CN116403876A - X-ray anode target disk and preparation method thereof - Google Patents

Abstract

The embodiment of the specification provides an X-ray anode target disk and a preparation method thereof, wherein the target disk comprises a substrate and an electron beam track formed on a preset position of the substrate; the matrix material is a monocrystalline material; the electron beam track comprises a metal coating coated at the preset position of the substrate, and the metal coating is formed by carrying out laser cladding on metal powder at the preset position; the melting point of the metal powder is higher than that of the single crystal material; the preset position is located at the outer ring position of the upper surface of the substrate, and the upper surface of the substrate is one side of the substrate with the electron beam track.

Description

X-ray anode target disk and preparation method thereof

Technical Field

The specification relates to the field of medical imaging equipment, in particular to an X-ray anode target disc and a preparation method thereof.

Background

An X-ray generator is a vacuum tube that converts a power input into X-rays. The X-ray generator consists of an X-ray tube, a high voltage generator, a tube voltage and tube flow stabilizing circuit, a protection circuit and the like. The essence of the X-ray tube is a vacuum diode comprising a cathode and an anode. The anode target disk is an important component of the X-ray generator, and when the X-ray generator works, the anode target disk needs to bear electron impact from the cathode end of the X-ray generator to generate X-rays. When high-energy electrons strike on the target surface, the working temperature of the track surface of the target disk is up to 2600-2700 ℃, so that the anode target disk needs to have excellent high-temperature strength and thermal stability.

The anode target disk of the traditional X-ray tube is mostly made of refractory metal powder such as molybdenum, tungsten, niobium and alloy thereof through forging after powder metallurgy, and the target material has fine grains and contains a large number of powder grain interfaces and grain boundaries. Phonons, however, act as a medium for heat transfer, and cannot cross grain boundaries and grain boundaries, causing boundary scattering, which hinders heat transfer. And a large amount of gas is stored in the gaps between powder particles and particles, and can be released under the vacuum condition, which is unfavorable for the operation of the X-ray tube. Meanwhile, the heat dissipation capacity of the anode target plate is poor, cracks are usually generated on the target surface of the anode target plate, and the generated heat energy cannot be dissipated in time, so that the anode target plate is difficult to work stably for a long time, and the service life of the anode target plate is short.

Therefore, it is desirable to provide an X-ray anode target disk and a preparation method thereof, which effectively reduce the influence of grain boundaries and grain interfaces on the gas discharge amount and the heat dissipation process, and improve the heat dissipation efficiency and the high-temperature creep resistance of the X-ray anode target.

Disclosure of Invention

Because the working temperature of the anode target disk of the X-ray tube is high, creep is easy to occur through dislocation sliding and grain boundary sliding, and the use quality at high temperature is affected.

One of the embodiments of the present specification provides an X-ray anode target disk including a base body and an electron beam track formed on a preset position of the base body; the matrix material is a monocrystalline material; the electron beam track comprises a metal coating coated at the preset position of the substrate, and the metal coating is formed by carrying out laser cladding on metal powder at the preset position; the melting point of the metal powder is higher than that of the single crystal material; the preset position is located at the outer ring position of the upper surface of the substrate, and the upper surface of the substrate is one side of the substrate with the electron beam track.

In some embodiments, the single crystal material comprises at least one of a pure metallic molybdenum single crystal, a pure metallic tungsten single crystal, an alloy single crystal.

In some embodiments, the single crystal material is made using a metal feedstock and a single crystal seed, the single crystal material having a range of crystal orientations that is the same as the range of crystal orientations of the single crystal seed.

In some embodiments, the metal feedstock is the same metal species as the single crystal seed.

In some embodiments, the metal coating is columnar grain structure.

In some embodiments, the angular deviation between the target growth direction of the columnar grains and the direction of the temperature gradient provided by the laser cladding nozzle is less than a preset threshold.

In some embodiments, the target growth direction of the columnar grains is parallel to the temperature gradient direction.

In some embodiments, the bottom of the target disk includes a graphite base, one side of the graphite base being connected to a lower surface of a substrate, the lower surface of the substrate being a backside of an upper surface of the substrate.

In some embodiments, the metal coating comprises at least one of a tungsten rhenium coating and a tungsten coating.

One embodiment of the present disclosure provides a method for manufacturing an X-ray anode target disk, the target disk including a substrate and a track disposed on the substrate, the track and the substrate forming a track surface, the method including: acquiring a monocrystalline material as a matrix of an X-ray anode target disk; carrying out laser cladding on the metal powder at the preset position of the substrate to form a metal coating, wherein the position of the metal coating forms an electron beam track of the X-ray anode target disk; the preset position is positioned at the outer ring position of the upper surface of the substrate, and the melting point of the metal powder is higher than that of the monocrystalline material.

