A heat storage layer welding surface and a processing method thereof, a target disc and a preparation method thereof

Abstract

The present application relates to the technical field of rotary anode target, and particularly relates to a heat storage layer welding surface and a processing method thereof, a target disc and a preparation method thereof. The processing method comprises the following steps: preparing a metal mixed powder: mixing each raw material powder of the metal mixed powder and uniformly dispersing; through a pretreatment means, metal powder is deposited and infiltrated into the heat storage layer welding surface to form a metal pretreatment layer; wherein the pretreatment means is a discharge plasma sintering treatment, a cold-pressing sintering treatment or a laser cladding treatment. By using the processing method provided by the present application, a metal pretreatment layer can be formed on the heat storage layer welding surface, and the metal pretreatment layer can be melted and infiltrated into the pores of the heat storage layer to form a pinning effect or a solid solution strengthening effect on the welding surface, so as to improve the welding layer strength of the subsequent welding surface and the metal matrix layer, and the safety of the target disc product in the use process can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of rotating anode target technology, and in particular to a heat storage layer welding surface and its processing method, a target disk and its preparation method. Background Technology

[0002] CT (Computed Tomography) imaging is a non-invasive, high-resolution imaging technique that clearly displays lesions inside the human body. It has become an indispensable tool in modern medical diagnosis and healthcare. The CT tube is the X-ray source in the entire CT scanner, considered the "core" of the CT scanner, while the rotating anode target, as the source of X-rays from the CT tube, is its "heart."

[0003] During operation, the anode target (tungsten-rhenium orbital layer) generates X-rays under high-energy electron beam bombardment. Due to the bombardment, the overall temperature of the target disk rises rapidly. Since graphite has a specific heat capacity several times greater than tungsten-molybdenum, graphite is typically welded onto the TZM molybdenum alloy substrate as a heat storage layer to increase the continuous operating time of the rotating anode target. The heat storage effect of graphite slows down the temperature rise of the target disk during continuous operation. Therefore, the structure of a common rotating anode target for CT tubes is as follows: a thin tungsten-rhenium alloy layer is placed on top as the orbital layer, which is then bonded to the TZM molybdenum alloy substrate layer. Graphite is welded onto the back of the molybdenum alloy target surface as a heat storage layer.

[0004] However, during the use of the rotating anode target, the temperature will constantly change. Due to the difference in thermal expansion coefficients between the TZM molybdenum alloy substrate layer and graphite, there will be a certain degree of thermal stress between the two materials. This thermal stress will adversely affect the connection stability between the two, thus affecting the working effect of the target disk. Therefore, the metal substrate layer and the heat storage layer need to have high welding strength. However, the existing target disk manufacturing process generally involves directly welding the substrate layer and the graphite layer together. This method does not pre-treat the welding surface of the graphite layer before welding, resulting in low welding strength at the weld joint, which affects the subsequent use effect of the target disk. Summary of the Invention

[0005] To address the shortcomings of the prior art mentioned in the background section, this invention provides a method for treating the welding surface of a thermal storage layer to improve the welding strength between the thermal storage layer and the metal substrate layer. The technical solution is as follows:

[0006] The method for treating the welded surface of the thermal storage layer includes the following steps:

[0007] Preparation of metal mixed powder: The raw material powders of the metal mixed powder are mixed and dispersed evenly; wherein, the metal mixed powder includes the following elemental components: Mo 10-50 at%, Ti 10-50 at%, Zr 10-50 at%, Nb 5-10 at%, Hf 5-10 at%, W 0-5 at%, Ta 0-5 at%; through pretreatment, the metal powder is deposited and penetrated into the welding surface of the heat storage layer to form a metal pretreatment layer; wherein, the pretreatment method is spark plasma sintering, cold pressing sintering, or laser cladding.

[0008] In one embodiment, the metal mixed powder is composed of the following elemental components: Mo 10-50 at%, Ti 10-50 at%, Zr 10-50 at%, Nb 5-10 at%, Hf 5-10 at%, W 0-5 at%, Ta 0-5 at%, and unavoidable impurities.

