High-purity oxygen-free copper rotating target tube and preparation method thereof

Abstract

The invention discloses a high-purity oxygen-free copper rotating target material pipe and a preparation method thereof, the preparation method comprises the steps of heating extrusion, acid liquor cleaning, stretching, straightening and the like, and finally the high-purity oxygen-free copper rotating target material pipe with the pipe diameter being 178 + / -1 mm, the wall thickness being 27.5 + / -1 mm, the hardness being 80-100 HV, the length being larger than or equal to 3010 mm and the average grain size being smaller than 60 microns is obtained. According to the method, a low-temperature rapid heating method is adopted firstly, growth of oxygen-free copper ingot crystal grains is inhibited, the crystal grains are fine and uniform, and the structure uniformity is better; then, the tensile deformation is controlled through extrusion, diameter-reducing stretching and wall-reducing stretching, so that the dimensional tolerance and tensile deformation are reduced, meanwhile, the internal structure and performance of metal are improved, defects are reduced, and the hardness of the pipe is synchronously improved in combination with refined grains; and meanwhile, the straightness of the pipe is ensured by controlling the stretching machining rate through a stretching method, so that the problem that the average grain size, dimensional tolerance, hardness and straightness of the target pipe are difficult to control is solved.

Description

Technical Field

[0001] The invention relates to the technical field of nonferrous metal processing, and in particular to a high-purity oxygen-free copper rotary target tube and a preparation method thereof. Background Art

[0002] High-purity oxygen-free copper with the copper grade of TU00 is a high-quality electrolytic copper material with excellent electrical conductivity, thermal conductivity and corrosion resistance. It is widely used in electronics, electrical, communications, aerospace and other fields. High-purity oxygen-free copper rotating target tube is a high-purity, high-precision oxygen-free copper tube with a purity of up to 99.99%. It has fine and uniform grains and a low erosion rate during sputtering coating. Therefore, it is widely used as a key material in the fields of semiconductor manufacturing, flat panel displays and touch panels. However, due to its small dimensional tolerance, the wall thickness uniformity and straightness requirements of the finished tube are high, and the hardness requirement is ≤100HV. The existing extrusion process has a high eccentricity of the finished product and many surface defects of the tube, which can no longer meet the product demand. Summary of the invention

[0003] The invention provides a method for preparing a high-purity oxygen-free copper rotating target tube. By changing the processing technology and adding two stretching passes, the eccentricity and straightness of the finished tube can be ensured while eliminating the surface defects of the tube.

[0004] The present invention adopts the following technical solution: A method for preparing a high-purity oxygen-free copper rotating target tube comprises the following steps: (1) The oxygen-free copper ingot is heated to 710-720°C within 40 minutes and then extruded into a billet tube, and then the extruded billet tube is cooled to <60°C within 3 minutes by a full water seal water cooling method to obtain a cooled billet tube; (2) cleaning the oxide on the surface of the billet tube after cooling in step (1) with an acid solution to obtain a clean billet tube; (3) The clean billet tube obtained in step (2) is stretched twice by a stretching machine, and straightened while being stretched to obtain a high-purity oxygen-free copper rotating target tube.

[0005] Furthermore, the oxygen-free copper ingot in step (1) is a TU00 oxygen-free copper ingot with a diameter of φ440±1 mm.

[0006] Furthermore, the oxygen-free copper ingot of step (1) is heated by a medium frequency induction furnace.

[0007] Furthermore, a 55MN forward extruder is used during extrusion in step (1).

[0008] Furthermore, the lubricating medium of the extrusion die and the piercing needle of the extruder is a lubricant mixed with asphalt and graphite in a ratio of 9:1.

[0009] Furthermore, in step (1), the cooling water inlet temperature during full water-seal cooling is less than 30° C., and the cooling water is dynamically circulated.

[0010] Furthermore, the acid solution used for cleaning in step (2) is 16-18% H2SO4, and the pickling time is 30-60 minutes.

[0011] Furthermore, the stretching in step (3) adopts a 100T hydraulic drawing machine; the two stretching steps are respectively a diameter reducing stretching and a wall reducing stretching, the diameter reducing stretching is performed until the finished tube diameter is Φ178±1mm, and the wall reducing stretching is performed until the finished tube wall thickness is 27.5±1mm.

[0012] Furthermore, in step (3), the stretching die of the stretching machine is made of YG12, and the stretching die includes a transition zone, a deformation zone and a sizing zone, wherein the length of the transition zone H1 = 28 mm, the length of the deformation zone H2 = 20 mm, and the length of the sizing zone H3 = 15 mm.

[0013] The high-purity oxygen-free copper rotating target tube prepared by the preparation method has a diameter of 178±1 mm, a wall thickness of 27.5±1 mm, a hardness of 80-100 HV, a length of ≥3010 mm, and an average grain size of <60 μm.

