A highly economical laser shock peening method for anode targets

Abstract

The present invention discloses a highly economical laser shock peening method for an anode target disk, belonging to the technical field of anode target disk surface treatment, comprising the following processes: clamping the anode target disk to be strengthened on a laser shock peening treatment device, with the disk surface layer of the anode target disk facing the laser head of the laser shock peening treatment device; emitting a pulsed laser beam through the laser shock peening treatment device; shocking a target coverage area with the pulsed laser beam, wherein the target coverage area consists of an annular side surface of the disk surface layer and an area between the outer edge of the annular bombardment zone and the outer ring edge of the end face of the disk surface layer; the present invention simultaneously takes into account the release behavior of residual stress holes at high temperature without strengthening the annular bombardment area, and has the best impact strength and the most economical cost advantage.

Description

Technical Field

[0001] The invention relates to a highly economical laser shock strengthening method for an anode target disk, and belongs to the technical field of anode target disk surface treatment. Background Art

[0002] The anode target disk is the core component of the tube, which directly bears the bombardment of the electron beam. Therefore, the high-temperature fatigue resistance of the anode target disk directly determines the service life of the tube. Laser shock peening is an emerging surface treatment process. It uses a high-energy laser beam to load the metal surface and induces a plasma explosion to generate a shock wave. The mechanical effect causes the metal surface to produce compressive stress perpendicular to the material surface. The residual compressive stress will reduce the tensile stress level in the alternating load, reduce the average stress level, and effectively inhibit the initiation and evolution of cracks, thereby effectively improving the strength, hardness, wear resistance and stress corrosion resistance of metal parts. At present, the academic community has tried to apply the laser shock peening method to the anode target disk in order to improve the fatigue resistance of the anode target disk. However, the current strengthening method has not achieved satisfactory strengthening effect on the anode target disk.

[0003] Based on this understanding, the industry has proposed a design scheme that the path setting of laser shock peening needs to use the edge of the anode target disk as the endpoint, such as the scheme described in Shanghai United Imaging's patent application 201911369715.3, which includes: clamping the anode target disk to be strengthened on the laser shock peening processing equipment; emitting a pulsed laser beam through the laser shock peening processing equipment; and scanning the surface of the anode target disk along a preset path; wherein, one endpoint of the preset path is the center of the anode target disk, and the other endpoint of the preset path is located at the edge of the anode target disk, and the direction of the line connecting the two endpoints of the preset path is the radial direction of the anode target disk.

[0004] Incorporating stress vibration into the electron beam bombardment process, thus considering the process design of laser shock peening, is an improvement. However, while this approach currently has significant strengthening performance advantages over earlier strengthening methods because it takes into account the rotating working environment of the anode target and the electron beam bombardment mechanism, it still does not achieve the best strengthening effect and the most economical cost control.

[0005] After extensive theoretical research and experiments, we found that there are two reasons for the poor impact effect and economic efficiency of the current anode target:

[0006] First, due to the current analysis model, the specific shape of the anode target disk in the disk surface layer is ignored. It recognizes the "冖" - shaped form of the disk surface layer prepared by the chemical vapor deposition method as a model for stress vibration analysis of the "一" - shaped form formed by machining, that is, it ignores the side surface of the disk surface layer and only considers the end surface of the disk surface layer, and simplifies the analysis object of stress vibration from a disc - shaped to a plate - shaped for analysis. Although this simplification reduces the analysis difficulty, it also magnifies the gap between the actual object and the theory, resulting in insufficient strengthening effect. In other words, the strengthening method obtained by taking the flat - shaped disk surface layer as the analysis object is not applicable to the disc - shaped disk surface layer prepared by the vapor deposition method.

