Method for producing an aluminium-based composite strip

Abstract

The application discloses a preparation method of an aluminum-based composite strip, which comprises the following steps: preparing a skin material and a core material; stacking the first skin material, the core material and the second skin material in sequence to obtain a composite ingot; sequentially performing first heating and composite rolling on the composite ingot to obtain a composite slab; cutting off opposite two side surfaces of the composite slab; turning the cut-off composite slab by 90 degrees; sequentially performing second heating and hot rolling on the composite slab to obtain a hot-rolled strip; sequentially performing cold rough rolling, cleaning, intermediate annealing, cold finish rolling, cleaning, finished product annealing, edge cutting, cleaning and straightening on the hot-rolled strip to obtain a cold-rolled strip; longitudinally cutting the cold-rolled strip to obtain a coiled material; and sequentially performing anodic oxidation and electrolytic coloring on the coiled material to obtain the aluminum-based composite strip. The preparation method can make the aluminum-based composite strip have two different colors through one-time coloring.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum processing, in particular to a preparation method of aluminum-based composite strip.

BACKGROUND

[0002] After the aluminum alloy plate is subjected to sand blasting, anodic oxidation, electrolytic coloring and sealing treatment, a dense oxide film and uniform color can be formed on the surface of the aluminum alloy plate to improve the corrosion resistance, wear resistance, insulation and ornamental properties of the aluminum alloy plate. The aluminum alloy plate is widely used in the appearance parts of 3C electronic appliances such as notebook computers and the field of building wall decoration, as shown in Figure 1 .

[0003] In order to meet the aesthetic needs of consumers, a new anodic oxidation process has been developed, which produces two different colors on the surface of the aluminum alloy plate, making the appearance parts of 3C electronic appliances such as notebook computers more beautiful, as shown in Figure 2 . The new anodic oxidation process is to first immerse the whole aluminum alloy plate into a certain coloring tank for the first coloring, and then immerse part of the aluminum alloy plate into another coloring tank with different formula and different working conditions for the second coloring.

[0004] In summary, in the related art, in order to produce two different colors on the surface of the aluminum alloy plate, it is necessary to sequentially immerse the aluminum alloy plate into two different coloring tanks for two colorings. This new anodic oxidation process is not only complex, but also has high cost.

SUMMARY

[0005] The purpose of the embodiment of the present application is to provide a preparation method of aluminum-based composite strip, so as to solve the problem that in the related art, in order to produce two different colors on the surface of the aluminum alloy plate, it is necessary to sequentially immerse the aluminum alloy plate into two different coloring tanks for two colorings, resulting in complex process and high cost.

[0006] The embodiment of the present application provides a preparation method of aluminum-based composite strip, which comprises the following steps:

[0007] Step S1, preparing a skin material and a core material respectively; wherein the skin material comprises a first skin material and a second skin material, and the composition elements of the skin material and the composition elements of the core material have at least one same element with different content ranges;

[0008] Step S2, stacking and fixing the first skin material, the core material and the second skin material in order to obtain a composite ingot;

[0009] Step S3, sequentially performing first heating and composite rolling on the composite ingot to obtain a composite slab; wherein the temperature of the composite ingot is maintained at 490-500℃ during heating;

[0010] Step S4, cutting off opposite two sides of the composite slab; wherein the cutting off starts from the lowest point of the side recess of the composite slab, and each side of the composite slab is cut off by 10-12 mm;

[0011] Step S5, turning the cut-off composite slab by 90°;

[0012] Step S6, sequentially performing second heating and hot rolling on the turned composite slab to obtain a hot-rolled strip with a thickness of 5.0-8.0 mm; wherein the temperature of the composite slab during the second heating is 490-500℃, and the final rolling temperature of the hot rolling is 345±5℃;

[0013] Step S7, sequentially performing cold rough rolling, first cleaning, intermediate annealing under nitrogen protection, cold finish rolling, second cleaning, finished product annealing under nitrogen protection, edge cutting, third cleaning and straightening on the hot-rolled strip to obtain a cold-rolled strip with a thickness of 0.5-3.0 mm;

[0014] Step S8, longitudinally cutting the cold-rolled strip to obtain a coiled material; wherein the coiled material at least simultaneously includes a part of the width of the skin material and the width of the core material;

[0015] Step S9, sequentially performing anodic oxidation and electrolytic coloring on the coiled material to obtain an aluminum-based composite strip.

[0016] Preferably, in the step S1, the core material is an aluminum alloy of one of the following series: 1 series, 3 series, 5 series, 6 series and 7 series; the skin material is an aluminum alloy of a different series or an aluminum alloy of the same series but different grades.

[0017] Preferably, in the step S1, the preparation method of the skin material is sequentially melting and casting, sawing, milling and steel wire brushing; or the preparation method of the skin material is sequentially melting and casting, sawing, milling, heating, hot rolling, fixed-length sawing and slab steel wire brushing.

[0018] The preparation method of the core material is sequentially melting and casting, sawing, milling and steel wire brushing; or the preparation method of the core material is sequentially melting and casting, sawing, milling, heating, hot rolling, fixed-length sawing and slab steel wire brushing.

