hydride added is 0.5% to 1.5% by mass of the aluminum alloy used, the particle size is 30μm to 75μm, and the magnesium hydride is pre-oxidized in air at 200-250°C for 1-3h; the amount of calcium carbonate added is 2% to 6% by mass of the aluminum alloy used, the particle size is 30μm to 100μm; the amount of magnesium carbonate added is 1% to 5% by mass of the aluminum alloy used, and the particle size is 30μm to 150μm.

[0049] Furthermore, in step 2, the surface pressure of the original melt is pressed to 1-3 MPa.

[0050] Furthermore, in step 2, the original melt is sprayed from the spiral nozzle 15 at the outlet of the melt channel A12 at a rate of 60-200 ml / min, and the additive is sprayed from the spiral nozzle 15 at the side of the mixing chamber 17 at a rate of 3-50 ml / min.

[0051] Furthermore, in step 3 and step 4, the positive pressure in the mixing chamber 17 is 1.5-5 MPa.

[0052] Furthermore, in step 4, a release agent is applied to the inner surface of the mold cavity, and the release agent is one of an oil-based, powder-based or water-based release agent.

[0053] Furthermore, in step 4, the mixed melt in the mold cavity 21 is kept at 650-720° C. for foaming for 3-10 minutes.

[0054] Furthermore, the cooling method in step 4 is water cooling or air cooling.

[0055] Example 1.

[0056] like Figure 1 As shown, when the melt extrusion device uses gas pressure:

[0057] A device for preparing foamed aluminum special-shaped parts includes a metal melting and extrusion system, the metal melting and extrusion system is connected to a melt and additive mixing system, and the melt and additive mixing system is connected to a melt filling and foaming system, wherein:

[0058] The metal melting and extrusion system includes a resistance furnace A7, which has openings at its upper and lower portions. A melting chamber 11 is provided within the resistance furnace A7, and the melting chamber 11 has openings at its upper and lower portions. The upper opening of the melting chamber 11 corresponds to the upper opening of the resistance furnace A7, and the lower opening of the melting chamber 11 corresponds to the lower opening of the resistance furnace A7. The upper opening of the melting chamber 11 and the upper opening of the resistance furnace A7 are connected to a melt extrusion device. The lower opening of the melting chamber 11 and the lower opening of the resistance furnace A7 are connected to a melt and additive mixing system via a melt channel A12. A shutoff baffle A13 is provided on the melt channel A12 to separate and connect the melting chamber 11 and the mixing chamber 17.

[0059] The melt and additive mixing system includes a resistance furnace B16, which is provided with openings at the upper and lower parts respectively; a mixing chamber 17 is provided in the resistance furnace B16, and the mixing chamber 17 is provided with openings at the upper and lower parts respectively; the upper opening of the mixing chamber 17 corresponds to the upper opening of the resistance furnace B16, and the lower opening of the mixing chamber 17 corresponds to the lower opening of the resistance furnace B16; the upper opening of the mixing chamber 17 and the upper opening of the resistance furnace B16 are connected to the melt channel A12, and the outlet of the melt channel A12 is provided with a spiral nozzle 15; the lower opening of the mixing chamber 17 and the lower opening of the resistance furnace B16 are connected to the mixed melt filling and foaming system through the melt channel B19; a cut-off baffle B is provided on the melt channel B19. 18, realizes the separation and connection between the mixing chamber 17 and the mold cavity 21; a hole is opened on the side of the mixing chamber 17, and the hole is connected to the feeding tank 24 through the feeding channel 3, and a spiral nozzle 15 is provided at the outlet of the feeding channel 3 in the mixing chamber 17; a resistance furnace D 23 is set outside the feeding tank 24, and the feeding tank 24 is connected to the gas booster pump B 27 through the gas channel C 26; the additive is sprayed from the feeding tank 24 through the two spiral nozzles on the side of the mixing chamber 17 to the mixing chamber 17 by the air pressure provided by the gas booster pump B 27, and at the same time, the spiral nozzle on the top of the mixing chamber 17 is used to spray the original melt in the melting chamber 11.

[0060] The melt filling and foaming system includes a resistance furnace C 22, which has an opening on its upper portion. A mold cavity 21 is provided in the resistance furnace C 22, and an opening is provided on its upper portion. The opening on the upper portion of the mold cavity 21 corresponds to the opening on the upper portion of the resistance furnace C 22, and the opening on the upper portion of the mold cavity 21 and the opening on the upper portion of the resistance furnace C 22 are connected to the melt channel B 19.