[0009] In one embodiment, each raw material powder of the metal mixed powder is an elemental metal powder with a purity ≥99.5% and a particle size range of 0.1 to 50 μm.

[0010] In one embodiment, the pretreatment method is spark plasma sintering, the process of which is as follows: the metal mixed powder is subjected to plasma sintering at a sintering temperature of 1400-1650℃, a pressure of 20-50MPa, and a holding time of 0.1-1h to obtain a sintered alloy block; the sintered alloy block is processed to the required shape and size specifications according to the size requirements; then the sintered alloy block is placed on the welding surface of the heat storage layer, and the heat storage layer with the sintered alloy block is subjected to vacuum high-temperature treatment; wherein the conditions of the vacuum high-temperature treatment are a holding time of 1700-1900℃ for 0.5-3h.

[0011] In one embodiment, the pretreatment method is cold pressing sintering, the process of which is as follows: placing the metal mixed powder in a mold and pressing it into a sheet alloy block; wherein, the pressing pressure is 100-400 MPa and the holding time is 0.1 min-1 h; then placing the sheet alloy block on the welding surface of the heat storage layer, and subjecting the heat storage layer with the sheet alloy block to vacuum high-temperature treatment; wherein, the conditions of the vacuum high-temperature treatment are holding at 1700-1900°C for 0.5-3 h.

[0012] In one embodiment, the pretreatment method is laser cladding, the process of which is as follows: a metal mixed powder is covered on the welding surface of the heat storage layer, and the welding surface of the graphite is treated by laser cladding so that the metal mixed powder melts and penetrates into the pores of the heat storage layer under the action of the laser; wherein, the laser power is 50-3000W, the laser scanning rate is 1-500mm / min, and the thickness of the powder layer of the metal mixed powder covering the welding surface of the heat storage layer is 10-100μm.

[0013] In one embodiment, the raw material powders of the metal mixed powder are ball-milled and mixed. The process is as follows: the raw material powders of the metal mixed powder are added into a ball milling jar and ball-milled for 6 to 100 hours under a protective atmosphere; wherein the protective atmosphere is one or more of argon, nitrogen and helium, and the ball-to-powder mass ratio is (1 to 30): 1.

[0014] The present invention also provides a welding surface for a heat storage layer, which is pretreated using the heat storage layer welding surface treatment method described above.

[0015] The present invention also provides a method for preparing a target disk, which includes a welding step; the welding step is: welding the welding surface of the heat storage layer to the metal substrate layer; wherein the welding surface of the heat storage layer is pretreated by the heat storage layer welding surface treatment method described above.

[0016] The present invention also provides a target disk, comprising a heat storage layer, a metal substrate layer and an orbital layer; the metal substrate layer is disposed on the upper surface of the heat storage layer, and the orbital layer is covered on the upper surface of the metal substrate layer; it is prepared by the target disk preparation method described above.

[0017] Based on the above, compared with the prior art, the method for treating the welding surface of a thermal storage layer provided by the present invention has the following beneficial effects:

[0018] The heat storage layer welding surface treatment method provided by the present invention can form a metal pretreatment layer on the heat storage layer welding surface, and the metal pretreatment layer can melt and penetrate into the pores of the heat storage layer, forming a pinning effect or solid solution strengthening effect on the welding surface, thereby improving the weld strength between the subsequent welding surface and the metal substrate layer, which can effectively enhance the safety of the target plate product during use.

[0019] Other features and beneficial effects of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other beneficial effects of the invention can be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Unless otherwise specified, the positional relationships shown in the drawings in the following description are based on the direction in which the components are drawn in the figure.

[0021] Figure 1 A schematic diagram of the target disk structure provided by the present invention in the frontal view;

[0022] Figure 2 A schematic diagram of the target disk structure provided by the present invention from a top view.

[0023] Figure 3 for Figure 2 AA cross-section view;

[0024] Figure 4 This is a schematic diagram of the structure of the sample provided by the present invention;

[0025] Figure 5 This is a schematic diagram of the welding strength test process provided by the present invention.

