A method for stress relief shaping of brittle metal targets

Abstract

The present application relates to a kind of brittle metal target stress relieving shaping method, the stress relieving shaping method includes: on the target surface of target assembly, then four times shaping is carried out to target assembly;The diameter of pad in the four times shaping process gradually increases.This application is shaped by using pad with gradually increasing diameter combined with corresponding pressure, and the target is shaped with multiple gradients, which ensures that the flatness of the target is less than 0.1 mm, and there is no distortion, collapse phenomenon;Multiple shaping is beneficial to the release of internal residual welding stress, controls the deformation of product in subsequent processing, and improves product yield.

Description

Technical Field

[0001] This invention belongs to the field of target material shaping technology, and particularly relates to a stress-relieving shaping method for brittle metal targets. Background Technology

[0002] In the integrated circuit industry, sputtering target assemblies consist of a target material that meets sputtering performance requirements and a backplate bonded to the target material with a certain strength. Brittle metal targets are often used in high-power sputtering processes. During sputtering, high-speed particles bombard the target surface, causing the surface temperature of the target material to rise sharply. Therefore, copper alloys with good thermal conductivity are often used as backplate materials, and the welding method also needs to employ diffusion welding, which has a high welding bonding rate, high welding strength, and better high-temperature stability. However, the coefficient of thermal expansion of brittle metals is much lower than that of backplate materials (Cu, Al), resulting in large thermal stress after welding that is not easily released. This causes the target material to bulge and deform towards the brittle metal target blank side, and large welding stress still exists at the weld joint.

[0003] To address the technical challenge of target material deformation, existing technologies typically involve adding a thermal expansion system buffer layer between the target material and the backing plate during welding, or improving the welding process.

[0004] CN106702333A discloses a method for manufacturing a target assembly. A buffer layer with a thermal expansion system is added between the target and the backing plate by diffusion welding to buffer stress. This results in lower stress at the diffusion interface between the target and the buffer layer when the target assembly is cooled from high temperature to room temperature, thus preventing the target from breaking. However, the method requires finding buffer layer materials of different materials for different target and backing plate materials.

[0005] CN110814096A discloses a method for shaping a metal target material after welding and a welding method. The method involves sequentially placing a buffer pad and a pad block above the target material in a target assembly from bottom to top, followed by pressure shaping. The buffer pad has a hardness of 30-60 HA and a tensile strength of 50-00 kg / cm². 2 It effectively alleviates the problem of the target surface being subjected to a large amount of pressure during the shaping process, which can easily lead to through cracks and cracking, and provides good protection and buffering for the target material.

[0006] However, the target assembly will undergo certain deformation after welding. Existing improved processes still cannot guarantee the flatness of the target. The main reasons are: using a single pressure block, the surface of the target blank is prone to twisting, deformation, and edge collapse after shaping; the internal residual stress is large after shaping, which will cause serious dynamic deformation during subsequent processing of the target blank or back plate, and may even cause the target blank to crack.

[0007] Therefore, there is an urgent need to develop a new, universally applicable and high-yield method for shaping the target material after welding, so that the target material does not exhibit distortion, edge collapse, or other phenomena, and the internal residual welding stress can be released. Summary of the Invention

[0008] The purpose of this invention is to provide a stress-relieving shaping method for brittle metal targets. The shaping process uses pads with progressively increasing diameters to perform multiple gradient shapings on the target, which can ensure that the flatness of the target is <0.1mm and prevent twisting, deformation, and edge collapse. Repeated shaping helps to release residual welding stress, control the amount of deformation in subsequent processing, and improve product yield.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] The present invention provides a stress-relieving shaping method for brittle metal targets, the stress-relieving shaping method comprising: setting a pad on the upper surface of the target of the target assembly, and then shaping the target assembly four times;

[0011] The diameter of the pad increases gradually during the four shaping processes.

[0012] In this invention, the diameter of the pad increases gradually during the four shaping processes, and multiple gradient shaping pressures are applied. These work together to perform multiple gradient shapings on the target material, ensuring that the flatness of the target material is <0.1mm and that there is no twisting, deformation, or edge collapse. Repeated shaping helps to release residual welding stress inside, controls the amount of deformation of the product in subsequent processing, and improves the product yield.

