A method of machining a chromium rotating target

Abstract

The present application relates to the technical field of target material preparation, and provides a machining method of a chromium rotating target material, comprising the following steps: (1) adopting a three-jaw hollow chuck to fix the outer surface of the chromium rotating target material, fixing the hollow chuck on a lathe, making the hollow chuck drive the rotating target material to rotate around its axis, and adopting a boring tool to machine the stainless steel inner hole of the chromium rotating target material; (2) using a clamp and a center to fix the inner hole of the chromium rotating target material, fixing the clamp on the lathe, making the clamp drive the rotating target material to rotate around its axis, machining the outer surface of the chromium rotating target material, and using a laser light source to irradiate the cutting position during machining; and (3) air tightness detection, to obtain the chromium rotating target material after machining. The present application adopts the lathe to machine the chromium rotating target material, can improve the machining efficiency and save the machining time under the premise of ensuring the accuracy.

Description

Technical Field

[0001] This invention relates to the field of target preparation technology, specifically to a machining method for a chromium rotary target. Background Technology

[0002] The surface roughness of rotating targets affects the film formation rate and uniformity of magnetron sputtering. Traditional polishing techniques for rotating targets are usually done by manual polishing, which is labor-intensive, results in uneven polishing, and has low polishing precision. Moreover, the powder generated during polishing is easy to disperse everywhere, and long-term inhalation can harm the health of processing personnel.

[0003] To address the aforementioned issues, CN202210211199.7 discloses a method for grinding the surface of a rotating target. This method employs longitudinal grinding for rough machining of the rotating target's surface, followed by transverse cutting for finishing, thereby improving grinding efficiency. The technical solution is as follows: A method for grinding the surface of a rotating target includes the following steps: Step 1: Fixing the rotating target and allowing it to rotate around its axis; Step 2: Adjusting the grinding wheel so that its axis is parallel to the axis of the rotating target, and the distance between the generatrix of the grinding wheel and the axis of the rotating target is greater than the maximum radius of the rotating target; positioning the grinding wheel at one end of the rotating target without coinciding with it; Step 3: Moving the grinding wheel axially along the rotating target, gradually bringing it closer to the other end of the rotating target, wherein the moving distance of the grinding wheel is less than its width; Step 4: Moving the grinding wheel radially along the rotating target, gradually bringing it closer to the rotating target to grind its surface; this method belongs to the field of target processing technology.

[0004] However, while grinding the surface of a rotating target material with a grinding machine offers high precision, it is also inefficient and takes a long time to complete a single rotating target material. Therefore, a processing method that can improve processing efficiency while ensuring processing precision is needed. Summary of the Invention

[0005] This invention provides a machining method for a chromium rotating target. The method primarily utilizes a machine tool. When machining the inner diameter, a hollow chuck is used to fix the chromium rotating target. The hollow chuck is fixed to the machine tool, and the chromium rotating target rotates around its axis to perform the inner diameter machining. When machining the outer diameter, a fixture and a center are used to fix the inner diameters at both ends of the chromium rotating target. The hollow chuck rotates the chromium rotating target around its axis to perform the outer surface machining. During machining, a laser light source is used to irradiate the cutting area, causing localized softening of the chromium rotating target for cutting. This method improves machining efficiency and saves machining time while ensuring accuracy.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A machining method for a chromium rotating target includes the following steps:

[0008] (1) A three-jaw hollow chuck is fixed on the outer surface of the chromium rotating target. The hollow chuck is fixed on a lathe so that the hollow chuck drives the chromium rotating target to rotate around its axis. A boring tool is used to process the stainless steel inner hole of the chromium rotating target.

[0009] (2) Use a fixture and a center to fix the inner hole of the chromium rotating target. Fix the fixture on the lathe and make the fixture drive the rotating target to rotate around its axis to process the outer surface of the chromium rotating target. Use a laser light source to irradiate the cutting area during processing.

[0010] (3) Air tightness test to obtain the machined chromium rotating target.

[0011] In the above-mentioned machining method for a chromium rotating target, in step (1), when machining the inner hole, it includes rough machining of the inner hole. The feed rate of the rough machining of the inner hole is 0.2-0.3mm, including but not limited to 0.2mm, 0.25mm, and 0.3mm. The feed rate is 40-70mm / min, including but not limited to 40mm / min, 50mm / min, 60mm / min, and 70mm / min. The rotation speed of the chuck is 200-300rpm, including but not limited to 200rpm, 210rpm, 220rpm, 230rpm, 240rpm, 250rpm, 260rpm, 270rpm, 280rpm, 290rpm, and 300rpm.