In some embodiments, the method comprises: the included angle between the temperature gradient direction provided by the laser cladding spray head and the inclined surface of the target disc is set to be in a preset range, the inclined surface of the target disc is positioned at the outer ring position of the upper surface of the substrate, and the inclined surface of the target disc is a plane where the preset position is located.

In some embodiments, the temperature gradient direction is perpendicular to the target disk sloped surface.

In some embodiments, the direction of the temperature gradient is perpendicular to a target disk surface, the target disk surface is located at an inner ring position of the upper surface of the substrate, the target disk surface is a plane parallel to the lower surface of the substrate in the upper surface of the substrate, an included angle exists between the target disk surface and the inclined surface of the target disk, and the lower surface of the substrate is the back side of the upper surface of the substrate.

In some embodiments, the method comprises: and spraying the metal powder and cladding by adopting a spray head, wherein the spray head is perpendicular to the inclined surface of the target disc.

In some embodiments, the single crystal material is made from a metal feedstock and a single crystal seed, the single crystal material having a range of crystal orientations that is the same as the range of crystal orientations of the single crystal seed; the method for obtaining the single crystal material as the matrix of the X-ray anode target disk comprises the following steps: and smelting the metal raw material to form a molten liquid, and solidifying the molten liquid to perform directional growth under the seeding action of the single crystal seed crystal to obtain the single crystal material.

Some embodiments of the present description include at least the following benefits:

(1) The metal coating is prepared by the mode of one or more embodiments in the specification, so that the crystal orientation can be controlled, the dislocation density and the number of crystal boundaries of crystal grains can be reduced, the heat conduction capability and creep resistance of the anode target disk under high temperature condition can be improved, the achievable peak power of the X-ray tube can be improved, and the service life of the X-ray tube in a high temperature working environment can be prolonged;

(2) The refractory metal is adopted to prepare the matrix, so that the density of the matrix can be increased, the hidden danger of gas storage in gaps of traditional powder metallurgy particles is weakened, the air release amount of an X-ray tube is reduced, and the ignition is avoided.

Drawings

The present specification will be further elucidated by way of example embodiments, which will be described in detail by means of the accompanying drawings. The embodiments are not limiting, in which like numerals represent like structures, wherein:

FIGS. 1A and 1B are schematic illustrations of exemplary structures of an X-ray anode target disk according to some embodiments of the present disclosure

FIG. 2 is an exemplary flow chart of a method of making an X-ray anode target disk according to some embodiments of the present description;

FIG. 3 is an exemplary flow chart for preparing single crystal material according to some embodiments of the present description;

FIG. 4 is an exemplary schematic illustration of grain boundary variations shown in accordance with some embodiments of the present description;

reference numerals illustrate: 100. an X-ray anode target disk; 101. a base; 102. electron beam trajectories; 103. a metal coating; 104. a graphite base; 105. and (3) the outer ring position.

Detailed Description

In order to more clearly illustrate the technical solutions of the embodiments of the present specification, the drawings that are required to be used in the description of the embodiments will be briefly described below. It is apparent that the drawings in the following description are only some examples or embodiments of the present specification, and it is possible for those of ordinary skill in the art to apply the present specification to other similar situations according to the drawings without inventive effort. Unless otherwise apparent from the context of the language or otherwise specified, like reference numerals in the figures refer to like structures or operations.

It will be appreciated that "system," "apparatus," "unit" and/or "module" as used herein is one method for distinguishing between different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

As used in this specification and the claims, the terms "a," "an," "the," and/or "the" are not specific to a singular, but may include a plurality, unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that the steps and elements are explicitly identified, and they do not constitute an exclusive list, as other steps or elements may be included in a method or apparatus.

A flowchart is used in this specification to describe the operations performed by the system according to embodiments of the present specification. It should be appreciated that the preceding or following operations are not necessarily performed in order precisely. Rather, the steps may be processed in reverse order or simultaneously. Also, other operations may be added to or removed from these processes.

In some embodiments, an X-ray anode target disk may include a substrate and an electron beam track disposed on the substrate.

The substrate is the main body portion of the X-ray anode target disk. The substrate may serve as a thermally conductive layer. The substrate may take a variety of forms. For example, the substrate may have a columnar structure such as a columnar structure, an elliptic columnar structure, a circular columnar structure, or the like. In some embodiments, the diameter of the substrate may be greater than or equal to 100mm, meeting the requirements of an X-ray generator.