[0013] As a preferred technical solution of the present invention, the target assembly is a target assembly consisting of a welded target and a backplate.

[0014] Preferably, the target material is made of brittle metal.

[0015] In this invention, the brittle metal target material refers to a material with high hardness and insufficient toughness, which is mostly prepared by powder metallurgy. For example, it can be W, Si, Ta, WSi, TiAl or TaSi, etc. This is because the destructive stress of the brittle metal target material is much lower than the yield limit of the material, and it is easy to crack or develop cracks.

[0016] Preferably, the back plate is made of Al alloy or Cu alloy.

[0017] As a preferred embodiment of the present invention, the axes of the pad and the target assembly are collinear.

[0018] Preferably, the pad is made of hard aluminum alloy.

[0019] In this invention, the pad is placed on the upper surface of the target material, so that the pressure of the shaping machine is first transmitted to the pad during the shaping process, which can avoid the target material surface from being directly subjected to high pressure, thus preventing cracks and splits.

[0020] As a preferred embodiment of the present invention, washers are symmetrically provided at both ends of the lower surface of the back plate.

[0021] Preferably, the outer diameter of the washer coincides with the diameter of the back plate.

[0022] Preferably, the inner diameter of the washer is larger than the diameter of the target material.

[0023] Preferably, the washer is made of stainless steel.

[0024] In this invention, by setting gaskets at both ends below the back plate, a certain hollow space is formed in the middle of the target material during the shaping of the target material assembly, which can ensure the flatness of the target material after shaping.

[0025] As a preferred technical solution of the present invention, the stress-relief shaping method specifically includes the following steps:

[0026] (1) Place the first pad on the upper surface of the target material of the welded target material assembly coaxially, perform the first stage of shaping, and remove the first pad.

[0027] (2) Place the second pad on the upper surface of the target material in the target material assembly, perform the second stage of shaping, and remove the second pad.

[0028] (3) Place a third pad on the upper surface of the target material of the target material assembly coaxially, perform the third stage of shaping, and remove the third pad.

[0029] (4) Place the fourth pad on the upper surface of the target material of the target material assembly coaxially, perform stress relief shaping, and remove the fourth pad.

[0030] In this invention, the target assembly welded in step (1) is cooled to room temperature and then subjected to stress relief shaping.

[0031] In this invention, the diameter of the target material is 300-450mm, for example, it can be 300mm, 320mm, 340mm, 360mm, 380mm, 400mm, 420mm, 440mm or 450mm, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0032] As a preferred technical solution of the present invention, the ratio of the diameter of the first pad to the diameter of the target material is (0.35 to 0.45):1, for example, it can be 0.35:1, 0.37:1, 0.39:1, 0.41:1, 0.43:1 or 0.45:1, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0033] Preferably, the ratio of the diameter of the second pad to the diameter of the target material is (0.55 to 0.65):1, for example, it can be 0.55:1, 0.57:1, 0.59:1, 0.61:1, 0.63:1 or 0.65:1, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0034] As a preferred technical solution of the present invention, the diameter ratio of the third pad to the target material is (0.75~0.85):1, for example, it can be 0.75:1, 0.77:1, 0.79:1, 0.81:1, 0.83:1 or 0.85:1, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0035] Preferably, the ratio of the diameter of the fourth pad to the diameter of the target material is (0.95 to 1):1, for example, it can be 0.95:1, 0.96:1, 0.97:1, 0.98:1, 0.99:1 or 1:1, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0036] In this invention, the thickness of the pad is not limited. By using pads with progressively larger diameters and corresponding pressure for shaping, the flatness of the target material can be guaranteed to be <0.1mm, and there will be no twisting, deformation, or edge collapse. Multiple shapings help release residual welding stress inside, control the amount of deformation of the product in subsequent processing, and improve product yield.