[0019] Preferably, the flat ingots obtained in the step of melting and casting of the skin material and the core material both satisfy the following conditions:

[0020] The slag content is less than or equal to 0.012 mm 2 The inclusion size is less than or equal to 5μm, the hydrogen content is less than or equal to 0.12mL / 100g-Al, the coarse grain layer is less than or equal to 8mm, and the composition is uniform.

[0021] Preferably, the skin material and the core material are cut 350-360mm from the head and 150-160mm from the tail after the step of melting and casting to obtain the cast ingot; the cast ingot obtained by the skin material in the step of melting and casting is milled 15-20mm from the large face close to the core material and 5-7mm from the large face away from the core material; the cast ingot obtained by the core material in the step of melting and casting is milled 15-20mm from the large face close to the first skin material and the large face close to the second skin material, respectively; the opposite two sides of the cast ingot obtained by the skin material in the step of melting and casting and the opposite two sides of the cast ingot obtained by the core material in the step of melting and casting are milled 5-7mm, respectively.

[0022] Preferably, the cast ingot obtained by the skin material and the core material in the step of melting and casting satisfies the following conditions:

[0023] The thickness tolerance is less than or equal to 2mm, the large face bending is less than or equal to 2mm, the side face bending is less than or equal to 2mm, and the end face bending is less than or equal to 2mm.

[0024] Preferably, the diameter of the brush of the steel wire brush used for polishing during the preparation of the skin material and the core material is 0.3-0.4mm, and the assembly density is 100 roots / cm 2 -120 roots / cm 2 , and the polishing process is equipped with an air pipe with compressed air. After polishing, a magnetic bar with a magnetic force greater than or equal to 12000GS is used to remove magnetic substances, and then a towel dipped in D30 cleaning agent is used to wipe off foreign matters.

[0025] Preferably, in the step S3, the preparation method of the composite rolling comprises the following steps:

[0026] Step S31, hot rolling of the heated composite ingot; wherein the hot rolling is performed by a hot rolling mill, and the emulsion spraying of the hot rolling mill is closed before the hot rolling;

[0027] Step S32, transporting the composite ingot to the working rolls of the hot rolling mill until half of the length of the composite ingot is transported to the working rolls of the hot rolling mill, stopping the transportation of the composite ingot and closing the hot rolling mill;

[0028] Step S33, adjusting the working rolls of the hot rolling mill to perform static pressure on the composite ingot; wherein the rolling force of the static pressure is 120-200T;

[0029] Step S34, starting the hot rolling mill to perform composite rolling of the composite ingot without disengaging the working rolls at both ends to obtain the composite slab; wherein the composite rolling comprises five passes, and the reduction of the five passes is 1mm, 3mm, 5mm, 7mm and 9mm, respectively.

[0030] Step S35, after the completion of the composite rolling, the emulsion spray of the hot rolling mill is opened and re-rolling is carried out until the composite slab is obtained.

[0031] Preferably, the maximum opening degree of the upper work roll and the lower work roll in the hot rolling mill is 1700mm; in the step S4, the equipment used for cutting is a precision saw installed on the roller way of the hot rolling mill, and the maximum opening degree of the precision saw is 1700mm.

[0032] Preferably, in the step S3, the thickness of the core material is defined as H0, the thickness of the skin material is defined as H1, and the thickness of the composite slab is defined as H3, and the thickness of the composite slab satisfies the following formula:

[0033] H3 / (2H1+H0)≥0.9.

[0034] Compared with the related art, the preparation method of the aluminum-based composite strip in the present application can make the aluminum-based composite strip have two or more different colors through one-time coloring by limiting the content range of the same element of the composition elements of the skin material and the composition elements of the core material, greatly simplifying the preparation process and reducing the production cost.

DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0036] Figure 1 A schematic diagram of a notebook computer shell with a single color in the related art;

[0037] Figure 2 A schematic diagram of a notebook computer shell with two different colors in the related art;

[0038] Figure 3 A step flowchart of a preparation method of an aluminum-based composite strip provided in an embodiment of the present application;

[0039] Figure 4 A structural schematic diagram of a composite ingot in a preparation method of an aluminum-based composite strip provided in an embodiment of the present application;

[0040] Figure 5 A structural schematic diagram of a composite slab after turning over in a preparation method of an aluminum-based composite strip provided in an embodiment of the present application;

[0041] Figure 6 This is a schematic diagram of the structure of the hot-rolled strip in a method for preparing an aluminum-based composite strip according to an embodiment of the present invention;

[0042] Figure 7 This is a schematic diagram of the roll material structure in a method for preparing an aluminum-based composite strip according to an embodiment of the present invention.

[0043] Figure 8 This is a schematic diagram of the structure of an aluminum-based composite strip in a specific embodiment of the present invention.

[0044] Figure 9 This is a schematic diagram of the structure of an aluminum-based composite strip in a specific embodiment two of the present invention.

Detailed Implementation Methods

[0045] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] This invention provides a method for preparing an aluminum-based composite strip, which includes the following steps:

[0047] S1. Prepare the leather and core materials separately.

[0048] The leather material includes a first leather material and a second leather material, wherein the constituent elements of the leather material and the constituent elements of the core material have different content ranges for at least one of the same elements.

