Magnesium-based coated copper composite board strip and continuous cast rolling processing method and equipment thereof

Abstract

The invention relates to a magnesium-based copper-clad composite plate strip and a continuous cast rolling processing method and equipment thereof. The processing method comprises the following steps: melting magnesium alloy, guiding flow under pressure, releasing melt, dividing flow by a casting nozzle, cladding a copper strip, casting and rolling a vertical plate of a composite plate, coiling, shearing and discharging. A magnesium and magnesium alloy layer with the thickness of 4-6 mm is arranged in the middle of the magnesium-based coated copper composite plate strip in the thickness direction, the upper side and the lower side of the magnesium and magnesium alloy layer are each coated with a copper strip with the thickness of 0.1-0.3 mm, and the product density is 2.0-2.7 g / cm < 3 >. The continuous casting and rolling processing equipment comprises a smelting furnace, a liquid transfer pipe, a front box, a liquid discharge guide pipe, a casting nozzle, an unreeling machine, an inlet guide roller, a casting roller and a reeling machine. Casting forming and rolling are combined into a whole, liquid magnesium alloy and a solid copper strip are directly adopted for preparing the magnesium-based copper-clad composite plate strip, and the problem that magnesium and magnesium composite materials are difficult to carry out plastic processing at the normal temperature is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal processing, and in particular relates to a magnesium-based copper-clad composite plate strip and a continuous casting and rolling processing method and equipment thereof. Background Art

[0002] As a new type of composite material, magnesium-based copper-clad composite strip has the advantages of high electrical conductivity and good thermal conductivity of copper, and low density, high specific strength and low price of magnesium, and has attracted more and more attention in recent years. Studies have shown that due to the "skin effect", the use of magnesium-based copper-clad composite materials instead of copper, aluminum and other materials as conductive busbars can not only have higher electrical conductivity, but also have unique advantages in inductance, shielding and other aspects. At the same time, it can also greatly reduce weight, with excellent lightweight and cost advantages.

[0003] At present, the methods used to prepare heterogeneous metal composite plates and strips include explosive compounding, rolling compounding, casting and rolling compounding, etc. Since magnesium and magnesium alloys are highly chemically active, non-dense oxide scales are easily generated on the surface in the air. If explosive compounding or rolling compounding is used, the oxides on the surface will remain at the interface as oxide inclusions, which will affect both the internal purity of the product and the bonding strength of the composite interface, resulting in poor composite effect.

[0004] The casting and rolling composite process has the advantages of good formability, short process, low cost, and high interface bonding strength, and is an important development direction in the future. However, compared with aluminum and aluminum alloys, magnesium and magnesium alloys are very chemically active and easily react with oxygen and water vapor in the molten state. Therefore, it is difficult to produce magnesium-based composite materials by casting and rolling, and it has its own particularity and is not universal with other metal casting and rolling composite technologies. Therefore, although there is a demand for lightweight, there has been very little research and testing on magnesium-based composite cast-rolled plates and strips. Summary of the invention

[0005] The purpose of the present invention is to provide a magnesium-based copper-clad composite plate strip and its continuous casting and rolling processing method and equipment, which combines casting molding and rolling into one, directly uses liquid magnesium alloy and solid copper strip to prepare the magnesium-based copper-clad composite plate strip, and solves the problem that magnesium and its composite materials are difficult to plastically process at room temperature.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is: a continuous casting and rolling processing method of a magnesium-based copper-clad composite plate strip, comprising the following steps: Step 1: Put magnesium and magnesium alloy ingots into a smelting furnace under the protection of protective gas to melt and obtain a magnesium alloy melt; Step 2: Using pressure diversion to transfer the magnesium alloy melt in the smelting furnace to a box outside the furnace; Step 3, the magnesium alloy melt in the box is discharged to the casting nozzle; Step 4: The magnesium alloy melt flows evenly to the roll gap of two casting rolls configured in the casting and rolling mill through the diversion effect of the casting nozzle, and the magnesium alloy melt contacts the copper strips passing through the upper and lower sides of the casting nozzle outlet when flowing out of the casting nozzle, and then enters the roll gap together; Step 5: Under the combined effect of the pre-compression stress of the casting roll and the cooling and solidification of the casting roll, the magnesium alloy melt and the copper strips on the upper and lower sides are bonded at the magnesium-copper interface to form a magnesium-based copper-coated cast-rolled composite plate with a tightly bonded magnesium-copper composite interface; Step six, the magnesium-based clad copper cast-rolled composite plate is coiled by a coiler into a coil of a certain weight or a certain length, and cut off the line to complete the preparation of the magnesium-based clad copper composite plate strip.