[0026] Figure label:

[0027] 200 Metal substrate layer 300 Thermal storage layer 400 Orbital layer

[0028] 310 welding surface 100 metal pretreatment layer Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all embodiments. The technical features designed in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0030] In the description of this invention, it should be noted that all terms used in this invention (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains, and should not be construed as limiting the invention; it should be further understood that the terms used in this invention should be understood to have the same meaning as those in the context of this specification and in the relevant field, and should not be understood in an idealized or overly formal sense, except as expressly defined in this invention.

[0031] The present invention provides the following embodiments and comparative examples:

[0032] The formulations (unit: atomic percentage, at%) of the embodiments and comparative examples provided by the present invention are shown in Table 1 below:

[0033] Table 1

[0034]

[0035]

[0036] According to the formula in Table 1, the 310 welding surface of the rotating anode target heat storage layer 300 is treated. The specific process is as follows:

[0037] Example 1

[0038] (1) Mo powder (particle size 1 μm), Ti powder (particle size 1 μm), Zr powder (particle size 1 μm), Nb powder (particle size 1 μm), and Hf powder (particle size 1 μm) were mixed in a molybdenum-lined mixing tank at a ratio of 10:50:20:10:10 at%, under argon protection at a slightly positive pressure (0.105-0.11 MPa), with a ball-to-particle mass ratio of 1:1 (pure molybdenum balls were used), and the mixing time was 6 h to obtain a metal mixed powder.

[0039] (2) The powder was subjected to discharge plasma sintering at a temperature of 1600℃ and a pressure of 40MPa for 0.5h to obtain sintered alloy blocks.

[0040] (3) The sintered alloy block slices are polished and placed on the brazing surface of the graphite in the heat storage layer 300. Then the graphite is placed in a high-temperature vacuum furnace and kept at 1750℃ for 1 hour before being cooled down with the furnace. The brazing surface 310 is then completed.

[0041] The dimensions of the sintered alloy block are φ120mm (diameter) × 0.3mm (height), and the dimensions of the welding surface 310 of the heat storage layer 300 are φ130mm (diameter).

[0042] (4) The treated heat storage layer 300 (graphite) is welded to the metal substrate layer 200 (TZM) to prepare the finished target disk.

[0043] The welding conditions in this process are: vacuum degree 0.01 Pa, holding temperature at 1750℃ for 30 min, pressure 0.1 MPa, and the raw material composition of the metal substrate layer 200 (TZM) is 0.513 wt% Ti, 0.109 wt% Zr, 0.375 wt% C, with the balance being Mo and unavoidable small amounts of impurities.

[0044] During this preparation process, the metal mixed powder melts and penetrates into the pores of graphite at high temperature, forming a pinning effect that increases the welding strength. Testing and analysis show that the welding strength of the untreated graphite (310 surface) is 12 MPa, while the welding strength of the treated graphite (Example 1) is 21 MPa, effectively increasing the safety of the product during use.

[0045] Example 2

[0046] (1) Mo powder (50μm), Ti powder (50μm), Zr powder (50μm), Nb powder (50μm), Hf powder (50μm), W powder (50μm), and Ta powder (50μm) were ball-milled in a molybdenum-lined ball mill jar at a ratio of 10:20:50:5:5:5:5 at%, under argon protection, with the argon pressure being slightly positive (0.105-0.11 MPa), the ball-to-material mass ratio being 20:1, and the ball material being pure molybdenum. The ball milling time was 48 hours to obtain a mixed metal powder.

[0047] (2) The metal mixture powder after ball milling is pressed into sheet alloy in a steel mold.

[0048] The pressing pressure is 300 MPa, and the holding time is 0.5 h.

[0049] (3) Place the sheet alloy on the brazing surface of the graphite, place it in a high-temperature vacuum furnace, keep it at 1850℃ for 2 hours, and then cool it down with the furnace.

[0050] The sheet alloy has dimensions of φ120mm (diameter) × 0.5mm (height), and the welding surface 310 of the heat storage layer 300 has dimensions of φ130mm (diameter).

