A method for manufacturing a CT machine anode target disk using a composite material

Abstract

The present application relates to the technical field of anode target disc, in particular to a manufacturing method of a CT machine anode target disc prepared by using a new composite material. The anode target disc comprises a tungsten-based high specific gravity alloy disc and a graphite disc. The inner side surface of the tungsten-based high specific gravity alloy disc is uniformly provided with a plurality of protrusions. The inner side surface of the graphite disc is uniformly provided with a plurality of recesses. The tungsten-based high specific gravity alloy disc and the graphite disc are connected by embedding the protrusions in the recesses. The outer side surface of the tungsten-based high specific gravity alloy disc is provided with a tungsten or tungsten-rhenium coating. Compared with the prior art, the tungsten-based high specific gravity alloy and the graphite can be combined by the embedded design of the interface, thereby avoiding the problem of poor brazing strength. The interface between the tungsten-based high specific gravity alloy and the graphite is formed by a heat treatment process, thereby meeting the requirements of high interface strength and high heat conduction efficiency. The coating is prepared by using a sintering process, thereby avoiding the problem of high sintering temperature of tungsten-rhenium and traditional molybdenum-zirconium-titanium composite.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of anode target disc, in particular to a manufacturing method of a CT machine anode target disc prepared by using a composite material. BACKGROUND

[0002] With the development of computer technology, medical imaging technology has become a common diagnosis and treatment method in the medical industry. Among different imaging technologies, computed tomography (CT) equipment is one of the currently large-scale commercial technologies. CT scans a certain part of the human body by using an X-ray beam to surround it and then scans it in layers with a certain thickness. Finally, it becomes a digital image. The main work of the X-ray generator, CT tube, is to generate bremsstrahlung radiation by using an electron beam to bombard an anode target disc. However, only 1%-2% of the energy is used to emit X-rays, and the rest of the energy is converted into heat and stored in the anode target disc and the tube. The commonly used rotating target disc on the market is made of multiple layers of composite materials. Generally, the target disc is divided into three layers. The first layer is a tungsten-rhenium surface coating directly bombarded by the electron beam, which is used to generate X-rays. Tungsten has a high melting point, high thermal conductivity, low vapor pressure, high atomic number, and can produce high-intensity bremsstrahlung radiation. Adding rhenium to it can improve plasticity, reduce the ductile-brittle transition temperature, increase yield strength, and prevent deep crack propagation. The second layer is a molybdenum-zirconium-titanium (TZM) alloy, which is mainly used to connect with the bearing and store and conduct the heat generated during CT operation. This alloy has high melting point, high strength, small linear expansion coefficient, low vapor pressure, and good high-temperature mechanical properties. The third layer is graphite, which is mainly used for radiation and heat dissipation due to its large specific heat, small specific gravity, low vapor pressure, large radiation coefficient, and fast heat dissipation. The existing target disc needs to use brazing process to composite graphite and molybdenum-zirconium-titanium alloy together, and the solder is Ti, V / Ta / Zr, etc. Due to the difficulty of the process, few domestic manufacturers can produce it.

[0003] However, tungsten-based high-specific-gravity alloy has high strength, high hardness, good ductility, good toughness, good machinability, good corrosion and oxidation resistance, good electrical and thermal conductivity, good weldability, and small thermal expansion coefficient. Its combination with tungsten-rhenium alloy is better than that of tungsten-rhenium alloy with molybdenum-zirconium-titanium alloy, so it can replace molybdenum-zirconium-titanium alloy as the intermediate layer material of the target disc. The present application aims to provide a manufacturing method of a tungsten-rhenium-tungsten-based high-specific-gravity alloy-graphite composite CT machine anode target disc, which uses tungsten-based high-specific-gravity alloy and composite sintering process to replace the existing products on the market. SUMMARY

[0004] The application provides a manufacturing method of a CT machine anode target disc prepared from a composite material, which realizes the combination of tungsten-based high specific gravity alloy and graphite through the combined interface fitting design, avoids the problem of poor brazing strength, realizes the metallurgical combination of the tungsten-based high specific gravity alloy and the graphite combination interface through a heat treatment process, and meets the requirements of high connection interface strength and high heat conduction efficiency; and the tungsten or tungsten-rhenium coating is prepared on the tungsten-based high specific gravity alloy through a sintering process, and the combination force is better than that of the tungsten-rhenium coating and the traditional molybdenum-zirconium-titanium alloy.

