Ultrahigh-temperature thermal protection coating, workpiece comprising coating and preparation method of workpiece

Abstract

The invention relates to an ultrahigh-temperature thermal protection coating, a workpiece comprising the coating and a preparation method of the workpiece. The coating comprises a protective layer, the material of the protective layer is an ultrahigh-temperature-resistant ceramic composite powder material, the ultrahigh-temperature-resistant ceramic composite powder material is a solid solution compound prepared from hafnium oxide and rare earth oxide, the rare earth oxide is one or two of ytterbium oxide and lutetium oxide, and the protective layer is prepared from the following components in percentage by mole: 1-10% of ytterbium oxide and 1-10% of lutetium oxide. The content of hafnium oxide in the raw materials is 70 to 90 mol.%, and the content of the rare earth oxide in the raw materials is 10 to 30 mol.%. In a 2810 DEG C plasma long-time simulation ablation test, the coating prepared from the ceramic composite powder material does not generate obvious ablation damage within at least 300 seconds, preferably within 690 seconds, and more preferably within 730 seconds, and has good high temperature resistance.

Description

Technical Field

[0001] This invention relates to the field of coating materials technology, and in particular to an ultra-high temperature thermal protection coating, a workpiece containing the coating, and a method for preparing the same. Background Technology

[0002] Refractory metals and their alloys possess excellent high-temperature mechanical properties, low coefficients of thermal expansion, and high electrical and thermal conductivity, making them commonly used as high-temperature structural and functional materials. They are now widely applied in aerospace, machinery, metallurgy, and many other fields. However, refractory metals and alloys are prone to oxidation in high-temperature, oxygen-rich environments. When the temperature exceeds 800℃, refractory metals such as tungsten and molybdenum undergo volatile oxidation, resulting in significant weight loss.

[0003] A more ideal solution is to prepare a high-temperature resistant and antioxidant coating on the surface of the refractory metal substrate to improve its antioxidant properties and increase its operating temperature.

[0004] CN111500967A discloses an integrated composite coating for heat insulation and ablation resistance on a tungsten-copper alloy surface. Starting from the surface of the tungsten-copper alloy, from bottom to top, it includes a metal bonding layer, a ceramic inner layer, a ceramic transition layer, and a ceramic outer layer. The ceramic inner layer is an alumina layer, the ceramic transition layer is an alumina-rare earth zirconate layer, and the ceramic outer layer is a rare earth zirconate layer. Since the melting points of zirconates are all below 2300℃, and the melting point of alumina is only 2054℃, the coating will be rapidly washed away by airflow after exceeding the temperature limit, losing its protective effect on the substrate. Therefore, the main drawback of this coating is its low temperature resistance, limiting its use to below 2300℃.

[0005] CN112662978A discloses a coating for tungsten-copper alloy materials and its preparation method. The coating includes a transition layer and an anti-oxidation layer sequentially formed on the surface of the alloy material. The transition layer comprises the following raw materials in parts by weight: 15-20 parts nano-tin oxide, 10-15 parts strontium fluoride, 0.1-0.5 parts tetrabutyl titanate, and 1-5 parts polyvinyl alcohol. The anti-oxidation layer comprises the following raw materials in parts by weight: 10-20 parts nano-cerium oxide and 30-50 parts silicon-barium-iron alloy powder. Because both nano-cerium oxide and silicon-barium-iron alloy have melting points below 2000℃, they will be rapidly washed away by airflow after exceeding the temperature, losing their protective effect on the substrate. Therefore, the main disadvantage of this coating is its low temperature resistance, limiting its use to below 2000℃.

[0006] CN104372192A discloses a nano-tungsten-copper composite material and its preparation method. The composite material includes a matrix material and a surface coating. The matrix material is a tungsten-copper alloy, wherein a layer of nano-copper particles with a thickness of 50-200 nm is coated on the surface of tungsten powder. The surface coating is a resin coating, which includes the following components in the indicated mass percentages: 30-50 parts epoxy resin, 4-9 parts nano-titanium oxide, 3-8 parts nano-zinc oxide, and 3-9 parts curing agent. The preparation method of the nano-tungsten-copper composite material includes chemical vapor deposition and coating the surface. This patent mainly introduces the preparation method of tungsten-copper alloy materials and their coatings for the electronics industry. The heat-protective coating is mainly composed of resin materials with a temperature resistance not exceeding 1000℃ and is not resistant to high-temperature oxidation.