[0007] Second, the current impact method understands the "high temperature" during the operation of the anode target disk as the "high temperature" of conventional mechanical parts in service, such as the temperature of several hundred degrees Celsius at which a bearing is located under normal service conditions. In fact, taking a tungsten target as an example, the annular bombardment area, which is the hottest part of the entire target disk, can reach a service temperature of even 2300 degrees Celsius. Such a high temperature will surely change the strengthening mechanism of the anode target disk. Summary of the Invention

[0008] In view of the problems existing in the above - mentioned prior art, the present invention provides a high - economy laser shock strengthening method for an anode target disk. This technical solution considers the release behavior of residual stress holes at high temperatures and does not perform strengthening on the annular bombardment area, having the best shock intensity and the most economical cost advantage.

[0009] To achieve the above object, the technical solution adopted by the present invention is: a high - economy laser shock strengthening method for an anode target disk. The anode target disk includes a disk body, a disk surface layer fixedly connected above the disk body, and a base layer located below the disk body; the disk surface layer includes an end surface and an annular side surface arranged at the outer side of the end surface; an outer - ring edge is formed between the end surface and the annular side surface; the end surface has an annular bombardment area for carrying electron beam bombardment and generating X - rays.

[0010] The laser shock strengthening method based on the above - mentioned anode target disk includes the following steps:

[0011] Step S1: Clamp the anode target disk to be strengthened on a laser shock strengthening processing device, with the disk surface layer of the anode target disk facing the laser head of the laser shock strengthening device;

[0012] Step S2: Emit a pulsed laser beam through the laser shock strengthening processing device;

[0013] Step S3: Impact the target coverage area through the pulsed laser beam. The target coverage area is composed of the annular side surface of the disk surface layer and the area between the outer edge of the annular bombardment area and the outer - ring edge on the end surface of the disk surface layer.

[0014] Furthermore, the step S3 is specifically as follows:

[0015] S31: impacting the outer edge of the disk surface layer with a pulsed laser beam;

[0016] S32: impacting the annular side surface of the disk surface layer point by point in a direction away from the center of the disk surface layer;

[0017] S33: Returning in the direction pointing to the center of the disk surface layer and impacting the annular side surface of the disk surface layer point by point;

[0018] S34: Sequentially impacting the area on the end surface of the disk surface layer between the outer edge of the annular bombardment zone and the outer ring edge in the direction pointing to the center of the disk surface layer.

[0019] Furthermore, in step S32, a laser shock path that strikes the annular side surface of the disk surface layer in a direction away from the center of the disk surface layer is defined as a first path; in step S33, a laser shock path that returns toward the center of the disk surface layer and strikes the annular side surface of the disk surface layer point by point is defined as a second path; and in step S34, a laser shock path that sequentially strikes the area between the outer edge of the annular bombardment zone and the outer ring edge on the end surface of the disk surface layer in a direction toward the center of the disk surface layer is defined as a third path;

[0020] On the first path, positions of the first laser shock spots formed by the pulsed laser beam are spaced apart from each other;

[0021] On the second path, positions of the second laser shock spots formed by the pulsed laser beam are spaced apart from each other, and the position of each second laser shock spot is located between two first laser shock spots;

[0022] On the third path, the third laser shock spots formed by the pulsed laser beam are spaced apart from each other.

[0023] Furthermore, in the step S32, the laser shock path that strikes the side of the disk surface layer in a direction away from the center of the disk surface layer is defined as a first path; in the step S33, the laser shock path that returns in a direction pointing to the center of the disk surface layer and strikes the side of the disk surface layer point by point is defined as a second path; in the step S34, the laser shock path that sequentially strikes the area between the outer edge of the annular bombardment zone and the outer ring edge in the end face (11) of the disk surface layer in a direction pointing to the center of the disk surface layer is defined as a third path;

[0024] On the first path, positions of the first laser shock spots formed by the pulsed laser beam are spaced apart from each other;

[0025] On the second path, positions of the second laser shock spots formed by the pulsed laser beam are spaced apart from each other, and each second laser shock spot overlaps two adjacent first laser shock spots;

[0026] On the third path, the third laser shock spots formed by the pulsed laser beam are distributed overlapping with each other.