[0014] The beneficial effects of the present invention are as follows: The preparation method of the high-purity oxygen-free copper rotating target tube provided by the present invention includes the steps of heating extrusion, acid cleaning, stretching and straightening, and finally obtains a high-purity oxygen-free copper rotating target tube with a tube diameter of 178±1mm, a wall thickness of 27.5±1mm, a hardness of 80-100HV, a length ≥3010mm, and an average grain size of <60μm. The present invention first adopts a low-temperature rapid heating method to inhibit the growth of oxygen-free copper ingot grains, reduce the presence of large-sized grains, make the grains fine and uniform, and have better organizational uniformity; then, the tensile deformation is controlled by extrusion, diameter reduction stretching and wall reduction stretching to reduce the dimensional tolerance, and the internal organization and performance of the metal are improved while the tensile deformation is performed, and the generation of defects is reduced, and the hardness of the tube is simultaneously improved in combination with the refined grains. At the same time, the use of the stretching method to control the stretching processing rate also ensures the straightness of the tube, thereby solving the problem of difficult control of the average grain size, dimensional tolerance, hardness and straightness of the target tube, realizing the continuous and stable production of high-precision rotating target tubes, and improving the quality and pass rate of high-purity oxygen-free copper target tubes. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a physical picture of a billet tube extruded by an extruder in Example 1 of the present invention; Figure 2 This is a physical picture of the high-purity oxygen-free copper rotating target tube product in Example 1 of the present invention; Figure 3It is a schematic diagram of the stretching die structure of the present invention. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with embodiments: In the following embodiments of the present invention, the extruder is a 55MN forward extruder provided by the purchaser PRESEZZI, and the lubricating medium for the extrusion die and the piercing needle of the extruder is a lubricant mixed with asphalt and graphite in a ratio of 9:1. The stretching adopts a 100T hydraulic drawing machine, and the stretching die of the stretching machine is made of YG12. The stretching die of the stretching machine is modified from the original die, such as Figure 3 As shown, specifically, the transition zone length H1 is increased from 25mm to 28mm, the deformation zone length H2 is increased from 16mm to 20mm, and the sizing zone length H3 is increased from 10mm to 15mm. Combined with process adjustment, the processing rate is appropriately increased to ensure the straightness of the finished pipe.

[0017] Example 1 A method for preparing a high-purity oxygen-free copper rotating target tube comprises the following steps: (1) Using the method of low-temperature rapid heating, a TU00 oxygen-free copper ingot with a diameter of φ440 mm was sent into a medium-frequency induction furnace for heating for 36 minutes. When the temperature of the TU00 oxygen-free copper ingot was measured to be 710°C, it was sent into an extruder and extruded into the following Figure 1 The Φ179×29mm billet tube shown in the figure is then sent into a dynamic circulation water tank with an inlet temperature of 25°C for water cooling by a full water seal water cooling method, and the billet tube is cooled to 40°C within 2 minutes to obtain a cooled billet tube; (2) using 16% H2SO4 to pickle the oxide on the surface of the billet tube after cooling in step (1), pickling for 58 minutes to obtain a clean billet tube, and using an angle grinder to grind the surface defects of the clean billet tube; (3) The clean billet tube obtained in step (2) is stretched twice by a stretching machine. In the first diameter-reducing stretching process, the tube is stretched from Φ179×29 mm to Φ177×28 mm. In the second wall-reducing stretching process, the tube is stretched from Φ177×28 mm to Φ177×26.5 mm. Straightening is performed while stretching to increase the processing rate to ensure the straightness of the finished tube. After stretching and straightening, the tube is obtained as shown in FIG. Figure 2 As shown, the high-purity oxygen-free copper rotating target tube has specifications of Φ177×26.5×3010mm, hardness of 80HV, and average grain size of 55μm.

[0018] Example 2 A method for preparing a high-purity oxygen-free copper rotating target tube comprises the following steps: (1) Using the method of low-temperature rapid heating, a TU00 oxygen-free copper ingot with a diameter of φ439 mm was sent into a medium-frequency induction furnace for heating for 38 minutes. When the temperature of the TU00 oxygen-free copper ingot was measured to be 715°C, it was sent to an extruder for extrusion into a Φ180×30 mm billet tube. The extruded billet tube was then sent into a dynamic circulating water tank with an inlet temperature of 26°C for water cooling by a full water seal method, and the billet tube was cooled to 47°C within 2 minutes to obtain a cooled billet tube; (2) using 18% H2SO4 to pickle the oxide on the surface of the billet tube after cooling in step (1), pickling for 30 minutes to obtain a clean billet tube, and using an angle grinder to grind the surface defects of the clean billet tube; (3) The clean billet tube obtained in step (2) is stretched twice by a stretching machine. In the first diameter-reducing stretching process, the tube is stretched from Φ180×30 mm to Φ178×29 mm. In the second wall-reducing stretching process, the tube is stretched from Φ178×29 mm to Φ178×27.5 mm. Straightening is performed while stretching to increase the processing rate to ensure the straightness of the finished tube. After stretching and straightening, a high-purity oxygen-free copper rotary target tube with a specification of Φ178×27.5×3020 mm, a hardness of 90 HV, and an average grain size of 58 μm is obtained.