[0049] The core material is one of the following aluminum alloys: 1050, 3003, 5005, 5052, 5754, 5182, 5083, 6063, and 7075. The skin material and the core material can be different series of aluminum alloys, such as when the core material is 5052, the skin material is 1070. The skin material and the core material can also be the same series but different grades of aluminum alloys, such as when the core material is 5052, the skin material is 5005. The skin material and the core material can also be the same series and the same grade of aluminum alloys, but the content range of a certain element is different, such as when the core material is 5052-A, the element Cu is ≤0.003%, and the skin material is 5052-B, the element Cu is 0.07-0.095%, i.e., the element Cu content of the skin material is 23-31 times that of the core material. This design can make the aluminum-based composite strip have two different colors by coloring once, because the content of elements such as Si, Fe, Cu, Mn, Mg, Cr, Zn, etc. in the aluminum alloy is different, the types of solid solutions in the aluminum alloy are different, the types, content, and size of the second phase are different, and the product composition after anodizing and coloring is very complex, which can exist in the form of "element, oxide, or intermetallic compound" and have differences, thereby affecting the types, thickness, and morphology of the oxide film layer, ultimately leading to different reflections of light, i.e., color difference phenomenon when observed by the naked eye, thereby appearing two different colors.

[0050] The preparation method of the skin material is melting, sawing, milling, and steel wire brushing in sequence; or the preparation method of the skin material is melting, sawing, milling, heating, hot rolling, fixed-length sawing, and slab steel wire brushing in sequence.

[0051] The preparation method of the core material is melting, sawing, milling, and steel wire brushing in sequence; or the preparation method of the core material is melting, sawing, milling, heating, hot rolling, fixed-length sawing, and slab steel wire brushing in sequence.

[0052] The flat ingots obtained in the melting step of the skin material and the core material satisfy the following conditions:

[0053] The slag content is less than or equal to 0.012 mm 2 The inclusion size is less than or equal to 5 μm, the hydrogen content is less than or equal to 0.12 mL / 100 g-Al, the coarse grain layer is less than or equal to 8 mm, and the composition is uniform. This can ensure that the aluminum-based composite strip does not have excessive and basic defects such as material lines and stripes during subsequent anodizing.

[0054] The "big face" described below is the upper surface and / or lower surface of the slab obtained from the core material and / or the skin material in the step of melting and casting; the "side face (or small face)" is the left side face and / or right side face of the slab obtained from the core material and / or the skin material in the step of melting and casting; the "end face" is the front end (or head) or the rear end (or tail) of the slab obtained from the core material and / or the skin material in the step of melting and casting.

[0055] After the slab obtained from the core material and the skin material in the step of melting and casting is milled, the following conditions are met:

[0056] The thickness tolerance is less than or equal to 2 mm, the big face bending is less than or equal to 2 mm, the side face bending is less than or equal to 2 mm, and the end face bending is less than or equal to 2 mm. Since these conditions will affect the process and effect of composite rolling, and will also affect the final anodizing and coloring effect, such as the width of different colors, the straightness of the skin material and core material boundary, etc., they must be controlled.

[0057] After the slab obtained from the core material and the skin material in the step of melting and casting is milled, the head is cut off by 350-360 mm and the tail is cut off by 150-160 mm. This design can avoid defects such as cracks, slag inclusion, porosity, and element segregation in the head and tail of the slab.

[0058] The big face of the slab obtained from the skin material in the step of melting and casting is milled by 15-20 mm near the core material and by 5-7 mm away from the core material; the big face of the slab obtained from the core material in the step of melting and casting is milled by 15-20 mm near the first skin material and by 15-20 mm near the second skin material; the opposite two side faces of the slab obtained from the skin material in the step of melting and casting are milled by 5-7 mm, and the opposite two side faces of the slab obtained from the core material in the step of melting and casting are milled by 5-7 mm. By milling the side face, defects such as cracks, slag inclusion, porosity, coarse grains, and element segregation in the side face of the slab can be avoided to ensure that the slab does not crack during hot rolling; by milling the big face of the skin material and the core material, defects such as cracks, slag inclusion, porosity, coarse grains, and element segregation in the big face of the slab can be avoided to ensure that the slab does not crack during hot rolling, while not affecting the effects of composite rolling, final anodizing, and coloring.

[0059] The diameter of the steel wire brush used for polishing during the preparation of the skin material and the core material is 0.3-0.4 mm, and the assembly density is 100 roots / cm 2 -120 roots / cm 2, and the polishing process is equipped with an air pipe with compressed air, and after polishing, a magnetic bar with a magnetic force greater than or equal to 12000GS is used to remove magnetic substances, and then a towel dipped in D30 cleaning agent is used to wipe off foreign matters. The magnetic bar can adsorb and remove aluminum powder generated on the upper and lower surfaces of the flat ingot or slab, and the towel can wipe off dust and other foreign matters. This design can better realize metallurgical welding when the skin material and the core material are combined, and prevent cracks and holes from occurring at the interface between the skin material and the core material.

[0060] S2, stacking and fixing in the order of the first skin material, the core material and the second skin material to obtain a composite ingot.