[0007] Furthermore, during the melting process, the melting temperature of the magnesium alloy melt is based on the melting temperature of the corresponding magnesium alloy.

[0008] Furthermore, in step three, the magnesium alloy melt flows into the casting nozzle under the dual effects of its own gravity and the gas pressure in the box.

[0009] Furthermore, a gap is left between the casting nozzle and the roller surface of the casting roller, and the gap is protected by protective gas.

[0010] Furthermore, the protective gas used is SF 6 With N 2 mixed gas, or SF 6 Replace with SO 2 or C 2 H 2 F 4 .

[0011] The present invention also proposes a magnesium-based copper-clad composite plate strip, which is made by the above-mentioned continuous casting and rolling method. The middle part of the plate in the thickness direction is a 4-6 mm thick magnesium and magnesium alloy layer, and the upper and lower sides of the magnesium and magnesium alloy layer are respectively coated with a 0.1-0.3 mm thick copper strip. The product density is 2.0-2.7 g / cm 3 .

[0012] The present invention further provides a continuous casting and rolling processing equipment for magnesium-based copper-clad composite plate strips, comprising a smelting furnace, a liquid transfer pipe, a front box, a liquid discharge conduit, a casting nozzle, an unwinding machine, an inlet guide roller, a casting and rolling roller and a coiler; The smelting furnace is used to melt magnesium and magnesium alloys. The furnace mouth of the smelting furnace is closed and is equipped with a pressure input pipe for inputting protective gas into the furnace. The smelting furnace is also connected to a liquid transfer pipe. The inlet of the liquid transfer pipe is located below the melt level in the smelting furnace, and the outlet of the liquid transfer pipe is connected to the front box. The front box is a closed box, the bottom of which is connected with a drainage conduit for discharging the magnesium alloy melt to the casting nozzle for diversion; The liquid outlet of the casting nozzle is located at the roller gap of the two casting rolls. Inlet guide rollers are also arranged above and below the casting nozzle. An unwinder is arranged on one side of each inlet guide roller. The unwinder is used to realize the unwinding of the copper strip coil. After the copper strip of the copper strip coil passes around the corresponding inlet guide roller, it passes through the roller gap from the gap between the casting nozzle and the casting roll, so that the magnesium alloy melt can contact the copper strip after flowing out from the liquid outlet of the casting nozzle; A cooling water channel is provided inside the casting roll to allow circulating cooling water to flow in; The coiler is used to coil the magnesium-based copper-clad composite plate formed by continuous casting and rolling by casting and rolling rollers into a strip coil.

[0013] Furthermore, the casting nozzle is arranged in an inclined manner so that the inlet of the casting nozzle is lower than the liquid outlet.

[0014] Furthermore, the bottom of the front box is arranged in an inclined manner, and the connection position of the drainage conduit on the front box is adjacent to the highest end of the bottom of the box.

[0015] Furthermore, a protective gas input pipe is connected to the top of the front box for inputting protective gas into the front box and establishing a pressure in the box for the magnesium alloy melt to flow out.

[0016] The beneficial effects of the present invention are as follows: 1. The present invention combines casting and rolling into one, and directly uses liquid magnesium alloy and solid copper strip to prepare magnesium-based copper-clad composite plate and strip, solving the problem that magnesium and its composite materials are difficult to plastically process at room temperature.

[0017] 2. The magnesium-based coated copper casting and rolling composite production method in the present invention can effectively avoid the generation of oxide inclusions at the composite interface on the surface of the magnesium material due to gas protection. Compared with the explosive composite and rolling composite methods, the composite plate and strip produced has fewer oxide inclusions, better internal quality, better composite interface bonding, and greater bonding strength.

[0018] 3. The present invention adopts a short-process production method. The base magnesium plate no longer undergoes production processes such as melting-casting-hot rolling-sanding. The high-purity magnesium alloy is directly melted and transferred to the front box through a liquid transfer pipe, and then a casting and rolling composite operation is performed. This is a semi-solid composite molding method with a short production process, low production cost, and cost advantage.