In some embodiments, the matrix material is a single crystal material, e.g., a single crystal material of a refractory metal. Refractory metals have high melting point, high hardness, small expansion coefficient, good thermal conductivity, and good plasticity at high temperatures. The refractory metal is adopted as the heat conducting layer of the X-ray anode target plate, so that the heat absorbed by the electron beam track can be effectively conducted to the substrate, the anode target plate can work stably for a long time, and the service life of the anode target plate is prolonged.

In some embodiments, a single crystal material may be obtained as a substrate for an X-ray anode target disk. For more on single crystal material see fig. 2, 3 and their associated description.

The electron beam trajectory is the trajectory area on the X-ray anode target disk that receives the impact of high-speed electrons. The electron beam orbit may serve as a scattering layer for receiving the impact of high-speed electrons and radiating the generated heat.

In some embodiments, the electron beam trajectories may be formed at predetermined positions of the substrate. In some embodiments, the electron beam track may be formed on a partial region within the preset position. In some embodiments, the electron beam track may be formed over the entire area of the preset position.

In some embodiments, the predetermined location may be at the outer ring location of the upper surface of the substrate. The upper surface of the substrate is one side of the substrate with electron beam tracks. The outer ring position is an annular position located at the periphery of the upper surface of the base.

In some embodiments, the upper surface of the substrate may be a centrally-extending annular planar surface. The predetermined position may be located in a first annular region of the outer ring of the annular plane and the electron beam trajectory may be located in a second annular region of the outer ring of the annular plane. Wherein the inner diameter of the first annular region may be less than or equal to the inner diameter of the second annular region and/or the outer diameter of the first annular region may be greater than or equal to the outer diameter of the second annular region.

In some embodiments, the upper surface of the substrate may include a centrally-extending annular planar surface and an inclined annular planar surface contiguous with the annular planar surface. The inclined annular plane is the side surface of the round table. The preset position may be located in a third annular region of the outer ring of the inclined annular plane, and the electron beam trajectory may be located in a fourth annular region of the outer ring of the inclined annular plane. Wherein the inner diameter of the third annular region may be less than or equal to the inner diameter of the fourth annular region and/or the outer diameter of the third annular region may be greater than or equal to the outer diameter of the fourth annular region.

The preset position may be determined in a variety of ways. In some embodiments, the preset position may be determined according to a position of the electron beam impact. In some embodiments, the preset location may be preset by a system or by human beings.

In some embodiments, the electron beam rail includes a metal coating applied to a predetermined location of the substrate.

The metal coating is a coating structure coated on the electron beam rail. The metal coating may be applied to the entire electron beam track or to a portion of the electron beam track, which is not limited in this specification. In some embodiments, the electron beam trajectories of the X-ray anode target disk may be formed at the locations of the metal coating.

In some embodiments, the metal coating may include at least one of a tungsten rhenium coating and a tungsten coating. The tungsten-rhenium alloy is used as a coating material, so that the characteristics of the tungsten-rhenium alloy, such as high hardness, high stability and strength at high temperature, and the like, can be fully utilized, and the anode target disk can bear the impact of high-speed electron flow for many times under the conditions of high temperature, high vacuum and high-speed rotation, thereby effectively prolonging the service life of the anode target disk. The metal coating may also be other metal materials, which is not limited in this specification.

In some embodiments, the thickness of the metal coating may be 500 μm-1000 μm. The thickness of the metal coating layer can be set according to actual requirements, and the specification is not limited to the thickness.

In some embodiments, the metal coating may be formed by laser cladding the metal powder at a preset location. Wherein the melting point of the metal powder is higher than the melting point of the monocrystalline material. For more on metal powder, laser cladding see fig. 2 and its related description.

In some embodiments, the metal coating may be columnar grain structure. The columnar grain structure may be a structure formed during laser cladding.

The columnar grains may be long grains exhibiting columnar morphology in a three-dimensional space. The direction of the temperature gradient provided by the spray head of the laser cladding can guide the target growth direction of the columnar grains to be the same as or similar to the direction of the temperature gradient. The target growth direction is the main growth direction of columnar grains, and the growth speed of the grains in the target growth direction is higher. In some embodiments, the target growth direction may be the direction of the primary crystal axis of the columnar grains.

In some embodiments, the angular deviation between the target growth direction of the columnar grains and the direction of the temperature gradient provided by the laser cladding nozzle may be less than a preset threshold. The preset threshold value refers to a threshold value condition related to the angle deviation and is used for screening crystal grains with the same or similar target growth direction and the temperature gradient direction. The preset threshold may be a system default value, an empirical value, an artificial preset value, or any combination thereof, and may be set according to actual requirements, which is not limited in this specification.