[0037] As a preferred technical solution of the present invention, the pressure of the first stage shaping is 8.0 to 10.0 MPa, for example, it can be 8.0 MPa, 8.2 MPa, 8.4 MPa, 8.6 MPa, 8.8 MPa, 9.0 MPa, 9.2 MPa, 9.4 MPa, 9.6 MPa, 9.8 MPa or 10.0 MPa, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0038] Preferably, the first-stage shaping time is 8 to 12 minutes, for example, it can be 8 minutes, 8.5 minutes, 9 minutes, 9.5 minutes, 10 minutes, 10.5 minutes, 11 minutes, 11.5 minutes or 12 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0039] Preferably, the pressurization rate of the first stage shaping is 0.8 to 1 MPa / min, for example, it can be 0.8 MPa / min, 0.85 MPa / min, 0.9 MPa / min, 0.95 MPa / min or 1 MPa / min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0040] Preferably, the pressure of the second-stage shaping is 8.0 to 10.0 MPa, for example, it can be 8.0 MPa, 8.2 MPa, 8.4 MPa, 8.6 MPa, 8.8 MPa, 9.0 MPa, 9.2 MPa, 9.4 MPa, 9.6 MPa, 9.8 MPa or 10.0 MPa, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0041] Preferably, the second-stage shaping time is 8 to 12 minutes, for example, it can be 8 minutes, 8.5 minutes, 9 minutes, 9.5 minutes, 10 minutes, 10.5 minutes, 11 minutes, 11.5 minutes or 12 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0042] Preferably, the pressurization rate of the second stage shaping is 0.8 to 1 MPa / min, for example, it can be 0.8 MPa / min, 0.85 MPa / min, 0.9 MPa / min, 0.95 MPa / min or 1 MPa / min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0043] As a preferred technical solution of the present invention, the pressure of the third-stage shaping is 10.0 to 12.0 MPa, excluding 10.0 MPa. For example, it can be 10.2 MPa, 10.4 MPa, 10.6 MPa, 10.8 MPa, 11.0 MPa, 11.2 MPa, 11.4 MPa, 11.6 MPa, 11.8 MPa, or 12.0 MPa, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0044] Preferably, the time for the third-level shaping is 8 to 12 minutes, for example, it can be 8 minutes, 8.5 minutes, 9 minutes, 9.5 minutes, 10 minutes, 10.5 minutes, 11 minutes, 11.5 minutes or 12 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0045] Preferably, the pressurization rate of the third-stage shaping is 1 to 1.2 MPa / min, for example, it can be 1 MPa / min, 1.05 MPa / min, 1.1 MPa / min, 1.15 MPa / min or 1.2 MPa / min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0046] Preferably, the pressure of the fourth stage of shaping is 5.0 to 6.0 MPa, for example, it can be 5.2 MPa, 5.4 MPa, 5.6 MPa, 5.8 MPa or 6.0 MPa, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0047] Preferably, the fourth-level shaping time is 8 to 12 minutes, for example, it can be 8 minutes, 8.5 minutes, 9 minutes, 9.5 minutes, 10 minutes, 10.5 minutes, 11 minutes, 11.5 minutes or 12 minutes, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0048] Preferably, the pressurization rate of the fourth stage shaping is 0.5 to 0.7 MPa / min, for example, it can be 0.5 MPa / min, 0.55 MPa / min, 0.6 MPa / min, 0.65 MPa / min or 0.7 MPa / min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0049] As a preferred technical solution of the present invention, the stress-relief shaping method includes the following steps:

[0050] (1) Place the first pad on the upper surface of the target material of the welded target material assembly coaxially, pressurize at a rate of 0.8 to 1 MPa to 8.0 to 10.0 MPa for 8 to 12 minutes for first-stage shaping, and remove the first pad.

[0051] The diameter ratio of the first pad to the target material is (0.35~0.45):1;

[0052] (2) Place the second pad on the upper surface of the target material of the target material assembly coaxially, pressurize at a rate of 0.8 to 1 MPa / min to 8.0 to 10.0 MPa for 8 to 12 minutes for the second stage of shaping, and then remove the second pad.

[0053] The diameter ratio of the second pad to the target material is (0.55~0.65):1;

[0054] (3) Place a third pad on the upper surface of the target material of the target material assembly coaxially, pressurize to 10.0-12.0 MPa at a pressurization rate of 1-1.2 MPa / min, excluding the third-stage shaping at 10.0 MPa for 8-12 minutes, and remove the third pad.

[0055] The diameter ratio of the third pad to the target material is (0.75~0.85):1;

[0056] (4) Place the fourth pad on the upper surface of the target material of the target material assembly coaxially, pressurize to 5.0-6.0 MPa at a pressurization rate of 0.5-0.7 MPa / min, and perform fourth-stage shaping for 8-12 minutes. Then remove the fourth pad.