[0012] In the above-mentioned machining method for a chromium rotating target, step (1) further includes internal hole finishing, wherein the feed rate for internal hole finishing is 0.04-0.06mm, including but not limited to 0.04mm, 0.05mm, and 0.06mm, the feed rate is 40-70mm / min, including but not limited to 40mm / min, 50mm / min, 60mm / min, and 70mm / min, and the chuck rotation speed is 300-400rpm, including but not limited to 300rpm, 310rpm, 320rpm, 330rpm, 340rpm, 350rpm, 360rpm, 370rpm, 380rpm, 390rpm, and 400rpm.

[0013] In the above-mentioned machining method for a chromium rotating target, the cutting tool used in step (1) is an anti-vibration boring tool, and the surface of the anti-vibration boring tool is coated with a thin film of aluminum titanium nitride.

[0014] In the above-mentioned machining method for a chromium rotating target, step (2) includes rough machining of the outer surface. The rough machining feed rate is 0.2-0.3 mm, including but not limited to 0.2 mm, 0.25 mm, and 0.3 mm. The feed rate is 70-100 mm / min, including but not limited to 70 mm / min, 80 mm / min, 90 mm / min, and 100 mm / min. The chuck rotation speed is 150-250 rpm, including but not limited to 150 rpm, 160 rpm, 170 rpm, 180 rpm, 190 rpm, 200 rpm, 210 rpm, 220 rpm, 230 rpm, 240 rpm, and 250 rpm.

[0015] In the above-mentioned machining method for a chromium rotating target, step (2) further includes finishing of the outer surface. The feed rate for finishing of the outer surface is 0.05-0.15mm, including but not limited to 0.05mm, 0.1mm, and 0.15mm. The feed rate is 70-100mm / min, including but not limited to 70mm / min, 80mm / min, 90mm / min, and 100mm / min. The chuck speed is 450-550rpm, including but not limited to 450rpm, 460rpm, 470rpm, 480rpm, 490rpm, 500rpm, 510rpm, 520rpm, 530rpm, 540rpm, and 550rpm.

[0016] In the above-mentioned machining method for a chromium rotating target, in step (2), the laser source is 200-500W, including but not limited to 200W, 300W, 400W, and 500W.

[0017] In the above-mentioned machining method for a chromium rotating target, the cutting tool used in step (2) is a ceramic insert.

[0018] In the above-mentioned machining method for a chromium rotating target, in step (2), the fixture is an aluminum alloy chuck.

[0019] A method for preparing a chromium rotating target in step (1) of the machining method for a chromium rotating target as described above includes the following steps:

[0020] (1) The outer diameter surface of the back tube is machined with spiral patterns and sandblasted;

[0021] (2) Weld the bottom surface of the back tube to the sleeve to create a cavity between the back tube and the sleeve. Add chromium powder into the cavity. After welding the upper surfaces of the back tube and the sleeve, degassing, dehydration and vacuuming are performed in sequence.

[0022] (3) Place it in a hot isostatic pressing equipment, set the air pressure to 20-25MPa, the temperature to 635-650℃, and process for 6-8 hours to preform it;

[0023] (4) In the hot isostatic pressing equipment, maintain the air pressure in step (3), set the temperature to 1100-1300℃, process for 6-8 hours and continue hot isostatic pressing.

[0024] (5) Annealing.

[0025] In the above-mentioned method for preparing chromium rotating target, the gas pressure set in step (3) of 20-25MPa includes, but is not limited to, 20MPa, 21MPa, 22MPa, 23MPa, 24MPa, and 25MPa; the temperature set in step (3) of 635-650℃ includes, but is not limited to, 635℃, 640℃, 645℃, and 650℃; and the processing time in step (3) of 6-8h includes, but is not limited to, 6h, 7h, and 8h.

[0026] In the above-mentioned method for preparing chromium rotating target, the temperature set in step (4) is 1100-1300℃, including but not limited to 1100℃, 1200℃, and 1300℃; the processing time is 6-8h, including but not limited to 6h, 7h, and 8h.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] This invention uses a lathe to machine a chromium rotating target. When machining the outer surface, a laser light source is used to irradiate the chromium rotating target, which softens the target locally for cutting. This improves machining efficiency and saves machining time while ensuring accuracy. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the outer surface of the chromium rotating target material processed according to the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] Part 1: Preparation of Chromium Rotating Target Raw Materials

[0032] Unless otherwise specified, the experimental methods used in the embodiments are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0033] Example A1

[0034] A method for preparing a chromium rotating target includes the following steps:

[0035] (1) A stainless steel back tube with a length of 1000mm, an inner diameter of 123mm, and an outer diameter of 133mm is used. Spiral patterns are machined and sandblasted on the outer diameter surface of the back tube. The cross section of the spiral pattern is an equilateral triangle with a diameter of 0.5mm. The thread pitch is 4mm. The surface roughness of the back tube after sandblasting is Ra8μm.