[0061] The structure of the composite ingot is as shown in Figure 4 The first skin material and the second skin material are respectively fixed with the core material through spot welding at the gaps of the head, middle and tail of the two sides. The length of spot welding is 30-40mm. This design facilitates the stacking and fixing of the first skin material, the core material and the second skin material.

[0062] S3, sequentially performing first heating and composite rolling on the composite ingot to obtain a composite slab.

[0063] During heating, the temperature of the composite ingot is maintained at 490-500℃, and the holding time is 2h.

[0064] The thickness of the core material is defined as H0, the thickness of the skin material is defined as H1, and the thickness of the composite slab is defined as H3. The thickness of the composite slab satisfies the following formula:

[0065] H3 / (2H1+H0)≥0.9.

[0066] The preparation method of the composite rolling includes the following steps:

[0067] S31, hot rolling the composite ingot after heating.

[0068] The hot rolling is performed by a hot rolling mill, and the emulsion spraying of the hot rolling mill is closed before hot rolling. Closing the emulsion spraying of the hot rolling mill can better realize metallurgical welding of the skin material and the core material during subsequent composite rolling, prevent cracks and holes from occurring at the interface between the skin material and the core material, and even prevent peeling and separation between the skin material and the core material.

[0069] The maximum opening degree between the upper work roll and the lower work roll of the hot rolling mill is 1700mm. The opening degree between the work rolls of the hot rolling mill in the related art is generally 320-670mm, and in order to facilitate the smooth implementation of the present preparation method under the industrial mass production conditions, the maximum opening degree between the work rolls of the hot rolling mill is limited to 1700mm.

[0070] S32, transporting the composite cast ingot between the work rolls of the hot rolling mill until half of the length of the composite cast ingot is transported between the work rolls of the hot rolling mill, stopping the transportation of the composite cast ingot and closing the hot rolling mill.

[0071] S33, adjusting the work rolls of the hot rolling mill to perform static pressing on the composite cast ingot.

[0072] The rolling force of the static pressing is 120-200T.

[0073] S34, starting the hot rolling mill to perform composite rolling on the composite cast ingot without disengaging the work rolls to obtain the composite slab.

[0074] The composite rolling includes five passes, and the reduction amount of the five passes is 1mm, 3mm, 5mm, 7mm and 9mm respectively. Of course, the passes and the reduction amount of the composite rolling can be adjusted according to actual needs.

[0075] Step S35, after the completion of the composite rolling, starting the emulsion spraying of the hot rolling mill and performing re-rolling until the composite slab is obtained.

[0076] The re-rolling also belongs to the rolling part of the composite rolling, and the difference from the rolling of steps S2-S4 is that the emulsion spraying of the hot rolling mill needs to be started.

[0077] S4, cutting off the opposite two side surfaces of the composite slab.

[0078] The cutting is calculated at the lowest point of the side surface recess of the composite slab, and each side surface of the composite slab is cut off by 10-12mm, that is, each side surface is cut off by 10-12mm from the lowest point to the direction close to the middle of the composite slab. In this way, the end surface of the composite slab can be smooth, without metal or non-metal pressing in, and without obvious knife marks.

[0079] The equipment used for cutting is a precision saw installed on the roller way of the hot rolling mill, and the maximum opening degree of the precision saw is 1700mm. The roller way of the hot rolling mill in the related art is not installed with a large precision saw, and in order to facilitate the smooth implementation of the present preparation method under the industrial mass production conditions and to cope with the abnormal situations in the production process, a large precision saw device must be installed on the hot rolling mill.

[0080] Of course, according to actual needs, the cutting equipment can also use a milling machine.

[0081] S5, turn the cut composite slab 90°.

[0082] Wherein, the structure of the turned composite slab is as shown in Figure 5 ; A large slab turner is used during turning.

[0083] S6, sequentially heat and hot-rolling the turned composite slab to obtain a hot-rolled strip with a thickness of 5.0-8.0mm.

[0084] Wherein, the structure of the hot-rolled strip is as shown in Figure 6 ; The temperature of the composite slab during the second heating is 490-500℃, the holding time is 2h, and a heating furnace is used for heating, and hot-rolling is performed after heating is completed.

[0085] The hot-rolling process is the process of anodized aluminum alloy strip, and the final rolling temperature of hot-rolling is 345±5℃.

[0086] S7, sequentially cold rough rolling, first cleaning, nitrogen-protected intermediate annealing, cold finishing rolling, second cleaning, nitrogen-protected finished annealing, edge cutting, third cleaning, and straightening of the hot-rolled strip to obtain a cold-rolled strip with a thickness of 0.5-3.0mm.

[0087] Wherein, the process parameters and quality requirements of this step are the process parameters and quality requirements of the anodized aluminum alloy strip.

[0088] S8, longitudinally cutting the cold-rolled strip to obtain a coiled material.

[0089] Wherein, the structure of the coiled material is as shown in Figure 7 , wherein a is a structure diagram only including the first skin material and the core material, and b is a structure diagram including the first skin material, the core material, and the second skin material; the coiled material at least simultaneously includes a part of the width of the skin material and the width of the core material.

[0090] S9, sequentially anodizing and electrolytic coloring the coiled material to obtain an aluminum-based composite strip.

