Anode rotor thermal radiation coating as well as preparation method and application thereof

Abstract

The invention provides an anode rotor thermal radiation coating and a preparation method and application thereof, and belongs to the technical field of metal surface treatment.The anode rotor thermal radiation coating comprises a bonding layer, a stress slow release layer and a thermal radiation layer which are sequentially stacked on the surface of an anode rotor base body; the bonding layer comprises a Ni layer, the stress slow release layer comprises a metal-carbon composite layer, metal elements in the metal-carbon composite layer comprise Cr and / or Ti, and the heat radiation layer comprises a graphite-like carbon material layer. According to the anode rotor coating, the problem of internal stress of the coating is effectively solved, the heat conduction and vacuum heat dissipation performance of the coating is improved, under the working condition of high-temperature thermal cycle of an anode rotor, the coating does not release gas and does not contain volatile substances, the coating keeps good compactness and bonding strength, and therefore the stability of the anode rotor under the thermal shock working condition is effectively improved, and the service life of the anode rotor under the thermal shock working condition is effectively prolonged.

Description

Technical Field

[0001] This invention belongs to the field of metal surface treatment technology, specifically relating to an anode rotor thermal radiation coating, its preparation method, and its application. Background Technology

[0002] The X-ray tube in a computed tomography (CT) scanner is the core radiation source for modern medical imaging, and its performance directly determines imaging speed, resolution, and equipment reliability. Inside the tube, the rotating anode assembly is a critical energy conversion and load-bearing component, consisting of a high-speed rotating target disk, rotor, and substrate. During the CT working cycle, an electron beam emitted from the cathode continuously bombards the focal trajectory of the target surface at extremely high power, generating X-rays and generating enormous heat, causing the instantaneous temperature of the target disk to exceed 2000°C. The rotating anode assembly therefore operates under extremely harsh conditions for extended periods.

[0003] Since the bearing operates in a vacuum environment, the rotor's heat dissipation efficiency and the stability of the coating structure are prerequisites for ensuring stable bearing operation. The rotor itself directly determines the X-ray tube's power load and imaging stability.

[0004] Anode rotors typically use oxygen-free copper or copper alloys with high thermal conductivity as the base material. They rotate at high speeds (usually thousands or even tens of thousands of revolutions per minute) to disperse the enormous heat load generated by the electron beam bombardment of the target surface, preventing localized overheating and target surface melting. During operation, the rotor not only endures extremely high centrifugal forces and mechanical stresses, but its temperature field is also in a state of violent cycling due to the intermittent bombardment of the electron beam, with surface temperatures fluctuating rapidly between room temperature and 400°C or even higher. This extreme thermal shock condition places stringent requirements on the rotor's performance, demanding excellent wear resistance, stable thermal conductivity, high radiative heat dissipation efficiency, and durability under long-term thermal shock conditions.

[0005] Currently, the industry commonly uses thermal spraying to coat alumina or titanium dioxide materials, or electroplating to deposit hard chromium or black chromium layers, to form a functional coating, i.e., a heat radiation layer, on the surface of copper-based rotors for radiative heat dissipation. However, thermally sprayed coatings generate significant thermal stress, and copper, being relatively soft, is prone to deformation. Electroplating uses electrochemical methods, with the deposition process taking place in a liquid environment. The electrodeposition process requires various inorganic or organic compounds as corrosion inhibitors to reduce stress, inevitably introducing impurities and causing outgassing at high temperatures. Furthermore, coatings generally suffer from high internal stress and expansion mismatch with the substrate. Under actual high-power and high-cycle thermal conditions, if cracks exist initially, the coating is highly susceptible to crack propagation and peeling failure after a period of service. Coating failure not only reduces the rotor's heat radiation efficiency and affects heat dissipation balance, but the peeling material can also disrupt the vacuum environment inside the X-ray tube or cause arcing, leading to decreased image quality and even premature equipment failure.

[0006] Therefore, there is a need to provide a coating that can adapt to the extreme operating conditions of the anode rotor, improve the rotor's thermal radiation performance and thermal cycling stability, thereby improving the overall performance and reliability of the X-ray tube. Summary of the Invention

[0007] The purpose of this invention is to provide an anode rotor thermal radiation coating, its preparation method and application, to improve the thermal radiation performance and thermal cycling stability of the anode rotor.

[0008] To achieve this objective, the present invention employs the following technical solution:

[0009] In a first aspect, the present invention provides an anode rotor thermal radiation coating, the anode rotor thermal radiation coating comprising: a bonding layer, a stress relief layer and a thermal radiation layer sequentially stacked on the surface of an anode rotor substrate; the bonding layer comprising a Ni layer, the stress relief layer comprising a metal-carbon composite layer, the metal element in the metal-carbon composite layer comprising Cr and / or Ti, and the thermal radiation layer comprising a graphite-like carbon material layer.