[0051] (4) Weld the treated heat storage layer 300 graphite layer to the metal substrate layer 200 to prepare the finished target disk.

[0052] The welding conditions in this process are: vacuum degree 0.01 Pa, holding temperature at 1750℃ for 30 min, pressure 0.1 MPa, and the formulation of the metal substrate layer 200 (TZM) is 0.513 wt% Ti, 0.109 wt% Zr, 0.375 wt% C, with the balance being Mo and unavoidable small amounts of impurities.

[0053] During this preparation process, the metal mixed powder melts and penetrates into the pores of graphite at high temperature, creating a pinning effect. Simultaneously, due to the presence of various high-melting-point elements on the welding surface 310 of the graphite, a solid solution strengthening effect is formed in the weld layer after welding, increasing the welding strength. Testing and analysis show that the welding strength of graphite without welding surface 310 pretreatment is 12 MPa, while the welding strength of graphite after treatment in Example 2 is 24 MPa, effectively increasing the safety of the product during use.

[0054] Example 3

[0055] (1) Mo powder (20μm), Ti powder (20μm), Zr powder (20μm), Nb powder (20μm), Hf powder (20μm), W powder (20μm), and Ta powder (20μm) are mixed in a ratio of 50:10:10:10:10:5:5 at.% and then mixed in a molybdenum-lined mixing tank under argon protection at a slightly positive pressure (0.105-0.11 MPa). The ball-to-powder mass ratio is 1:1 (pure molybdenum balls are used) and the mixing time is 6 hours to obtain a metal mixed powder.

[0056] (2) The metal mixed powder is covered on the welding surface 310 of the heat storage layer 300, and the welding surface 310 of the graphite is treated by laser cladding so that the metal mixed powder melts and penetrates into the pores of the heat storage layer 300 under the action of the laser.

[0057] The laser power is 200W, the scanning rate is 300mm / min, and the thickness of the metal mixed powder covering the welding surface 310 of the heat storage layer 300 is 100μm.

[0058] (3) Weld the treated heat storage layer 300 graphite layer to the metal substrate layer 200 to prepare the finished target disk.

[0059] The welding conditions in this process are: vacuum degree 0.01 Pa, holding temperature at 1750℃ for 30 min, pressure 0.1 MPa, and the formulation of the metal substrate layer 200 (TZM) is 0.513 wt% Ti, 0.109 wt% Zr, 0.375 wt% C, with the balance being Mo and unavoidable small amounts of impurities.

[0060] During the preparation process, in the laser cladding, the metal mixture powder melts and penetrates into the pores of the graphite under the action of the laser, forming a pinning effect. Simultaneously, due to the presence of various high-melting-point elements on the welding surface 310 of the graphite, a solid solution strengthening effect is formed in the weld layer after welding, which increases the welding strength. Testing and analysis show that the welding strength of graphite without welding surface 310 pretreatment is 12 MPa, while the welding strength of graphite after treatment in Example 2 is 23 MPa, effectively increasing the safety of the product during use.

[0061] Comparative Example 1

[0062] Compared to the embodiment, Comparative Example 1 did not perform pretreatment on the welding surface 310 of the heat storage layer 300, and directly performed welding, with other conditions being the same as the embodiment.

[0063] Comparative Examples 2-7

[0064] Compared with Examples 1-3, the only difference between Comparative Examples 2-7 and Examples 1-3 is that the formulation of the pretreated metal mixed powder is different (see Table 1 for details); the steps of other metal mixed powder mixing steps, various spark plasma sintering treatments, cold pressing sintering treatments, and laser cladding treatments are consistent with the corresponding examples.

[0065] The products obtained in the examples and comparative examples were tested for relevant indicators under the same test conditions and methods. The test results are shown in Table 2 below.