[0005] To achieve the above object, a CT machine anode target disc prepared from a composite material is designed, the anode target disc is a reverse buckling disc, a center hole is arranged in the middle of the anode target disc, and the anode target disc is characterized in that: the anode target disc comprises a tungsten-based high specific gravity alloy disc and a graphite disc, a plurality of protrusions are uniformly arranged on the inner side surface of the tungsten-based high specific gravity alloy disc, a plurality of grooves are uniformly arranged on the inner side surface of the graphite disc, and the tungsten-based high specific gravity alloy disc and the graphite disc are connected by being embedded in the grooves through the protrusions.

[0006] The protrusions are cylindrical structures, rectangular columnar structures or circular table structures.

[0007] The protrusions are cylindrical structures, rectangular columnar structures or circular table structures.

[0008] The structure and number of the grooves are matched with those of the protrusions.

[0009] A manufacturing method of a CT machine anode target disc prepared from a composite material is provided, and the specific method is as follows:

[0010] S1, tungsten-based high specific gravity alloy powder required for 3D printing is configured, wherein the tungsten content is 85-99%, the nickel content is 0.5%-10.5%, the iron or copper content is 0.3%-7.5%, and the balance is trace amounts of cobalt, molybdenum, chromium and other elements;

[0011] S2, a tungsten-based high specific gravity alloy disc structure is prepared by using a 3D printing process;

[0012] S3, a graphite disc structure is prepared by using an isostatic pressing process;

[0013] S4, surface treatment processes are performed on the tungsten-based high specific gravity alloy disc and the graphite disc;

[0014] S5, the tungsten-based high specific gravity alloy disc and the graphite disc after the surface treatment are subjected to composite connection;

[0015] S6, the tungsten-based high specific gravity alloy disc and the graphite disc after the composite connection are subjected to a sintering process treatment, the sintering temperature is 1410-1560 DEG C, and the holding time is 60-120 minutes;

[0016] S7, the tungsten-based high specific gravity alloy disc and graphite disc after sintering are subjected to a tungsten or tungsten-rhenium coating (optional: tungsten, 5% tungsten-rhenium, 10% tungsten-rhenium) process, the coating thickness is 0.8-1.2 mm, the coating axial pressure is 20-60 MPa, the connecting temperature is 800-1100 DEG C, and the holding time is 20-120 minutes;

[0017] S8, the tungsten-based high specific gravity alloy disc and graphite disc after coating are subjected to ultrasonic cleaning, distilled water is used, the temperature is 50 DEG C, and the time is 30 minutes;

[0018] S9, the tungsten-based high specific gravity alloy disc and graphite disc after cleaning are subjected to degassing treatment, vacuum furnace annealing is used, the temperature is 900-1400 DEG C, and the holding time is 90-120 minutes, and finally the anode target disc is prepared.

[0019] In the step S1, the laser intensity of the 3D printing process is 100-250 W, the printing speed is 300-1000 mm / s, and the printing layer thickness is 20-40 um.

[0020] In the step S3, the specific process of the surface treatment process is as follows:

[0021] S31, 10% H2SO4 solution is used for immersion and washing, then deionized water is used for washing, and finally drying is carried out;

[0022] S32, 5% NaOH solution is used for immersion and washing, then deionized water is used for washing, and finally drying is carried out;

[0023] S33, the groove surface of the tungsten-based high specific gravity alloy disc and graphite disc connecting interface is cleaned by using a steel wire brush, the oxide layer is removed and the new base is completely exposed, and then acetone is used for cleaning.

[0024] Compared with the prior art, the application provides a manufacturing method of a CT machine anode target disc prepared from a composite material, the tungsten-based high specific gravity alloy and the graphite can be combined through the interface fitting design, the problem of poor brazing strength is avoided, the tungsten-based high specific gravity alloy and the graphite can form metallurgical combination through a heat treatment process, the requirements of high connection interface strength and high heat conduction efficiency are met, and the tungsten-rhenium and the traditional molybdenum-zirconium-titanium composite sintering temperature is high. BRIEF DESCRIPTION OF DRAWINGS

[0025] Fig. 1 It is a schematic diagram of the anode target disc structure.