[0019] 4. The magnesium-based copper-clad composite cast-rolled plate of the present invention can be directly used as a conductive bar, which has a high conductivity and a significant lightweight effect. Compared with copper conductive bars, it can reduce weight by more than 70%. Compared with aluminum conductive bars, it can increase conductivity by 30% to 50% and still reduce weight by up to 25%.

[0020] 5. Compared with aluminum and aluminum alloys, magnesium and magnesium alloys have better thermal diffusion coefficients and better heat dissipation effects. Magnesium-based coated copper composite cast-rolled plates and strips have better heat dissipation effects than aluminum and copper-aluminum composite plates and strips.

[0021] 6. Magnesium-based coated copper cast-rolled composite plate and strip are used to form a protective layer on the surface of the magnesium material by composite copper material. Since the corrosion resistance of copper is far superior to that of magnesium, the copper-magnesium composite cast-rolled plate and strip can effectively overcome the shortcomings of poor corrosion resistance of magnesium alloy and maximize its advantages such as light specific gravity. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic diagram of the continuous casting and rolling processing equipment of the magnesium-based clad copper composite plate strip of the present invention.

[0024] Markings in the figure: 1. Crucible furnace, 2. Pressure input port, 3. Liquid transfer pipe, 4. Protective gas input pipe, 5. Front box, 6. Unwinder, 7. Inlet guide roller, 8. Casting roller, 9. Water inlet and outlet, 10. Pinch guide roller, 11. Composite cast-rolled coil, 12. Coiler, 13. Drainage duct, 14. Casting nozzle. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the invention in any way.

[0026] Embodiment 1: A continuous casting and rolling method for a magnesium-based copper-clad composite plate strip comprises the following steps: 1. Magnesium alloy melting: high-purity magnesium and magnesium alloy ingots are melted under the protection of protective gas. No refining, degassing and flux covering are performed during the melting process to ensure that the magnesium alloy melt has a high purity; 2. Pressure diversion: after melting, the magnesium alloy melt in the melting furnace is transferred to the external box by pressure diversion; 3. Melt discharge: the magnesium alloy melt in the box is discharged to the casting nozzle under the dual effects of gravity and gas pressure in the box; 4. Dividing the casting nozzle and covering the copper belt, the magnesium alloy melt entering the casting nozzle flows evenly to the roll gap between the two casting rolls configured in the casting and rolling mill through the diversion of the casting nozzle. After flowing out through the liquid outlet of the casting nozzle, the magnesium alloy melt contacts the copper belts arranged on the upper and lower sides of the liquid outlet of the casting nozzle, and then passes through the roll gap of the casting rolls together; 5. Cast-rolled composite plate vertical plate, continuous casting and rolling is carried out by a casting and rolling mill, and cooling water is passed through the casting and rolling mill's casting and rolling rollers. As the casting and rolling rollers cool, the heat of the melt is transferred to the casting and rolling roller surface through the copper belt, and then discharged through the cooling water inside the casting and rolling rollers. As the heat is discharged, the magnesium alloy melt forms a liquid phase region-liquid-solid two-phase region-solid phase region in the cooling process of the casting and rolling rollers. The magnesium alloy melt solidifies and adheres to the surface of the copper belt during the cooling process. Under the combined action of the pre-compression stress of the casting and rolling rollers and cooling and solidification, the magnesium-copper interface is combined to form a magnesium-copper composite layer. During the solidification process, due to the pre-compression stress of the casting and rolling rollers, there is a certain degree of plastic deformation, which makes the magnesium-copper composite interface more firmly bonded, forming a magnesium-based copper-coated cast-rolled composite plate with a tightly bonded interface, that is, a magnesium-based copper-coated composite plate with a magnesium alloy in the middle and copper bonded on the upper and lower surfaces; It should be noted that there is a small gap between the casting nozzle and the roller surface of the casting roller, and the gap is protected by protective gas; the casting speed range is 800-3000mm / min.

[0027] 6. Coiling and shearing off the line. After the vertical plate is completed, the magnesium-based clad copper composite plate is coiled by the coiler to a coil of a certain weight or a certain length, and then sheared off the line to complete the preparation of the magnesium-based clad copper composite plate strip.