[0066] Table 2

[0067] Graphite welding strength, MPa 21 24 23 12 16 project Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Graphite welding strength, MPa 17 14 15 13 13

[0068] In Table 2, the testing process for graphite welding strength is as follows: A sample of a certain size is prepared by cutting a section from the welding area between the heat storage layer 300 and the metal substrate layer 200; (e.g., ...) Figure 4 As shown, the metal substrate layer 200 of the sample is placed on two rows of symmetrically designed support points, with three support points in each row and a span of 10 mm between adjacent support points; pressure is applied to the centerline of the heat storage layer 300 of the sample, and the force value when the metal substrate layer 200 of the sample separates from the welding surface 310 of the heat storage layer 300 is recorded and converted to obtain the welding strength.

[0069] Among them, such as Figure 4-5 As shown, the left and right sides of the sample are the heat storage layer 300 and the metal substrate layer 200, respectively. The length of the sample L1 is 50 mm, the width of the sample W is 10 mm, and the thickness H1 is 5 mm. The length of the heat storage layer 300 is 25 mm, and the length of the metal substrate layer 200 is 25 mm.

[0070] The test results from the examples and comparative examples show that:

[0071] (1) Analysis of data from Comparative Example 1 and Example 2:

[0072] In Comparative Example 1, the graphite welding strength of the untreated surface 310 was 12 MPa. In the embodiment of the present invention, the graphite welding strength after treatment was 21-24 MPa, which can effectively increase the safety of the product during use.

[0073] It is known that by using the processing method of the present invention, a metal pretreatment layer 100 can be formed on the welding surface 310 of the heat storage layer 300, and the metal pretreatment layer 100 can melt and penetrate into the pores of the heat storage layer 300, forming a pinning effect or solid solution strengthening effect on the welding surface 310, thereby improving the weld strength between the subsequent welding surface 310 and the metal substrate layer 200, and effectively enhancing the safety of the target plate product during use.

[0074] (2) Analysis of data from Comparative Examples 2 and 3 and Example 1:

[0075] In Comparative Examples 2 and 3, the contents of Ti and Zr exceeded the specified range, and the contents of Nb and Hf were lower than the specified range (no addition). The weld strength of the treated graphite was 16-17 MPa, compared to 21-24 MPa in the embodiment of the present invention, indicating a decrease in weld strength.

[0076] Analysis of the pretreatment process of Comparative Examples 2-3 shows that when using the metal mixed powder formulation and treatment method of Comparative Examples 2 and 3, a large amount of liquid phase will be squeezed out or flow out under the given temperature and pressure, resulting in uneven alloy composition. This will affect the weld strength during the subsequent treatment and final welding of the 300 graphite heat storage layer.

[0077] It can be seen that: by using the metal mixed powder composed of the specific formula of the present invention, and using a specific pretreatment method to pretreat the welding surface 310 of the heat storage layer 300, the safety of the product during use can be effectively increased.

[0078] (3) Analysis of comparative examples 4, 5, 6 and example data:

[0079] In Comparative Example 4, the contents of Mo, Nb, and Hf are outside the scope defined in this application; in Comparative Example 5, the contents of Nb are outside the scope defined in this application; and in Comparative Example 6, the contents of Hf are outside the scope defined in this application. The weld strength of the treated graphite is 13-15 MPa, which is lower than that of the embodiments of the present invention.

[0080] Analysis of the pretreatment process of Comparative Examples 4-6 shows that when the alloy is treated with graphite using the treatment methods of Comparative Examples 4, 5, and 6 at a given temperature, a large number of unmeltable phases appear in the alloy. This results in uneven alloy composition and insufficient penetration and pinning effect of the alloy on graphite during graphite pretreatment, which will affect the strength of the weld layer during final welding.

[0081] It can be seen that: by using the metal mixed powder composed of the specific formula of the present invention, and using a specific pretreatment method to pretreat the welding surface 310 of the heat storage layer 300, the safety of the product during use can be effectively increased.

[0082] (4) Analysis of data from Comparative Example 7 and Example 1:

[0083] In Comparative Example 7, the W and Ta components exceeded the specified range, and the weld strength of the treated graphite was 13 MPa, which is lower than that of the embodiment of the present invention.