[0036] (2) A 1.5mm thick 45 carbon steel sheath is used to weld the back tube to the bottom surface of the sheath, so that there is a cavity between the back tube and the sheath. Non-spherical chromium powder with a particle size of D50 and 315 mesh is added into the cavity. After welding the upper surface of the back tube and the sheath, degassing, dehydration and vacuuming are carried out at 300℃ for 6 hours.

[0037] (3) Place it in a hot isostatic pressing equipment, set the air pressure to 20MPa, the temperature to 650℃, and process for 6 hours to preform it;

[0038] (4) In the hot isostatic pressing equipment, maintain the air pressure in step (3), set the temperature to 1200℃, process for 6 hours and continue hot isostatic pressing.

[0039] (5) Annealing.

[0040] Example A2

[0041] It is basically the same as Example A1, except that the air pressure is set to 20MPa and the temperature to 635℃ in step (3).

[0042] Example A3

[0043] It is basically the same as Example A1, except that the air pressure is set to 25MPa and the temperature to 635℃ in step (3).

[0044] Example A4

[0045] It is basically the same as Example A1, except that the air pressure is set to 25MPa and the temperature to 650℃ in step (3).

[0046] Example A5

[0047] It is basically the same as Example A1, except that the processing time in step (3) is 8 hours.

[0048] Example A6

[0049] It is basically the same as Example A1, except that sandblasting is not performed in step (1).

[0050] Example A7

[0051] It is basically the same as Example A1, except that the chromium powder in step (2) is 200 mesh.

[0052] Example A8

[0053] It is basically the same as Example A1, except that the chromium powder in step (2) is 400 mesh.

[0054] Comparative Example A1

[0055] It is basically the same as Example A1, except that step (3) is not performed and the air pressure in step (4) is 20 MPa.

[0056] Comparative Example A2

[0057] It is basically the same as Example A1, except that in step (3), the pre-forming temperature is 600°C.

[0058] Comparative Example A3

[0059] It is basically the same as Example A1, except that in step (3), the pre-forming temperature is 700°C.

[0060] Comparative Example A4

[0061] It is basically the same as Example A1, except that in step (3), the pre-forming temperature is 640°C and the treatment time is 3h.

[0062] Comparative Example A5

[0063] It is basically the same as Example A1, except that step (3) is not performed and the air pressure in step (4) is 60 MPa.

[0064] Comparative Example A6

[0065] It is basically the same as Example A1, except that step (3) is not performed and the air pressure in step (4) is 100MPa.

[0066] The tubular targets prepared by the methods described in Examples A1-8 and Comparative Examples A1-5 were subjected to performance tests, and the results are shown in Table 1.

[0067] Table 1

[0068]

[0069]

[0070] Part Two: Machining of Chromium Rotary Targets

[0071] Unless otherwise specified, the experimental methods used in the embodiments are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0072] Example B1

[0073] The chromium rotary target material machined in this embodiment B1 is the chromium rotary target material formed using the method of embodiment A1 in the first part.

[0074] refer to Figure 1 A machining method for a chromium rotating target includes the following steps:

[0075] (1) A three-jaw hollow chuck is fixed on the outer surface of the chromium rotating target 1. The hollow chuck is fixed on a lathe so that the hollow chuck rotates the chromium rotating target 1 around its axis. A boring tool with a thin film of aluminum titanium nitride on its surface is used to rough machine the stainless steel inner hole of the chromium rotating target 1. The rough machining feed rate of the inner hole is 0.25 mm, the feed rate is 50 mm / min, and the chuck speed is 240 rpm. Then the inner hole is finished. The finishing feed rate of the inner hole is 0.05 mm, the feed rate is 50 mm / min, and the chuck speed is 350 rpm.

[0076] (2) Use aluminum alloy chuck 2 and center 3 to fix the inner hole of chromium rotating target 1. Fix aluminum alloy chuck 2 on the lathe so that aluminum alloy chuck 2 drives chromium rotating target 1 to rotate around its axis. Use ceramic inserts to rough machine the outer surface of chromium rotating target 1. The rough machining feed rate of the outer surface is 0.25mm, the feed rate is 80mm / min, and the chuck speed is 200rpm. Then perform finishing machining of the outer surface. The feed rate is 0.1mm, the feed rate is 80mm / min, and the chuck speed is 500rpm. Use a 300W laser light source to irradiate the cutting area during machining.