Preferably, the angular deviation between the target growth direction of the columnar grains and the direction of the temperature gradient provided by the laser cladding nozzle may be zero, and the target growth direction of the columnar grains may be parallel to the direction of the temperature gradient provided by the laser cladding nozzle. For more explanation about the direction of the temperature gradient, see fig. 2 and its associated description.

In some embodiments, the bottom of the X-ray anode target disk may also include a graphite base. In some embodiments, one side of the graphite base is connected to the lower surface of the substrate, which is the backside of the upper surface of the substrate.

The graphite base may be used for heat dissipation. The graphite material is adopted as the base, so that the characteristics of graphite, namely high temperature resistance, good thermal conductivity and the like, can be fully utilized, the heat of the anode target disk can be rapidly emitted, and meanwhile, the anode target disk can not generate cracks after being cooled in a high-temperature environment.

In some embodiments, the graphite base and the lower surface of the substrate may be brazed with a braze such that the graphite base and the lower surface of the substrate are bonded together. Exemplary braze materials may include, but are not limited to, metals such as zirconium, titanium, and the like. The manner of brazing may include, but is not limited to, resistance brazing, induction brazing, brazing in a shielding gas furnace, brazing in a vacuum furnace, and the like.

For example only, the brazing process may include: placing the substrate, the base and the brazing material in a vacuum environment (for example, in a vacuum heating furnace), placing the brazing material and the base at preset positions on the substrate, heating the brazing material, the base and the substrate to a temperature above the melting point of the brazing material, and welding the base and the substrate through the melting and generated reaction of the brazing material.

The graphite base is not an essential structure of the X-ray anode target disk. In some embodiments, a pure metal target disc can be adopted, and a bearing and other structures are connected with the pure metal target disc, so that the effects of heat dissipation and the like are realized. The bearing heat dissipation efficiency is higher, and the radiating effect is better. The lubricating medium of the exemplary bearing may be liquid metal or the like.

Some of the examples described below may be understood with reference to fig. 1A and 1B, but the drawings are merely illustrative of some of the embodiments and are not limiting of the embodiments.

As shown in fig. 1A, 100 is an X-ray anode target plate, 101 is a substrate, 102 is an electron beam track, 103 is a metal coating, and 104 is a graphite base. As shown in fig. 1B, 105 is the outer ring position.

In some embodiments, the X-ray anode target disk 100 may include a substrate 101 and an electron beam track 102 disposed on the substrate 101, the electron beam track 102 having a metal coating 103 applied thereto. The metal coating 103 may be applied to a predetermined location of the substrate 101 at an outer annular location 105 of the upper surface of the substrate.

Fig. 2 is an exemplary flow chart of a method of manufacturing an X-ray anode target disk according to some embodiments of the present description. In some embodiments, the process 200 may be performed by a processor. The processor may execute computer instructions (e.g., program code) that may include, for example, methods, procedures, objects, components, data structures, procedures, modules, and/or functions that perform the particular functions described herein. The processor may execute the methods described in some embodiments of the present description in computer instructions.

As shown in fig. 2, the process 200 includes the following steps.

At step 210, monocrystalline material is obtained as a substrate for an X-ray anode target disk.

Monocrystalline materials can be obtained in a variety of ways.

In some embodiments, the monocrystalline material may be made using a metal feedstock and a monocrystalline seed crystal.

The metal raw material refers to a metal material used for preparing a single crystal material. The metal feedstock may be obtained in a variety of ways. For example, obtained directly by purchase, etc.

In some embodiments, the metal feedstock may be high purity molybdenum metal or tungsten metal. In some embodiments, the metal feedstock may also be high purity niobium metal, tantalum metal, vanadium metal, zirconium metal, rhenium metal, hafnium metal, or the like.

In some embodiments, the metal feedstock may also be an alloy metal rod of a molybdenum-niobium alloy, a molybdenum-hafnium alloy, or the like. Wherein, the proportion range of the molybdenum-niobium alloy can be that the niobium content accounts for 0-10wt%, and the proportion range of the molybdenum-hafnium alloy can be that the hafnium content accounts for 0-10wt%.

A single crystal seed is a small crystal with the same crystal orientation as the desired crystal and is the seed for growing a single crystal. The single crystal seed crystal has a certain crystal orientation. Monocrystalline seeds can be obtained in a number of ways. For example, obtained directly by purchase, etc.

In some embodiments, the single crystal material may include at least one of a pure metallic molybdenum single crystal, a pure metallic tungsten single crystal, and an alloy single crystal. In some embodiments, the alloy single crystal comprises at least one of a molybdenum niobium alloy single crystal, a molybdenum hafnium alloy single crystal.