[0057] The diameter ratio of the fourth pad to the target material is (0.95~1):1.

[0058] In this invention, the shaping process further includes: performing target flatness testing and residual stress ultrasonic testing on the target assembly.

[0059] Preferably, the apparatus for residual stress ultrasonic testing includes: a residual stress ultrasonic testing instrument.

[0060] Preferably, the residual stress ultrasonic testing specifically includes: using a residual stress ultrasonic testing instrument to perform stress testing on the shaped target material assembly, scanning the shaped welding surface, and then judging the generated visual view.

[0061] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0062] Compared with the prior art, the present invention has the following beneficial effects:

[0063] This invention uses pads with progressively increasing diameters combined with corresponding pressure to shape the target material in a multi-gradient manner, ensuring that the flatness of the target material is <0.1mm and that there is no twisting, deformation, or edge collapse. Multiple shapings help release residual welding stress inside, control the amount of deformation in the subsequent processing, and improve product yield. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the first stage of shaping in the stress-relief shaping method provided by the present invention, with the arrow pointing in the direction of applied pressure;

[0065] Figure 2 This is a schematic diagram of the second stage of shaping in the stress-relief shaping method provided by the present invention, with the arrow pointing in the direction of applied pressure;

[0066] Figure 3 This is a schematic diagram of the third stage of shaping in the stress-relief shaping method provided by the present invention, with the arrow pointing in the direction of applied pressure;

[0067] Figure 4 This is a schematic diagram of the fourth stage of shaping in the stress-relief shaping method provided by the present invention, with the arrow pointing in the direction of applied pressure;

[0068] Among them, 1-Al alloy backing plate, 2-W target material, 3-first pad, 4-second pad, 5-third pad, 6-fourth pad, 7-washer. Detailed Implementation

[0069] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be considered as specific limitations thereof.

[0070] Target assembly: A target assembly formed by HIP welding of W target 2 and Al alloy backing plate 1. Washers 7 are symmetrically arranged at both ends of the lower surface of the Al alloy backing plate 1; the outer diameter of the washers 7 coincides with the diameter of the Al alloy backing plate 1; the inner diameter of the washers 7 is larger than the diameter of the W target 2; the material of the washers 7 is stainless steel.

[0071] This embodiment provides a stress-relief shaping method for brittle metal targets, the stress-relief shaping method comprising the following steps:

[0072] (1) When the welded target assembly cools to room temperature, a first pad 3 with a diameter of 0.35Da to 0.45Da is placed coaxially on the upper surface of the W target 2 with a diameter of Da. Figure 1 As shown), use a hydraulic press to pressurize to 8.0-10.0 MPa at a pressurization rate of 0.85-1 MPa / min for 8-12 minutes for the first stage of shaping, and then remove the first pad 3;

[0073] (2) A second pad 4 with a diameter of 0.55 Da to 0.65 Da is placed coaxially on the upper surface of the W target 2 of the target assembly. Figure 2 As shown), use a hydraulic press to pressurize to 8.0-10.0 MPa at a pressurization rate of 0.85-1 MPa / min for 8-12 minutes for the second stage of shaping, and then remove the second pad 4;

[0074] (3) A third pad 5 with a diameter of 0.75 Da to 0.85 Da is placed coaxially on the upper surface of the W target 2 of the target assembly. Figure 3 As shown), use a hydraulic press to pressurize to 10.0-12.0 MPa at a pressurization rate of 1-1.2 MPa / min, excluding the third-stage shaping at 10.0 MPa for 8-12 minutes, and then remove the third pad 5;

[0075] (4) A fourth pad 6 with a diameter of 0.95 Da to 1 Da is placed coaxially on the upper surface of the W target 2 of the target assembly. Figure 4 As shown), use a hydraulic press to pressurize to 5.0-6.0 MPa at a pressurization rate of 0.5-0.7 MPa / min for 8-12 minutes for the fourth stage of shaping, and then remove the fourth pad 6;

[0076] The pads are all made of hard aluminum alloy; the thickness of the pads is the same.