[0077] (3) Air tightness test to obtain the machined chromium rotating target.

[0078] In this embodiment B1, in step (1), the inner diameter of the three-jaw hollow chuck is larger than the outer diameter of the chromium rotating target. Therefore, the hollow chuck can accommodate the chromium rotating target in the inner hole, so that the three-jaw hollow chuck can clamp 1 / 2 of the length of the chromium rotating target and provide stable support.

[0079] In this embodiment B1, in step (2), the aluminum alloy chuck can prevent scratches on the already machined inner diameter surface of the back tube.

[0080] In this embodiment B1, the role of the laser source in step (2) is to reduce the hardness of the chromium rotating target surface so that it has good cutting performance.

[0081] Example B2

[0082] This is basically the same as Example B1, except that the chromium rotating target machined in Example B2 is the chromium rotating target formed by the method of Example A2 in the first part. In step (2), the feed rate for roughing the outer surface is 70 mm / min, the chuck speed is 150 rpm, the feed rate for finishing the outer surface is 70 mm / min, the chuck speed is 450 rpm, and the laser source is 200W.

[0083] Example B3

[0084] This is basically the same as Example B1, except that the chromium rotating target machined in Example B3 is the chromium rotating target formed by the method in Example A3 in the first part. In step (2), the roughing feed rate of the outer surface is 100 mm / min, the chuck speed is 250 rpm, the finishing feed rate of the outer surface is 100 mm / min, the chuck speed is 550 rpm, and the laser source is 500W.

[0085] Example B4

[0086] This is basically the same as Example B1, except that the chromium rotating target machined in Example B4 is the chromium rotating target formed by the method in Example A4 in the first part. In step (2), the feed rate for rough machining of the outer surface is 70 mm / min, the chuck speed is 150 rpm, the feed rate for finishing machining of the outer surface is 70 mm / min, the chuck speed is 450 rpm, and the laser source is 500W.

[0087] Example B5

[0088] This is basically the same as Example B1, except that the chromium rotating target machined in Example B5 is the chromium rotating target formed by the method in Example A1 in the first part. In step (2), the roughing feed rate of the outer surface is 100 mm / min, the chuck speed is 250 rpm, the finishing feed rate of the outer surface is 100 mm / min, the chuck speed is 550 rpm, and the laser source is 200W.

[0089] Comparative Example B1

[0090] This is basically the same as Example B1, except that the chromium spindle target machined in Comparative Example B1 is the chromium spindle target formed by the method of Example A1 in the first part. In step (2), laser light source irradiation is not performed.

[0091] Comparative Example B2

[0092] Similar to Example B1, except that the chromium rotating target machined in Comparative Example B2 is the chromium rotating target formed by the method of Example A1 in Part 1. In step (2), the feed rate for roughing the outer surface is 70 mm / min, the chuck speed is 150 rpm, the feed rate for finishing the outer surface is 70 mm / min, the chuck speed is 450 rpm, and no laser light source irradiation is performed.

[0093] Comparative Example B3

[0094] This is basically the same as Example B1, except that the chromium rotating target machined in Comparative Example B3 is the chromium rotating target formed by the method of Example A1 in Part 1. In step (2), the feed rate for rough machining of the outer surface is 100 mm / min, the chuck speed is 250 rpm, the feed rate for finish machining of the outer surface is 100 mm / min, the chuck speed is 550 rpm, and no laser light source irradiation is performed.

[0095] Comparative Example B4

[0096] This is basically the same as Example B1, except that the chromium rotating target machined in Comparative Example B4 is the chromium rotating target formed by the method of Example A1 in Part 1. In step (2), the feed rate for roughing the outer surface is 70 mm / min, the chuck speed is 250 rpm, the feed rate for finishing the outer surface is 70 mm / min, the chuck speed is 550 rpm, and no laser light source irradiation is performed.

[0097] Comparative Example B5

[0098] Similar to Example B1, except that the chromium rotating target machined in Comparative Example B5 is the chromium rotating target formed by the method of Example A1 in Part 1. In step (2), the feed rate for roughing the outer surface is 100 mm / min, the chuck speed is 150 rpm, the feed rate for finishing the outer surface is 100 mm / min, the chuck speed is 450 rpm, and no laser light source irradiation is performed.