[0061] In this embodiment, the melt extrusion device includes a gas booster pump A1, which is connected to the upper opening of the melting chamber 11 and the upper opening of the resistance furnace A7 through a gas channel A8; the gas booster pump A1 is connected to the mixing chamber 17 through a gas channel B14.

[0062] In this embodiment, the melting chamber 11 is provided with a detachable top cover, and the melting chamber 11 and the top cover are fixed by bolts 9 to ensure the sealing of the melting chamber; and at the same time, it is used for adding aluminum or aluminum alloy raw materials.

[0063] In this embodiment, a valve A4 is provided on the gas channel A8; a three-way valve 2 is provided on the gas channel B14 to remove excess gas from the mixing chamber during mixing; and a valve B25 is provided on the gas channel C26.

[0064] In this embodiment, the angle α between the two spiral nozzles 15 on the side of the mixing chamber 17 and the vertical direction is 30-60 degrees, ensuring uniform mixing of the additive and the original melt during the blowing process.

[0065] In this embodiment, an air hole 20 is provided on the top of the mold cavity 21 to ensure the discharge of excess gas during the foaming process.

[0066] The preparation method of foam aluminum special-shaped parts is as follows:

[0067] Step 1: Place Al-7Si-1Mg-2Ca alloy in the melting chamber 11, connect the top cover to the main body of the melting chamber 11 with bolts 9, melt it at 680°C, keep it warm for 15 minutes, and then cool it to 595°C;

[0068] Step 2: Open the three-way valve 2 to connect the mixing chamber 17 to the air, open the valve 4, start the gas booster pump A1, and suppress the melt surface by increasing the gas pressure in the melting chamber 11. The pressing pressure is 1.5 MPa.

[0069] The shutoff baffle A 13 is opened, and the three spiral nozzles 15 are opened simultaneously. The original melt is sprayed from the melting chamber 11 into the mixing chamber 17 at 400° C. using the spiral nozzle at the outlet of the melt channel A 12 at a spray rate of 150 ml / min. A mixed additive of titanium hydride and silicon carbide (mass ratio of 1:4) is sprayed into the mixing chamber 17 using the spiral nozzle on the side of the mixing chamber 17. The amount of titanium hydride added is 1.5% by mass of the aluminum alloy used, and the particle size is 50 μm. The titanium hydride has been previously oxidized in air at 420° C. for 3 h. The spray rate is 40 ml / min. The angle α between the side rotating nozzle and the vertical direction is 30°. The mixed additive is preheated at 400° C. for 30 min to disperse and evenly mix the original melt and the solid-phase additive to form a mixed melt.

[0070] Step 3: After the volume of the mixed melt reaches 1 / 2 of the internal volume of the mixing chamber, close the intercepting baffle A 13 and the spiral nozzle 15; adjust the three-way valve 2 to isolate the mixing chamber 17 from the outside air, turn on the gas booster pump A 1 to pressurize the mixing chamber 17 to a positive pressure of 2 MPa, turn on the resistance furnace B 16 to heat the mixing chamber 17, and keep the mixed melt at 620°C;

[0071] Step 4: Remove the interception baffle B 18, and fill the mixed melt under positive pressure into a mold cavity 21 with air holes 20 at a pressure of 2 MPa. Apply a powder-based release agent to the inner surface of the mold cavity 21, and then foam at 650° C. for 8 minutes in the mold cavity 21. Finally, air cool and demold to obtain a foamed aluminum special-shaped part.

[0072] Example 2.

[0073] like Figure 1 As shown, when the melt extrusion device uses mechanical pressure:

[0074] A device for preparing foamed aluminum special-shaped parts includes a metal melting and extrusion system, the metal melting and extrusion system is connected to a melt and additive mixing system, and the melt and additive mixing system is connected to a melt filling and foaming system, wherein:

[0075] The metal melting and extrusion system includes a resistance furnace A7, which has openings at its upper and lower portions. A melting chamber 11 is provided within the resistance furnace A7, and the melting chamber 11 has openings at its upper and lower portions. The upper opening of the melting chamber 11 corresponds to the upper opening of the resistance furnace A7, and the lower opening of the melting chamber 11 corresponds to the lower opening of the resistance furnace A7. The upper opening of the melting chamber 11 and the upper opening of the resistance furnace A7 are connected to a melt extrusion device. The lower opening of the melting chamber 11 and the lower opening of the resistance furnace A7 are connected to a melt and additive mixing system via a melt channel A12. A shutoff baffle A13 is provided on the melt channel A12 to separate and connect the melting chamber 11 and the mixing chamber 17.