[0091] Wherein, the anodizing and electrolytic coloring of this step can also be performed after the coiled material is transversely cut to form a small piece structure.

[0092] Compared with the related art, the preparation method of the aluminum-based composite strip in the embodiment has the content range of at least one same element of the composition elements of the skin material and the composition elements of the core material, and the skin material and the core material are subjected to composite rolling, and then subjected to anodic oxidation and electrolytic coloring, so that the aluminum-based composite strip has two or more different colors through one-time coloring, the preparation process is greatly simplified, and the production cost is reduced.

[0093] In order to better reflect the specific effects brought by the preparation method of the aluminum-based composite strip in the application, two specific embodiments will be used for illustration below. Specific embodiment one

[0095] The embodiment provides a preparation method of an aluminum-based composite strip, which comprises the following steps:

[0096] S1, preparing the required skin material and core material according to the requirements of the aluminum alloy material for anodic oxidation.

[0097] The skin material comprises a first skin material and a second skin material, and the skin material is an aluminum alloy with a brand of 5052-A, which is prepared through the preparation steps of melting, sawing, milling and steel wire brushing polishing, to obtain a skin material slab with a specification of a thickness of 380 mm* a width of 890 mm* a length of 5500 mm.

[0098] The chemical composition and weight percentage of the aluminum alloy of 5052-A are as shown in Table 1.

[0099] Table 1, chemical composition and weight percentage of the aluminum alloy of 5052-A

[0100]

[0101] The detection result of the melt is that the slag content is 0.009 mm 2 / Kg, the proportion of the size of the inclusions less than or equal to 3 μm is 95%, the proportion of the size of the inclusions of 4-5 μm is 5%, the hydrogen content is 0.10 mL / 100g-A, and the coarse grain layer is 5-6 mm.

[0102] The specification of the ingot after melting is a thickness of 400 mm* a width of 900 mm* a length of 6000 mm, the head is sawed by 350 mm, the tail is sawed by 150 mm, so that the specification of the ingot after sawing is a thickness of 400 mm* a width of 900 mm* a length of 5500 mm, one large face of the flat ingot is milled by 15 mm, and the other large face is milled by 5 mm, and the opposite two side faces of the flat ingot are milled by 5 mm respectively. The specification of the net ingot after milling is a thickness of 380 mm* a width of 890 mm* a length of 5500 mm.

[0103] Appearance size detection of the flat cast ingot after milling: thickness tolerance is 1mm, large face bending is 1mm, side face bending is 1mm, and end face bending is 1mm.

[0104] The core material is an aluminum alloy with a brand of 5052-B, which is prepared through the preparation steps of melting, sawing, milling and steel wire brushing, and a core material slab with a specification of thickness 600mm* width 890mm* length 5500mm is obtained.

[0105] The chemical composition and weight percentage of the aluminum alloy of 5052-B are as shown in Table 2:

[0106] Table 2, chemical composition and weight percentage of the aluminum alloy of 5052-B

[0107]

[0108] The detection result of the melt is: slag content is 0.010mm 2 / Kg, the proportion of inclusions with a size of less than or equal to 3μm is 93%, the proportion of inclusions with a size of 4-5μm is 7%, the hydrogen content is 0.09mL / 100g-A, and the coarse grain layer is 6-7mm.

[0109] The ingot size after melting is: thickness 630mm* width 900mm* length 6000mm, the head is sawed by 350mm, the tail is sawed by 150mm, so the size of the ingot after sawing is: thickness 630mm* width 900mm* length 5500mm; the two large faces of the flat cast ingot are milled by 15mm respectively, and the opposite two sides of the flat cast ingot are milled by 5mm respectively. The net ingot size after milling is: thickness 600mm* width 890mm* length 5500mm.

[0110] Appearance size detection of the flat cast ingot after milling: thickness tolerance is 1.5mm, large face bending is 1mm, side face bending is 1mm, and end face bending is 1.3mm.

[0111] S2, after the first skin material, the core material and the second skin material are cooled to room temperature, the first skin material, the core material and the second skin material are stacked in order, it should be noted that the large face of the skin material which has been milled by 15mm is in contact with the core material and fixed, and the other large face of the skin material which has been milled by 5mm is outward; then the head, middle and tail gaps between the skin material and the core material are fixed by spot welding, the length of spot welding is 30-40mm, and a composite cast ingot is obtained, at this time, the specification of the composite cast ingot is: thickness 1360mm* width 890mm* length 5500mm.

[0112] S3, after the composite ingot is heated at a metal temperature of 495℃ for 2h, it is discharged, the hot rolling mill emulsion spraying is turned off, the composite ingot is transported between the working roll gaps, when the length of the composite ingot is 1 / 2 to the working roll gap, the movement of the composite ingot is stopped, the upper working roll and the lower working roll are pressed to perform static pressing, when the static pressing rolling force reaches 140T, the working roll is rotated to start the composite to the two ends out of the gap respectively, then the composite ingot is rolled for 5 passes according to the pass reduction amount of 1mm, 3mm, 5mm, 7mm and 9mm respectively, so as to realize the metallurgical welding between the skin material and the core material. After the composite is completed, the hot rolling mill emulsion spraying is turned on, and the conventional rolling is started. When the thickness is 1224mm, the slab is sawed to obtain a composite slab with a specification of thickness 1224mm* width 890mm* length 6111mm.