In some embodiments, the melting point of the metal feedstock or monocrystalline material may be greater than a first preset threshold. The first preset threshold is a threshold condition related to the melting point of the material from which the matrix is made. The first preset threshold may be a system default value, an empirical value, an artificial preset value, or any combination thereof, and may be set according to an actual requirement, which is not limited in this specification. For example, the first preset threshold may be set higher than the temperature range to which the anode target disk is subjected when the X-ray generator is in operation.

The description of the material types of the metal raw material and the single crystal material is merely exemplary and does not constitute a limitation of the embodiment.

In some embodiments, the range of crystal orientation of the monocrystalline material is the same as the range of crystal orientation of the monocrystalline seed crystal. For example, when the crystal orientation of the tungsten single crystal seed is the <110> direction, the atomic direction of the tungsten single crystal material is also the <110> direction. Wherein, the crystal orientation may refer to the direction of the atomic arrangement inside the crystal grain.

In some embodiments, the metal feedstock is the same metal species as the monocrystalline seed crystal. For example, when the metal raw material is molybdenum metal, the single crystal seed is a single crystal seed corresponding to molybdenum; when the metal raw material is tungsten metal, the single crystal seed crystal is a single crystal seed crystal corresponding to tungsten, and the like.

In some embodiments, the single crystal material may be prepared by electron beam suspension zone melting or plasma arc melting techniques. In some embodiments, the process of preparing a single crystal material may include melting a metal feedstock to form a molten liquid, and directionally growing the single crystal material by solidification of the molten liquid under seeding of a single crystal seed. For more description of the preparation of single crystal materials, see fig. 3 and its associated description.

And 220, carrying out laser cladding on the metal powder at the preset position of the substrate to form a metal coating, wherein the position of the metal coating forms an electron beam track of the X-ray anode target disk.

The laser cladding can adopt high-energy laser as a heat source, metal powder as a raw material, and the laser and the metal powder synchronously act on the surface of another metal to be rapidly melted to form a molten pool, and then the molten pool is rapidly solidified to form a compact, uniform and thickness-controllable metallurgical bonding layer. The preparation of a metal coating by laser cladding will be exemplified below by step S1 and step S2.

Step S1, conveying metal powder to a preset position of a substrate.

Metal powders are materials used to prepare metal coatings. In some embodiments, the metal powder may include at least one of tungsten metal powder, rhenium metal powder. In some embodiments, the metal powder may be a tungsten rhenium alloy powder.

In some embodiments, the melting point of the metal powder may be higher than the melting point of the monocrystalline material. In some embodiments, the melting point of the metal powder may be greater than a second preset threshold. The second preset threshold is a threshold condition related to the melting point of the metal powder used to prepare the metal coating. It should be noted that the second preset threshold may be set higher than the first preset threshold. The temperature difference between the second preset threshold and the first preset threshold may be less than the preset temperature difference threshold. The second preset threshold value and the preset temperature difference threshold value may be a system default value, an empirical value, an artificial preset value, or any combination thereof, and may be set according to actual requirements, which is not limited in this specification.

The melt ratio of the cladding surface becomes large due to the excessively high or excessively low temperature difference. The too high melting point of the cladding material can lead to less melting amount of the material and the matrix in the cladding process, and the surface roughness of the cladding layer is higher; and too low melting point can cause excessive melting amount of cladding materials, strong metal fluidity and easy generation of air holes and inclusions. In some embodiments of the present disclosure, a better metallurgical bonding effect may be obtained by setting the temperature difference between the second preset threshold and the first preset threshold within a preset temperature difference threshold.

In some embodiments, a powder feeder may be used to deliver the metal powder to a predetermined location on the substrate.

The powder feeder is used for conveying metal powder and providing raw materials for laser cladding. In some embodiments, the powder feeder may be configured to feed the metal powder to a predetermined location on the substrate using a particular powder feed pattern. Exemplary powder feeding methods may include a powder preset method, a synchronous powder feeding method, and the like.

In some embodiments, the powder feeder includes an in-line gas shield spray head. The coaxial gas protection spray head can spray inert gas at the same time of spraying metal powder, and the direction of spraying the metal powder is consistent with the direction of spraying the inert gas. The sprayed inert gas plays a role in protection and isolation on the outer layer of the metal powder. Exemplary inert gases may include argon, helium, or argon/helium mixtures, and the like.

In some embodiments, a capacity detection module may be provided in the powder feeder. The capacity detection module is used for automatically alarming when the powder quantity is insufficient, so that an operator can conveniently supply the powder at any time.