[0010] The anode rotor uses copper as its substrate. The thermal radiation coating provided by this invention forms a gradient structure on the surface of the copper substrate. The innermost layer is a Ni layer, utilizing the good solid solution ability of Ni with the copper substrate to ensure the structural stability of the thermal radiation layer. The stress relief layer uses Cr and / or Ti as its metallic element composition. It has a certain solid solution effect with the bonding layer and forms a gradient effect with the outer thermal radiation layer, further enhancing the bonding force of the thermal radiation layer and effectively regulating and releasing surface thermal stress. The outermost layer is a graphite-like thermal radiation layer, which can provide good thermal radiation performance, quickly and effectively dissipating heat from the anode components, ensuring stable bearing operation, and sp 2 The high content of orbital hybrid bonds avoids the impact of excessive DLC (diamond-like carbon) phase on the total emissivity. By adapting and coordinating the various functional layers of the coating, the internal stress of the coating is resolved, and the thermal conductivity and heat dissipation performance of the coating are improved. Through the synergistic improvement of these two properties, the quality and bonding strength of the coating under thermal shock conditions of the anode rotor are improved, thereby effectively improving the stability and lifespan of the anode rotor under thermal shock conditions.

[0011] Preferably, the anode rotor substrate is made of copper; the copper includes dispersed copper and / or oxygen-free copper.

[0012] Preferably, the thickness of the bonding layer is 0.1-0.5 μm, for example, it can be 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm or 0.5 μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0013] Preferably, the thickness of the stress relief layer is 0.2-2μm, for example, it can be 0.2μm, 0.5μm, 1μm, 1.5μm or 2μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0014] Preferably, in the metal-carbon composite layer, the content of metal elements gradually decreases from the anode rotor substrate to the coating surface.

[0015] Preferably, the metal-carbon composite layer comprises a metal layer and a metal-carbon composite material layer stacked sequentially.

[0016] Preferably, the thickness of the metal layer is 0.1-1.0 μm, for example, it can be 0.1 μm, 0.3 μm, 0.5 μm, 0.8 μm or 1.0 μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0017] Preferably, the atomic percentage of the metal element in the metal-carbon composite material layer is 5%-99%, for example, it can be 5%, 10%, 30%, 50%, 80%, 90% or 99%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0018] The metal-carbon composite layer is composed of a metal-carbon composite material, which includes a metal, a metal carbide, and a component with sp. 2 Hybridized carbon.

[0019] Preferably, the metal-carbon composite material layer comprises at least two gradient layers stacked together.

[0020] Preferably, the metal-carbon composite material layer comprises: a first gradient layer and a second gradient layer stacked together, or a first gradient layer, a second gradient layer and a third gradient layer stacked together.

[0021] Preferably, in the first gradient layer, the atomic percentage of metal elements is 60%-99%, for example, it can be 60%, 70%, 80%, 90% or 99%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0022] Preferably, the thickness of the first gradient layer is 0.1-0.3 μm, for example, it can be 0.1 μm, 0.15 μm, 0.2 μm, 0.25 μm or 0.3 μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0023] Preferably, in the second gradient layer, the atomic percentage of metal elements is 20%-60%, for example, it can be 20%, 30%, 40%, 50% or 60%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0024] Preferably, the thickness of the second gradient layer is 0.1-0.2 μm, for example, it can be 0.1 μm, 0.12 μm, 0.15 μm, 0.18 μm, or 0.2 μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0025] Preferably, in the third gradient layer, the atomic percentage of metal elements is 5%-20%, for example, it can be 5%, 8%, 10%, 15% or 20%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0026] Preferably, the thickness of the third gradient layer is 0.1-0.2 μm, for example, it can be 0.1 μm, 0.12 μm, 0.15 μm, 0.18 μm, or 0.2 μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0027] Preferably, the thickness of the thermal radiation layer is 0.2-2.0 μm, for example, it can be 0.2 μm, 0.4 μm, 0.6 μm, 0.8 μm, 1.0 μm, 1.2 μm, 1.6 μm, 1.8 μm or 2.0 μm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0028] Preferably, the emissivity of the material of the thermal radiation layer is ≥0.8 across all wavelengths.

[0029] Emissivity refers to the ratio of the radiant energy emitted by a material surface at a specific temperature to the radiant energy emitted by a blackbody at the same temperature. In this invention, the temperature is 300°C, and the full wavelength generally refers to the range of 0.2-50 μm. The emissivity is determined using the steady-state calorimetry method commonly used in this field.

[0030] Preferably, in the graphite-like carbon material layer, the graphite-like carbon material contains sp 2 The percentage of hybridized carbon atoms in the total number of carbon atoms is ≥70%, for example, it can be 70%, 75%, 80%, 85%, 90% or 99%, but is not limited to the listed values. Other unlisted values ​​within the range also apply.

