Ultra-thin wall alloy pipe and preparation method and application thereof

Abstract

The present invention relates to an ultra-thin-wall alloy pipe and its preparation method and application. The present invention adds B, Mg and P to the common copper-based alloy. The compound of the three can improve the plastic deformation ability of the copper-based alloy. In order to avoid the copper pipe being easily broken after double-drawing and disc-drawing, the present invention performs an online annealing step of a specific current after obtaining the tube blank, and also selects an outer mold with a smaller angle and a shorter sizing length and a floating core head with a shorter sizing length in the drawing process after annealing, while ensuring dimensional accuracy, reducing tensile resistance. The preparation method of the present invention can realize the production of copper pipes with a wall thickness of 0.05-0.10mm, with a high product qualification rate and practical processing value.

Description

Technical Field

[0001] The invention relates to the technical field of copper alloy thin-walled pipes, and in particular to an ultra-thin-walled alloy pipe and a preparation method and application thereof. Background Art

[0002] Copper tube heat dissipation is the most commonly used heat dissipation method in electronic devices and is widely used in mobile phones, laptops, high-performance and high-power computers and other devices. Its heat dissipation mechanism relies on the excellent thermal conductivity of copper tubes and the phase change heat transfer of internal liquids, which can quickly dissipate the heat generated inside the device to the external environment. In order to meet the needs of highly integrated electronic equipment, R&D personnel have successfully developed ultra-thin thermal conductive copper tubes with a tube thickness of less than 2mm. However, even so, these copper tubes are still difficult to meet the rapid increase in the degree of internal integration of current electronic equipment, occupy a large space, and limit the further integration of electronic equipment. In order to further reduce the thickness of the thermal conductive copper tube, the first task is to reduce its wall thickness.

[0003] At present, the wall thickness of ultra-thin thermal conductive copper tubes on the market is generally around 0.3mm, and some high-quality products can reach 0.25mm, but it is difficult to further thin it. The reduction in wall thickness will significantly increase the difficulty of processing and reduce the product yield. For example, when using existing technology to process thermal conductive copper tubes with a wall thickness of 0.3mm, the breakage rate per 100 meters can be controlled below 0.01%; when the wall thickness is reduced to 0.25mm, the breakage rate rises to 0.05%; if it is further reduced to 0.15mm, the breakage rate is as high as about 6%. Each break requires the machine to be shut down to adjust the equipment parameters, resulting in low processing efficiency and extremely low yield, which cannot meet normal production and sales needs.

[0004] The reduction in the wall thickness of the copper tube will lead to a decrease in its plastic deformation ability, and multiple annealing treatments are required. At the same time, the processing yield and precision of ultra-thin copper tubes are low, which makes it difficult to meet the high quality requirements of high-end electronic products for heat pipes. Research by the technicians of the present invention shows that the problem of high breakage rate in the production of existing ultra-thin wall thermal conductive copper tubes is mainly due to the unreasonable composition design of the copper alloy, which leads to insufficient plastic deformation ability of the material during processing such as stretching, as well as crystal defects and residual stress generated during the drawing process. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide an ultra-thin-wall alloy pipe and a preparation method and application thereof, so as to realize the production of copper pipes with a wall thickness of 0.05-0.10 mm, with a high product qualification rate and practical processing value.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides a method for preparing an ultra-thin-wall alloy tube, wherein the ultra-thin-wall alloy tube comprises the following components in mass percentage: B: 1-2%, Mg: 2-4%, P: 0.5-1%, Zn: 0.1-0.5%, Ni: 0.5-1%, and the balance is Cu and unavoidable impurities;

[0008] The preparation method comprises the following steps:

[0009] S1. Ingredients: Ingredients are prepared according to the formula, wherein B, Mg, P, Zn, Ni and Cu are added in the form of Cu-B master alloy, Cu-Mg master alloy, Cu-P master alloy, metal Zn, metal Ni and electrolytic Cu respectively, the mass percentage of B in the Cu-B master alloy is 5-15%, the mass percentage of Mg in the Cu-Mg master alloy is 10-20%, and the mass percentage of P in the Cu-P master alloy is 10-20%;