[0084] Analysis of the pretreatment process of Comparative Example 7 shows that when the alloy is treated with the treatment method of Comparative Example 7 under given laser conditions, a large number of unmeltable phases will appear in the alloy. This will result in uneven alloy composition and insufficient penetration and pinning effect of the alloy on the graphite during graphite pretreatment, which will affect the strength of the weld layer during the final welding.

[0085] It can be seen that: by using the metal mixed powder composed of the specific formula of the present invention, and using a specific pretreatment method to pretreat the welding surface 310 of the heat storage layer 300, the safety of the product during use can be effectively increased.

[0086] The present invention also provides a target disk:

[0087] like Figure 1-3 As shown, a metal substrate layer 200 is disposed on the upper surface of the heat storage layer 300, and a track layer 400 is covered on the upper surface of the metal substrate layer 200. In its preparation process, the welding surface 310 of the rotating anode target heat storage layer 300 of the present invention is pretreated by the welding surface 310 of the heat storage layer 300, and then the welding surface 310 is welded to the metal substrate layer 200.

[0088] As described above, the processing method of the present invention can improve the weld strength between the subsequent welding surface 310 and the metal substrate layer 200, thereby improving the connection strength between the heat storage layer 300 and the metal substrate layer 200, and effectively enhancing the safety of the target plate product during use.

[0089] The method for treating the welding surface 310 of the rotating anode target heat storage layer 300 provided by the present invention is used to improve the weld strength between the welding surface 310 of the heat storage layer 300 and the metal substrate layer 200, and includes at least the following mechanisms and beneficial effects:

[0090] The heat storage layer 300 welding surface 310 processing method provided by this invention, through the specific metal pretreatment layer 100 formulation design (i.e. metal mixed powder formulation design) on the welding surface 310, combined with specific pretreatment methods and processes (electrostatic plasma sintering, cold pressing sintering, or laser cladding), can form a metal pretreatment layer 100 on the welding surface 310 of the heat storage layer 300. The metal pretreatment layer 100 can melt and penetrate into the pores of the heat storage layer 300, forming a pinning effect or solid solution strengthening effect on the welding surface 310, thereby improving the weld strength between the subsequent welding surface 310 and the metal substrate layer 200, which can effectively enhance the safety of the target plate product during use.

[0091] The comparative results of the above-mentioned embodiments and comparative examples of this application show that when a combination of formulations beyond the scope of this application is used in conjunction with a specific pretreatment method (electromagnetic plasma sintering, cold pressing sintering, or laser cladding), the weld strength between the welding surface 310 of the heat storage layer 300 and the metal substrate layer 200 does not achieve the desired effect.

[0092] In addition, specific pretreatment methods (spark plasma sintering, cold pressing sintering, laser cladding) need to be matched with the metal mixed powder formulation, specifically:

[0093] (1) For plasma sintering:

[0094] The plasma sintering process for the metal mixed powder is as follows: sintering temperature is 1400–1650℃, pressure is 20–50 MPa, and holding time is 0.1–1 h. The upper limit of pressure is limited by the equipment and mold's pressure-bearing capacity, and cannot be too high during processing. Pressure below the range specified in this application will make it difficult to sinter the alloy block, affecting subsequent welding results. Similarly, if the sintering temperature is too high, a large amount of liquid phase will appear in the alloy, with many low-melting-point components melting and escaping under pressure, while high-melting-point components remain in the alloy, resulting in alloy composition deviation and poor demolding effect, leading to poor subsequent welding results. Thus, sintering temperature, pressure, and time interact and limit each other to achieve the desired effect.

[0095] The subsequent high-temperature treatment process is as follows: the vacuum high-temperature treatment conditions are 1700–1900℃ for 0.5–3 hours. If the high-temperature treatment temperature is too short or the time is too low, the sintered alloy ingot on the heat storage layer 300 will not completely melt to form a pinning effect or solid solution strengthening effect on the welding surface 310 of the heat storage layer 300. If the high-temperature treatment temperature is too high, a large amount of low-melting-point components in the sintered alloy ingot will volatilize, damaging the equipment and affecting the overall alloy composition ratio of the welding surface 310 (i.e., the metal pretreatment layer 100), resulting in poor subsequent welding strength. Therefore, the temperature and time of the high-temperature treatment interact and limit each other to achieve the desired effect.