[0031] By controlling the sp in the graphite-like carbon material layer 2 The proportion of hybrid carbon atoms can improve coating stress and enhance the thermal radiation performance of the coating, thereby improving the thermal cycling stability of the anode rotor.

[0032] Preferably, the material of the graphite-like carbon material layer includes graphite-like carbon doped with metal elements.

[0033] By doping graphite-like carbon materials with metal elements, the stress generated by phase transformation can be avoided, further increasing the service temperature of the coating to over 600℃ and improving the stability of the coating.

[0034] Preferably, the metal elements in the graphite-like carbon material layer include at least the metal elements of the stress-relieving layer.

[0035] Preferably, in the graphite-like carbon material layer, the atomic percentage of metal elements is ≤3%, for example, it can be 0%, 0.5%, 1%, 1.5%, 2%, 2.5% or 3%, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable, and it is further preferred to be 1%-3%.

[0036] In a second aspect, the present invention provides a method for preparing the anode rotor thermal radiation coating described in the first aspect, the method comprising the following steps:

[0037] A bonding layer, a stress relief layer, and a thermal radiation layer are sequentially deposited on the surface of the anode rotor substrate using a vapor phase deposition method.

[0038] The coating preparation method of this invention adopts vapor phase deposition and is prepared in a vacuum environment, which is very suitable for the high vacuum operating environment of X-ray tubes. The vapor phase deposition method can eliminate impurities and volatile substances, and obtain a dense film layer. The graphite-like carbon material layer prepared under vacuum vapor phase deposition conditions can avoid the formation of hydrogen-containing carbon films, improve film stability, relieve internal stress of the coating, and inhibit coating cracks. Deposition at a certain temperature can improve the stability of the coating during thermal cycling service.

[0039] Preferably, during the vapor deposition process, the temperature of the anode rotor substrate is controlled to be 100-400℃, for example, 100℃, 150℃, 200℃, 250℃, 300℃, 350℃ or 400℃, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0040] By controlling the temperature of the anode rotor substrate during the deposition process, the sp content in the graphite-like carbon material layer can be increased. 2 The number of hybrid carbon atoms increases, thereby improving the thermal cycling stability of the anode rotor.

[0041] Preferably, the preparation method further includes: pretreating the surface of the anode rotor substrate.

[0042] Preferably, the pretreatment method includes sequentially performing degreasing cleaning and plasma cleaning on the anode rotor substrate.

[0043] Preferably, the degreasing and cleaning process uses at least one of hydrocarbon cleaning agents, alcohol, or acetone.

[0044] The hydrocarbon cleaning agent can be any conventional hydrocarbon cleaning agent used in this field.

[0045] Preferably, the degreasing and cleaning method employs ultrasonic cleaning.

[0046] Preferably, the temperature for the degreasing and cleaning is 40-60℃, for example, 40℃, 45℃, 50℃, 55℃ or 60℃, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0047] Preferably, the plasma cleaning is performed under vacuum conditions, wherein the vacuum degree is 10. -4 Pa-10 - 3 Pa, for example, could be 1×10 -4 Pa, 2×10 -4 Pa, 4×10 -4 Pa, 6×10 -4 Pa, 8×10 -4 Pa or 10×10 -4 Pa, but not limited to the listed values, applies to other unlisted values ​​within the range as well.

[0048] Preferably, the bias voltage for plasma cleaning is -600V to -1000V, for example, it can be -600V, -700V, -800V, -900V or -1000V, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0049] Preferably, the plasma source gas for the plasma cleaning includes argon.

[0050] Preferably, the flow rate of the plasma source gas is 30-60 sccm.

[0051] Preferably, the plasma cleaning time is 10-30 min, for example, it can be 10 min, 15 min, 20 min, 25 min or 30 min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0052] Preferably, the vapor deposition method includes arc ion plating and / or magnetron sputtering.

[0053] Preferably, the working vacuum degree of the magnetron sputtering is 0.1-1 Pa, for example, it can be 0.1 Pa, 0.2 Pa, 0.3 Pa, 0.5 Pa or 1 Pa, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0054] Preferably, the working gas for magnetron sputtering includes argon.

[0055] Preferably, the flow rate of the working gas in the magnetron sputtering is 10-30 sccm, for example, it can be 10 sccm, 15 sccm, 20 sccm, 25 sccm or 30 sccm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0056] Preferably, the bias voltage of the magnetron sputtering is -50V to -200V, for example, it can be -50V, -80V, -100V, -150V or -200V, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0057] Preferably, the target current of the magnetron sputtering is 0.2-3A, for example, it can be 0.2A, 0.4A, 0.8A, 1.0A, 2A or 3A, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0058] Preferably, in the magnetron sputtering, the temperature of the anode rotor substrate is controlled to be 100-300℃, for example, 100℃, 150℃, 200℃, 250℃ or 300℃, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0059] Preferably, the arc ion plating is performed using magnetically filtered cathode arc ion plating.