[0099] Chromium rotating targets were machined using the machining methods described in Examples B1-5 and Comparative Examples B1-5 in Part II. The inner diameter of the targets was machined from D123 to D125, and the outer diameter was machined from D160 to D156. The resulting chromium tubular targets were then subjected to performance tests, and the results are shown in Table 2.

[0100] Table 2

[0101] Surface roughness (μm) Bonding rate of Cr material to back tube (%) Example B1 1.6 99 Example B2 1.8 99 Example B3 1.83 98 Example B4 2 96 Example B5 1.83 96 Comparative Example B1 6 97 Comparative Example B2 6.3 98 Comparative Example B3 6.81 96 Comparative Example B4 5.5 96 Comparative Example B5 6.33 97

[0102] Results Analysis: The results show that the present invention uses a lathe to machine a chromium rotating target. During the machining of the outer surface, laser irradiation reduces the surface hardness of the target, improving machining efficiency and achieving higher precision. The results of Examples B1-B5 and Comparative Examples B1-B5 show that the present invention uses a 200-500W laser light source to achieve higher precision on the target's outer surface. However, excessively high laser power leads to higher temperatures on the target, significantly reducing surface hardness and resulting in lower precision. Conversely, excessively low laser power results in very low temperatures on the target, failing to reduce surface hardness and also leading to low precision. While high feed rates and high chuck speeds improve machining efficiency, they decrease precision. The above results indicate that the machining method of the present invention is not related to the bonding rate between Cr and the back tube.

Claims

1. A machining method for a chromium rotating target, characterized in that, Includes the following steps: (1) A three-jaw hollow chuck is fixed on the outer surface of the chromium rotating target. The hollow chuck is fixed on a lathe so that the hollow chuck drives the chromium rotating target to rotate around its axis. A boring tool is used to process the stainless steel inner hole of the chromium rotating target. (2) Use a fixture and a center to fix the inner hole of the chromium rotating target, fix the fixture on the lathe, and make the fixture drive the rotating target to rotate around its axis to process the outer surface of the chromium rotating target. During processing, use a laser light source to irradiate the cutting area. (3) Air tightness test to obtain the machined chromium rotating target; The preparation method of the chromium rotating target in step (1) is as follows, including the following steps: (101) The outer diameter surface of the back tube is machined with spiral patterns and sandblasted; (102) Weld the bottom surface of the back tube to the sleeve to create a cavity between the back tube and the sleeve. Add chromium powder into the cavity. After welding the upper surfaces of the back tube and the sleeve, degassing, dehydration and vacuuming are performed in sequence. (103) Place it in a hot isostatic pressing equipment, set the air pressure to 20-25MPa, the temperature to 635-650℃, and process for 6-8 hours to preform; (104) In the hot isostatic pressing equipment, maintain the air pressure in step (103), set the temperature to 1100-1300℃, process for 6-8 hours and continue hot isostatic pressing; (105) Annealing.

2. The machining method for a chromium rotating target according to claim 1, characterized in that, In step (1), the machining of the inner hole includes rough machining of the inner hole. The feed rate of the rough machining of the inner hole is 0.2-0.3mm, the feed speed is 40-70mm / min, and the rotation speed of the chuck is 200-300RPM.

3. The machining method for a chromium rotating target according to claim 2, characterized in that, Step (1) also includes internal hole finishing, wherein the feed rate for internal hole finishing is 0.04-0.06mm, the feed rate is 40-70mm / min, and the chuck rotation speed is 300-400RPM.

4. The machining method for a chromium rotating target according to claim 1, characterized in that, The cutting tool used in step (1) is an anti-vibration boring tool, and the surface of the blade of the anti-vibration boring tool is coated with a thin film of aluminum titanium nitride.

5. The machining method for a chromium rotating target according to claim 1, characterized in that, In step (2), the outer surface is machined, including rough machining of the outer surface. The rough machining feed rate is 0.2-0.3 mm, the feed rate is 70-100 mm / min, and the chuck rotation speed is 150-250 RPM.

6. The machining method for a chromium rotating target according to claim 5, characterized in that, Step (2) also includes surface finishing, wherein the feed rate for surface finishing is 0.05-0.15mm, the feed speed is 70-100mm / min, and the chuck speed is 450-550RPM.

7. The machining method for a chromium rotating target according to claim 1, characterized in that, In step (2), the laser source is 200-500W.

8. The machining method for a chromium rotating target according to claim 1, characterized in that, The cutting tool used in step (2) is a ceramic blade.

9. The machining method for a chromium rotating target according to claim 1, characterized in that, In step (2), the clamp is an aluminum alloy chuck.

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