Highly thermally conductive air conditioning foil and method for producing the same

Abstract

The present application relates to aluminum alloy manufacturing technology field, provide a kind of high thermal conductivity air conditioning foil, including the following weight parts of component: iron 0.15-0.25 parts, silicon 0.15-0.25 parts, manganese 0.15-0.20 parts, magnesium 0.02-0.06 parts, copper 0.10-0.25 parts, titanium 0.01-0.03 parts, aluminum 85-98 parts, a kind of high thermal conductivity air conditioning foil preparation method, mainly including the following process steps: S1, smelting and refining: the above component is first smelted in smelting furnace, then in stationary furnace refining treatment;S2, cast rolling: the raw material after refining in step S1 is carried out continuous casting and rolling on continuous casting and rolling machine, and electromagnetic field is applied in casting and rolling area, and electromagnetic oscillation treatment is assisted in casting and rolling process;S3, primary cold rolling: the cast rolling roll of 6.0~7.8mm thickness is cold rolled on cold rolling mill, and the aluminum strip with the thickness of 3.4~3.7mm is rolled. By adding nanocrystalline seed material and applying electromagnetic field in casting and rolling area, the aluminum foil prepared has higher thermal conductivity and better strength.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum alloy manufacturing, in particular to a high-thermal-conductivity air conditioner foil and a preparation method thereof. BACKGROUND

[0002] Aluminum is made into aluminum foil for air conditioner heat exchanger heat-conducting fin material due to its advantages of small density, good thermal conductivity, easy processing, no odor, environmental protection and low price. Nowadays, air conditioners are gradually developing towards miniaturization, high efficiency and long service life, so the air conditioner heat exchange fins are also developing towards ultra-thinness and high strength. According to the thickness, it can be divided into thin plates and medium plates, and the GB / T3880-2006 standard stipulates that the thickness below 0.2mm is called aluminum foil. In the 1980s, the thickness of the heat exchange fin was 0.15-0.20mm, and the thickness of the present is only between 0.09 and 0.15mm.

[0003] The existing aluminum foil for air conditioners is generally prepared by hot rolling or cast rolling process. Although the cast rolling process has a simple process flow and low energy consumption, the organization and performance of the product produced thereby are unstable, the foil material is prone to coarse grains, the deformation performance is extremely poor, and cracking is prone to occur, thereby greatly reducing the yield. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a high-thermal-conductivity air conditioner foil and a preparation method thereof, which solves the problem that the aluminum alloy foil is difficult to simultaneously meet the requirements of high thermal conductivity and strength.

[0005] To achieve the above object, the present application is implemented by the following technical scheme: a high-thermal-conductivity air conditioner foil comprising the following components by weight: iron 0.15-0.25 parts, silicon 0.15-0.25 parts, manganese 0.15-0.20 parts, magnesium 0.02-0.06 parts, copper 0.10-0.25 parts, titanium 0.01-0.03 parts, and aluminum 85-98 parts.

[0006] A preparation method of a high-thermal-conductivity air conditioner foil mainly comprises the following process steps:

[0007] S1, melting and refining: the above components are first melted in a melting furnace and then refined in a static furnace;

[0008] S2, cast rolling: the refined raw material in step S1 is continuously cast rolled on a continuous casting and rolling machine, and an electromagnetic field is applied in the cast rolling area, and electromagnetic oscillation treatment is assisted in the cast rolling process;

[0009] S3, primary cold rolling: the cast rolling coil with a thickness of 6.0-7.8mm is cold rolled on a cold rolling mill to an aluminum strip with a thickness of 3.4-3.7mm;

[0010] S4, homogenizing annealing: the aluminum strip with thickness of 3.4-3.7 mm is placed in an annealing furnace for homogenizing annealing, and then cooled to room temperature;

[0011] S5, secondary cold rolling: the aluminum strip after homogenizing annealing is rolled on a cold rolling mill to an aluminum foil with thickness of 0.09-0.15 mm;

[0012] S6, product annealing: the aluminum foil with thickness of 0.09-0.15 mm is placed in an annealing furnace for product annealing, and then cooled to room temperature.

[0013] Preferably, in the step S1, the temperature of the smelting is 755-780℃, and the time is 20-25 minutes, and the temperature of the refining treatment is 755℃-765℃, and the time is 20-25 minutes.