[0028] In the above steps, pay attention to the following points: (1) During the melting process of magnesium alloy, the melting temperature of the melt shall be based on the melting temperature of the corresponding magnesium alloy; (2) The protective gas used is SF 6 With N 2 Mixed gas, SF 6 Can also be replaced by SO 2 , C 2 H 2 F 4 Other protective gases with similar protective effects; (3) The copper strip used in the present invention is a copper strip with a thickness of 0.1 to 0.3 mm, the surface of which has been treated to remove the oxide film and rolling oil; and is preferably oxygen-free copper.

[0029] Example 2 A magnesium-based copper-clad composite plate strip is prepared by the processing method described in Example 1, wherein the middle of the plate has a 4-6 mm thick magnesium or magnesium alloy layer, and the upper and lower layers are each coated with a 0.1-0.3 mm thick copper strip, and the product density is 2.0-2.7 g / cm 3This product has excellent electrical and thermal conductivity and corrosion resistance, and is lighter than pure copper and copper-aluminum composite plates and strips. It can be used directly as a finished product or as a blank for subsequent plastic processing.

[0030] Example 3 This embodiment is a continuous casting and rolling processing equipment for magnesium-based copper-clad composite plate strips. The method described in Example 1 can be better implemented by using this equipment.

[0031] The structure of the continuous casting and rolling processing equipment described in this embodiment is as follows Figure 1 As shown, it includes a crucible furnace 1, a liquid transfer tube 3, a front box 5, a liquid discharge duct 13, a casting nozzle 14, an unwinding machine 6, an inlet guide roller 7, a casting roller 8, a pinch guide roller 10 and a coiler 12 which are arranged in sequence according to the process.

[0032] The crucible furnace 1 is a smelting furnace for smelting magnesium and magnesium alloys. The furnace mouth of the crucible furnace 1 is sealed and equipped with a pressure input pipe 2. The outlet end of the pressure input pipe 2 is higher than the melt level in the crucible furnace 1. The protective gas enters the crucible furnace 1 through the pressure input pipe 2 to protect the melting process and avoid oxidation of the melt. The protective gas introduced into the crucible furnace 1 can also play a role in pressurizing the melt, thereby realizing pressure diversion of the melt. In other embodiments, smelting furnaces of other structural forms can also be used.

[0033] The crucible furnace 1 is also connected to a liquid transfer tube 3, the inlet of which is located in the crucible furnace 1 and extends below the liquid surface of the melt, and the outlet of which is located outside the crucible furnace 1 and connected to the front box 5. By increasing the pressure of the protective gas in the crucible furnace 1, the magnesium and magnesium alloy melt therein is guided to the front box 5 through the liquid transfer tube 3.

[0034] The front box 5 is a closed box, and a drain pipe 13 is connected to the bottom of the box to discharge the melt to the casting nozzle 14 for diversion. In order to ensure the smooth discharge of the melt, a protective gas input pipe 4 is also connected to the top of the front box 5. The protective gas input pipe 4 is used to pass protective gas into the front box 5 to prevent the melt from oxidizing and provide pressure for the melt to flow out smoothly.

[0035] The casting nozzle 14 is a melt distributor, which realizes the flow division of the melt. The structure and flow division mode of the casting nozzle 14 are implemented by the distributor described in the implementation method of the prior art "A distributor for continuous casting and rolling of deformed magnesium alloy thin strip" (ZL2005200309187), so the detailed structure of the casting nozzle 14 is not repeated. The inlet of the casting nozzle 14 is connected to the outlet end of the drainage conduit 13, and the liquid outlet of the casting nozzle 14 is located at the roll gap of the casting roll 8, and there is a small gap between the liquid outlet of the casting nozzle 14 and the roll surface of the casting roll 8, and protective gas is passed through the gap.

[0036] Preferably, the casting nozzle 14 is arranged in an inclined manner, that is, the inlet of the casting nozzle 14 is lower than its outlet, so that when the magnesium melt leaks, the melt can flow back to avoid the melt continuing to flow out and causing production accidents.

[0037] Further preferably, the bottom of the front box 5 is also arranged in an inclined manner to facilitate melt reflow, and the connection position of the drainage conduit 13 on the front box is adjacent to the highest end of the bottom of the box.

[0038] Inlet guide rollers 7 are also arranged above and below the casting nozzle 14, and an unwinder 6 is arranged on one side of the inlet guide roller 7. The copper strip is rolled on the unwinder 6. After the copper strip passes around the inlet guide roller 7, it can pass through the gap between the casting nozzle 14 and the casting roller 8 and pass through the roller gap. The magnesium melt flowing out of the liquid outlet of the casting nozzle 14 contacts the copper strip under the protection of the protective gas.