[0027] Furthermore, in step S31, the pulsed laser beam impacts the outer edge of the disk surface layer in an oblique impact manner.

[0028] Furthermore, a flexible constraint layer is provided on the edge of the outer ring.

[0029] Furthermore, the flexible constraint layer is water or an inorganic salt solution.

[0030] Furthermore, the flexible constraint layer is a saturated inorganic salt melt.

[0031] Furthermore, the anode target disk is a tungsten target.

[0032] The beneficial effects of the above technical solution of the present invention are as follows:

[0033] The present invention proposes a highly economical laser shock strengthening method for anode target disks. The method performs a model analysis of the impact dynamic stress vibration based on the actual butterfly shape of the disk surface layer. At the same time, it overcomes the high-temperature release behavior ignored in the common anode target disk laser shock schemes. The method creatively proposes a scheme in which laser shock strengthening is performed on the annular side of the disk surface layer instead of the annular bombardment area. The method takes into account the release behavior of residual stress holes at high temperatures and does not perform strengthening on the annular bombardment area. The method has the best impact strength and the most economical cost advantage.

[0034] (2) The laser shock strengthening method for the surface treatment of the anode target disk adopted in the present invention is aimed at the anode target disk with a butterfly-shaped disk surface layer. The pulsed laser beam first impacts the outer ring edge of the disk surface layer, and then impacts the annular side surface of the disk surface layer point by point along the direction away from the center of the disk surface layer, and then returns along the direction pointing to the center of the disk surface layer and impacts the annular side surface of the disk surface layer point by point, and then successively impacts the area between the outer edge of the annular bombardment zone and the outer ring edge of the end face of the disk surface layer along the direction pointing to the center of the disk surface layer. The strengthening effect of the laser shock is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the structure of the anode target in an embodiment of the present invention;

[0036] Figure 2 1. It is a parts expansion diagram of the anode target plate in an embodiment of the present invention;

[0037] Figure 3A bottom view of the disk surface layer in an embodiment of the present invention;

[0038] Figure 4 A path diagram of a disk surface layer path processing method in an embodiment of the present invention;

[0039] Figure 5 : is a distribution diagram of the first laser shock spot and the second laser shock spot in an embodiment of the present invention;

[0040] Figure 6 Schematic diagram of the specific process of the method of the present invention.

[0041] In the figure: 10, disk surface layer; 11, end face; 12, annular side surface; 13, outer ring edge; 14, inner ring edge; 15, annular bombardment area; 16, bottom edge; 20, disk body; 30, base layer; 21, first path; 22, second path; 23, third path; 24, fourth path; 211, first laser shock spot; 221, second laser shock spot. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention pertains. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0044] The present invention proposes a highly economical laser shock peening method for anode target disk, such as Figure 1-Figure 3 shown.

[0045] The anode target disk includes a disk body 20, a disk surface layer 10 fixedly connected to the top of the disk body 20, and a base layer 30 fixedly connected to the bottom of the disk body 20; the disk surface layer 10 includes an end face 11 and an annular side surface 12 arranged at an outer position of the end face 11, and the annular side surface 12 is perpendicular to the end face 11; an outer ring edge 13 is formed between the end face 11 and the annular side surface 12; the end face 11 has an annular bombardment area 15 that carries the electron beam bombardment and generates X-rays.

[0046] Laser shock peening methods include:

[0047] Step S1: clamping the anode target disk to be strengthened on a laser shock peening device, with the disk surface layer 10 of the anode target disk facing the laser head of the laser shock peening device.

[0048] Specifically, the anode target disk, as a disk-type part, can be positioned on the impact workbench of the laser shock peening equipment by clamping with claws or V-blocks; the laser shock peening equipment can use a solid pulse laser, a gas pulse laser, or a fiber pulse laser.

[0049] Step S2: emitting a pulsed laser beam through the laser shock peening equipment.