[0007] Currently, refractory metal materials have surface coatings such as multi-element rare earth silicon oxide and rare earth silicate thermal protective coatings, but their operating temperature is no higher than 2300℃ and their service life is very short. Therefore, it is necessary to develop thermal protective coatings with longer service life.

[0008] Existing conventional thermal barrier and environmental barrier coatings are zirconia or rare-earth-doped zirconia-based coating systems. These coating systems generally have a temperature resistance not exceeding 2300℃, which cannot meet the higher temperature resistance requirements of materials. On the other hand, single-structure coatings have problems with bonding strength and thermal matching during operation, which can easily lead to premature failure of the coating.

[0009] In view of this, the present invention is hereby proposed. Summary of the Invention

[0010] The purpose of this invention is to provide an ultra-high temperature thermal protection coating, a workpiece containing the coating, and a method for preparing the coating. This coating has a good protective effect against refractory metals in a high-temperature environment. Under plasma simulated ablation conditions of 2810°C, the coating shows no obvious ablation damage for at least 300 seconds, preferably 690 seconds.

[0011] To achieve the above objectives, the present invention adopts the following technical solution: The first aspect of the present invention provides an ultra-high temperature thermal protection coating, the coating being disposed on the surface of a substrate, the coating comprising: a protective layer; The protective layer is made of ultra-high temperature resistant ceramic composite powder material, which is a solid solution composite material made of raw material hafnium oxide and rare earth oxides. The rare earth oxides are one or both of ytterbium oxide and lutetium oxide. The content of hafnium oxide in the raw material is 70%~90 mol.% and the content of rare earth oxides is 10~30 mol.% by molar percentage.

[0012] In the aforementioned ultra-high temperature thermal protective coating of the first aspect, as a preferred embodiment, the rare earth oxide is a mixture of ytterbium oxide and lutetium oxide, wherein, by molar percentage, the content of hafnium oxide in the raw material is 75%~82 mol.% and the content of the rare earth oxide is 18~25 mol.%. In the ultra-high temperature thermal protection coating of the first aspect above, as a preferred embodiment, the ultra-high temperature resistant ceramic composite powder is a spherical powder obtained by granulation and plasma spheroidization of a mixture of raw materials hafnium oxide and rare earth oxides.

[0013] Furthermore, the mixture is subjected to wet ball milling before granulation; And / or, the particle size of the spherical powder is from 500 nm to 100 μm; And / or, the granulation is spray granulation.

[0014] In the ultra-high temperature thermal protective coating of the first aspect above, as a preferred embodiment, the molar ratio of ytterbium oxide and lutetium oxide in the rare earth oxide is (0.8~1.2):1, preferably 1:1; More preferably, the content of ytterbium oxide in the raw material is 11 mol.% and the content of lutetium oxide is 11 mol.%.

[0015] In the ultra-high temperature thermal protective coating of the first aspect described above, as a preferred embodiment, the coating further includes: an adhesive layer disposed between the substrate surface and the protective layer, wherein the adhesive layer is composed of one or two of tungsten and molybdenum; and the substrate is a tungsten-copper material. Furthermore, the coating further includes a transition layer disposed between the adhesive layer and the protective layer, wherein the material of the transition layer is composed of 45-55% adhesive layer material and 45-55% protective layer material by mass fraction.

[0016] In the ultra-high temperature thermal protective coating of the first aspect described above, as an optional embodiment, the thickness of the adhesive layer is 0.10~0.20mm; and / or, the thickness of the transition layer is 0.20~0.50mm; and / or, the thickness of the protective layer is 0.40~0.80mm.

[0017] A second aspect of the present invention provides a workpiece resistant to ultra-high temperature and ablation, the workpiece comprising a substrate and an ultra-high temperature thermal protection coating as described in the first aspect above disposed on the surface of the substrate.

[0018] In a preferred embodiment of the workpiece in the second aspect of the present invention, the substrate is a tungsten-copper material.

[0019] Furthermore, the tungsten-copper material comprises a modified tungsten framework and copper distributed in the pores of the modified tungsten framework. The modified tungsten framework is made by sintering tungsten powder, ceramic powder, and metal powder. The ceramic powder accounts for 1.2-4.5% by mass, the metal powder accounts for 0-10%, and the remainder is tungsten powder. The ceramic powder is one or more of tantalum, titanium, niobium, zirconium, and hafnium borides, carbides, or oxides. The metal powder is one or two of molybdenum powder and rhenium powder. Furthermore, the proportion of copper in the tungsten-copper material is 6~12wt%.