[0113] S4, after the composite slab is cooled to room temperature, it is cut and milled by 10mm (calculated from the lowest point of the side recess) with a milling machine relative to the two sides, at this time the specification of the composite slab is thickness 1204mm* width 890mm* length 6111mm.

[0114] S5, the composite slab is turned over 90° on the turnover machine, that is, the original side is laid flat as the large face of the composite slab, and the original large face is vertically placed as the side of the composite slab. At this time, the specification of the composite slab is thickness 890mm* width 1204mm* length 6111mm.

[0115] S6, the composite slab is sent into the heating furnace, after being heated at a metal temperature of 490℃ for 2h, it is discharged, and is hot rolled according to the process of the anodizing aluminum alloy strip, the final rolling temperature is 348℃, finally a hot rolled strip with a thickness of 5.0mm and a width of 1164mm is obtained.

[0116] S7, the hot rolled strip is processed according to the process route of “cold rough rolling to 1.25mm→ cleaning→ nitrogen protection intermediate annealing→ cold precision rolling to 1.0mm→ cleaning→ nitrogen protection finish annealing→ edge cutting (edge cutting amount 10mm per side), cleaning and straightening”, and the process parameters and quality requirements of the anodizing aluminum alloy strip, to obtain a finished cold rolled strip with a thickness of 1.0mm and a width of 1144mm.

[0117] S8, the cold rolled strip is cut longitudinally and transversely to obtain a cold rolled strip with a thickness of 1.0mm and a width of 258mm, that is, the following coiled material, among the width, the width of the skin material is 129mm, and the width of the core material is 129mm. The width can be further cut into 15.6 inches, that is, a cold rolled strip with a thickness of 1.0mm, a width of 238mm and a length of 366mm, for use in notebook computer panels.

[0118] S9, the coiled material is anodized and electrolytic colored once, or the coiled material is cut into small pieces first, and then anodized and electrolytic colored, so as to obtain an aluminum-based composite strip with two different colors, such as Figure 8 as shown. Specific embodiment two

[0120] The embodiment provides a preparation method of an aluminum-based composite strip, which comprises the following steps:

[0121] S1, according to the requirements of the aluminum alloy material for anodization, the required skin material and core material are prepared.

[0122] The skin material includes a first skin material and a second skin material, and the skin material is an aluminum alloy with a brand of 1070, which is prepared through the preparation steps of melting, sawing, milling, heating, hot rolling, fixed-length sawing and steel wire brush polishing, to obtain a skin material slab with a specification of a thickness of 380 mm* a width of 990 mm* a length of 5789 mm.

[0123] The chemical composition and weight percentage of the aluminum alloy with 1070 are as shown in Table Three:

[0124] Table Three, chemical composition and weight percentage of the aluminum alloy with 1070

[0125]

[0126] The detection result of the melt is that the slag content is 0.008 mm 2 / Kg, the proportion of the size of the inclusions less than or equal to 3 μm is 98%, the proportion of the size of the inclusions of 4-5 μm is 2%, the hydrogen content is 0.095 mL / 100g-A, and the coarse grain layer is 5-6 mm.

[0127] The specification of the ingot after melting is: thickness 420 mm* width 1000 mm* length 6000 mm, the head is sawed by 350 mm, the tail is sawed by 150 mm, so that the specification of the ingot after sawing is: thickness 420 mm* width 1000 mm* length 5500 mm; one large face of the flat ingot is milled by 15 mm, and the other large face is milled by 5 mm; the opposite two side faces of the flat ingot are milled by 5 mm respectively. The specification of the net ingot after milling is: thickness 400 mm* width 990 mm* length 5500 mm, and the specification after hot rolling is: thickness 380 mm* width 990 mm* length 5789 mm.

[0128] The appearance size detection of the flat ingot after milling is: thickness tolerance is 1.2 mm, large face bending is 1.4 mm, side face bending is 1.9 mm, and end face bending is 1.1 mm.

[0129] The core material is an aluminum alloy with a brand of 5052, which is prepared through the preparation steps of melting, sawing, milling, heating, hot rolling, fixed-length sawing, and steel wire brushing, and has a core material slab with a specification of a thickness of 570 mm* a width of 990 mm* a length of 5789 mm.

[0130] The chemical composition and weight percentage of the aluminum alloy of 5052 are as shown in Table Four:

[0131] Table Two, chemical composition and weight percentage of the aluminum alloy of 5052

[0132]

[0133] The detection result of the melt is that the slag content is 0.011 mm 2 / Kg, the proportion of inclusions with a size of less than or equal to 3 μm is 92%, the proportion of inclusions with a size of 4-5 μm is 8%, the hydrogen content is 0.01 mL / 100g-A, and the coarse grain layer is 6-7 mm.