[0050] Specifically, the present invention does not limit specific processing parameters. Considering that too low power of the laser shock pulse laser beam will lead to poor impact effect, and too high power of the pulse laser beam will cause ablation problems on the impact surface, the pulse energy of the laser beam preferably adopts energy values ​​such as 3.89J, 5.43J, and 8J.

[0051] Considering that an excessively large spot diameter will lead to dispersion of laser pulse energy, and an excessively small spot diameter will lead to a substantial increase in the number of pulse processing times, the spot diameter of the laser beam is preferably 5 mm.

[0052] Preferably, before laser impact, aluminum foil, black glue or flexible medium can be provided on the upper surface of the end face 11 of the anode target disk as an absorption layer to prevent the laser beam from directly impacting the surface of the anode target disk and causing ablation of the anode target disk surface.

[0053] Of course, the present invention does not limit the specific pulse parameters and processing structure during laser shock processing, as long as the pulse parameters or processing structure can successfully realize the loading of the pulsed laser beam and complete the laser shock strengthening process.

[0054] Step S3: The pulsed laser beam impacts the target coverage area of ​​the anode target disk. The target coverage area consists of the annular side surface 12 of the disk surface layer 10 and the area between the outer edge of the annular bombardment zone 15 and the outer annular edge 13 of the end surface 11 of the disk surface layer 10. In other words, the pulsed laser beam only covers these two areas of the target coverage area of ​​the anode target disk to achieve stable strengthening.

[0055] At the same time, the laser shock peening still needs to impact the outer ring edge 13 of the disk surface layer 10 first, that is, the outer ring edge 13 is still the source point of crack initiation.

[0056] Specifically, step S3 includes:

[0057] S31, impacting the outer edge of the disk surface layer with a pulsed laser beam;

[0058] S32, impacting the annular side surface of the disk surface layer point by point in a direction away from the center of the disk surface layer;

[0059] S33, returning in the direction pointing to the center of the disk surface layer and impacting the annular side surface of the disk surface layer point by point;

[0060] S34, impacting the area between the outer edge of the annular bombardment zone and the outer ring edge on the end surface of the disk surface layer in sequence along the direction pointing to the center of the disk surface layer.

[0061] Regarding the reasons for the poor impact effect of the anode target disk mentioned above, that is, the reason why the target coverage area needs to cover the annular side surface 12 of the disk surface layer 10 in order to solve the first technical problem proposed in this article, a specific analysis is as follows:

[0062] The shape of the disk surface layer is not a flat plate as usually analyzed. That is, the disk surface layer has not only an end surface 11, but also an annular side surface 12. The end surface 11 and the annular side surface 12 intersect at an outer ring edge 13. Generally speaking, the end surface 11 and the annular side surface 12 are perpendicular to each other. As an embodiment of the present invention, the middle position of the end surface 11 has an inner ring edge 14, and the bottom position of the annular side surface 12 has a bottom edge 16.

[0063] When an electron beam, acting as a particle beam, bombards the anode target disk, it induces stress vibrations in the disk surface layer. The electron beam first compresses the material at the impact point, generating a shock wave within the anode target disk. The material at the impact point rebounds, and the shock wave propagates to the outer edge 13 of the anode target disk's disk surface layer 10, causing the material to compress before returning in the opposite direction and rebounding. Cracks propagated by material rebound at high temperatures are much smaller than those at low temperatures, and the temperature of the inner edge 14 is much higher than that of the outer edge 13.

[0064] Therefore, the butterfly analysis model and the plate analysis model share the same response to stress vibration: the outer ring edge 13, due to its raised shape, will compress and rebound under the impact of the shock wave, making the outer ring edge the source of crack initiation. In the plate analysis model, the shock wave will rebound at the outer ring edge 13, and cracks initiated there will develop as the reverse shock wave propagates toward the center of the disk surface layer. This is why the industry recommends that the laser shock strengthening area extend to the outer ring edge 13 and the center of the disk surface layer 10.