[0060] Preferably, the working vacuum degree of the arc ion plating is (1-5)×10⁻⁶. -3 Pa, for example, could be 1.0 × 10⁻⁶. - 3 Pa, 1.5 × 10 -3 Pa, 2.0×10 -3 Pa, 3.5 × 10 -3 Pa or 5.0 × 10 -3 Pa, but not limited to the listed values, applies to other unlisted values ​​within the range as well.

[0061] Preferably, the working gas for the arc ion plating includes argon.

[0062] Preferably, the flow rate of the working gas in the arc ion plating is 1-3 sccm, for example, it can be 1.0 sccm, 1.5 sccm, 2.0 sccm, 2.5 sccm or 3.0 sccm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0063] Preferably, the target current of the arc ion plating is 50-80A, for example, it can be 50A, 60A, 70A or 80A, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0064] Preferably, in the arc ion plating, the temperature of the anode rotor substrate is controlled to be 200-400℃, for example, 200℃, 250℃, 300℃ or 400℃, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0065] Preferably, the raw materials for preparing the bonding layer include a nickel target.

[0066] Preferably, the raw materials for the stress corrosion inhibitor layer include metal targets and graphite targets. The metal targets include chromium targets and / or titanium targets.

[0067] The raw materials for the thermal radiation layer include metal targets and / or graphite targets, and the metal targets include chromium targets and / or titanium targets.

[0068] In this invention, all the targets used are high-purity targets with a purity of >99.99%.

[0069] Thirdly, the present invention provides an anode rotor, the anode rotor comprising an anode rotor substrate and the anode rotor thermal radiation coating described in the first aspect on the anode rotor substrate.

[0070] Compared with the prior art, the present invention has the following beneficial effects:

[0071] The anode rotor coating of this invention, through a gradient structure design of a bonding layer, a stress-relieving layer, and a heat-radiating layer, solves the expansion mismatch between the substrate and the coating, and resolves the internal stress problem of the coating, thereby improving the adhesion between the coating and the substrate. Simultaneously, the heat-radiating layer enhances the heat dissipation efficiency of the coating. Through the synergistic improvement of internal stress resolution and thermal performance, the coating maintains good quality and bonding strength under the high-temperature thermal cycling conditions of the anode rotor, effectively improving the stability and lifespan of the anode rotor under thermal shock conditions. Attached Figure Description

[0072] Figure 1 This is a schematic diagram of the structure of the anode rotor thermal radiation coating provided in Example 1;

[0073] Wherein, 100 is the anode rotor substrate; 200 is the bonding layer; 301 is the metal layer; 302 is the first gradient layer; and 400 is the thermal radiation layer.

[0074] Figure 2 This is a schematic diagram of the structure of the anode rotor thermal radiation coating provided in Example 2;

[0075] Wherein, 100 is the anode rotor substrate; 200 is the bonding layer; 301 is the metal layer; 302 is the first gradient layer; 303 is the second gradient layer; and 400 is the thermal radiation layer.

[0076] Figure 3 This is a schematic diagram of the structure of the anode rotor thermal radiation coating provided in Example 3;

[0077] Wherein, 100 is the anode rotor substrate; 200 is the bonding layer; 301 is the metal layer; 302 is the first gradient layer; 303 is the second gradient layer; 304 is the third gradient layer; and 400 is the thermal radiation layer.

[0078] Figure 4 This is a schematic diagram of the structure of the anode rotor thermal radiation coating provided in Example 4;

[0079] Wherein, 100 is the anode rotor substrate; 200 is the bonding layer; 301 is the metal layer; 302 is the first gradient layer; 303 is the second gradient layer; 304 is the third gradient layer; 305 is the fourth gradient layer; and 400 is the thermal radiation layer. Detailed Implementation

[0080] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0081] Example 1

[0082] This embodiment provides a method such as Figure 1 The anode rotor thermal radiation coating shown includes a bonding layer 200, a stress relief layer, and a thermal radiation layer 400 sequentially stacked on the surface of the anode rotor substrate 100.

[0083] The bonding layer 200 is a nickel layer with a thickness of 0.15 μm.

[0084] The stress relief layer is a Ti-C composite layer, comprising a metal layer 301 and a first gradient layer 302 stacked sequentially, with a total thickness of 0.5 μm; wherein, the metal layer 301 is a metallic Ti layer with a thickness of 0.3 μm; the first gradient layer 302 is a Ti-C composite material layer with a thickness of 0.2 μm, and the Ti-C composite material has a Ti atom percentage of 90%.

[0085] The thermal radiation layer 400 is a graphite-like carbon layer with a thickness of 0.5 μm and no metal elements are doped in the layer.

[0086] The thermal radiation coating of the anode rotor was prepared using the following method:

[0087] (1) The surface of the anode rotor substrate is subjected to plasma cleaning. The parameters of the plasma cleaning include: bias voltage -600V, vacuum degree of 0.6Pa, and time of 30min.