[0019] Example 3 A method for preparing a high-purity oxygen-free copper rotating target tube comprises the following steps: (1) Using the method of low-temperature rapid heating, a TU00 oxygen-free copper ingot with a diameter of φ440 mm was sent into a medium-frequency induction furnace for heating for 39 minutes. When the temperature of the TU00 oxygen-free copper ingot was measured to be 720°C, it was sent into an extruder and extruded into a Φ181×31 mm billet tube. The extruded billet tube was then sent into a dynamic circulation water tank with an inlet temperature of 20°C for water cooling by a full water seal, and the billet tube was cooled to 40°C within 2 minutes to obtain a cooled billet tube; (2) using 18% H2SO4 to pickle the oxide on the surface of the billet tube after cooling in step (1), pickling for 32 minutes to obtain a clean billet tube, and using an angle grinder to grind the surface defects of the clean billet tube; (3) The clean billet tube obtained in step (2) is stretched twice by a stretching machine. In the first diameter-reducing stretching process, the tube is stretched from Φ181×31 mm to Φ179×30 mm. In the second wall-reducing stretching process, the tube is stretched from Φ179×30 mm to Φ179×28.5 mm. Straightening is performed while stretching to increase the processing rate to ensure the straightness of the finished tube. After stretching and straightening, a high-purity oxygen-free copper rotary target tube with a specification of Φ179×28.5×3030 mm, a hardness of 100 HV, and an average grain size of 54 μm is obtained.

Claims

1. A method for preparing a high-purity oxygen-free copper rotating target tube, characterized in that: The following steps are involved: (1) The oxygen-free copper ingot is heated to 710-720°C within 40 minutes and then extruded into a billet tube, and then the extruded billet tube is cooled to <60°C within 3 minutes by a full water seal water cooling method to obtain a cooled billet tube; (2) cleaning the oxide on the surface of the billet tube after cooling in step (1) with an acid solution to obtain a clean billet tube; (3) The clean billet tube obtained in step (2) is stretched twice by a stretching machine, and straightened while being stretched to obtain a high-purity oxygen-free copper rotating target tube.

2. The method for preparing a high-purity oxygen-free copper rotating target tube according to claim 1, characterized in that: The oxygen-free copper ingot in step (1) is a TU00 oxygen-free copper ingot with a diameter of φ440±1 mm.

3. The method for preparing a high-purity oxygen-free copper rotating target tube according to claim 2, characterized in that: The oxygen-free copper ingot of step (1) is heated by a medium frequency induction furnace.

4. The method for preparing a high-purity oxygen-free copper rotating target tube according to claim 3, characterized in that: In step (1), a 55MN forward extruder is used for extrusion.

5. The method for preparing a high-purity oxygen-free copper rotating target tube according to claim 4, characterized in that: The lubricating medium of the extrusion die and the piercing needle of the extruder is a lubricant mixed with asphalt and graphite in a ratio of 9:

1.

6. The method for preparing a high-purity oxygen-free copper rotating target tube according to claim 5, characterized in that: In step (1), the cooling water inlet temperature during full water seal cooling is less than 30°C, and the cooling water is dynamically circulated.

7. The method for preparing a high-purity oxygen-free copper rotating target tube according to claim 6, characterized in that: The acid solution used for cleaning in step (2) is 16-18% H2SO4, and the pickling time is 30-60 minutes.

8. The method for preparing a high-purity oxygen-free copper rotating target tube according to claim 7, characterized in that: Step (3) stretching adopts a 100T hydraulic drawing machine; the two stretching steps are diameter reducing stretching and wall reducing stretching, the diameter reducing stretching is until the finished tube diameter is Φ178±1mm, and the wall reducing stretching is until the finished tube wall thickness is 27.5±1mm.

9. The method for preparing a high-purity oxygen-free copper rotating target tube according to claim 8, characterized in that: In step (3), the stretching die of the stretching machine is made of YG12, and the stretching die includes a transition zone, a deformation zone and a sizing zone, wherein the length of the transition zone H1 = 28 mm, the length of the deformation zone H2 = 20 mm, and the length of the sizing zone H3 = 15 mm.

10. A high-purity oxygen-free copper rotating target tube prepared by the preparation method according to any one of claims 1 to 9, wherein the target tube has a diameter of 178±1 mm, a wall thickness of 27.5±1 mm, a hardness of 80-100 HV, a length of ≥3010 mm, and an average grain size of <60 μm.

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