[0096] (2) For cold pressing and sintering:

[0097] The metal mixed powder pressing process is as follows: pressing pressure is 100-400MPa, and holding time is 0.1min-1h; the upper limit of pressure is limited by the pressure bearing capacity of the equipment and mold, and cannot be too high during the process; while too low pressure or holding time will result in poor forming of the sintered alloy block, affecting the subsequent welding effect; the pressing pressure and time of cold pressing work together and limit each other to achieve the desired effect;

[0098] The subsequent high-temperature treatment process is as follows: the vacuum high-temperature treatment conditions are 1700–1900℃ for 0.5–3 hours. If the temperature and time of the high-temperature treatment are too low, the sheet-like alloy blocks on the heat storage layer 300 will not completely melt to form a pinning effect or solid solution strengthening effect on the welding surface 310 of the heat storage layer 300. If the temperature of the high-temperature treatment is too high, a large amount of low-melting-point components in the sheet-like alloy blocks will volatilize, damaging the equipment and affecting the overall alloy composition ratio of the welding surface 310 (i.e., the metal pretreatment layer 100), resulting in poor subsequent welding strength. Therefore, the temperature and time of the high-temperature treatment interact and limit each other to achieve the desired effect.

[0099] (3) For laser cladding:

[0100] The laser processing technique is as follows: the laser power is 50-3000W, the laser scanning rate is 1-500mm / min, and the thickness of the metal mixed powder covering the welding surface 310 of the heat storage layer 300 is 10-100μm. If the laser power is too low or the scanning rate is too fast (resulting in a short scanning dwell time), the laser processing applied after the laser scan will be insufficient, and the metal mixed powder will not melt. Similarly, if the thickness of the metal mixed powder layer is too high, the laser scan will not penetrate, and the metal mixed powder will not melt. This results in the metal mixed powder not being able to completely melt to form a pinning effect or solid solution strengthening effect on the welding surface 310 of the heat storage layer 300.

[0101] If the laser power is too high and the scanning rate is too slow (resulting in a long scanning dwell time), a large amount of low-melting-point components in the metal mixture powder will volatilize, damaging the equipment and affecting the overall alloy composition ratio of the welding surface 310 of the heat storage layer 300 (i.e., the metal pretreatment layer 100), leading to poor subsequent welding strength. Similarly, if the metal mixture powder layer thickness is too small, the local temperature during laser scanning will be too high, affecting the overall alloy composition ratio of the welding surface 310 of the heat storage layer 300, resulting in poor subsequent welding strength. Thus, laser power, scanning rate, and powder layer thickness interact and limit each other to achieve the desired effect. It should be noted that:

[0102] In addition to the actual selections shown in the specific embodiments above, the metal mixed powder includes the following elemental components: Mo 10-50 at%, Ti 10-50 at%, Zr 10-50 at%, Nb 5-10 at%, Hf 5-10 at%, W 0-5 at%, and Ta 0-5 at%. Each of the above elemental components can be within the above proportion range, including but not limited to the above embodiment schemes.

[0103] In this article, “~” is used to represent the range of values, and the range of values ​​represented by this expression includes two endpoint values.

[0104] The W, Mo, Ta, Nb, Hf, Ti, and Zr mentioned in this article are the metallic elements tungsten, molybdenum, tantalum, niobium, hafnium, titanium, and zirconium, respectively.

[0105] In summary, the specific parameters or some commonly used reagents or raw materials in the above embodiments are specific or preferred embodiments under the concept of this invention, and not limitations thereof; those skilled in the art can make adaptive adjustments within the concept and protection scope of this invention. Furthermore, unless otherwise specified, the raw materials used can also be commercially available products in the art, or prepared by conventional methods in the art.