[0026] Fig. 2 It is a schematic diagram of the tungsten-based high specific gravity alloy disc and graphite disc structure.

[0027] Figs. 3-5A schematic view of the protrusion structure. DETAILED DESCRIPTION

[0028] The application is further described below with reference to the accompanying drawings.

[0029] As Figs. 1-5 A CT machine anode target disc prepared using a composite material, the anode target disc is a reverse-dipped disc, a central hole 1 is arranged in the middle of the anode target disc, and the anode target disc comprises a tungsten-based high-specific-gravity alloy disc 2 and a graphite disc 3, a plurality of protrusions 4 are arranged on the inner side surface of the tungsten-based high-specific-gravity alloy disc 2, a plurality of grooves 5 are arranged on the inner side surface of the graphite disc 3, the tungsten-based high-specific-gravity alloy disc 2 and the graphite disc 3 are connected by the plurality of protrusions 4 embedded in the plurality of grooves 5, and a tungsten or tungsten-rhenium coating layer 6 is arranged on the outer side surface of the tungsten-based high-specific-gravity alloy disc 2.

[0030] The protrusions 4 are cylindrical structures, rectangular columnar structures, or circular truncated cone structures.

[0031] The protrusions 4 are at least nine.

[0032] The structure and number of the grooves 5 match those of the protrusions 4.

[0033] A manufacturing method of a tungsten or tungsten-rhenium-tungsten-based high-specific-gravity alloy-graphite composite CT machine anode target disc, and the specific method is as follows:

[0034] S1, configuring tungsten-based high-specific-gravity alloy powder required for 3D printing, wherein the tungsten content is 85-99%, the nickel content is 0.5%-10.5%, the iron or copper content is 0.3%-7.5%, and the balance is trace amounts of cobalt, molybdenum, chromium, palladium, manganese, and the like;

[0035] S2, using a 3D printing process to obtain a tungsten-based high-specific-gravity alloy disc structure;

[0036] S3, using an isostatic pressing process to obtain a graphite disc structure;

[0037] S4, performing a surface treatment process on the tungsten-based high-specific-gravity alloy disc and the graphite disc;

[0038] S5, performing composite connection on the tungsten-based high-specific-gravity alloy disc and the graphite disc after surface treatment;

[0039] S6, performing a sintering process on the tungsten-based high-specific-gravity alloy disc and the graphite disc after composite connection, the sintering temperature is 1410-1560°C, and the holding time is 60-120 minutes;

[0040] S7, the sintered tungsten-based high specific gravity alloy disc and the graphite disc are subjected to a tungsten or tungsten-rhenium coating process, the coating thickness is 0.8-1.2 mm, the coating axial pressure is 20-60 MPa, the connecting temperature is 800-1100 DEG C, and the holding time is 20-120 minutes;

[0041] S8, the coated tungsten-based high specific gravity alloy disc and the graphite disc are subjected to ultrasonic cleaning, distilled water is used, the temperature is 50 DEG C, and the time is 30 minutes;

[0042] S9, the cleaned tungsten-based high specific gravity alloy disc and the graphite disc are subjected to degassing treatment, vacuum furnace annealing is used, the temperature is 1200-1400 DEG C, and the holding time is 90-120 minutes, and finally, the anode target disc is obtained.

[0043] In step S1, the laser intensity of the 3D printing process is 100-250 W, the printing speed is 300-1000 mm / s, and the printing layer thickness is 20-40 um, and the overlap thickness is 60-100 um.

[0044] In step S3, the specific process of the surface treatment process is as follows:

[0045] S31, 10% H2SO4 solution is used for immersion washing, then deionized water is used for washing, and finally drying is carried out;

[0046] S32, 5% NaOH solution is used for immersion washing, then deionized water is used for washing, and finally drying is carried out;

[0047] S33, the groove surface of the tungsten-based high specific gravity alloy disc 2 and the graphite disc 3 connecting interface is cleaned with a steel wire brush, the oxide layer is removed and the new base body is completely exposed, and then acetone is used for cleaning.