[0039] The casting rolls 8 are arranged in a pair and rotate in opposite directions. The melt and the copper strips on the upper and lower sides of the melt pass through the roll gap between the two casting rolls 8. The casting rolls 8 are internally cooled rolls. A cooling water pipeline is arranged in the roll body. The roll body is provided with water inlet and outlet 9, which can be one inlet and one outlet or multiple inlets and multiple outlets. The cooling water inlet and outlet speed is determined according to the cooling water amount required for the corresponding specifications of the magnesium-based clad copper cast-rolled sheet and strip.

[0040] A pair of pinch guide rollers 10 are provided on the outlet side of the casting roller 8 . The magnesium-based copper-clad composite plate after casting passes through the roller gap of the pinch guide rollers 10 and is wound on a coiler 12 .

[0041] The following takes the preparation of two specifications of magnesium-based copper-clad composite plates as an example to further illustrate the processing method and equipment of the present invention.

[0042] Example 4 This embodiment is described by taking the production of an oxygen-free copper strip with a base of AZ31B magnesium alloy, a surface copper coating of 0.15 mm thick, and a grade of TU1-M, and a finished product specification size of 6.0×1000×L1mm (L1 is the length of the plate and strip, which is cut according to specific requirements) as an example, and the steps are as follows.

[0043] 1. Magnesium alloy melting: First, select AZ31B magnesium alloy ingots with high purity, put them into the crucible furnace for heating and melting, the melting temperature is 720℃~750℃, until it is completely melted. During melting, the crucible furnace is sealed and 2%~5% SF 6 N 2 Protective gas for protection; Pressure diversion: Increase the gas pressure in the crucible furnace to 0.1-0.8 MPa, so that the molten alloy melt can be diverted to the front box through the liquid transfer pipe; Front box discharge: When the liquid level in the front box reaches a certain height, the melt is discharged to the casting nozzle under the combined action of the melt gravity and the gas pressure in the front box; Nozzle diversion: There are 6 to 7 diversion blocks in the nozzle, and the outlet size of the nozzle is 6.5×1005mm; the gap between the nozzle and the casting roll surface of the casting and rolling mill is 0.3 to 0.4mm, and the gap is filled with 2% to 5% SF 6 N 2 Protected by protective gas, the magnesium alloy melt flows evenly to the roll gap between the two casting rolls after being diverted through the casting nozzle; Copper-coated strip: Unwinders are respectively arranged above and below the casting nozzle, and oxygen-free copper strip coils with a thickness of 0.15 mm and a width of 1000 mm are placed on the unwinders; inlet guide rollers are respectively arranged on the upper and lower surfaces of the casting nozzle, and the oxygen-free copper strip coil passes through the roller gap of the casting roller after passing through the inlet guide rollers and fitting the liquid outlet of the casting nozzle; Casting and rolling composite plate vertical plate: continuous casting and rolling is carried out by continuous casting and rolling mill, the casting and rolling mill is equipped with two internally cooled rollers, cooling water is passed through the inside, the cooling water temperature is maintained at 20℃~50℃, the roller form is backward tilting installation, the backward tilting angle is 15° (consistent with the tilting angle of the casting nozzle), and the roller gap between the two casting and rolling rollers is 5.8~6.0mm; the casting and rolling speed is set to 1000mm / min; the magnesium alloy melt contacts the copper belt after flowing out of the casting nozzle outlet, and rapidly cools and crystallizes under the rapid heat conduction of the copper belt. When passing through the roller gap of the casting and rolling roller, liquid phase area-liquid-solid two-phase area-solid phase area are formed successively. During the solidification process, due to the pre-compression stress of the casting and rolling roller, there is a certain degree of pressure deformation, forming a magnesium-copper cast and rolled composite plate with a tight interface; Coiling and shearing: After the vertical plate is completed, a magnesium-based clad copper cast-rolled composite plate with AZ31B magnesium alloy in the middle and oxygen-free copper on the upper and lower surfaces is formed. The thickness is 6.0mm. A coiler with a jaw set at the tail of the casting and rolling mill is used to coil it synchronously with the continuous casting and rolling speed to prepare a magnesium-based clad copper cast-rolled coil with a surface copper material thickness of 0.15mm and a finished product specification of 6.0×1000×L1mm. It is sheared off the line after reaching a certain coiling length (i.e. L1) or a certain weight.