[0088] (2) A bonding layer was deposited on the substrate surface by magnetron sputtering. The target material was a nickel target, the working gas was argon, the vacuum degree of magnetron sputtering was 0.6 Pa, the bias voltage was -150 V, the target current was 0.8 A, the deposition time was 15 min, and the nickel layer was obtained after the deposition was completed.

[0089] (3) A stress-relieving layer was deposited on the bonding layer surface using a magnetically filtered cathode arc ion plating method. A titanium metal target was used as the target material, with a target current of 80A. Deposition lasted for 5 minutes, and the bias voltage was -100V. Then, a non-metallic graphite target was turned on, with a graphite target current of 110A and a Ti target current of 50A. Dual-target co-deposition was carried out for 10 minutes, and the bias voltage was reduced to -80V. The vacuum degree was maintained at 5×10⁻⁶ throughout the process. - 3 Pa, deposition temperature is 400℃.

[0090] (4) Deposit a thermal radiation layer on the surface of the stress relief layer, turn off the titanium target, turn on the high-purity graphite target, set the target current to 80A, deposit for 120 minutes, set the bias voltage to -150V, and the vacuum degree to 5×10 -3 The deposition temperature was 400℃, and the final thermal radiation layer was obtained. Argon was used as the working gas throughout the deposition process.

[0091] Example 2

[0092] This embodiment provides a method such as Figure 2 The anode rotor thermal radiation coating shown includes a bonding layer 200, a stress relief layer, and a thermal radiation layer 400 sequentially stacked on the surface of the anode rotor substrate 100.

[0093] The bonding layer 200 is a nickel layer with a thickness of 0.1 μm.

[0094] The stress-relieving layer is a Cr-C composite layer, comprising a metal layer 301, a first gradient layer 302, and a second gradient layer 303 stacked sequentially, with a total thickness of 0.6 μm; wherein, the metal layer 301 is a metallic Cr layer with a thickness of 0.2 μm; the first gradient layer 302 is a first Cr-C composite material layer with a thickness of 0.2 μm, and the Cr atomic percentage in the first Cr-C composite material is 80%; the second gradient layer 303 is a second Cr-C composite material layer with a thickness of 0.2 μm, and the Cr atomic percentage in the second Cr-C composite material is 60%.

[0095] The thermal radiation layer 400 is a chromium-doped graphite-like carbon layer with a thickness of 1.5 μm and a Cr atom content of 2%.

[0096] The thermal radiation coating of the anode rotor was prepared using the following method:

[0097] (1) The surface of the anode rotor substrate is subjected to plasma cleaning. The parameters of the plasma cleaning include: bias voltage -800V, vacuum degree of 0.3Pa, and time of 20min.

[0098] (2) A bonding layer was deposited on the substrate surface by magnetron sputtering. The target material was a nickel target, the working gas was argon, the vacuum degree of magnetron sputtering was 0.6 Pa, the bias voltage was -150 V, the target current was 0.8 A, the deposition time was 10 min, and the nickel layer was obtained after the deposition was completed.

[0099] (3) A stress relief layer was deposited on the surface of the bonding layer by magnetron sputtering. In the first stage, a chromium metal target was used as the target material, the target current was 1.5A, the deposition time was 10min, and the bias voltage was -150V. In the second stage, a non-metallic graphite target was turned on, the target current was 1.0A, and dual-target co-sputtering was carried out for 10min. In the third stage, the chromium target current was reduced to 1A, the graphite target current was increased to 3A, the deposition time was 20min, and the vacuum degree was maintained at 0.3Pa throughout the process to obtain the final stress relief layer.

[0100] (4) A thermal radiation layer was deposited on the surface of the stress relief layer using magnetron sputtering. Dual-target co-sputtering was used, with a chromium target at a target current of 0.2A and a graphite target at a target current of 3.5A. The deposition time was 250 min, the bias voltage was -80V, and the vacuum was maintained at 0.35 Pa. The substrate temperature was 300℃ during the deposition process. Argon was used as the working gas during the deposition process.

[0101] Example 3

[0102] This embodiment provides a method such as Figure 3 The anode rotor thermal radiation coating shown includes a bonding layer 200, a stress relief layer, and a thermal radiation layer 400 sequentially stacked on the surface of the anode rotor substrate 100.

[0103] The bonding layer 200 is a nickel layer with a thickness of 0.5 μm.

[0104] The stress-relieving layer is a Ti-C composite layer, comprising a metal layer 301, a first gradient layer 302, a second gradient layer 303, and a third gradient layer 304 stacked sequentially, with a total thickness of 1.0 μm. Specifically, the metal layer 301 is a Ti metal layer with a thickness of 0.5 μm; the first gradient layer 302 is a first Ti-C composite material layer with a thickness of 0.2 μm, containing 90% Ti atoms; the second gradient layer 303 is a second Ti-C composite material layer with a thickness of 0.2 μm, containing 60% Ti atoms; and the third gradient layer 304 is a third Ti-C composite material layer with a thickness of 0.1 μm, containing 20% ​​Ti atoms.