[0077] Flatness testing was performed on the target material assembly after each shaping step; the specific results are shown in Table 1.

[0078] Table 1

[0079] Flatness before shaping (mm) Flatness after shaping (mm) first step 2.5 +1.3～+1.5 Step 2 +1.3～+1.5 +0.8～+1.0 Step 3 +0.8～+1.0 -0.2～-0.4 Step 4 -0.2～-0.4 -0.1～+0.1

[0080] In Table 1, a "+" indicates that the product bulges towards the back panel, while a "-" indicates that the product is recessed towards the back panel.

[0081] Example 1

[0082] This embodiment provides a stress-relief shaping method for brittle metal targets, the stress-relief shaping method comprising the following steps:

[0083] (1) When the welded target assembly cools to room temperature, place the first pad with a diameter of 160mm on the upper surface of the W target with a diameter of 400mm on the same axis. Use a hydraulic press to pressurize to 9.0MPa at a pressurization rate of 0.9Mpa / min for 10min and then remove the first pad.

[0084] (2) Place a second pad with a diameter of 240 mm coaxially on the upper surface of the W target of the target assembly, and use a hydraulic press to pressurize to 9.0 MPa at a pressurization rate of 0.9 MPa / min for 10 min to shape it, and then remove the second pad.

[0085] (3) Place a third pad with a diameter of 320 mm coaxially on the upper surface of the W target of the target assembly, pressurize it to 11.0 MPa at a pressurization rate of 1.1 MPa / min using a hydraulic press and shape it for 10 min, then remove the third pad.

[0086] (4) Place a fourth pad with a diameter of 400 mm coaxially on the upper surface of the W target of the target assembly, pressurize it to 5.5 MPa at a pressurization rate of 0.55 MPa / min using a hydraulic press for 10 minutes, and then remove the fourth pad.

[0087] The pads are all made of hard aluminum alloy; the thickness of the pads is the same.

[0088] Example 2

[0089] This embodiment provides a stress-relief shaping method for brittle metal targets, the stress-relief shaping method comprising the following steps:

[0090] (1) When the welded target assembly cools to room temperature, place the first pad with a diameter of 110 mm on the upper surface of the W target with a diameter of 300 mm. Use a hydraulic press to pressurize to 8.0 MPa at a pressurization rate of 1 MPa / min for 8 min to shape it, and then remove the first pad.

[0091] (2) Place a second pad with a diameter of 170 mm coaxially on the upper surface of the W target of the target assembly, and use a hydraulic press to pressurize to 8.0 MPa at a pressurization rate of 1 MPa / min for 8 minutes to shape it, and then remove the second pad.

[0092] (3) Place a third pad with a diameter of 230 mm coaxially on the upper surface of the W target of the target assembly, pressurize it to 10.0 MPa at a pressurization rate of 1 MPa / min using a hydraulic press and shape it for 10 min, then remove the third pad.

[0093] (4) Place a fourth pad with a diameter of 300 mm coaxially on the upper surface of the W target of the target assembly, and use a hydraulic press to pressurize to 5.0 MPa at a pressurization rate of 0.625 MPa / min for 8 minutes to shape it, and then remove the fourth pad.

[0094] The pads are all made of hard aluminum alloy; the thickness of the pads is the same.

[0095] Example 3

[0096] This embodiment provides a stress-relief shaping method for brittle metal targets, the stress-relief shaping method comprising the following steps:

[0097] (1) When the welded target assembly cools to room temperature, place the first pad with a diameter of 200mm on the upper surface of the W target with a diameter of 450mm on the same axis. Use a hydraulic press to pressurize to 10.0MPa at a pressurization rate of 0.83Mpa / min for 12min and then remove the first pad.

[0098] (2) Place a second pad with a diameter of 290 mm coaxially on the upper surface of the W target of the target assembly, and use a hydraulic press to pressurize to 10.0 MPa at a pressurization rate of 0.83 MPa / min for 12 min to shape it, and then remove the second pad.

[0099] (3) Place a third pad with a diameter of 380 mm coaxially on the upper surface of the W target of the target assembly, pressurize it to 12.0 MPa at a pressurization rate of 1 MPa / min using a hydraulic press and shape it for 12 min, then remove the third pad.