[0065] However, the butterfly analysis model and the plate analysis model differ in their responses to stress vibration. In the butterfly analysis model, the outer ring edge 13 is not the end of the entire disk surface layer solid material; the shock wave does not undergo interface reflection at the outer ring edge 13, but continues to propagate on the annular side surface 12 of the disk surface layer along the initial propagation direction; therefore, the cracks initiated from the outer ring edge 13 will first develop on the annular side surface 12 of the disk surface layer as the shock wave propagates, and then develop toward the center of the disk surface layer along the propagation of the reverse shock wave.

[0066] Based on the above reasons, the coverage area of ​​the laser shock on the anode target disk surface layer proposed in the present invention needs to cover the annular side surface 12 of the disk surface layer.

[0067] The applicant would like to emphasize that the proposed strengthening of the annular side surface 12 of the disk surface layer in this application does not simply apply the analytical model of the plate. This is because if the butterfly-shaped annular side surface 12 is simply understood as an extension of the plate at the outer annular edge 13 according to the analytical model of the plate, then according to the analytical model of the plate, the shock wave will rebound at the bottom edge 16 of the annular side surface 12. The bottom edge 16 will be the maximum point of material compression and reverse rebound, and the bottom edge 16 will be the source of crack initiation, rather than the outer annular edge 13 as still proposed in this application.

[0068] Under the butterfly analysis model, the outer ring edge 13 still has the largest mechanical response. This is because the shock wave is reflected during its propagation from the outer ring edge 13 to the annular side 12, and some energy is lost as it is transmitted from the outer ring edge 13. Therefore, the dynamic response at the outer ring edge 13 is still greater than that at the bottom edge 16, and the outer ring edge 13 is still the source of crack initiation. This is sufficient to prove that the solution proposed in this application is not a simple application of the butterfly shape under the plate model.

[0069] The reasons for the poor economic efficiency and high cost of the anode target shock peening mentioned above, and the reasons for excluding the annular bombardment zone 15 from the laser shock peening loading area in order to solve the second technical problem proposed in this paper, are explained in detail as follows:

[0070] It's well known that different metals have varying sensitivities to the high-temperature thermal release of residual compressive stress, but this sensitivity increases significantly with increasing temperature above a certain point. For example, researchers have measured that the stress release rate of nickel-based alloys increases from 12.5% ​​to 77.7% and 82.1% at 600°C, 700°C, and 800°C, respectively.

[0071] To address this, the applicant conducted experiments to investigate the degree of residual stress release in tungsten targets at temperatures of 2300°C and 1800°C (using a high-energy pulsed lamp pumped by a YAG laser (Gaia-R series, THALES, France), with a spot diameter of 5 mm, a wavelength of 1064 nm, a pulse width of 10 nm, and a pulse energy of 5.43 joules). The experiments revealed that at 2300°C, the residual stress release in the tungsten target exceeded 90%, while at 1800°C, the residual stress release was approximately 10%.

[0072] The service temperature of the anode target's annular bombardment zone 15 is 2300°C, while the service temperature of the anode target's outer edge 13 is 1800°C (the anode target dissipates heat during service due to high-speed rotation). Therefore, considering the release of residual stress in the tungsten target at high temperatures, the annular bombardment zone 15 does not need to be loaded with shock waves, while the outer edge 13 can still be effectively loaded with shock waves.

[0073] Therefore, this application proposes not to strengthen the annular bombardment zone 15 of the disk surface layer. On the one hand, the residual compressive stress in the annular bombardment zone 15 after processing will be significantly released as the temperature increases; on the other hand, the annular bombardment zone is not the source of cracks and is not the core area of ​​strengthening.