[0048] The application does not need expensive equipment and a large number of operators, the process is simple and easy to operate, the production cycle and cost are reduced, the tungsten-based high specific gravity alloy is used to replace the traditional molybdenum-zirconium-titanium alloy, the sintering and graphite combination is used, the brazing step is omitted, the 3D printing and sintering process are used to replace the traditional powder metallurgy without reducing the performance, the sintering temperature is reduced, and then the energy consumption and production cost are reduced.

Claims

1. A CT machine anode target disk prepared using a composite material, the anode target disk being a reverse-buckled disc, a central hole (1) being formed in the middle of the anode target disk, characterized in that: The anode target disc comprises a tungsten-based high specific gravity alloy disc (2) and a graphite disc (3), a plurality of protrusions (4) are uniformly arranged on the inner side surface of the tungsten-based high specific gravity alloy disc (2), a plurality of grooves (5) are uniformly arranged on the inner side surface of the graphite disc (3), the tungsten-based high specific gravity alloy disc (2) is connected with the graphite disc (3) by being embedded in the grooves (5) through the protrusions (4); and the outer side surface of the tungsten-based high specific gravity alloy disc (2) is provided with a tungsten or tungsten-rhenium coating (6). A manufacturing method of an anode target disc of a CT machine prepared by using a composite material, and the specific method is as follows: S1, configuring tungsten-based high specific gravity alloy powder required for 3D printing, wherein the tungsten content is 85-99%, the nickel content is 0.5%-10.5%, the iron or copper content is 0.3%-7.5%, and the balance is trace amounts of cobalt, molybdenum, chromium, palladium and manganese elements; S2, using a 3D printing process to obtain a tungsten-based high specific gravity alloy disc structure; S3, using an isostatic pressing process to obtain a graphite disc structure; S4, performing a surface treatment process on the tungsten-based high specific gravity alloy disc and the graphite disc; S5, performing composite connection on the tungsten-based high specific gravity alloy disc and the graphite disc after surface treatment; S6, performing a sintering process on the tungsten-based high specific gravity alloy disc and the graphite disc after composite connection, the sintering temperature is 1410-1560 DEG C, and the holding time is 60-120 minutes; S7, performing a tungsten or tungsten-rhenium coating process on the tungsten-based high specific gravity alloy disc and the graphite disc after sintering, the coating thickness is 0.8-1.2 mm, the coating axial pressure is 20-60 MPa, the connection temperature is 800-1100 DEG C, and the holding time is 20-120 minutes; S8, performing ultrasonic cleaning on the tungsten-based high specific gravity alloy disc and the graphite disc after coating, using distilled water, the temperature is 50 DEG C, and the time is 30 minutes; S9, performing degassing treatment on the tungsten-based high specific gravity alloy disc and the graphite disc after cleaning, using a vacuum furnace annealing, the temperature is 900-1400 DEG C, and the holding time is 90-120 minutes, to finally obtain an anode target disc.

2. The CT machine anode target disk prepared using a composite material according to claim 1, characterized in that: The protrusions (4) are in cylindrical structure, rectangular columnar structure or circular table structure.

3. The CT machine anode target disk prepared using a composite material according to claim 1, characterized in that: The protrusions (4) are at least 9.

4. The CT anode target disk prepared using a composite material according to claim 1, characterized in that: The structure and number of the grooves (5) are matched with the structure and number of the protrusions (4).

5. The CT anode target disk prepared using a composite material according to claim 1, characterized in that: In step S1, the laser intensity of the 3D printing process is 100-250 W, the printing speed is 300-1000 mm / s, the printing layer thickness is 20-40 um, and the overlapping thickness is 60-100 um.

6. The CT anode target disk prepared using a composite material according to claim 1, wherein: In step S3, the specific process of the surface treatment process is as follows: S31, immersing in 10% H2SO4 solution, then cleaning with deionized water, and finally drying; S32, immersing in 5% NaOH solution, then cleaning with deionized water, and finally drying; S33, cleaning the groove surface of the tungsten-based high specific gravity alloy disc and the graphite disc connection interface with a steel wire brush, removing the oxide layer and completely exposing the new matrix, and then cleaning with acetone.

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