[0044] Example 5 This embodiment is described by taking the production of an oxygen-free copper strip with a base of ME20M magnesium alloy, a surface copper coating of 0.2 mm thickness, and a grade of TU1-M, and a finished product with a specification size of 5.0×800×L2mm (L2 is the length of the plate and strip, and the specific length can be cut according to requirements) as an example, and the steps are as follows.

[0045] 1. Magnesium alloy melting: First, select ME20M magnesium alloy ingots with high purity, put them into a crucible furnace for heating and melting, the melting temperature is 730℃~780℃, until it is completely melted. During melting, the crucible furnace is sealed and 2%~5% SF 6 N 2 Protective gas for protection; Pressure diversion: Increase the gas pressure in the crucible furnace to 0.1-0.8 MPa, so that the molten alloy melt can be diverted to the front box through the liquid transfer pipe; Front box discharge: When the liquid level in the front box reaches a certain height, the melt is discharged to the casting nozzle under the combined action of the melt gravity and the gas pressure in the front box; Nozzle diversion: There are 4 to 6 diversion blocks in the nozzle, and the outlet size of the nozzle is 5.3×805mm; the gap between the nozzle and the casting roll surface of the casting and rolling mill is 0.4 to 0.5mm, and the gap is filled with 2% to 5% SF 6 N 2 Protected by protective gas, the magnesium alloy melt flows evenly to the roll gap between the two casting rolls after being diverted through the casting nozzle; Copper-coated strip: Unwinders are respectively arranged above and below the casting nozzle, and oxygen-free copper strip coils with a thickness of 0.2 mm and a width of 800 mm are placed on the unwinders; inlet guide rollers are respectively arranged on the upper and lower surfaces of the casting nozzle, and the oxygen-free copper strip coil passes through the roller gap of the casting roller after passing the inlet guide rollers and fitting the liquid outlet of the casting nozzle; Casting and rolling composite plate vertical plate: continuous casting and rolling is carried out by continuous casting and rolling mill, the casting and rolling mill is equipped with two internally cooled rollers, cooling water is passed through the inside, the cooling water temperature is maintained at 15℃~50℃, the roller form is backward tilting installation, the backward tilting angle is 15° (consistent with the tilting angle of the casting nozzle), and the roller gap between the two casting and rolling rollers is 4.8~5.0mm; the casting and rolling speed is set to 2500mm / min; the magnesium alloy melt contacts the copper belt after flowing out of the casting nozzle outlet, and rapidly cools and crystallizes under the rapid heat conduction of the copper belt. When passing through the roller gap of the casting and rolling roller, liquid phase area-liquid-solid two-phase area-solid phase area are formed successively. During the solidification process, due to the pre-compression stress of the casting and rolling roller, there is a certain degree of pressure deformation, forming a magnesium-copper cast and rolled composite plate with a tight interface; Coiling and shearing: After the vertical plate is completed, a magnesium-based clad copper cast-rolled composite plate with a middle layer of ME20M magnesium alloy and oxygen-free copper on the upper and lower surfaces is formed. The thickness is 5.0 mm. A coiler with a jaw installed at the tail of the casting and rolling mill is used to coil it synchronously with the continuous casting and rolling speed to prepare a magnesium-based clad copper cast-rolled coil with a surface copper material thickness of 0.2 mm and a finished product specification of 5.0×800×L2mm. It is sheared off the line after reaching a certain coiling length (i.e. L2) or a certain weight.

[0046] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Those skilled in the art should understand that the specific implementation modes of the present invention may be modified or replaced by equivalents with reference to the above embodiments. Any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention are within the scope of protection of the pending claims.