[0106] Furthermore, those skilled in the art should understand that although many problems exist in the prior art, each embodiment or technical solution of the present invention can be improved in only one or a few aspects, without necessarily solving all the technical problems listed in the prior art or the background art simultaneously. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as a limitation on that claim.

[0107] Although this document frequently uses terms such as metallic substrate layer and orbital layer, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for treating the welding surface of a heat storage layer, characterized in that, Includes the following steps: Preparation of metal mixed powder: Mix the raw material powders of the metal mixed powder and disperse them evenly; The metal mixed powder comprises the following elemental components: Mo 10-50 at%, Ti 10-50 at%, Zr 10-50 at%, Nb 5-10 at%, Hf 5-10 at%, W 0-5 at%, Ta 0-5 at%. Through pretreatment, metal powder is deposited and infiltrated into the welding surface of the heat storage layer to form a metal pretreatment layer; wherein, the material of the heat storage layer is graphite; The pretreatment method is either spark plasma sintering, cold pressing sintering, or laser cladding. The discharge plasma sintering process is as follows: The metal mixture powder is subjected to plasma sintering at a temperature of 1400–1650°C, a pressure of 20–50 MPa, and a holding time of 0.1–1 h to obtain a sintered metal block. The sintered alloy block is processed into the required shape and size specifications according to the size requirements; Then, the sintered alloy block is placed on the welding surface of the heat storage layer, and the heat storage layer with the sintered alloy block is subjected to vacuum high-temperature treatment; wherein, the conditions for the vacuum high-temperature treatment are to hold at 1700-1900℃ for 0.5-3 hours. The cold pressing and sintering process is as follows: The metal mixture powder is placed in a mold and pressed into sheet-like alloy blocks; wherein the pressing pressure is 100-400 MPa and the holding time is 0.1 min-1 h. Then, the sheet-like alloy block is placed on the welding surface of the heat storage layer, and the heat storage layer with the sheet-like alloy block is subjected to vacuum high-temperature treatment; wherein, the conditions for the vacuum high-temperature treatment are to hold at 1700-1900℃ for 0.5-3 hours. The laser cladding process is as follows: the metal mixed powder is covered on the welding surface of the heat storage layer, and the welding surface of the heat storage layer is treated by laser cladding so that the metal mixed powder melts and penetrates into the pores of the heat storage layer under the action of the laser. The laser power is 50–3000W, the laser scanning rate is 1–500mm / min, and the thickness of the metal mixed powder covering the welding surface of the heat storage layer is 10–100μm.

2. The method for treating the welding surface of the heat storage layer according to claim 1, characterized in that: The metal mixed powder is composed of the following elemental components: Mo 10-50 at%, Ti 10-50 at%, Zr 10-50 at%, Nb 5-10 at%, Hf 5-10 at%, W 0-5 at%, Ta 0-5 at%, and unavoidable impurities.

3. The method for treating the welding surface of the heat storage layer according to claim 1, characterized in that: All raw material powders in the metal mixed powder are elemental metal powders with a purity ≥99.5% and a particle size range of 0.1~50μm.

4. The method for treating the welding surface of the heat storage layer according to claim 1, characterized in that: The process of mixing the raw material powders of the metal mixture is as follows: The raw material powders of the metal mixture are added into a ball mill jar and ball milled for 6 to 100 hours under a protective atmosphere. The protective atmosphere is one or more of argon, nitrogen, and helium, and the mass ratio of the balls to the material is (1-30):

1.

5. A welding surface for a heat storage layer, characterized in that: The pretreatment is performed using the heat storage layer welding surface treatment method as described in any one of claims 1-4.

6. A method for preparing a target disk, characterized in that: Including welding steps; The welding step is as follows: welding the welding surface of the heat storage layer to the metal substrate layer; The welding surface of the thermal storage layer is pretreated using the thermal storage layer welding surface treatment method as described in any one of claims 1-4.

7. A target disk, characterized in that: It includes a heat storage layer, a metal substrate layer, and a track layer; the upper surface of the heat storage layer is provided with a metal substrate layer, and the upper surface of the metal substrate layer is covered with a track layer; The target disk is prepared using the method described in claim 6.

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