[0105] The thermal radiation layer 400 is a titanium-doped graphitic carbon layer with a thickness of 1.0 μm and a Ti atom content of 1%.

[0106] The thermal radiation coating of the anode rotor was prepared using the following method:

[0107] (1) The surface of the anode rotor substrate is subjected to plasma cleaning. The parameters of the plasma cleaning include: bias voltage -1000V, vacuum degree of 0.6Pa, and time of 30min.

[0108] (2) A bonding layer was deposited on the substrate surface by magnetron sputtering. The target material was a metallic nickel target, the working gas was argon, the vacuum degree of magnetron sputtering was 0.6 Pa, the bias voltage was -150 V, the target current was 2 A, the deposition time was 30 min, and the nickel layer was obtained after the deposition was completed.

[0109] (3) A stress-relieving layer was deposited on the bonding layer surface using magnetron sputtering. A titanium metal target was used as the target material, with a target current of 3.0 A. Deposition lasted for 20 min, and the bias voltage was -150 V. In the second stage, a non-metallic graphite target was turned on, with a target current of 0.8 A. Dual-target co-sputtering was performed, and deposition lasted for 20 min, with the bias voltage dropping to -80 V. In the third stage, the titanium target current was reduced to 1.5 A, and the graphite target current was increased to 2.0 A. Deposition lasted for 30 min, and the bias voltage dropped to -80 V. In the fourth stage, the titanium target current was continuously reduced to 0.5 A, and the graphite target current was increased to 3 A. Deposition lasted for 30 min, and the bias voltage was -80 V. The vacuum level was maintained at 0.3 Pa throughout the process to obtain the final stress-relieving layer.

[0110] (4) A thermal radiation layer was deposited on the surface of the stress relief layer using magnetron sputtering. Dual-target co-sputtering was used, with a titanium metal target and a target current of 0.3A, and a graphite target and a target current of 3.5A. The deposition time was 210 min, the bias voltage was -80V, the vacuum degree was maintained at 0.3Pa, and the substrate temperature was 200℃ during the deposition process. Argon was used as the working gas during the deposition process.

[0111] Example 4

[0112] This embodiment provides a method such as Figure 4 The anode rotor thermal radiation coating shown includes a bonding layer 200, a stress relief layer, and a thermal radiation layer 400 sequentially stacked on the surface of the anode rotor substrate 100.

[0113] The bonding layer 200 is a nickel layer with a thickness of 0.2 μm.

[0114] The stress-relieving layer is a Cr-C composite layer, comprising a metal layer 301, a first gradient layer 302, a second gradient layer 303, a third gradient layer 304, and a fourth gradient layer 305 stacked sequentially, with a total thickness of 2.0 μm. Specifically, the metal layer 301 is a metallic Cr layer with a thickness of 1.0 μm; the first gradient layer 302 is a first Cr-C composite material layer with a thickness of 0.5 μm and a Cr atomic percentage of 80%; the second gradient layer 303 is a second Cr-C composite material layer with a thickness of 0.2 μm and a Cr atomic percentage of 50%; the third gradient layer 304 is a third Cr-C composite material layer with a thickness of 0.2 μm and a Cr atomic percentage of 20%; and the fourth gradient layer 305 is a fourth Cr-C composite material layer with a thickness of 0.1 μm and a Cr atomic percentage of 10%.

[0115] The thermal radiation layer 400 is a chromium-doped graphite-like carbon layer with a thickness of 2.0 μm and a Cr atom content of 1%.

[0116] The thermal radiation coating of the anode rotor was prepared using the following method:

[0117] (1) The surface of the anode rotor substrate is subjected to plasma cleaning. The parameters of the plasma cleaning include: bias voltage -1000V, vacuum degree of 0.6Pa, and time of 30min.

[0118] (2) A bonding layer was deposited on the substrate surface by magnetron sputtering. The target material was a metallic nickel target, the working gas was argon, the vacuum degree of magnetron sputtering was 0.6 Pa, the bias voltage was -150 V, the target current was 2 A, the deposition time was 10 min, and a nickel layer was obtained after deposition.

[0119] (3) A stress relief layer was deposited on the surface of the bonding layer by magnetron sputtering. The target material was a chromium target metal target with a target current of 3.0A. The deposition time was 25 min and the bias voltage was -100V. In the second stage, the non-metallic graphite target was turned on with a target current of 0.5A. The chromium target current was reduced to 2.5A. Dual-target co-sputtering was carried out for 20 min and the bias voltage was reduced to -60V. In the third stage, the chromium target current was reduced to 2.0A and the graphite target current was increased to 1.0A. The deposition time was 15 min and the bias voltage was -60V. In the fourth stage, the chromium target current was reduced to 1.0A and the graphite target current was increased to 2.0A. The deposition time was 10 min and the bias voltage was -60V. In the fifth stage, the chromium target current was reduced to 0.5A and the graphite target current was increased to 3.0A. The deposition time was 10 min and the bias voltage was -60V. The vacuum degree was maintained at 0.3Pa throughout the process to obtain the final stress relief layer.