[0020] A third aspect of the present invention provides a method for preparing a workpiece as described in the second aspect above, comprising: a substrate preparation step and an ultra-high temperature thermal protective coating preparation step, wherein, The preparation steps of the ultra-high temperature thermal protective coating include: substrate sandblasting, adhesive layer spraying, transition layer spraying, and protective layer spraying; all spraying is carried out by plasma spraying.

[0021] In the preparation method of the third aspect of the present invention, as a preferred embodiment, the substrate preparation step includes: S1. Powder processing: First, tungsten-metal powder is prepared by co-reduction, and then it is mechanically mixed with ceramic powder to obtain a uniformly mixed raw material powder; or, the tungsten powder, metal powder and ceramic powder are directly mixed by mechanical mixing to obtain the raw material powder. S2. Forming: The raw material powder obtained in step S1 is pressed into shape, and the pressed blank is shaped. S3. Sintering: The pressed blank obtained in step S2 is sintered to obtain a modified tungsten framework; S4. Copper infiltration: The modified tungsten skeleton is subjected to copper infiltration treatment.

[0022] The present invention provides an ultra-high temperature thermal protection coating, a workpiece containing the coating, and a method for preparing the same, the advantages of which are: (1) The protective layer in the coating provided by the present invention is prepared by a powder obtained by combining rare earth oxides ytterbium oxide and / or lutetium oxide with hafnium oxide in a specific ratio. It has good high temperature stability. In particular, the coating is prepared by using a specific ratio of ytterbium oxide, lutetium oxide and hafnium oxide as ceramic composite powder materials. The high temperature resistance is even better, the solid solubility is sufficient and the composition is uniformly distributed. In the long-term simulated ablation test of plasma at 2810℃, the coating prepared by the ceramic composite powder material does not undergo obvious ablation damage for at least 300s, preferably within 690s, more preferably within 730s, and has good high temperature resistance. (2) Further, the powder used to prepare the protective layer of the present invention is obtained by wet ball milling of oxide raw materials, followed by spray granulation and plasma spheroidization treatment. The powder has good solid solubility, smooth surface, and uniform composition. The coating prepared from it has good stability during high-temperature use, avoiding premature failure caused by phase transformation at high temperatures; (3) Furthermore, the coating of the present invention also includes an adhesive layer and / or a transition layer, which can further improve the bonding strength and thermal compatibility between the protective layer and the substrate, thereby preventing the coating from being damaged and failing prematurely.

[0023] (4) Furthermore, in addition to the high-temperature resistance and ablation resistance of the coating, the workpiece provided by this invention also possesses excellent properties in its tungsten-copper substrate, such as high-temperature resistance, ablation resistance, and good high-temperature mechanical properties. The tungsten-copper material exhibits a tensile strength ≥100MPa at 1600℃ and an ablation time ≥210s at 2810℃. Therefore, the workpiece provided by this invention meets the current demand for long-term use in harsh environments in the field of high-temperature resistance and ablation resistance, and provides a reference for the future development and application prospects of similar products. Attached Figure Description

[0024] Figure 1 This is a microscopic morphology diagram of the high-temperature resistant ceramic composite powder provided in Embodiment 1 of the present invention.

[0025] Figure 2 The image shows the surface of the coating obtained by preparing the coating from the ultra-high temperature ceramic composite powder in Example 1 of this invention during the plasma simulation ablation test. The ablation test lasted for 563 seconds, and the test was stopped when the coating burned through and exposed the substrate.

[0026] Figure 3 The image shows the surface of the coating obtained from the preparation of ultra-high temperature ceramic composite powder in Example 3 of this invention when the coating was not burned through in the plasma simulation ablation test. The ablation test time was 690 seconds.

[0027] Figure 4 The image shows the metallographic structure of the modified novel tungsten-copper material prepared in Example 15 of this invention.

[0028] Figure 5 The image shows a SEM image of the novel HfB2 and Re modified tungsten copper material provided in Example 11 of this invention.

[0029] Figure 6 This is a plasma ablation experiment diagram used in the performance testing example of the tungsten-copper material of this invention.

[0030] Figure 7 The XRD patterns of the modified tungsten copper materials provided in the embodiments of the present invention are shown, wherein W-Re-HfB2 is the XRD pattern of Example 11 and W-Re-HfC is the XRD pattern of Example 14.

[0031] Figure 8 This is a metallographic image of Comparative Example 9 of the present invention. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Those skilled in the art should understand that the embodiments described are merely illustrative of the invention and should not be considered as specific limitations thereof. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. Process parameters not specifically specified in the following embodiments are generally performed under conventional conditions.