[0100] (4) Place a fourth pad with a diameter of 450 mm coaxially on the upper surface of the W target of the target assembly, pressurize it to 6.0 MPa at a pressurization rate of 0.5 MPa / min using a hydraulic press for 12 minutes, and then remove the fourth pad.

[0101] The pads are all made of hard aluminum alloy; the thickness of the pads is the same.

[0102] Example 4

[0103] This embodiment provides a stress-relieving shaping method for brittle metal targets. Except that the shaping pressure in steps (1) and (2) is 12.0 MPa, all other conditions are the same as in embodiment 1.

[0104] Example 5

[0105] This embodiment provides a stress-relief shaping method for brittle metal targets. Except for the shaping pressure of 11.0 MPa in step (4), all other conditions are the same as in embodiment 1.

[0106] Example 6

[0107] This embodiment provides a stress-relief shaping method for brittle metal targets. Except for not performing the operation described in step (2), all other conditions are the same as in embodiment 1.

[0108] Example 7

[0109] This embodiment provides a stress-relief shaping method for brittle metal targets. Except for not performing the operation described in step (3), all other conditions are the same as in embodiment 1.

[0110] Example 8

[0111] This embodiment provides a stress-relief shaping method for brittle metal targets. Except for not performing the operation described in step (4), all other conditions are the same as in embodiment 1.

[0112] Comparative Example 1

[0113] This comparative example provides a stress-relief shaping method for brittle metal targets. Except that the diameter of the pad is 160 mm in steps (2) to (4), all other conditions are the same as in Example 1.

[0114] Comparative Example 2

[0115] This comparative example provides a stress-relief shaping method for brittle metal targets. Except that the diameter of the pad is 240 mm in steps (1) to (4), all other conditions are the same as in Example 1.

[0116] Comparative Example 3

[0117] This comparative example provides a stress-relief shaping method for brittle metal targets. Except that the diameter of the pad in steps (1) to (4) is 400 mm, 320 mm, 240 mm and 160 mm respectively, all other conditions are the same as in Example 1.

[0118] The target material assemblies of the above embodiments and comparative examples were subjected to ultrasonic testing for product qualification rate, flatness, and residual stress. The flatness test was performed using the feeler gauge measurement method. The residual stress ultrasonic testing specifically included: using a residual stress ultrasonic testing instrument to perform stress testing on the shaped target material assembly, scanning the shaped welding surface, and then determining whether the target material was deformed based on the generated visualization view. The specific results are shown in Table 2.

[0119] Table 2

[0120]

[0121]

[0122] The following points can be drawn from Table 2:

[0123] (1) As can be seen from the comprehensive examples 1 to 3, the stress relief shaping method for brittle metal targets provided by the present invention uses pads with progressively larger diameters combined with corresponding pressure to shape the target material in a multi-gradient manner, so that the flatness of the target material is <0.1mm and there is no twisting deformation or edge collapse; multiple shaping is conducive to the release of internal residual welding stress, and the product qualification rate is as high as 98% or more.

[0124] (2) As can be seen from the comparison between Example 1 and Example 5, when the fourth shaping pressure is the same as the third shaping pressure, the fourth shaping pressure is too large, which is not conducive to reducing the flatness of the target assembly and causes the target to deform; As can be seen from the comparison between Example 1 and Examples 6 to 8, when a certain step is reduced for shaping, the flatness of the target assembly will be too high.

[0125] (3) As can be seen from the comparison between Example 1 and Comparative Examples 1 and 2, when the same diameter pad is used in all four shaping processes, the surface of the target material is prone to twisting, deformation and collapse after shaping, and it is not conducive to reducing the flatness of the target material assembly.

[0126] (4) As can be seen from the comparison between Example 1 and Comparative Example 3, during the stress relief shaping process, the diameter of the pad gradually decreases, making it difficult to shape the target material and causing operational difficulties, which in turn leads to a larger flatness of the target material assembly.