And S2, controlling the cladding nozzle to carry out laser scanning on a preset position of the substrate, and rapidly melting metal powder at the preset position to form a high-temperature molten pool, and forming a metal coating after the metal powder is metallurgically combined with the upper surface of the substrate and solidified.

The cladding nozzle is used for emitting laser beams and the like. In some embodiments, the cladding nozzle may employ a specific cladding process to perform laser scanning along the track surface. Exemplary cladding processes may include gas fed powder cladding, gravity powder cladding, hot wire cladding, and the like.

In some embodiments, when laser cladding is used to prepare the coating, the dilution rate of the coating can be reduced by increasing the powder delivery rate of the powder delivery device and/or reducing the scanning speed of the cladding nozzle, preventing void generation. In some embodiments, the powder feeder may feed powder at a particular powder feed rate. In some embodiments, the cladding nozzle may be laser scanned at a particular scan speed. The powder feeding rate and the scanning speed can be a system default value, an empirical value, an artificial preset value, etc. or any combination thereof, and can be set according to actual requirements, which is not limited in the specification.

In some embodiments, the powder feeder and the cladding nozzle may be the same nozzle (hereinafter referred to as a laser cladding nozzle), i.e., one nozzle may be used for metal powder blowing and laser cladding.

In some embodiments, an included angle between a direction of a temperature gradient provided by the laser cladding nozzle and the inclined surface of the target disk may be set within a preset range. The inclined surface of the target disc is positioned on the plane of the preset position at the outer ring position of the upper surface of the substrate. The predetermined range refers to a range condition associated with the included angle for ensuring that the direction of the temperature gradient is substantially perpendicular to the inclined surface of the target disk (e.g., an included angle within the range of 80 ° -100 ° may be considered to be substantially perpendicular). Preferably, the direction of the temperature gradient may be set perpendicular to the inclined surface of the target plate.

In some embodiments, the angle between the direction of the temperature gradient and the surface of the target disk may be set within a preset range. The target disc surface is positioned at the inner ring position of the upper surface of the base body, the target disc surface is a plane parallel to the lower surface of the base body in the upper surface of the base body, an included angle exists between the target disc surface and the inclined surface of the target disc, and the lower surface of the base body is the back side of the upper surface of the base body. Preferably, the direction of the temperature gradient may be set perpendicular to the surface of the target disk.

In some embodiments of the present disclosure, by setting the included angle between the direction of the temperature gradient and the inclined surface of the target disc or the surface of the target disc within a preset range (preferably, setting the direction of the temperature gradient to be perpendicular to the inclined surface of the target disc or the surface of the target disc), grains having the primary crystal axis direction of columnar grains the same as or similar to the direction of the temperature gradient (for example, the included angle is within 10 ° and the directions of the primary crystal axis direction and the primary crystal axis direction are considered to be similar) can be rapidly grown along the direction of the temperature gradient, so as to generate columnar grains, and obtain the metal coating.

In some embodiments, the laser cladding heads may be disposed perpendicular to the inclined surface of the target disk. Through the arrangement, when the temperature gradient direction is difficult to accurately control and is perpendicular to the inclined surface of the target disc or the surface of the target disc, the included angle between the temperature gradient direction provided by the spray head and the inclined surface of the target disc or the surface of the target disc is in a preset range.

In some embodiments, the metal coating obtained by laser cladding may be columnar grain structure. In some embodiments, the angular deviation between the target growth direction of the columnar grains and the direction of the temperature gradient provided by the laser cladding nozzle is less than a preset threshold. Preferably, the target growth direction of the columnar grains may be parallel to the direction of the temperature gradient provided by the laser cladding nozzle. For more description of columnar grains, see the above-related description.

Because the anode target disk of the X-ray tube has high working temperature, creep deformation is easy to occur through dislocation sliding and grain boundary sliding, the service quality at high temperature is influenced, the crystal orientation can be controlled, the dislocation density and the grain boundary number of crystal grains can be reduced, the heat conduction capacity and creep resistance of the anode target disk under the high temperature condition are improved, the reachable peak power of the X-ray tube is improved, and the service life of the X-ray tube in the high temperature working environment is prolonged. As shown in fig. 4, fig. 4 is an exemplary schematic diagram of grain boundary variations shown in accordance with some embodiments of the present description. Fig. 4 is a schematic diagram of grain boundaries of a metal coating layer obtained by a conventional powder metallurgy forging preparation method, and fig. 4 is a schematic diagram of grain boundaries of a metal coating layer obtained by a metal coating layer preparation method according to some embodiments of the present specification. As shown in the left diagram of fig. 4, the metal coating 301 contains a large number of grain boundaries, and the dislocation density of the grain boundaries is high; as shown in the right hand graph of fig. 4, the dislocation density and the number of grain boundaries in the metal coating 302 are substantially reduced.