[0010] S2, smelting: electrolytic Cu, metal Zn, and metal Ni are placed in a melting furnace for heating and melting, charcoal is added to cover during the smelting process, and the temperature is kept for 30-60 minutes after melting, and the temperature is raised to 1050-1100°C, and Cu-B master alloy is added, and the temperature is raised to 1150-1200°C after it is completely melted, and Cu-P master alloy is added, and the temperature is raised to 1250-1300°C after it is completely melted, and Cu-Mg master alloy is added, and the temperature is kept for 20-30 minutes after it is completely melted, and slag is removed, and cryolite and calcium chloride are added for covering, and the covering thickness of the covering agent is more than 10 cm, and the alloy melt is obtained by heat preservation;

[0011] S3, horizontal continuous casting: horizontal continuous casting of the alloy melt to obtain a tube billet;

[0012] S4, rolling: rolling the tube blank to obtain a rolled tube;

[0013] S5, double drawing: double drawing operation is performed on the rolled tube to obtain a double drawn tube;

[0014] S6, coiling: the double-drawn tube is subjected to coiling process, and then rewinding to obtain a tube blank;

[0015] S7, online annealing: the tube blank is annealed online, the current of online annealing is 1000-1500A, and the speed of online annealing is 80-100m / min;

[0016] S8, drawing: the annealed tube blank is drawn multiple times to obtain an ultra-thin-wall alloy tube with an outer diameter of 2-8 mm and a wall thickness of 0.05-0.1 mm, wherein the multiple drawing is done by a moving core head, the outer surface of the tube blank contacts the outer die, and the inner surface of the tube blank contacts the moving core head.

[0017] The copper-based alloy used in the pipe of the present invention is prepared by first smelting Cu, Zn and Ni, and then adding Cu-B alloy, Cu-P alloy and Cu-Mg alloy in sequence according to the melting point of the metal for smelting. Among them, B has easy diffusibility and can deeply deoxidize the alloy, refine the grain structure, improve the mechanical properties of the product, and greatly improve the strength, elongation at break and hardness of the prepared copper-based alloy. The metal activity of Mg is higher than that of Zn, and it will preferentially combine with oxygen to reduce the burning loss of the material to improve the high-temperature oxidation resistance of the material. By improving the high-temperature oxidation resistance of the material, the performance stability of the material during high-temperature processing can be guaranteed, and the defects caused by oxidation can be reduced, thereby improving the plastic deformation ability of the material. Mg and P deoxidize the melt, which can reduce the content of hydrogen in the copper alloy, avoid the occurrence of hydrogen embrittlement, make the material less likely to break during processing, and maintain good plastic deformation ability. At the same time, the synergistic effect of B, Mg and P can also improve the microstructure of the material, further improve the comprehensive performance of the material, and enable the copper alloy to withstand greater deformation force during processing and not easily break.

[0018] The present invention integrates various metal elements into alloy melt through smelting parameters, adds various raw materials in a specific order, and strictly controls the temperature of each stage, so that the alloy elements are fully fused and evenly distributed, reducing component segregation, and helping the alloy to be uniformly stressed during subsequent plastic deformation, avoiding local stress concentration caused by component differences and affecting plastic deformation. The heating process is covered with cryolite and calcium chloride with a thickness of more than 10 cm. Cryolite can reduce the melting point of the alloy melt, improve fluidity and help refining and purification. Calcium chloride can play the role of fluxing, removing impurities and refining protection. Good melt fluidity allows the alloy to form a more uniform structure during solidification, reduce defects, and lay a good foundation for subsequent plastic deformation. It is beneficial for the alloy to deform smoothly during plastic processing such as cold drawing, and avoid processing difficulties and plasticity reduction problems caused by poor melt quality.

[0019] The copper tube is continuously hardened after double drawing and coil drawing. When drawn to the last few passes, the thin wall makes it very easy to break. In order to reduce the hardness of the copper tube and release the internal stress generated by the processing, the present invention performs an online annealing step after obtaining the tube blank. After annealing, the tube blank has a tensile strength of ≥240MPa, an elongation of ≥40%, and a yield strength of ≥60MPa, that is, it has good plastic deformation ability, so that the tube blank can better withstand deformation and is not easy to break when drawn again. According to the test, when the online annealing current is greater than 1500A, the tensile strength, elongation and yield strength are significantly reduced, indicating that when the online annealing current is in the range of 1000-1500A, the plastic deformation ability of the alloy can be at a better level.