[0033] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0034] According to a first aspect of the present invention, the present invention provides an ultra-high temperature thermal protective coating, the coating being disposed on a substrate surface, the coating comprising: a protective layer; the material used to prepare the protective layer is an ultra-high temperature resistant ceramic composite powder material, the ultra-high temperature resistant ceramic composite powder material being a solid solution composite material made from raw material hafnium oxide and rare earth oxides, wherein the rare earth oxides are one or both of ytterbium oxide and lutetium oxide, and the content of hafnium oxide in the raw material is 70%~90 mol.% and the content of rare earth oxides is 10~30 mol.% by molar percentage.

[0035] This invention uses a specific ratio of hafnium oxide to mix with at least one of the rare earth oxides ytterbium oxide and lutetium oxide to prepare an ultra-high temperature resistant ceramic composite powder material. This material exhibits excellent high-temperature resistance; tests have shown that when prepared as a coating, it can resist ablation at 2810℃ without damage. The hafnium oxide ratio in this invention is moderate, controlled within the range of 70% to 90 mol.%, such as 72%, 75%, 80%, 85%, and 88%. When the molar ratio of hafnium oxide is below 70% or above 90%, the ablation resistance temperature decreases, and the high-temperature stability deteriorates. Furthermore, this invention selects ytterbium oxide and / or lutetium oxide in combination with hafnium oxide. Compared to other rare earth oxides such as holmium oxide, erbium oxide, scandium oxide, yttrium oxide, and lanthanum oxide combined with hafnium oxide, or compared to the overall combination of ytterbium oxide, lutetium oxide, hafnium oxide, and at least one of the aforementioned rare earth oxides, the material of this invention exhibits superior high-temperature thermal stability. The applicant believes that the ionic radii of lutetium and ytterbium are closest to those of hafnium, resulting in smaller lattice distortion, smaller cell size, lower potential energy, and higher stability after doping with these two elements. Furthermore, compared to combinations of hafnium oxide with ytterbium oxide and magnesium oxide, the material of this invention has a lower vapor pressure and better resistance to ablation at high temperatures.

[0036] In the preparation of the material of this invention, rare earth oxides are selected instead of rare earth borides or carbides. High-temperature ceramics prepared from rare earth oxides have better stability than those prepared from borides or carbides and will not oxidize at high temperatures, thus avoiding problems such as volume changes and physical structure changes caused by oxidation.

[0037] The content of rare earth oxides in this invention is controlled at 10~30 mol.%, typically and non-limitingly, the content can be 12%, 15%, 20%, 25%, 28%, etc.

[0038] During the experiment, the inventors unexpectedly discovered that the rare earth oxides were a mixture of ytterbium oxide and lutetium oxide, and that the hafnium oxide content in the raw materials was 75%~82 mol.% (e.g., 76%, 77%, 78%, 79%, 80%, 81%), and the rare earth oxide content was 18~25 mol.% (e.g., 19%, 20%, 21%, 22%, 23%, 24%), resulting in more ideal high-temperature ablation resistance. In particular, the composite powder material obtained when the molar ratio of ytterbium oxide to lutetium oxide was (0.8-1.2):1, preferably 1:1, exhibited particularly ideal high-temperature ablation resistance. The optimal effect was achieved when the ytterbium oxide content and lutetium oxide content in the raw materials were both 11 mol.%.

[0039] Furthermore, the ultra-high temperature resistant ceramic composite powder material of the present invention is a spherical powder obtained by granulation and plasma spheroidization of a mixture of raw materials hafnium oxide and rare earth oxides. Plasma spheroidization after granulation not only ensures the uniformity of the final powder particles and composition but also allows for complete solid solution of the material components, thereby improving the high-temperature stability of the material. The ultra-high temperature resistant ceramic composite powder material is a spherical powder, which is a fluorite-like phase of ytterbium-lutetium-hafnium oxide, exhibiting high phase stability and will not be damaged by phase transformation stress or other issues during the ablation process.

[0040] As an optional implementation, the mixture is further subjected to wet ball milling before granulation to further homogenize the raw materials; As an optional implementation, the granulation is spray granulation.

[0041] The particle size of the spherical powder of the present invention is preferably 500 nm to 100 μm; the specific particle size requirements of the spherical powder vary depending on the application environment. When the high-temperature ceramic composite powder is used as a coating powder, the particle size range is preferably 20 to 75 μm. This particle size range can adapt to the process characteristics of plasma spraying, has good process stability, and produces coatings with good uniformity and high bonding strength.