[0074] The anode target disk laser shock method proposed in the present invention performs a model analysis of the impact dynamic stress vibration based on the actual butterfly shape of the disk surface layer, while overcoming the high-temperature release behavior ignored in the common anode target disk laser shock scheme, and creatively proposes a scheme in which laser shock strengthening is performed on the annular side 12 of the disk surface layer instead of the annular bombardment area.

[0075] The applicant also conducted experimental verification. Using a high-energy pulsed lamp pumped by a YAG laser (Gaia-R series, THALES, France), with a spot diameter of 5 mm, a wavelength of 1064 nm, a pulse width of 10 nm, and a pulse energy of 5.43 joules, the applicant demonstrated that the fatigue life of the anode target disk (the number of effective operating cycles) was increased by more than 15% compared to a conventional solution that only fully strengthened the end surface 11, by applying the pulsed laser beam to the annular side surface 12 of the disk surface layer and the area between the annular impact zone 15 and the outer ring edge 13 of the disk surface layer 10, without loading the annular impact zone 15. These experimental results are consistent with the theoretical qualitative analysis.

[0076] In summary, the laser shock peening method for the anode target disk provided by the present invention fully analyzes the differences in the shock responses of the anode target disk in the plate model and the butterfly model, and creatively proposes that the annular side surface 12 of the disk surface layer 10 needs to be strengthened. At the same time, the release behavior of the residual stress hole at high temperature is considered instead of strengthening the annular bombardment area 15, which has the best impact strength and the most economical cost advantage.

[0077] The applicant believes that it is also necessary to emphasize that strengthening the annular side surface 12 of the target disk is a technical means that the applicant has only recognized based on a large number of experimental observations and mechanism analysis. It is not a technical means that is easy to think of in this field and is not motivated to be adopted based on the current solution. The laser shock peening process requires the use of a high-power laser, and the limited rated shock life of a high-power laser means that the impact cost of a single point is often more than ten yuan or even dozens of yuan. This causes the entire strengthening cost to even exceed the manufacturing cost of conventional parts. Therefore, strengthening can only be carried out on the core working areas of core parts such as anode target disks and engine blades. This can be confirmed by the fact that no one in academia or industry has proposed a full-coverage strengthening solution for the workpiece. Due to cost issues, industrial personnel in this field have no motivation to perform shock strengthening on the annular side surface 12, which was originally recognized as a non-crack-derived area; strengthening the annular side surface 12 is not a conventional technical means in this field, and the current solution does not provide any technical inspiration.

[0078] Based on the above solution, the applicant further optimized the solution. Based on the understanding of the crack initiation and development laws of the butterfly model, in order to further improve the strengthening effect of laser shock peening on the anode target, the loading path of laser shock peening should be consistent with the crack extension law, thereby better suppressing cracks.

[0079] like Figure 4 As shown, in order to make the loading path of the pulsed laser beam match the development law of crack derivation, a three-path processing method is designed, that is, in a radial direction of the disk surface layer, the outer ring edge 13 of the disk surface layer is first impacted, and the outer ring edge 13 is used as the starting point. The annular side surface 12 of the disk surface layer is loaded along the direction away from the center of the disk surface layer 10 with the first path 21 shown in the figure; then the annular side surface 12 of the disk surface layer 10 is impacted point by point along the direction pointing to the center of the disk surface layer 10 with the second path 22 shown in the figure and returns to the outer ring edge 13, and finally the area between the outer edge of the annular bombardment zone 15 and the outer ring edge 13 is loaded.

[0080] The first path 21 , the second path 22 , and the third path 23 follow the same development rules as the shock wave and crack derivation, and thus have a better crack suppression effect.

[0081] Of course, if optimal economic efficiency is not considered, after the step of sequentially impacting the area between the outer edge of the annular bombardment zone 15 and the outer ring edge 13 on the end surface 11 of the disk surface layer 10 in the direction toward the center of the disk surface layer 10, step 131 further includes:

[0082] Then, the area between the inner edge of the annular bombardment zone 15 and the inner ring edge 14 is impacted point by point along the direction pointing to the center of the disk surface layer 10.