[0020] Preferably, in step S4, the rolling speed is 1-3 m / min.

[0021] Preferably, in step S5, the speed of the double pulling is 60-120 m / min.

[0022] Preferably, in step S6, the speed of coil pulling is 600-1000 m / min, and the speed of rewinding is 200-300 m / min.

[0023] Preferably, in step S7, the online annealing temperature is 300-400° C., and the online annealing time is 30-60 min.

[0024] Preferably, in step S8, the drawing speed is 30-40 m / min.

[0025] Preferably, in step S8, the angle of the outer die is 22-25°, the diameter is 5.0-12.5mm, and the sizing length is 1.0-2.5mm. The common angle of the outer die is 26-27°, but for the tube blanks with a wall thickness of ≤0.2mm in the annealed tube blanks, in order to prevent the streamline from bending sharply during the drawing process, the additional shear deformation is increased, and the tensile force is also increased, thereby increasing the risk of copper tube breakage, the angle of the outer die used in step S8 is adjusted to 22-25°. The sizing length of the outer die is determined according to the diameter of the tube specification. In order to ensure the dimensional accuracy and reduce the tensile resistance, the sizing length of the outer die used in step S8 is adjusted to 1.0-2.5mm. The small diameter of the floating core head is 4.8-12.1mm, the large diameter is 5.15-12.9mm, and the sizing length is 1.0-2.5mm. Similarly, for the tube blank with a wall thickness of ≤0.2 mm in step S7, in order to avoid the copper tube from breaking in the subsequent drawing process and to reduce the drawing resistance, the core head sizing length used in step S8 is adjusted from the common 6 mm-9 mm to 1.0-2.5 mm.

[0026] In a second aspect, the present invention provides an ultra-thin-wall alloy tube, which is prepared by the method for preparing the ultra-thin-wall alloy tube described in the first aspect.

[0027] In a third aspect, the present invention provides a use of the ultra-thin-wall alloy tube described in the second aspect in preparing at least one of a heat dissipation component of an electronic device, a fluid transmission pipeline and a heat exchange pipeline.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The present invention adds B, Mg and P to the common copper-based alloy and adopts a specific ratio for smelting, wherein B uses its easy diffusion to perform deep deoxidation, refine the grains and enhance the mechanical properties. The preferential oxygen binding property of Mg improves the high-temperature oxidation resistance of the alloy, ensures processing stability, reduces defects and improves the plastic deformation ability. Mg and P have good deoxidation effects, avoid hydrogen embrittlement and maintain the plastic deformation ability of the alloy. At the same time, B, Mg and P can synergistically improve the microstructure and properties of the material, so that the plastic deformation ability of the material can be improved during the processing.

[0030] (2) In order to avoid the copper tube from being easily broken after double drawing and coil drawing, to reduce the hardness of the copper tube and release the internal stress generated by the processing, the present invention performs an online annealing step after obtaining the tube blank. After annealing, the tube blank has a tensile strength of ≥240Mpa, an elongation of ≥40%, and a yield strength of ≥60Mpa, that is, it has good plastic deformation ability, so that the tube blank can better withstand deformation and is not prone to breakage when it is drawn again, thereby improving production efficiency.

[0031] (3) In order to further avoid the problem of high breakage rate of copper tubes during the drawing process, after obtaining the annealed tube blank, the present invention selects an outer die with a smaller angle and a shorter sizing length and a floating core head with a shorter sizing length, thereby reducing the tensile resistance while ensuring dimensional accuracy. DETAILED DESCRIPTION

[0032] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0033] Example 1

[0034] A method for preparing an ultra-thin-wall alloy tube, the ultra-thin-wall alloy tube comprising the following components in mass percentage: B: 1.5%, Mg: 3%, P: 0.6%, Zn: 0.2%, Ni: 0.8%, and the balance being Cu and unavoidable impurities;

[0035] The preparation method comprises the following steps:

[0036] S1. Ingredients: Ingredients are prepared according to the formula, wherein B, Mg, P, Zn, Ni and Cu are added in the form of Cu-B master alloy, Cu-Mg master alloy, Cu-P master alloy, metal Zn, metal Ni and electrolytic Cu respectively, the mass percentage of B in the Cu-B master alloy is 10%, the mass percentage of Mg in the Cu-Mg master alloy is 150%, and the mass percentage of P in the Cu-P master alloy is 15%;

[0037] S2, smelting: electrolytic Cu, metal Zn, and metal Ni are placed in a melting furnace and heated to melt. During the smelting process, charcoal is added to cover them. After they are melted, they are kept warm for 40 minutes. The temperature is raised to 1060°C, and Cu-B master alloy is added. After they are completely melted, the temperature is raised to 1100°C. Cu-P master alloy is added. After they are completely melted, the temperature is raised to 1260°C. Cu-Mg master alloy is added. After they are completely melted, the temperature is kept warm for 25 minutes. Slag is removed, and cryolite and calcium chloride are added for covering. The covering thickness of the covering agent is 10 cm. The alloy melt is obtained by keeping warm.

[0038] S3, horizontal continuous casting: horizontal continuous casting of the alloy melt to obtain a tube billet;

[0039] S4, rolling: placing the tube blank on an automatic rolling machine for processing to obtain a rolled tube; wherein the rolling speed is 2m / min;

[0040] S5, double pulling: double pulling operation is performed on the rolled tube to obtain a double pulled tube; wherein the speed of the double pulling is 100m / min;

[0041] S6, coiling: the double-drawn tube is subjected to a coiling process, and then rewinding to obtain a tube blank; wherein the coiling speed is 500 m / min, and the rewinding speed is 250 m / min;

[0042] S7, online annealing: the tube blank is annealed online, the online annealing current is 1200A, the online annealing speed is 90m / min, the online annealing temperature is 350℃, and the online annealing time is 40min;

[0043] S8, drawing: the annealed tube blank is drawn 7 times to obtain an ultra-thin-wall alloy tube with an outer diameter of 5 mm and a wall thickness of 0.08 mm, wherein the multiple drawing is done by a moving core head, the outer surface of the tube blank is in contact with the outer die, and the inner surface of the tube blank is in contact with the moving core head.

[0044] The angle of the outer die used in the 7 stretchings was 25°, the fixed diameter length was 2 mm, the fixed diameter length of the floating core was 2 mm, and the drawing speed was 35 m / min. The dimensions of the pipe, outer die and floating core for each stretching are shown in Table 1.

[0045] Table 1 Parameters of the stretching pass in step S8

[0046]

[0047] Example 2

[0048] A method for preparing an ultra-thin-wall alloy pipe, the ultra-thin-wall alloy pipe comprising the following components in mass percentage: B: 2%, Mg: 4%, P: 1%, Zn: 0.5%, Ni: 1%, and the balance being Cu and unavoidable impurities;

[0049] The preparation method comprises the following steps:

[0050] S1. Ingredients: Ingredients are prepared according to the formula, wherein B, Mg, P, Zn, Ni and Cu are added in the form of Cu-B master alloy, Cu-Mg master alloy, Cu-P master alloy, metal Zn, metal Ni and electrolytic Cu respectively, the mass percentage of B in the Cu-B master alloy is 15%, the mass percentage of Mg in the Cu-Mg master alloy is 20%, and the mass percentage of P in the Cu-P master alloy is 20%;

[0051] S2, smelting: electrolytic Cu, metal Zn, and metal Ni are placed in a melting furnace and heated to melt. During the smelting process, charcoal is added to cover them. After they are melted, they are kept warm for 60 minutes. The temperature is raised to 1100°C, and Cu-B master alloy is added. After they are completely melted, the temperature is raised to 1200°C. Cu-P master alloy is added. After they are completely melted, the temperature is raised to 1300°C. Cu-Mg master alloy is added. After they are completely melted, the temperature is kept warm for 20 minutes. Slag is removed, and cryolite and calcium chloride are added for covering. The covering thickness of the covering agent is 10 cm. The alloy is kept warm to obtain a molten alloy.