[0014] Preferably, the aluminum melt obtained in the step S2 is transferred to a cast-rolling unit for cast-rolling, and the temperature of the front box is 690-700℃, and the cast-rolling speed is 1200-1300 mm / min, to obtain a cast-rolling coil with thickness of 6.0-7.8 mm, and the same plate difference is ≤0.05 mm, the convexity is 0.01-0.08 mm, the longitudinal difference is ≤0.3 mm, and the thickest point deviates from the center by ≤120 mm.

[0015] Preferably, the homogenizing annealing condition of the cast-rolling blank is 450℃ annealing for 31-35 h, and the product performance annealing condition after cold rolling is 200℃ annealing for 25-28 h.

[0016] Preferably, the specific method of cold rolling is that the cast-rolling product coil is rough-rolled and cold-rolled to 0.09-0.15 mm for longitudinal edge cutting, and then the edge cutting is precisely rolled to the product thickness.

[0017] Preferably, in the step S3, the primary cold rolling is 4-pass cold rolling, and the distribution scheme of each pass is: 6.0-7.8 mm→5.0-6.5 mm→4.0-5.5 mm→3.5-4.5 mm→3.4-3.7 mm.

[0018] Preferably, in the step S5, the secondary cold rolling is 6-pass cold rolling, and the distribution scheme of each pass is: 3.4-3.7 mm→2.4-3.0 mm→2.0-2.5 mm→1.0-1.4 mm→0.55-0.85 mm→0.25-0.35 mm→0.09-0.15 mm.

[0019] Preferably, a metal container with a tightly-wound solenoid is placed at the inlet and outlet of the cast-rolling area, and the tightly-wound solenoid is powered to excite a magnetic field in the cast-rolling area.

[0020] Preferably, in the step S1, nano-crystal seed material is added, and continuous stirring and standing are alternately performed.

[0021] The application provides a high-thermal-conductivity air conditioner foil and a preparation method thereof.

[0022] The application improves the casting and cold rolling process conditions, improves the thermal conductivity and deformation performance of the aluminum foil under the condition of ensuring the mechanical properties, ensures high surface quality and yield, and meets the requirements of the mechanical properties of the aluminum foil forming for air conditioners. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0024] Embodiment one:

[0025] The application provides a high-thermal-conductivity air conditioner foil, and raw material proportions are calculated according to the following weight proportions: iron 0.15 parts, silicon 0.15 parts, manganese 0.15 parts, magnesium 0.02 parts, copper 0.10 parts, titanium 0.01 parts, and aluminum 85 parts.

[0026] The alloy is prepared according to the above-mentioned proportions, and the steps are as follows:

[0027] S1, melting and refining: the above-mentioned components are first melted in a melting furnace, and then refined in a static furnace, the melting temperature is 755 DEG C, the time is 20 minutes, the refining temperature is 755 DEG C, the time is 20 minutes, nano crystal seed material is added, and continuous stirring and cleaning are alternately performed;

[0028] S2, casting: the refined raw material in step S1 is continuously cast on a continuous casting mill, and an electromagnetic field is applied in the casting zone, and an electromagnetic oscillation treatment is assisted in the casting process, one metal container with a tightly wound solenoid is placed at the inlet and outlet of the casting zone, the tightly wound solenoid is energized to excite a magnetic field in the casting zone, and the tightly wound solenoid is energized with 265-295a alternating current to excite a magnetic field with a strength of 29-31mt in the casting zone, forming an electromagnetic oscillation treatment, on the one hand, the dendrites preferentially precipitated in the solidification process are broken, providing a large number of nucleation cores for the later solidification process, further improving the refining effect; on the other hand, the electromagnetic oscillation also increases the fluidity of the alloy melt, realizes the refinement of the aluminum alloy solidification structure and the uniform composition, prevents the appearance of micro-cracks in the cast rolling coil, improves the segregation of the middle layer of the strip, greatly improves the internal quality of the cast rolling slab, and the front box temperature during casting is 690-700℃, the casting speed is 1200-1300mm / min, the cast rolling coil with a thickness of 6.0mm is obtained, and the same plate difference is ≤0.05mm, the middle convexity is 0.01-0.08mm, the longitudinal difference is ≤0.3mm, and the thickest point deviates from the center by ≤120mm;

[0029] S3, primary cold rolling: the 6.0mm thick cast rolling coil is cold rolled on a cold rolling mill to an aluminum strip with a thickness of 3.4mm, the primary cold rolling is 4 passes of cold rolling, and the distribution scheme of each pass is: 6.0mm→5.0mm→4.0mm→3.5mm→3.4mm, and the specific method of cold rolling is: the cast rolling finished coil is rough cold rolled to 0.09-0.15mm for longitudinal edge cutting, and then fine rolling is performed to the finished thickness;