[0076] The melt and additive mixing system includes a resistance furnace B16, which is provided with openings at the upper and lower parts respectively; a mixing chamber 17 is provided in the resistance furnace B16, and the mixing chamber 17 is provided with openings at the upper and lower parts respectively; the upper opening of the mixing chamber 17 corresponds to the upper opening of the resistance furnace B16, and the lower opening of the mixing chamber 17 corresponds to the lower opening of the resistance furnace B16; the upper opening of the mixing chamber 17 and the upper opening of the resistance furnace B16 are connected to the melt channel A12, and the outlet of the melt channel A12 is provided with a spiral nozzle 15; the lower opening of the mixing chamber 17 and the lower opening of the resistance furnace B16 are connected to the mixed melt filling and foaming system through the melt channel B19; a cut-off baffle B is provided on the melt channel B19. 18, realizes the separation and connection between the mixing chamber 17 and the mold cavity 21; a hole is opened on the side of the mixing chamber 17, and the hole is connected to the feeding tank 24 through the feeding channel 3, and a spiral nozzle 15 is provided at the outlet of the feeding channel 3 in the mixing chamber 17; a resistance furnace D 23 is set outside the feeding tank 24, and the feeding tank 24 is connected to the gas booster pump B 27 through the gas channel C 26; the additive is sprayed from the feeding tank 24 through the two spiral nozzles on the side of the mixing chamber 17 to the mixing chamber 17 by the air pressure provided by the gas booster pump B 27, and at the same time, the spiral nozzle on the top of the mixing chamber 17 is used to spray the original melt in the melting chamber 11.

[0077] The melt filling and foaming system includes a resistance furnace C 22, which has an opening on its upper portion. A mold cavity 21 is provided in the resistance furnace C 22, and an opening is provided on its upper portion. The opening on the upper portion of the mold cavity 21 corresponds to the opening on the upper portion of the resistance furnace C 22, and the opening on the upper portion of the mold cavity 21 and the opening on the upper portion of the resistance furnace C 22 are connected to the melt channel B 19.

[0078] In this embodiment, the melt extrusion device includes a hydraulic or pneumatic system 6, which is connected to the upper opening of the melting chamber 11 and the upper opening of the resistance furnace A7 through a lifting rod 5; a pressure plate 10 is provided on the lifting rod 5 in the melting chamber 11.

[0079] In this embodiment, the melting chamber 11 is provided with a detachable top cover, and the melting chamber 11 and the top cover are fixed by bolts 9 to ensure the sealing of the melting chamber and to be used for adding aluminum or aluminum alloy raw materials.

[0080] In this embodiment, a valve A4 is provided on the gas channel A8; a three-way valve 2 is provided on the gas channel B14 to remove excess gas from the mixing chamber during mixing; and a valve B25 is provided on the gas channel C26.

[0081] In this embodiment, the angle α between the two spiral nozzles 15 on the side of the mixing chamber 17 and the vertical direction is 30-60 degrees, ensuring uniform mixing of the additive and the original melt during the blowing process.

[0082] In this embodiment, an air hole 20 is provided on the top of the mold cavity 21 to ensure the discharge of excess gas during the foaming process.

[0083] The preparation method of foam aluminum special-shaped parts is as follows:

[0084] Step 1: Place Al-2Mg-3Ca alloy in the melting chamber 11, connect the top cover to the main body of the melting chamber 11 with bolts 9, melt it at 740°C, keep it warm for 20 minutes, and then cool it to 600°C;

[0085] Step 2: Open the three-way valve 2 to connect the mixing chamber 17 to the air, start the hydraulic or pneumatic system 6, and use the hydraulic or pneumatic pressure to push the pressing plate 10 downward to press the melt surface at a pressing pressure of 3 MPa.