[0052] S3, horizontal continuous casting: horizontal continuous casting of the alloy melt to obtain a tube billet;

[0053] S4, rolling: placing the tube blank on an automatic rolling machine for processing to obtain a rolled tube; wherein the rolling speed is 3m / min,

[0054] S5, double drawing: double drawing operation is performed on the rolled tube to obtain a double drawn tube; wherein the speed of the double drawing is 1000m / min;

[0055] S6, coiling: the double-drawn tube is subjected to a coiling process, and then rewinding to obtain a tube blank; wherein the coiling speed is 1000 m / min, and the rewinding speed is 300 m / min;

[0056] S7, online annealing: the tube blank is annealed online, the online annealing current is 1500A, the online annealing speed is 80m / min, the online annealing temperature is 400℃, and the online annealing time is 30min;

[0057] S8, drawing: the annealed tube blank is drawn 10 times to obtain an ultra-thin-wall alloy tube with an outer diameter of 5 mm and a wall thickness of 0.05 mm, wherein the multiple drawing is performed by a moving core head, the outer surface of the tube blank is in contact with the outer die, and the inner surface of the tube blank is in contact with the moving core head.

[0058] The angle of the outer die used in the 10 stretchings was 25°, and the sizing length was 2 mm; the sizing length of the movable core head was 2 mm, and the drawing speed was 30 m / min; the dimensions of the pipe, outer die and movable core head for each stretching are shown in Table 2.

[0059] Table 2 Parameters of the stretching pass in step S8

[0060]

[0061] Example 3

[0062] A method for preparing an ultra-thin-wall alloy tube, the ultra-thin-wall alloy tube comprising the following components in mass percentage: B: 1%, Mg: 2%, P: 0.5%, Zn: 0.1%, Ni: 0.5%, and the balance being Cu and unavoidable impurities;

[0063] The preparation method comprises the following steps:

[0064] S1. Ingredients: Ingredients are prepared according to the formula, wherein B, Mg, P, Zn, Ni and Cu are added in the form of Cu-B master alloy, Cu-Mg master alloy, Cu-P master alloy, metal Zn, metal Ni and electrolytic Cu respectively, the mass percentage of B in the Cu-B master alloy is 5%, the mass percentage of Mg in the Cu-Mg master alloy is 10%, and the mass percentage of P in the Cu-P master alloy is 10%;

[0065] S2, smelting: electrolytic Cu, metal Zn, and metal Ni are placed in a melting furnace and heated to melt. During the smelting process, charcoal is added to cover them. After they are melted, they are kept warm for 30 minutes. The temperature is raised to 1050°C, and Cu-B master alloy is added. After they are completely melted, the temperature is raised to 1150°C. Cu-P master alloy is added. After they are completely melted, the temperature is raised to 1250°C. Cu-Mg master alloy is added. After they are completely melted, the temperature is kept warm for 30 minutes. Slag is removed, and cryolite and calcium chloride are added for covering. The covering thickness of the covering agent is 10 cm. The alloy melt is obtained by keeping the temperature.

[0066] S3, horizontal continuous casting: horizontal continuous casting of the alloy melt to obtain a tube billet;

[0067] S4, rolling: placing the tube blank on an automatic rolling machine for processing to obtain a rolled tube; wherein the rolling speed is 3m / min;

[0068] S5, double pulling: double pulling operation is performed on the rolled tube to obtain a double pulled tube; wherein the speed of the double pulling is 60m / min;

[0069] S6, coiling: the double-drawn tube is subjected to a coiling process, and then rewinding to obtain a tube blank; wherein the coiling speed is 35 m / min, and the rewinding speed is 200 m / min;

[0070] S7, online annealing: the tube blank is annealed online, the online annealing current is 1200A, the online annealing speed is 90m / min, the online annealing temperature is 300℃, and the online annealing time is 30min;

[0071] The parameters of step S8 are the same as those of Example 1, and an ultra-thin-wall alloy tube with an outer diameter of 5 mm and a wall thickness of 0.08 mm is also obtained.

[0072] Comparative Example 1

[0073] The difference between Comparative Example 1 and Example 1 is that B, Mg and P are not added to the alloy of Comparative Example 1, and the missing amounts are made up by the remaining components according to the proportions of Example 1.

[0074] Comparative Example 2

[0075] The difference between Comparative Example 2 and Example 1 is that no B is added to the alloy of Comparative Example 2, and the missing amount is made up by Mg and P according to the proportion of Example 1.