[0030] S4, homogenization annealing treatment: the 3.4mm aluminum strip is placed in an annealing furnace for homogenization annealing, and cooled to room temperature after annealing, and the homogenization annealing conditions of the cast rolling blank are 450℃ for 31-35h;

[0031] S5, secondary cold rolling: the aluminum strip after homogenization annealing is cold rolled on a cold rolling mill to an aluminum foil with a thickness of 0.09mm, the secondary cold rolling is 6 passes of cold rolling, and the distribution scheme of each pass is: 3.4mm→2.4mm→2.0mm→1.0mm→0.55mm→0.25mm→0.09mm;

[0032] S6, finished product annealing treatment: the 0.09mm thick aluminum foil is placed in an annealing furnace for finished product annealing, and cooled to room temperature, and the finished product performance annealing conditions after cold rolling are 200℃ for 25-28h.

[0033] Example two:

[0034] The embodiment of the present application provides a high-thermal-conductivity air conditioner foil, and raw material proportions are calculated according to the following weight proportions: 0.25 parts of iron, 0.25 parts of silicon, 0.20 parts of manganese, 0.06 parts of magnesium, 0.25 parts of copper, 0.03 parts of titanium, and 98 parts of aluminum.

[0035] The alloy is prepared according to the above-mentioned proportions, and the steps are as follows:

[0036] S1, smelting and refining: the above-mentioned components are first smelted in a smelting furnace and then refined in a static furnace, the smelting temperature is 780 DEG C, the time is 25 minutes, the refining temperature is 765 DEG C, the time is 25 minutes, nano seed material is added, and continuous stirring and standing are alternately performed;

[0037] S2, casting and rolling: the raw material after the refining in step S1 is continuously cast and rolled on a continuous casting and rolling machine, an electromagnetic field is applied in a casting and rolling area, electromagnetic oscillation treatment is assisted in the casting and rolling process, one metal container with a tightly-wound solenoid is placed at the inlet and outlet of the casting and rolling area respectively, the tightly-wound solenoid is powered, a magnetic field is excited in the casting and rolling area, the tightly-wound solenoid is powered with 265-295a alternating current, a magnetic field with a strength of 29-31mt is excited in the casting and rolling area, the electromagnetic oscillation treatment is formed, on the one hand, the crystal branches preferentially precipitated in the solidification process are broken, a large number of nucleation cores are provided for the later solidification process, and the refining effect is further improved; on the other hand, the electromagnetic oscillation also increases the fluidity of the alloy melt, realizes the refinement of the solidification structure of the aluminum alloy and the uniform composition, prevents the micro-cracks of the cast and rolled coil, improves the segregation of the middle layer of the strip, greatly improves the internal quality of the cast and rolled slab, the front box temperature is 690-700 DEG C during the casting and rolling, the casting and rolling speed is 1200-1300mm / min, the cast and rolled coil with a thickness of 6.0mm is obtained, the same plate difference is less than or equal to 0.05mm, the middle convexity is 0.01-0.08mm, the longitudinal difference is less than or equal to 0.3mm, and the thickest point deviates from the center by less than or equal to 120mm;

[0038] S3, primary cold rolling: the cast and rolled coil with a thickness of 7.8mm is cold rolled on a cold rolling machine to an aluminum strip with a thickness of 3.7mm, the primary cold rolling is 4 passes of cold rolling, and the distribution scheme of each pass is as follows: 7.8mm→6.5mm→5.5mm→4.5mm→3.7mm;

[0039] S4, homogenization annealing treatment: the aluminum strip with a thickness of 3.7mm is placed in an annealing furnace for homogenization annealing, and is cooled to room temperature after annealing, and the homogenization annealing condition of the cast and rolled slab is 450 DEG C for 31-35h;

[0040] S5, secondary cold rolling: the aluminum strip after homogenization annealing is rolled to an aluminum foil with a thickness of 0.15 mm on a cold rolling mill, the secondary cold rolling is 6 passes of cold rolling, and the allocation scheme of each pass is: 3.7 mm→3.0 mm→2.5 mm→1.4 mm→0.85 mm→0.35 mm→0.15 mm;

[0041] S6, product annealing treatment: the aluminum foil with a thickness of 0.15 mm is placed in an annealing furnace for product annealing, and cooled to room temperature, and the product performance annealing condition after cold rolling is 200℃ annealing for 25-28h.

[0042] Comparative Example 1

[0043] Compared with Example 1, no nano-seed material is added in Comparative Example 1, and the remaining formulation components and preparation methods are the same as those in Example 1.