[0083] After sequentially loading the first path 21, the second path 22, and the third path 23, the laser shock equipment then loads the area between the inner edge of the annular bombardment zone 15 and the inner ring edge 14 along the fourth path 24, as shown, pointing toward the center of the disk surface layer. This achieves a more effective laser shock strengthening effect.

[0084] Of course, since the temperature of the area between the inner edge of the annular bombardment zone 15 and the inner ring edge 14 is relatively high, the cracks propagated by the rebound of the material under high heat conditions are much smaller than the cracks propagated by the rebound of the material under low heat conditions. Therefore, the area between the inner edge of the annular bombardment zone 15 and the inner ring edge 14 may not be loaded by laser shock.

[0085] like Figure 5 As shown, the positions of each first laser shock spot 211 on the first path 21 are spaced apart from each other and do not overlap; and the position of each second laser shock spot 221 on the second path 22 is also spaced apart from each other, and the second laser shock spot 221 is located between the two first laser shock spots 211 on the first path 21.

[0086] At this time, the impact formed on the annular side surface 12 of the disk surface layer 10 has no repeated impact points, which has a better cost advantage.

[0087] Furthermore, the third laser shock spots (not shown) on the third path are also spaced apart from each other to match the first laser shock spots 211 and the second laser shock spots 221 spaced apart from each other on the annular side surface 12 .

[0088] As an optimization of the effect of the above embodiment, the positions of the first laser shock spots 211 on the first path 21 are spaced apart from each other and do not overlap; and the positions of the second laser shock spots 221 on the second path 22 are also spaced apart from each other, but overlap with two adjacent first laser shock spots 211, such as Figure 5 In this way, the annular side surface 12 of the disk surface layer 10 can form a continuously distributed impact strengthening path, which has a better strengthening effect.

[0089] Furthermore, the third laser shock spot on the third path is also overlapped to match the first laser shock spot 211 and the second laser shock spot 221 that are continuously overlapped and distributed on the annular side surface 12 .

[0090] Furthermore, the step of first impacting the outer edge 13 of the disk surface layer with a pulsed laser beam is specifically: impacting the outer edge 13 of the disk surface layer in an oblique manner. Because the outer edge 13 generally has chamfered or rounded corners, impacting the outer edge 13 perpendicular to the end face 11 of the disk surface layer 10 will not ensure that the laser shock wave fully covers the outer edge 13. Therefore, the present application adopts an oblique impact method to improve the strengthening effect of the outer edge 13.

[0091] Furthermore, since the oblique impact of the outer ring edge 13 would result in cumbersome processing if a rigid constraining layer (such as aluminum foil or black tape) were used, the constraining layer provided at the outer ring edge 13 is preferably a flexible constraining layer, such as water or an inorganic salt solution. A saturated inorganic salt solution is more optimally used. The reason for using an inorganic salt solution is that the high-density transparent liquid can better constrain the diffusion of impact products, enhance the amplitude of the shock wave, and prolong the duration of the shock wave action. This allows the shock wave generated on the workpiece surface to propagate directionally into the workpiece, allowing the distorted lattice in the stress-existing areas of the workpiece to be more effectively changed by the combined action of the shock wave and the original stress, thereby helping to improve the impact effect of the anode target.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A highly economical laser shock peening method for anode target disk, characterized in that: The anode target disk comprises a disk body (20), a disk surface layer (10) fixedly connected to the disk body (20), and a base layer (30) located below the disk body (20); the disk surface layer (10) comprises an end surface (11) and an annular side surface (12) arranged at an outer position of the end surface (11); an outer ring edge (13) is formed between the end surface (11) and the annular side surface (12); the end surface (11) has an annular bombardment area (15) that carries electron beam bombardment and generates X-rays; The laser shock peening method based on the above-mentioned anode target comprises the following steps: Step S1: clamping the anode target disk to be strengthened on the laser shock peening processing equipment, with the disk surface layer (10) of the anode target disk facing the laser head of the laser shock peening equipment; Step S2: emitting a pulsed laser beam through a laser shock peening treatment device; Step S3: impacting a target coverage area with a pulsed laser beam, wherein the target coverage area is composed of the annular side surface (12) of the disk surface layer (10) and the area between the outer edge of the annular bombardment zone (15) and the outer ring edge (13) in the end surface (11) of the disk surface layer (10).