[0076] Comparative Example 3

[0077] The difference between Comparative Example 3 and Example 1 is that: the alloy of Comparative Example 3 does not add Mg, and the missing amount is made up by B and P according to the proportion of Example 1.

[0078] Comparative Example 4

[0079] The difference between Comparative Example 4 and Example 1 is that: P is not added to the alloy of Comparative Example 4, and the missing amount is supplemented by B and Mg according to the ratio of Example 1.

[0080] Comparative Example 5

[0081] The difference between Comparative Example 5 and Example 1 is that: the smelting step in step S2 of Comparative Example 5 is to directly smelt the electrolytic Cu, metal Zn, metal Ni, Cu-B intermediate alloy, Cu-P intermediate alloy and Cu-Mg intermediate alloy at 1260°C until they are all melted, keep warm for 25 minutes, remove the slag, add cryolite and calcium chloride for covering, the covering thickness of the covering agent is 10 cm, and keep warm to obtain an alloy melt.

[0082] Comparative Example 6

[0083] The difference between Comparative Example 6 and Example 1 is that in step S7, the current of online annealing is 950A.

[0084] Comparative Example 7

[0085] The difference between Comparative Example 7 and Example 1 is that in step S7, the current of online annealing is 1550A.

[0086] Performance Testing

[0087] 1. The tensile strength, elongation and yield strength of the tube blanks annealed in step S6 in Examples 1-3 and Comparative Examples 1-7 were tested according to GB / T 228.1-2021 “Tensile test of metallic materials Part 1: Room temperature test method”, as shown in Table 3.

[0088] 2. The alloy pipes of Examples 1-3 and Comparative Examples 1-7 were recorded and compared for the processing fracture rate per 100 meters and the product yield rate. The product yield rate was determined by randomly selecting 20 measuring points per 100 meters of the product to test the thickness of the measuring points and the wall thickness of the pipe. If the thickness of at least 19 measuring points differed from the thickness in the calibration specification by less than 3%, and the wall thickness differed from the wall thickness in the calibration specification by less than 3%, it was recorded as a good product. The data is shown in Table 3.

[0089] Table 3 Performance data of each group of samples

[0090] Group / Performance Tensile strength / MPa Elongation / % Yield strength / Mpa Fracture rate per 100m processing / % Product yield / % Example 1 255 69.0 65 0.022 99.5 Example 2 252 69.5 60 0.024 98.7 Example 3 253 68.4 63 0.024 99.1 Comparative Example 1 187 31.9 47 0.130 75.3 Comparative Example 2 205 37.0 52 0.104 79.6 Comparative Example 3 205 36.6 53 0.105 79.5 Comparative Example 4 201 36.3 51 0.107 79.8 Comparative Example 5 223 44.0 56.4 0.081 89.2 Comparative Example 6 224 44.0 56.0 0.084 89.7 Comparative Example 7 220 44.3 56.8 0.083 90.1

[0091] It can be seen from Table 3 that, in combination with the data of Example 1 and Comparative Examples 1-4, the mechanical properties of the alloy, especially the plastic deformation ability, are significantly improved, and the processing fracture rate per 100 meters is significantly improved, indicating that B, Mg and P have a good synergistic effect, which can synergistically improve the microstructure and performance of the material, improve the plastic deformation ability of the material during the processing, and enable the tube blank to better withstand deformation and not easily break when it is drawn, thereby improving production efficiency.

[0092] Combining the data of Example 1 and Comparative Example 5, it can be seen that in Comparative Example 5, all elements are directly mixed, and the mechanical properties of the alloy are significantly reduced, and the fracture rate of the copper tube during the processing is also significantly reduced. It can be seen that the order of adding the alloy in step S3 in Example 1 helps the alloy to be uniformly stressed during the subsequent plastic deformation process, avoiding local stress concentration caused by composition differences and affecting the plastic deformation.

[0093] Combining the data of Example 1 and Comparative Examples 6-7, it can be seen that the tensile strength, elongation and yield strength of the tube blank after annealing are significantly reduced, which is not suitable for processing. This shows that when the online annealing current is in the range of 1000-1500A, the plastic deformation ability of the alloy can be at a better level.