It should be noted that the above description of the process 200 is for illustration and description only, and is not intended to limit the scope of applicability of the present disclosure. Various modifications and changes to flow 200 will be apparent to those skilled in the art in light of the present description. However, such modifications and variations are still within the scope of the present description.

Fig. 3 is an exemplary schematic diagram of preparing single crystal material according to some embodiments of the present description.

In some embodiments, the single crystal material may be prepared by electron beam suspension zone melting or plasma arc melting techniques.

In some embodiments, a process for preparing a single crystal material may include: smelting the metal raw material to form molten liquid, and under the seeding action of the monocrystalline seed crystal, solidifying the molten liquid to perform directional growth to obtain the monocrystalline material.

Smelting of the metal feedstock may be accomplished by a heating system. The heating system is related to smelting technology. When the electron beam suspension area smelting technology is adopted, the heating system can smelt the metal raw material in a mode that kinetic energy of electrons moving at high energy and high speed is converted into heat energy. When the plasma arc melting technology is adopted, the heating system can use high-temperature plasma arc as a heat source to melt the metal raw material.

A single crystal seed may be placed below the melt zone. The melting zone is a zone for melting the metal feedstock. In some embodiments, the melt zone may move between the metal feedstock and the solidified feedstock at a certain movement rate. Exemplary melt zone movement speeds may be 0.5mm/min to 3mm/min. The moving speed of the melting zone can be set according to actual requirements, and the moving speed is not limited in the specification.

In some embodiments, the molten liquid metal feedstock that is dropped onto the monocrystalline seed crystal may be grown under seeding of the monocrystalline seed crystal in accordance with the crystal orientation of the monocrystalline seed crystal to yield the monocrystalline material. For example, where the metal species of both the single crystal seed and the metal feedstock are tungsten, the molten tungsten metal feedstock may be grown according to the crystal orientation of the tungsten single crystal seed, such as in the <110> direction, to form single crystal tungsten.

Taking the preparation of tungsten single crystal as an example, the process for preparing single crystal tungsten by using an electron beam suspension area melting method comprises the following steps: and heating the tungsten metal rod by utilizing an electron beam under high vacuum to form a small melting area, wherein the small melting area is kept between the tungsten metal rod and the solidified raw material, and moves according to a preset moving speed, and directionally solidifies under the seeding effect of the tungsten single crystal seed crystal to prepare the single crystal tungsten.

In some embodiments of the present disclosure, refractory metals are used to prepare the substrate, which may increase the density of the substrate, reduce the potential for gas storage in gaps between conventional powder metallurgical particles, reduce the outgassing of the X-ray tube, and avoid sparking.

While the basic concepts have been described above, it will be apparent to those skilled in the art that the foregoing detailed disclosure is by way of example only and is not intended to be limiting. Although not explicitly described herein, various modifications, improvements, and adaptations to the present disclosure may occur to one skilled in the art. Such modifications, improvements, and modifications are intended to be suggested within this specification, and therefore, such modifications, improvements, and modifications are intended to be included within the spirit and scope of the exemplary embodiments of the present invention.

Meanwhile, the specification uses specific words to describe the embodiments of the specification. Reference to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic is associated with at least one embodiment of the present description. Thus, it should be emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various positions in this specification are not necessarily referring to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of the present description may be combined as suitable.

Furthermore, the order in which the elements and sequences are processed, the use of numerical letters, or other designations in the description are not intended to limit the order in which the processes and methods of the description are performed unless explicitly recited in the claims. While certain presently useful inventive embodiments have been discussed in the foregoing disclosure, by way of various examples, it is to be understood that such details are merely illustrative and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements included within the spirit and scope of the embodiments of the present disclosure. For example, while the system components described above may be implemented by hardware devices, they may also be implemented solely by software solutions, such as installing the described system on an existing server or mobile device.

Likewise, it should be noted that in order to simplify the presentation disclosed in this specification and thereby aid in understanding one or more inventive embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof. This method of disclosure, however, is not intended to imply that more features than are presented in the claims are required for the present description. Indeed, less than all of the features of a single embodiment disclosed above.

In some embodiments, numbers describing the components, number of attributes are used, it being understood that such numbers being used in the description of embodiments are modified in some examples by the modifier "about," approximately, "or" substantially. Unless otherwise indicated, "about," "approximately," or "substantially" indicate that the number allows for a 20% variation. Accordingly, in some embodiments, numerical parameters set forth in the specification and claims are approximations that may vary depending upon the desired properties sought to be obtained by the individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and employ a method for preserving the general number of digits. Although the numerical ranges and parameters set forth herein are approximations that may be employed in some embodiments to confirm the breadth of the range, in particular embodiments, the setting of such numerical values is as precise as possible.