[0086] The shutoff baffle A 13 is opened, and the three spiral nozzles 15 are opened simultaneously. The original melt is sprayed from the melting chamber 11 to the mixing chamber 17 through the spiral nozzle 15 at the outlet of the melt channel A 12 at a spray rate of 100 ml / min. The titanium hydride additive is sprayed into the mixing chamber 17 through the spiral nozzle 15 on the side of the mixing chamber 17. The titanium hydride is added in an amount of 1% by mass of the aluminum alloy used, has a particle size of 30 μm, and has been previously oxidized in air at 480° C. for 2 h. The spray rate is 15 ml / min. The angle α between the side rotating nozzle 15 and the vertical direction is 45°. The titanium hydride additive is preheated at 400° C. for 10 min to disperse and evenly mix the original melt and the solid-phase additive to form a mixed melt.

[0087] Step 3: After the volume of the mixed melt reaches 1 / 3 of the internal volume of the mixing chamber, close the intercepting baffle A 13 and the spiral nozzle 15; adjust the three-way valve 2 to isolate the mixing chamber 17 from the outside air, turn on the gas booster pump A 1 to pressurize the mixing chamber 17 to a positive pressure of 5 MPa; turn on the resistance furnace B 16 to heat the mixing chamber 17 and keep the mixed melt at 680°C;

[0088] Step 4: Remove the intercepting baffle B 18, and fill the mixed melt into the mold cavity 21 with air holes 20 under the action of a pressure of 5 MPa. Apply an oil-based mold release agent to the inner surface of the mold cavity 21, and then foam it in the mold cavity 21 at 700°C for 5 minutes. Finally, water-cool it and demold it to obtain the foamed aluminum special-shaped part.

Claims

1. A device for preparing foam aluminum special-shaped parts, characterized in that: It includes a metal melting and extrusion system, which is connected to a melt and additive mixing system, which is connected to a mixed melt filling and foaming system, wherein: The metal melting and extrusion system includes a resistance furnace A (7), wherein the upper and lower parts of the resistance furnace A (7) are respectively provided with openings; a melting chamber (11) is provided in the resistance furnace A (7), a melting chamber top cover is connected to the melting chamber body by bolts (9), and the upper and lower parts of the melting chamber (11) are respectively provided with openings; the upper opening of the melting chamber (11) corresponds to the upper opening of the resistance furnace A (7), and the lower opening of the melting chamber (11) corresponds to the lower opening of the resistance furnace A (7); the upper opening of the melting chamber (11) and the upper opening of the resistance furnace A (7) are connected to a melt extrusion device; the lower opening of the melting chamber (11) and the lower opening of the resistance furnace A (7) are connected to a melt and additive mixing system through a melt channel A (12); a cut-off baffle A (13) is provided on the melt channel A (12); The melt and additive mixing system includes a resistance furnace B (16), wherein the upper and lower parts of the resistance furnace B (16) are respectively provided with openings; a mixing chamber (17) is provided in the resistance furnace B (16), wherein the upper and lower parts of the mixing chamber (17) are respectively provided with openings; the upper opening of the mixing chamber (17) corresponds to the upper opening of the resistance furnace B (16), and the lower opening of the mixing chamber (17) corresponds to the lower opening of the resistance furnace B (16); the upper opening of the mixing chamber (17) and the upper opening of the resistance furnace B (16) are connected to the melt channel A (12), and the outlet of the melt channel A (12) is provided with a spiral nozzle (15); the lower opening of the mixing chamber (17) and the resistance furnace B (16) are connected to each other. The lower opening of the furnace B (16) is connected to the mixed melt filling and foaming system through the melt channel B (19); a cut-off baffle B (18) is provided on the melt channel B (19); an opening is provided on the side of the mixing chamber (17), and the opening on the side is connected to the feeding tank (24) through the feeding channel (3), and a spiral nozzle (15) is provided at the outlet of the feeding channel (3) in the mixing chamber (17); a resistance furnace D (23) is provided outside the feeding tank (24), and the feeding tank (24) is connected to the gas booster pump B (27) through the gas channel C (26), and a valve B (25) is installed on the gas channel C (26) to control the injection rate of the additive; The melt filling and foaming system includes a resistance furnace C (22), the upper portion of which is provided with an opening; a mold cavity (21) is provided in the resistance furnace C (22), the upper portion of which is provided with an opening; the upper portion of the mold cavity (21) has an opening corresponding to the upper portion of the resistance furnace C (22), and the upper portion of the mold cavity (21) and the upper portion of the resistance furnace C (22) are connected to the melt channel B (19); and an air hole (20) is provided at the upper portion of the mold cavity.