[0094] In summary, the present invention involves adjusting the alloy formula, adjusting the feeding sequence in the preparation method, adjusting the current of online annealing, and adjusting the size of the outer die and the movable core head for drawing the annealed tube blank. Through this method, the production of copper tubes with an outer diameter of Ø2 to Ø8 mm and a wall thickness of 0.05-0.10 mm can be achieved, the frequent breakage of copper tubes during production by traditional drawing process can be reduced, and production efficiency can be improved.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing an ultra-thin-wall alloy tube, characterized in that: The ultra-thin-wall alloy tube comprises the following components in percentage by mass: B: 1-2%, Mg: 2-4%, P: 0.5-1%, Zn: 0.1-0.5%, Ni: 0.5-1%, and the balance is Cu and unavoidable impurities; The preparation method comprises the following steps: S1. Ingredients: Ingredients are prepared according to the formula, wherein B, Mg, P, Zn, Ni and Cu are added in the form of Cu-B master alloy, Cu-Mg master alloy, Cu-P master alloy, metal Zn, metal Ni and electrolytic Cu respectively, the mass percentage of B in the Cu-B master alloy is 5-15%, the mass percentage of Mg in the Cu-Mg master alloy is 10-20%, and the mass percentage of P in the Cu-P master alloy is 10-20%; S2, smelting: electrolytic Cu, metal Zn, and metal Ni are placed in a melting furnace for heating and melting, charcoal is added to cover during the smelting process, and the temperature is kept for 30-60 minutes after melting, and the temperature is raised to 1050-1100°C, and Cu-B master alloy is added, and the temperature is raised to 1150-1200°C after it is completely melted, and Cu-P master alloy is added, and the temperature is raised to 1250-1300°C after it is completely melted, and Cu-Mg master alloy is added, and the temperature is kept for 20-30 minutes after it is completely melted, and slag is removed, and cryolite and calcium chloride are added for covering, and the covering thickness of the covering agent is more than 10 cm, and the alloy melt is obtained by heat preservation; S3, horizontal continuous casting: horizontal continuous casting of the alloy melt to obtain a tube billet; S4, rolling: rolling the tube blank to obtain a rolled tube; S5, double drawing: double drawing operation is performed on the rolled tube to obtain a double drawn tube; S6, coiling: the double-drawn tube is subjected to coiling process, and then rewinding to obtain a tube blank; S7, online annealing: the tube blank is annealed online, the online annealing current is 1000-1500A, the online annealing speed is 80-100m / min, the online annealing temperature is 300-400℃, and the online annealing time is 30-60min; S8. Drawing: The annealed tube blank is drawn multiple times to obtain an ultra-thin-wall alloy tube with an outer diameter of 2-8 mm and a wall thickness of 0.05-0.1 mm, wherein the multiple drawing is done by a floating core head, the outer surface of the tube blank is in contact with the outer die, and the inner surface of the tube blank is in contact with the floating core head; the angle of the outer die is 22-25°, the diameter is 5.0-12.5 mm, and the sizing length is 1.0-2.5 mm; the small diameter of the floating core head is 4.8-12.1 mm, the large diameter is 5.15-12.9 mm, and the sizing length is 1.0-2.5 mm.

2. The method for preparing the ultra-thin-wall alloy tube according to claim 1, characterized in that: In step S4, the rolling speed is 1-3 m / min.

3. The method for preparing the ultra-thin-wall alloy tube according to claim 1, characterized in that: In step S5, the speed of the double pulling is 60-120 m / min.

4. The method for preparing the ultra-thin-wall alloy tube according to claim 1, characterized in that: In step S6, the speed of coil pulling is 600-1000 m / min, and the speed of rewinding is 200-300 m / min.

5. The method for preparing the ultra-thin-wall alloy tube according to claim 1, characterized in that: In step S8, the pulling speed is 30-40 m / min.

6. An ultra-thin wall alloy pipe, characterized in that: The ultra-thin-wall alloy tube is prepared by the preparation method of any one of claims 1 to 5.

7. Use of the ultra-thin-wall alloy pipe according to claim 6 in the preparation of at least one of a fluid transmission pipe and a heat exchange pipe.

Images