Each patent, patent application publication, and other material, such as articles, books, specifications, publications, documents, etc., referred to in this specification is incorporated herein by reference in its entirety. Except for application history documents that are inconsistent or conflicting with the content of this specification, documents that are currently or later attached to this specification in which the broadest scope of the claims to this specification is limited are also. It is noted that, if the description, definition, and/or use of a term in an attached material in this specification does not conform to or conflict with what is described in this specification, the description, definition, and/or use of the term in this specification controls.

Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments of this specification. Other variations are possible within the scope of this description. Thus, by way of example, and not limitation, alternative configurations of embodiments of the present specification may be considered as consistent with the teachings of the present specification. Accordingly, the embodiments of the present specification are not limited to only the embodiments explicitly described and depicted in the present specification.

Claims (15)

1. An X-ray anode target disk, characterized in that the target disk comprises a substrate and electron beam tracks formed on preset positions of the substrate;

the matrix material is a monocrystalline material;

the electron beam track comprises a metal coating coated at the preset position of the substrate, and the metal coating is formed by carrying out laser cladding on metal powder at the preset position; the melting point of the metal powder is higher than that of the single crystal material; the preset position is located at the outer ring position of the upper surface of the substrate, and the upper surface of the substrate is one side of the substrate with the electron beam track.

2. The target disk of claim 1, wherein the single crystal material comprises at least one of a pure metallic molybdenum single crystal, a pure metallic tungsten single crystal, and an alloy single crystal.

3. The target disk of claim 2, wherein the single crystal material is made of a metal feedstock and a single crystal seed, and a crystal orientation range of the single crystal material is the same as a crystal orientation range of the single crystal seed.

4. The target disk of claim 2, wherein the metal source material is the same metal species as the single crystal seed.

5. The target disk of claim 1, wherein the metal coating is columnar grain structure.

6. The target disk of claim 5, wherein an angular deviation between a target growth direction of the columnar grains and a direction of a temperature gradient provided by the laser cladding showerhead is less than a preset threshold.

7. The target disk of claim 6, wherein a target growth direction of the columnar grains is parallel to the temperature gradient direction.

8. The target disk of claim 1, wherein the bottom of the target disk comprises a graphite base, one side of the graphite base being connected to a lower surface of a substrate, the lower surface of the substrate being a backside of an upper surface of the substrate.

9. The target disk of claim 1, wherein the metal coating comprises at least one of a tungsten rhenium coating and a tungsten coating.

10. A method of preparing an X-ray anode target disk, the method comprising:

acquiring a monocrystalline material as a matrix of an X-ray anode target disk;

carrying out laser cladding on the metal powder at the preset position of the substrate to form a metal coating, wherein the position of the metal coating forms an electron beam track of the X-ray anode target disk; the preset position is positioned at the outer ring position of the upper surface of the substrate, and the melting point of the metal powder is higher than that of the monocrystalline material.

11. The method of claim 10, wherein the method comprises: the included angle between the temperature gradient direction provided by the laser cladding spray head and the inclined surface of the target disc is set to be in a preset range, the inclined surface of the target disc is positioned at the outer ring position of the upper surface of the substrate, and the inclined surface of the target disc is a plane where the preset position is located.

12. The method of claim 11, wherein the direction of the temperature gradient is perpendicular to the sloped surface of the target disk.

13. The method of claim 11, wherein the temperature gradient is oriented perpendicular to a target surface, the target surface being positioned at an inner ring of the upper surface of the substrate, the target surface being a plane of the upper surface of the substrate that is parallel to a lower surface of the substrate, the target surface being at an angle to the inclined surface of the target surface, the lower surface of the substrate being a backside of the upper surface of the substrate.

14. The method of claim 11, wherein the method comprises: and spraying the metal powder and cladding by adopting a spray head, wherein the spray head is perpendicular to the inclined surface of the target disc.

15. The method of claim 10, wherein the single crystal material is made from a metal feedstock and a single crystal seed, the single crystal material having a crystal orientation range that is the same as a crystal orientation range of the single crystal seed; the method for obtaining the single crystal material as the matrix of the X-ray anode target disk comprises the following steps:

and smelting the metal raw material to form a molten liquid, and solidifying the molten liquid to perform directional growth under the seeding action of the single crystal seed crystal to obtain the single crystal material.

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