[0127] The applicant declares that the detailed structural features of the present invention are illustrated through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions for the components selected in the present invention, additions of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0128] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0129] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0130] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method of stress-relief shaping of a brittle metal target material, characterized in that, The stress relief shaping method comprises: (1) placing a first pad block coaxially on the upper surface of the target material of the target assembly after welding, performing first-stage shaping, and removing the first pad block; (2) placing a second pad block coaxially on the upper surface of the target material of the target assembly, performing second-stage shaping, and removing the second pad block; (3) placing a third pad block coaxially on the upper surface of the target material of the target assembly, performing third-stage shaping, and removing the third pad block; (4) placing a fourth pad block coaxially on the upper surface of the target material of the target assembly, performing fourth-stage shaping, and removing the fourth pad block; The diameters of the pad blocks gradually increase in the four shaping processes; the diameter ratio of the first pad block to the target material is (0.35-0.45):1; the diameter ratio of the second pad block to the target material is (0.55-0.65):1; the diameter ratio of the third pad block to the target material is (0.75-0.85):1; and the diameter ratio of the fourth pad block to the target material is (0.95-1):1; The pressure of the first-stage shaping is 8.0-10.0 MPa; the pressure of the second-stage shaping is 8.0-10.0 MPa; the pressure of the third-stage shaping is 10.0-12.0 MPa, and 10.0 MPa is excluded; and the pressure of the fourth-stage shaping is 5.0-6.0 MPa.

2. The stress-etching method of claim 1, wherein, The target assembly is a target assembly combined by a target material and a back plate after welding.

3. The stress-etching method of claim 2, wherein, The material of the back plate is Al alloy or Cu alloy.

4. The destressing reshaping method of claim 1, wherein, The material of the pad block is hard aluminum alloy.

5. The destressing reshaping method of claim 2, wherein, The lower surface of the back plate is symmetrically provided with a gasket at both end edges.

6. The stress-etching method of claim 5, wherein, The outer diameter of the gasket coincides with the diameter of the back plate.

7. The stress-etching method of claim 5, wherein, The inner diameter of the gasket is greater than the diameter of the target material.

8. The destressing reshaping method of claim 5, wherein, The material of the gasket is stainless steel.

9. The destressing reshaping method of claim 1, wherein, The time of the first-stage shaping is 8-12 min.

10. The destressing reshaping method of claim 1, wherein, The pressurizing rate of the first-stage shaping is 0.8-1 MPa / min.

11. The destressing reshaping method of claim 1, wherein, The time of the second-stage shaping is 8-12 min.

12. The destressing reshaping method of claim 1, wherein, The pressurizing rate of the second-stage shaping is 0.8-1 MPa / min.

13. The destressing reshaping method of claim 1, wherein, The time of the third-stage shaping is 8-12 min.

14. The destressing reshaping method of claim 1, wherein, The pressurizing rate of the third-stage shaping is 1-1.2 MPa / min.

15. The destressing reshaping method of claim 1, wherein, The time of the fourth-stage shaping is 8-12 min.

16. The destressing reshaping method of claim 1, wherein, The pressurizing rate of the fourth-stage shaping is 0.5-0.7 MPa / min.

17. The destressing reshaping method of claim 1, wherein, The stress relief shaping method comprises the following steps: (1) placing a first pad block coaxially on the upper surface of the target material of the target assembly after welding, pressurizing to 8.0-10.0 MPa at a pressurizing rate of 0.8-1 MPa / min, first-stage shaping for 8-12 min, and removing the first pad block; The diameter ratio of the first pad block to the target material is (0.35-0.45):1; (2) placing a second pad block coaxially on the upper surface of the target material of the target assembly, pressurizing to 8.0-10.0 MPa at a pressurizing rate of 0.8-1 MPa / min, second-stage shaping for 8-12 min, and removing the second pad block; The diameter ratio of the second pad block to the target material is (0.55-0.65):1; (3) placing a third pad coaxially on the upper surface of the target material of the target assembly, pressurizing to 10.0-12.0 MPa excluding 10.0 MPa at a pressurizing rate of 1-1.2 MPa / min, third stage shaping for 8-12 min, and removing the third pad; the ratio of the diameter of the third pad to the diameter of the target material is (0.75-0.85):1; (4) placing a fourth pad coaxially on the upper surface of the target material of the target assembly, pressurizing to 5.0-6.0 MPa at a pressurizing rate of 0.5-0.7 MPa / min, fourth stage shaping for 8-12 min, and removing the fourth pad; the ratio of the diameter of the fourth pad to the diameter of the target material is (0.95-1):1.

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