[0134] The specification of the ingot after melting is: thickness 630 mm* width 1000 mm* length 6000 mm, the head is sawed by 350 mm, the tail is sawed by 150 mm, and the specification of the ingot after sawing is: thickness 630 mm* width 1000 mm* length 5500 mm; the two large faces of the flat ingot are milled by 15 mm respectively, and the opposite two sides of the flat ingot are milled by 5 mm respectively. The specification of the net ingot after milling is: thickness 600 mm* width 990 mm* length 5500 mm, and the specification after hot rolling is: thickness 570 mm* width 990 mm* length 5789 mm.

[0135] The appearance size detection of the flat ingot after milling is: thickness tolerance 1.8 mm, large face bending 1.2 mm, side bending 1.1 mm, and end face bending 1.7 mm.

[0136] S2, after the first skin material, the core material, and the second skin material are cooled to room temperature, the first skin material, the core material, and the second skin material are stacked in order, and it should be noted that the large face of the skin material that has been milled by 15 mm is in contact with the core material, and the other large face of the skin material that has been milled by 5 mm is outward; then the head, the middle, and the tail gaps between the skin material and the core material are fixed by spot welding, and the length of the spot welding is 30-40 mm, to obtain a composite ingot, and at this time, the specification of the composite ingot is: thickness 1330 mm* width 990 mm* length 5789 mm.

[0137] S3, after the composite ingot is heated at a metal temperature of 492℃ for 2h, it is discharged, the hot rolling mill emulsion spraying is turned off, the composite ingot is transported between the working roll gaps, when the length of the composite ingot is 1 / 2 to the working roll gap, the movement of the composite ingot is stopped, the upper working roll and the lower working roll are pressed to perform static pressing, when the static pressing rolling force reaches 135T, the working roll is rotated to start the composite to the two ends out of the gap respectively, then the composite ingot is rolled for 5 passes according to the pass reduction amount of 1mm, 3mm, 5mm, 7mm and 9mm respectively, and the metallurgical welding between the skin material and the core material is realized. After the composite is completed, the hot rolling mill emulsion spraying is turned on, and the conventional rolling is started. When the thickness is 1197mm, the slab is sawed to obtain a composite slab with a specification of thickness 1197mm* width 990mm* length 6433mm.

[0138] S4, after the composite slab is cooled to room temperature, it is cut and milled by 10mm (calculated from the lowest point of the side recess) with a milling machine relative to the two sides, at this time the specification of the composite slab is thickness 1177mm* width 990mm* length 6433mm.

[0139] S5, the composite slab is turned over 90° on the turnover machine, that is, the original side is laid flat as the large face of the composite slab, and the original large face is vertically placed as the side of the composite slab. At this time, the specification of the composite slab is thickness 990mm* width 1177mm* length 6433mm.

[0140] S6, the composite slab is sent into the heating furnace, after being heated at a metal temperature of 499℃ for 2h, it is discharged, and is hot rolled according to the process of the anodizing aluminum alloy strip, the final rolling temperature is 346℃, and finally a hot rolled strip with a thickness of 5.0mm and a width of 1137mm is obtained.

[0141] S7, the hot rolled strip is processed according to the process route of “cold rough rolling to 1.25mm→ cleaning→ nitrogen protection intermediate annealing→ cold precision rolling to 1.0mm→ cleaning→ nitrogen protection finish annealing→ edge cutting (edge cutting amount of 10mm per side), cleaning and straightening”, and the process parameters and quality requirements of the anodizing aluminum alloy strip are processed, and a finished cold rolled strip with a thickness of 1.0mm and a width of 1117mm is obtained.

[0142] S8, the cold rolled strip is cut by longitudinal shearing and longitudinal cutting, the edge cutting amount is 10mm per side, and there is no intermediate strip drawing, a cold rolled strip with a thickness of 1.0mm and a width of 548mm is obtained, that is, the following coiled material, among the width, the width of the skin material is 292mm, and the width of the core material is 256mm. The width can be further cut into the 3C electronic product panel required by the customer.

[0143] S9, the coiled material is anodized and electrolytic colored once, or the coiled material is cut into small pieces first, and then anodized and electrolytic colored, so as to obtain an aluminum-based composite strip with two different colors, such as Figure 9

[0144] The above is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, which is made by using the content of the specification and drawings of the present application, is also included in the patent protection scope of the present application.​

Claims

1. A method for preparing an aluminum-based composite strip, characterized in that, The preparation method of the aluminum-based composite strip includes the following steps: Step S1: Prepare the skin material and the core material separately; wherein, the skin material includes a first skin material and a second skin material, and the constituent elements of the skin material and the constituent elements of the core material have different content ranges for at least one common element; the core material is an aluminum alloy of one grade from 1-series, 3-series, 5-series, 6-series, and 7-series aluminum alloys; the skin material and the core material are aluminum alloys of different series or aluminum alloys of the same series but different grades. Step S2: Stack and fix the first leather material, the core material, and the second leather material in that order to obtain a composite ingot; Step S3: The composite ingot is subjected to a first heating and composite rolling process to obtain a composite slab; wherein, the temperature of the composite ingot is maintained at 490-500℃ during heating. Step S4: Cut off the two opposite sides of the composite slab blank; wherein, when cutting, the cutting starts from the lowest point of the concave part of the side of the composite slab blank, and 10-12mm is cut off from each side of the composite slab blank; Step S5: Flip the cut composite slab blank 90°. Step S6: The composite slab after being flipped is subjected to a second heating and hot rolling to obtain a hot-rolled strip with a thickness of 5.0-8.0 mm; wherein, the temperature of the composite slab during the second heating is 490-500℃, and the final rolling temperature of the hot rolling is 345±5℃; Step S7: The hot-rolled strip is subjected to cold rough rolling, first cleaning, intermediate annealing under nitrogen protection, cold finish rolling, second cleaning, finished annealing under nitrogen protection, edge trimming, third cleaning and straightening in sequence to obtain a cold-rolled strip with a thickness of 0.5-3.0 mm. Step S8: Slit the cold-rolled strip to obtain a coil; wherein the coil includes at least a portion of the width of the sheath and a portion of the width of the core. Step S9: The roll material is sequentially anodized and electrolytically colored to obtain an aluminum-based composite strip.