[0120] (4) A thermal radiation layer was deposited on the surface of the stress relief layer using magnetron sputtering. Dual-target co-sputtering was used, with a chromium target at a target current of 0.2 A and a graphite target at a target current of 3.5 A. The deposition time was 250 min, the bias voltage was -80 V, and the vacuum was maintained at 0.3 Pa. The substrate temperature was 400 °C during the deposition process. Argon was used as the working gas during the deposition process.

[0121] Example 5

[0122] This embodiment provides an anode rotor thermal radiation coating. Compared with embodiment 2, no metal layer is provided, but all other aspects are the same as in embodiment 2.

[0123] The preparation method of the anode rotor thermal radiation coating is the same as that of Example 2, except that the first stage of step (3) is not performed.

[0124] Comparative Example 1

[0125] This comparative example provides an anode rotor thermal radiation coating. Compared with Example 2, it does not have a bonding layer and a stress relief layer. That is, only a thermal radiation layer is provided on the surface of the anode rotor substrate, and the rest is the same as in Example 2.

[0126] The method for preparing the anode rotor thermal radiation coating differs from that in Example 2 in that step (2) of depositing the bonding layer and step (3) of depositing the stress relief layer are not performed.

[0127] Comparative Example 2

[0128] This comparative example provides a thermal radiation coating for an anode rotor. Compared to Example 2, it does not have a bonding layer, but is otherwise identical to Example 2. That is, a stress relief layer and a thermal radiation layer are sequentially stacked on the anode rotor substrate.

[0129] The method for preparing the anode rotor thermal radiation coating differs from that in Example 2 in that step (2) of depositing the bonding layer is not performed.

[0130] Comparative Example 3

[0131] This comparative example provides a thermal radiation coating for an anode rotor. Compared to Example 2, it does not include a stress relief layer, but is otherwise identical to Example 2. That is, a bonding layer and a thermal radiation layer are sequentially stacked on the anode rotor substrate.

[0132] The method for preparing the anode rotor thermal radiation coating differs from that in Example 2 in that step (3) of depositing the stress relief layer is not performed.

[0133] Comparative Example 4

[0134] This comparative example provides an anode rotor coating. Compared with Example 3, the titanium-doped graphite-like carbon layer of the thermal radiation layer is replaced with a hydrogen-containing diamond carbon film, and the rest is the same as Example 3.

[0135] The method for preparing the anode rotor coating differs from that in Example 3 in that the working gas is replaced by a mixture of acetylene and argon (gas volume flow ratio of 3:1).

[0136] Comparative Example 5

[0137] This comparative example provides an anode rotor coating, which, compared to Example 3, replaces the titanium-doped graphite-like carbon layer with a diamond-like carbon layer, while all other aspects are the same as in Example 3.

[0138] The method for preparing the anode rotor coating differs from that in Example 3 in that the bias voltage is set to -50V and the substrate is not heated.

[0139] Performance testing

[0140] The performance of the anode rotor coatings in the examples and comparative examples was tested, including: thermal emissivity, and sp24-degree-of-care radiation of the coating surface. 2 Hybridized carbon atom content, coating adhesion rating, and crack density after thermal cycling.

[0141] sp on the coating surface 2 The atomic content of hybrid carbon atoms as a percentage of the total carbon atoms was determined by fitting and integrating the peak values ​​corresponding to narrow-band C(1s) scans using X-ray photoelectron spectroscopy. The sp content of the coating surface was then determined by analyzing the integrated area and elemental content. 2 The content of hybridized carbon atoms.

[0142] The method for testing the thermal radiation coefficient includes measuring the total emissivity of the material surface using steady-state calorimetry.

[0143] The test method for thermal cycling stability includes: placing a standard test sample in a medium-frequency induction heating furnace, heating to 600℃, holding for 2 minutes, and then cooling to room temperature as one thermal cycle. After 200 cycles, the coating cracks are observed under a light microscope, and the coating adhesion strength is tested. The test method for coating adhesion strength includes: using the standard test method for measuring coating adhesion performance / coating adhesion with adhesive tape, according to standard ASTM D3359, cross-cutting is performed on the coating with a blade; standard adhesive tape is pasted on the coating, then quickly peeled off, and the ratio of the peeled area to the total area is observed. The adhesion rating is determined based on the peeled area ratio. The adhesion ratings are as follows: Grade 0, peeled area ratio > 65%; Grade 1, 35% < peeled area ratio ≤ 65%; Grade 2, 15% < peeled area ratio ≤ 35%; Grade 3, 5% < peeled area ratio ≤ 15%; Grade 4, 0% < peeled area ratio ≤ 5%; Grade 5, peeled area ratio is 0%, i.e., no peeling at all.