2. The highly economical laser shock peening method for anode target according to claim 1, characterized in that: The step S3 is specifically as follows: S31: impacting the outer edge (13) of the disk surface layer (10) with a pulsed laser beam; S32: impacting the annular side surface (12) of the disk surface layer point by point in a direction away from the center of the disk surface layer (10); S33: Returning in the direction pointing to the center of the disk surface layer (10) and impacting the annular side surface (12) of the disk surface layer (10) point by point; S34: impacting the area between the outer edge of the annular bombardment zone (15) and the outer ring edge (13) in the end surface (11) of the disk surface layer (10) in sequence along the direction pointing to the center of the disk surface layer (10).

3. The highly economical laser shock peening method for an anode target according to claim 2, characterized in that: In the step S32, the laser shock path that strikes the annular side surface (12) of the disk surface layer (10) in a direction away from the center of the disk surface layer (10) is a first path (21); in the step S33, the laser shock path that returns to the direction toward the center of the disk surface layer (10) and strikes the annular side surface (12) of the disk surface layer (10) point by point is a second path (22); in the step S34, the laser shock path that sequentially strikes the area between the outer edge of the annular bombardment zone (15) and the outer ring edge (13) in the end surface (11) of the disk surface layer (10) in a direction toward the center of the disk surface layer (10) is a third path (23); On the first path (21), positions of the first laser shock spots (211) formed by the pulsed laser beam are spaced apart from each other; On the second path (22), the positions of the second laser shock spots (221) formed by the pulsed laser beam are spaced apart from each other, and the position of each second laser shock spot (221) is located between the two first laser shock spots (211); On the third path (23), the third laser shock spots formed by the pulsed laser beam are spaced apart from each other.

4. The highly economical laser shock peening method for an anode target according to claim 2, characterized in that: In the step S32, the laser shock path that strikes the side of the disk surface layer (10) in a direction away from the center of the disk surface layer (10) is the first path (21); in the step S33, the laser shock path that returns to the direction toward the center of the disk surface layer (10) and strikes the side of the disk surface layer (10) point by point is the second path (22); in the step S34, the laser shock path that sequentially strikes the area between the outer edge of the annular bombardment zone (15) and the outer ring edge (13) in the end face (11) of the disk surface layer (10) in the direction toward the center of the disk surface layer (10) is the third path (23); On the first path (21), positions of the first laser shock spots (211) formed by the pulsed laser beam are spaced apart from each other; On the second path (22), positions of the second laser shock spots (221) formed by the pulsed laser beam are spaced apart from each other, and each second laser shock spot overlaps two adjacent first laser shock spots (211); On the third path (23), the third laser shock spots formed by the pulsed laser beam are distributed overlapping with each other.

5. The highly economical laser shock peening method for anode target according to claim 2, characterized in that: In step S31, the pulsed laser beam impacts the outer ring edge (13) of the disk surface layer (10) in an oblique impact manner.

6. The highly economical laser shock peening method for an anode target according to claim 1, characterized in that: A flexible constraint layer is provided on the outer ring edge (13).

7. The highly economical laser shock peening method for an anode target according to claim 6, characterized in that: The flexible constraint layer is water or an inorganic salt solution.

8. The highly economical laser shock peening method for an anode target according to claim 7, characterized in that: The flexible constraint layer is a saturated inorganic salt melt.

9. The highly economical laser shock peening method for an anode target according to claim 1, characterized in that: The anode target disk is a tungsten target.

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