Claims

1. A continuous casting and rolling method for magnesium-based copper-clad composite plate strip, characterized in that: The steps include: Step 1: Put magnesium and magnesium alloy ingots into a smelting furnace under the protection of protective gas to melt and obtain a magnesium alloy melt; Step 2: Using pressure diversion to transfer the magnesium alloy melt in the smelting furnace to a box outside the furnace; Step 3, the magnesium alloy melt in the box is discharged to the casting nozzle; Step 4: The magnesium alloy melt flows evenly to the roll gap of two casting rolls configured in the casting and rolling mill through the diversion effect of the casting nozzle, and the magnesium alloy melt contacts the copper strips passing through the upper and lower sides of the casting nozzle outlet when flowing out of the casting nozzle, and then enters the roll gap together; Step 5: Under the combined effect of the pre-compression stress of the casting roll and the cooling and solidification of the casting roll, the magnesium alloy melt and the copper strips on the upper and lower sides are bonded at the magnesium-copper interface to form a magnesium-based copper-coated cast-rolled composite plate with a tightly bonded magnesium-copper composite interface; Step six, the magnesium-based clad copper cast-rolled composite plate is coiled by a coiler into a coil of a certain weight or a certain length, and cut off the line to complete the preparation of the magnesium-based clad copper composite plate strip.

2. The continuous casting and rolling processing method of the magnesium-based copper-clad composite plate strip according to claim 1 is characterized in that: During the melting process, the melting temperature of the magnesium alloy melt shall be based on the melting temperature of the corresponding magnesium alloy.

3. The continuous casting and rolling processing method of the magnesium-based copper-clad composite plate strip according to claim 1 is characterized in that: In step three, the magnesium alloy melt flows into the casting nozzle under the dual effects of its own gravity and the gas pressure in the box.

4. The continuous casting and rolling processing method of magnesium-based copper-clad composite plate strip according to claim 1, characterized in that: A gap is left between the casting nozzle and the roller surface of the casting roller, and the gap is protected by protective gas.

5. The continuous casting and rolling method of the magnesium-based copper-clad composite plate strip according to claim 1 or 4, characterized in that: The protective gas used is a mixed gas of SF6 and N2, or the SF6 in the mixed gas is replaced by SO2 or C2H2F4.

6. A magnesium-based copper-clad composite plate strip, characterized in that: The continuous casting and rolling method according to any one of claims 1 to 5 is used to produce the sheet, wherein the middle part of the sheet in the thickness direction is a 4-6 mm thick magnesium or magnesium alloy layer, and the upper and lower sides of the magnesium or magnesium alloy layer are each coated with a 0.1-0.3 mm thick copper strip, and the product density is 2.0-2.7 g / cm 3 .

7. A continuous casting and rolling processing equipment for magnesium-based copper-clad composite plate strip, characterized in that: It includes a melting furnace, a liquid transfer tube, a front box, a liquid discharge conduit, a casting nozzle, an unwinding machine, an inlet guide roller, a casting roll and a coiler; The smelting furnace is used to melt magnesium and magnesium alloys. The furnace mouth of the smelting furnace is closed and is equipped with a pressure input pipe for inputting protective gas into the furnace. The smelting furnace is also connected to a liquid transfer pipe. The inlet of the liquid transfer pipe is located below the melt level in the smelting furnace, and the outlet of the liquid transfer pipe is connected to the front box. The front box is a closed box, the bottom of which is connected with a drainage conduit for discharging the magnesium alloy melt to the casting nozzle for diversion; The liquid outlet of the casting nozzle is located at the roller gap of the two casting rolls. Inlet guide rollers are also arranged above and below the casting nozzle. An unwinder is arranged on one side of each inlet guide roller. The unwinder is used to realize the unwinding of the copper strip coil. After the copper strip of the copper strip coil passes around the corresponding inlet guide roller, it passes through the roller gap from the gap between the casting nozzle and the casting roll, so that the magnesium alloy melt can contact the copper strip after flowing out from the liquid outlet of the casting nozzle; A cooling water channel is provided inside the casting roll to allow circulating cooling water to flow in; The coiler is used to coil the magnesium-based copper-clad composite plate formed by continuous casting and rolling by casting and rolling rollers into a strip coil.

8. The continuous casting and rolling processing equipment for magnesium-based copper-clad composite plate strip according to claim 7, characterized in that: The casting nozzle is arranged in an inclined manner so that the inlet of the casting nozzle is lower than the liquid outlet.

9. The continuous casting and rolling processing equipment for magnesium-based copper-clad composite plate strip according to claim 7, characterized in that: The box bottom of the front box is arranged in an inclined manner, and the connection position of the drainage conduit on the front box is adjacent to the highest end of the box bottom.

10. The continuous casting and rolling processing equipment for magnesium-based copper-clad composite plate strip according to claim 7, characterized in that: The top of the front box is connected with a protective gas input pipe, which is used to input protective gas into the front box and establish a pressure in the box for the magnesium alloy melt to flow out.

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