[0144] Crack density after thermal cycling is as shown under an electron microscope in a specific region (500*400μm). 2 The ratio of the total length to the area of ​​the observed crack.

[0145] Table 1

[0146]

[0147] In the table, " / " indicates large-area peeling that cannot be measured.

[0148] As can be seen from the test results in Table 1, referring to Examples 1-5, the anode rotor thermal radiation coating of the present invention, through the gradient layer structure design of the bonding layer, stress relief layer, and thermal radiation layer, can effectively improve the coating's adhesion and avoid the generation of internal stress. The stress buffer layer of the gradient structure can effectively reduce the coating's hardness and residual stress, significantly improving the coating's fatigue resistance and high-temperature service performance. After high-temperature (600℃) thermal cycling, the coating exhibits good coating retention, with a peeling rate controlled below 15%, and extremely low crack density. Furthermore, the coating has good thermal radiation performance with an emissivity of over 0.84, effectively dissipating heat from the anode components and improving heat dissipation efficiency.

[0149] Compared with the results of the embodiments, in Comparative Examples 1-3, the lack of a bonding layer or stress-inhibiting layer significantly reduces the high-temperature service performance of the coating, resulting in a significant increase in the coating peeling rate and crack density after thermal cycling, and even large-area peeling. In Comparative Example 4, if a hydrogen-containing diamond carbon film is used, the graphite phase will be significantly reduced, and gas will be released under vacuum, further weakening the coating's adhesion, leading to decreased thermal fatigue performance and poor subsequent film performance. In Comparative Example 5, sp 2The reduced proportion of hybrid carbon atoms leads to decreased heat dissipation efficiency and poorer adhesion of the coating. Under thermal cycling, high stress further causes the coating to crack and peel off.

[0150] In summary, the anode rotor coating of this invention, through a gradient structure design of a bonding layer, a stress-relieving layer, and a heat-radiating layer, solves the expansion mismatch between the substrate and the coating, and resolves the internal stress problem of the coating, thereby improving the adhesion between the coating and the substrate. Simultaneously, the heat-radiating layer enhances the heat dissipation efficiency of the coating. Through the synergistic improvement of internal stress resolution and thermal performance, the coating maintains good quality and bonding strength under the high-temperature thermal cycling conditions of the anode rotor, thus effectively improving the stability and lifespan of the anode rotor under thermal shock conditions.

[0151] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A thermal radiation coating for an anode rotor, characterized in that, The anode rotor thermal radiation coating comprises: a bonding layer, a stress relief layer, and a thermal radiation layer sequentially stacked on the surface of the anode rotor substrate; the bonding layer comprises a Ni layer, the stress relief layer comprises a metal-carbon composite layer, the metal element in the metal-carbon composite layer comprises Cr and / or Ti, and the thermal radiation layer comprises a graphite-like carbon material layer.

2. The anode rotor thermal radiation coating according to claim 1, characterized in that, In the metal-carbon composite layer, the content of metal elements gradually decreases from the anode rotor substrate to the coating surface.

3. The anode rotor thermal radiation coating according to claim 2, characterized in that, The metal-carbon composite layer comprises a metal layer and a metal-carbon composite material layer stacked sequentially.

4. The anode rotor thermal radiation coating according to claim 3, characterized in that, In the metal-carbon composite material layer, the atomic percentage of metal elements is 5%-99%; And / or, the metal-carbon composite layer comprises at least two gradient layers stacked together.

5. The anode rotor thermal radiation coating according to claim 1, characterized in that, In the graphite-like carbon material layer, sp in the graphite-like carbon material 2 The percentage of hybrid carbon atoms in the total number of carbon atoms is ≥70%.

6. The anode rotor thermal radiation coating according to claim 1, characterized in that, The graphite-like carbon material layer is made of graphite-like carbon doped with metal elements; the metal elements in the graphite-like carbon material layer include at least the metal elements of the stress relief layer.

7. The anode rotor thermal radiation coating according to claim 6, characterized in that, In the graphite-like carbon material layer, the atomic percentage of metal elements is ≤3%.

8. The anode rotor thermal radiation coating according to claim 1, characterized in that, The thickness of the bonding layer is 0.1-0.5 μm; And / or, the thickness of the stress relief layer is 0.2-2 μm; And / or, the thickness of the thermal radiation layer is 0.2-2.0 μm.

9. A method for preparing an anode rotor thermal radiation coating as described in any one of claims 1-8, characterized in that, The preparation method includes the following steps: A bonding layer, a stress relief layer, and a thermal radiation layer are sequentially deposited on the surface of the anode rotor substrate using a vapor phase deposition method.

10. An anode rotor, characterized in that, The anode rotor includes an anode rotor substrate and an anode rotor thermal radiation coating of any one of claims 1-8 on the anode rotor substrate.

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