[0044] Comparative Example 2

[0045] Compared with Example 2, no electromagnetic field is applied in the casting and rolling area in Comparative Example 2, and the remaining formulation components and preparation methods are the same as those in Example 2.

[0046] The tensile strength, yield strength and thermal conductivity of the aluminum alloy materials prepared in Example 1, Example 2 and Comparative Examples 1 and 2 are determined, and the specific data are shown in Table 1.

[0047] Table 1:

[0048]

[0049] As can be seen from the data in Table 1, the aluminum foil prepared in Example 1 and Example 2 has a higher material thermal conductivity and better material mechanical strength performance. In the preparation method of Comparative Example 1, no nano-seed material is added, and the thermal conductivity is relatively lower than that of Example 1 and Example 2, indicating that the addition of nano-seed material has a good effect on improving the thermal conductivity of the material. In the preparation method of Comparative Example 2, no electromagnetic field is applied in the casting and rolling area, and the tensile strength and yield strength obtained are also relatively low, indicating that the preparation method of the present application realizes the preparation of aluminum foil with high thermal conductivity and good strength by adding nano-seed material and applying electromagnetic field in the casting and rolling area.

[0050] Although embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made thereto without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high thermal conductivity air conditioning foil, characterized in that, It comprises the following components in parts by weight: 0.15-0.25 parts iron, 0.15-0.25 parts silicon, 0.15-0.20 parts manganese, 0.02-0.06 parts magnesium, 0.10-0.25 parts copper, 0.01-0.03 parts titanium, and 85-98 parts aluminum; The method for preparing the air conditioning foil includes the following steps: S1. Melting and refining: The above components are first melted in a melting furnace according to the weight parts, wherein the melting temperature is 755-780℃ and the time is 20-25 minutes, and then refined in a settling furnace, wherein the refining temperature is 755℃-765℃ and the time is 20-25 minutes. During the step, nanocrystalline seed material is added, and continuous stirring and settling are carried out alternately. S2, Casting and Rolling: The refined raw material in step S1 is continuously cast and rolled on a continuous casting and rolling mill, and an electromagnetic field is applied in the casting and rolling zone to supplement the casting and rolling process with electromagnetic oscillation treatment. A metal container with a tightly wound solenoid coil is placed at the entrance and exit of the casting and rolling zone, and the tightly wound solenoid coil is energized to generate a magnetic field in the casting and rolling zone. S3, One-time cold rolling: Cold rolling a 6.0-7.8mm thick cast-rolled coil on a cold rolling mill to produce an aluminum strip with a thickness of 3.4-3.7mm; S4. Homogeneous annealing: Place the 3.4-3.7mm aluminum strip in an annealing furnace for homogeneous annealing. The homogeneous annealing conditions for the cast-rolled billet are annealing at 450℃ for 31-35h, and then cooling to room temperature after annealing. S5. Secondary cold rolling: The homogeneously annealed aluminum strip is rolled into aluminum foil with a thickness of 0.09 to 0.15 mm on a cold rolling mill; S6. Finished product annealing: Place the 0.09-0.15mm thick aluminum foil in an annealing furnace for finished product annealing. The finished product annealing conditions are 200℃ for 25-28h, followed by cooling to room temperature.

2. The method for preparing a high thermal conductivity air conditioning foil according to claim 1, characterized in that, The aluminum melt obtained in step S2 is transferred to the casting and rolling mill for casting and rolling. During casting and rolling, the temperature of the front box is 690-700℃, the casting and rolling speed is 1200-1300mm / min, and a cast and rolled coil with a thickness of 6.0-7.8mm is obtained. The thickness difference between the same plate is ≤0.05mm, the convexity is 0.01-0.08mm, the longitudinal difference is ≤0.3mm, and the thickness of the thickest point deviates from the center by ≤120mm.

3. The method for preparing a high thermal conductivity air conditioning foil according to claim 1, characterized in that, In step S3, the cold rolling process consists of four passes, with the following pass distribution: 6.0~7.8mm→5.0~6.5mm→4.0~5.5mm→3.5~4.5mm→3.4~3.7mm.

4. The method for preparing a high thermal conductivity air conditioning foil according to claim 1, characterized in that, In step S5, the secondary cold rolling is a 6-pass cold rolling, and the distribution scheme of each pass is: 3.4~3.7mm→2.4~3.0mm→2.0~2.5mm→1.0~1.4mm→0.55~0.85mm→0.25~0.35mm→0.09~0.15mm.

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