2. The device for preparing foam aluminum special-shaped parts according to claim 1, characterized in that: The melt extrusion device includes a gas booster pump A (1), which is connected to an upper opening of a melting chamber (11) and an upper opening of a resistance furnace A (7) through a gas channel A (8); the gas booster pump A (1) is connected to a mixing chamber (17) through a gas channel B (14); a valve A (4) is installed on the gas channel A (8) for controlling the gas pressure applied by the gas booster pump A (1) to the melting chamber (11); and a three-way valve (2) is installed on the gas channel B (14) for connecting the mixing chamber (17) with air and controlling the gas pressure applied by the gas booster pump A (1) to the mixing chamber (17).

3. The device for preparing foam aluminum special-shaped parts according to claim 1, characterized in that: The melt extrusion device includes a hydraulic or pneumatic system (6), which is connected to an upper opening of a melting chamber (11) and an upper opening of a resistance furnace A (7) via a lifting rod (5); a pressure plate (10) is provided on the lifting rod (5) in the melting chamber (11).

4. The device for preparing foam aluminum special-shaped parts according to claim 1, characterized in that: The angle α between the two spiral nozzles (15) on the side of the mixing chamber (17) and the vertical direction is 30-60°.

5. A method for preparing a foamed aluminum special-shaped part, using the apparatus for preparing a foamed aluminum special-shaped part according to claim 2, characterized in that: The following steps are involved: Step 1: Place pure aluminum or aluminum alloy in a melting chamber (11) and melt it. The heating temperature is set at 620-750° C. and the temperature is kept at this temperature for 15-25 minutes after melting. Step 2, lowering the temperature of the above-mentioned pure aluminum or aluminum alloy original melt to 580-660°C, opening the three-way valve (2) to connect the mixing chamber (17) to the air, pressing the melt surface with pressure, opening the interception baffle A (13) to control the flow of the pure aluminum or aluminum alloy melt, and simultaneously opening the three spiral nozzles (15), using the spiral nozzles (15) at the outlet of the melt channel A (12) to spray the original melt from the melting chamber (11) to the mixing chamber (17), and using the spiral nozzles (15) on the side of the mixing chamber to spray the additive preheated at 200-400°C for 10-30 minutes into the mixing chamber, so that the original melt and the additive are dispersed and evenly mixed to form a mixed melt, and the internal temperature of the mixing chamber (17) is controlled at 400-480°C; Step 3: After the volume of the mixed melt reaches 1 / 4-1 / 2 of the internal volume of the mixing chamber, close the intercepting baffle A (13) and close the spiral nozzle; adjust the three-way valve (2) to isolate the mixing chamber (17) from the outside air, turn on the gas booster pump A (1) to charge the mixing chamber (17) with positive pressure, and then heat the mixed melt to keep the mixed melt at 600-680°C; Step 4: Remove the intercepting baffle B (18), fill the mixed melt under positive pressure into the mold cavity (21) with air holes (20), then keep it warm and foam it in the mold cavity (21), and finally cool it and remove it from the mold to obtain the foamed aluminum special-shaped part.

6. The method for preparing foamed aluminum special-shaped parts according to claim 5, characterized in that: In the step 1, the composition of the aluminum alloy is an Al-Si-Mg-Ca alloy, wherein Si accounts for 6% to 13% by mass of the aluminum alloy used, Mg accounts for 1% to 4% by mass of the aluminum alloy used, Ca accounts for 1% to 3% by mass of the aluminum alloy used, and the balance is Al.

7. The method for preparing foam aluminum special-shaped parts according to claim 5, characterized in that: In the step 2, the surface pressure of the original melt is pressed to 1-3 MPa.

8. The method for preparing foam aluminum special-shaped parts according to claim 5, characterized in that: In the step 2, the original melt is sprayed by the spiral nozzle (15) at the outlet of the melt channel A (12) at a rate of 60 to 200 ml / min, and the additive is sprayed by the spiral nozzle (15) on the side of the mixing chamber (17) at a rate of 3 to 50 ml / min.

9. The method for preparing foam aluminum special-shaped parts according to claim 5, characterized in that: In step 3 and step 4, the positive pressure in the mixing chamber (17) is 1.5-5 MPa.

10. The method for preparing foam aluminum special-shaped parts according to claim 5, characterized in that: In step 4, the mixed melt in the mold cavity (21) is kept warm and foamed at 650-720°C for 3-10 minutes.

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