2. The method for preparing the aluminum-based composite strip as described in claim 1, characterized in that, In step S1, the leather material is prepared by casting, sawing, milling, and wire brush polishing in sequence; or, the leather material is prepared by casting, sawing, milling, heating, hot rolling, fixed-length sawing, and slab wire brush polishing in sequence. The core material is prepared by casting, sawing, milling, and wire brush grinding in sequence; or, the core material is prepared by casting, sawing, milling, heating, hot rolling, fixed-length sawing, and slab wire brush grinding in sequence.

3. The method for preparing the aluminum-based composite strip as described in claim 2, characterized in that, The flat ingots obtained from the outer material and the core material in the melting and casting step both satisfy the following conditions: The slag content is less than or equal to 0.012 mm² / Kg, the size of the inclusions is less than or equal to 5 μm, the hydrogen content is less than or equal to 0.12 mL / 100 g-Al, the coarse grain layer is less than or equal to 8 mm, and the composition is uniform.

4. The method for preparing the aluminum-based composite strip as described in claim 2, characterized in that, After the skin material and the core material are melted and cast to obtain a flat ingot, the head of the flat ingot is cut off by 350-360 mm and the tail is cut off by 150-160 mm. The large surface of the flat ingot obtained by the skin material in the melting and casting step is milled by 15-20 mm close to the core material and by 5-7 mm away from the core material. The large surface of the flat ingot obtained by the core material in the melting and casting step is milled by 15-20 mm close to the first skin material and the large surface is milled by 15-20 mm close to the second skin material. The two opposite sides of the flat ingot obtained by the skin material in the melting and casting step and the two opposite sides of the flat ingot obtained by the core material in the melting and casting step are milled by 5-7 mm respectively.

5. The method for preparing the aluminum-based composite strip as described in claim 4, characterized in that, After the flat ingots obtained from the melting and casting process, the sheath material and the core material, when milled, satisfy the following conditions: Thickness tolerance is less than or equal to 2mm, large surface bending is less than or equal to 2mm, side bending is less than or equal to 2mm, and end face bending is less than or equal to 2mm.

6. The method for preparing the aluminum-based composite strip as described in claim 2, characterized in that, The steel wire brushes used for polishing the leather and core materials during the preparation process have a bristle diameter of 0.3-0.4 mm and an assembly density of 100-120 bristles / cm². The polishing process is equipped with an air tube with compressed air. After polishing, a magnetic rod with a magnetic force greater than or equal to 12000GS is used to remove magnetic materials, and then a towel soaked in D30 cleaning agent is used to wipe away foreign matter.

7. The method for preparing the aluminum-based composite strip as described in claim 1, characterized in that, In step S3, the method for preparing the composite rolling process includes the following steps: Step S31: Hot rolling composite is performed on the heated composite ingot; wherein, hot rolling composite is performed using a hot rolling mill, and the emulsion spraying of the hot rolling mill is turned off before hot rolling composite; Step S32: Transport the composite ingot between the work rolls of the hot rolling mill until half the length of the composite ingot is transported between the work rolls of the hot rolling mill, stop transporting the composite ingot and shut down the hot rolling mill; Step S33: Adjust the work rolls of the hot rolling mill to perform static pressing on the composite ingot; wherein the static pressing rolling force is 120-200T; Step S34: Start the hot rolling mill to perform composite rolling on the composite ingot without both ends detaching from the work rolls to obtain the composite slab; wherein, the composite rolling includes five passes, and the reduction amounts of the five passes are 1mm, 3mm, 5mm, 7mm and 9mm respectively. Step S35: After the composite rolling is completed, the hot rolling mill is turned on for emulsion spraying and rolled again until the composite slab is obtained.

8. The method for preparing the aluminum-based composite strip as described in claim 7, characterized in that, The maximum opening of the upper and lower work rolls in the hot rolling mill is 1700mm; in step S4, the cutting device is a precision saw installed on the roller table of the hot rolling mill, and the maximum opening of the precision saw is 1700mm.

9. The method for preparing the aluminum-based composite strip as described in claim 1, characterized in that, In step S3, the thickness of the core material is defined as H0, the thickness of the sheath material as H1, and the thickness of the composite blank as H3. The thickness of the composite blank satisfies the following formula: H3 / (2H1+H0)≥0.9.

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