[0042] Ultra-high temperature resistant ceramic composite powder used to make protective layers; typical microstructure of the powder is as follows: Figure 1 As shown, the ultra-high temperature ceramic composite powder has a spherical microstructure, a smooth surface, and good powder flowability, making it suitable for thermal spraying to prepare thermal protective coatings.

[0043] The protective layer formed by the high-temperature resistant ceramic composite powder material can withstand a high temperature time of at least 300s (e.g., 350s, 400s, 450s, 500s, 550s, 600s, 650s), preferably 690s, and more preferably 730s at 2810℃ without ablation damage.

[0044] The specific preparation method of the above-mentioned ultra-high temperature resistant ceramic composite powder material is as follows: Slurry preparation: Mix one or two of the rare earth oxides ytterbium oxide and lutetium oxide powder, as well as hafnium oxide powder, according to the proportion, and then add deionized water and binder such as PVA adhesive in a certain proportion to prepare a slurry; Homogenization of the slurry: The slurry is homogenized by ball milling; Spray granulation: The process of preparing powder from a homogenized slurry using spray granulation. Drying: The spray-granulated powder is then heated in an oven to remove moisture and impurities; Densification and homogenization treatment: Plasma spheroidization is used to treat the dried powder to obtain powder with good solid solubility, smooth surface and uniform composition. Drying: The plasma-spheroidized powder is placed in an oven for drying.

[0045] Sieving: The dried powder is sieved to separate ultra-high temperature ceramic composite powder with the required particle size.

[0046] Furthermore, the amount of the binder accounts for 8-12% of the total mass of the powder raw material (e.g., 8.5%, 9%, 10%, 11%, 11.5%, etc.). The solvent is water, such as deionized water. Preferably, the amount of water used is 1.5-2.5 times (e.g., 1.8 times, 2 times, 2.3 times) of the total mass of the powder raw materials. The process parameters of the spray granulation method are as follows: inlet temperature is 240℃~260℃ (e.g., 245℃, 250℃, 255℃, etc.); outlet temperature is 100~110℃ (e.g., 102℃, 105℃, 108℃, etc.). The process parameters for plasma spheroidization are as follows: Current: 600~650 A (e.g., 610 A, 620 A, 630 A, 640 A, etc.); Main gas: 35~45 L / min (e.g., 37 L / min, 40 L / min, 42 L / min, 44 L / min); Power: >24 KW (e.g., 25 KW, 30 KW, 35 KW, 40 KW, etc.); Carrier gas: 7~10 L / min (e.g., 8 L / min, 9 L / min, 9.5 L / min); Powder feed rate: 20~30 g / min (e.g., 22 g / min, 25 g / min, 27 g / min, 29 g / min).

[0047] In a preferred embodiment, the coating further includes: an adhesive layer disposed between the substrate surface and the protective layer, the adhesive layer being composed of one or two of tungsten and molybdenum; the substrate being a tungsten-copper material; As the bonding layer between the protective layer and the substrate, in order to ensure the adhesion effect of the protective layer, the present invention selects a material similar to the substrate to make the bonding layer. The substrate of the present invention is a tungsten alloy, preferably a tungsten-copper material. Therefore, the bonding layer material is one or more of tungsten and molybdenum.

[0048] To ensure proper thermal stress matching between the adhesive layer and the protective layer and prevent coating cracking or detachment from the substrate, this invention preferably includes a transition layer between the adhesive layer and the protective layer. Typically, the transition layer is a single layer composed of 45-55% (e.g., 48%, 50%, 52%) adhesive layer material and 45-55% (e.g., 48%, 50%, 52%) protective layer material by mass. To enhance the effect, the transition layer can also be configured as multiple sub-layers, with the percentage of adhesive layer material gradually decreasing and the percentage of protective layer material gradually increasing from the transition sub-layer closest to the adhesive layer to the transition sub-layer furthest from the adhesive layer.

[0049] As an ultra-high temperature heat protection coating, generally speaking, the thicker the outermost protective layer, the longer the high temperature resistance and ablation resistance time. However, considering the adhesion of the protective layer to the substrate, the adhesive layer, transition layer, and protective layer of the present invention should not be too thick. The thickness of the adhesive layer is preferably 0.10~0.20mm (e.g., 0.12mm, 0.15mm, 0.17mm, or 0.19mm); and / or, the thickness of the transition layer is preferably 0.20~0.50mm (e.g., 0.22mm, 0.25mm, 0.30mm, 0.35mm, 0.40mm, 0.45mm, or 0.49mm); and / or, the thickness of the protective layer is preferably 0.40~0.80mm (e.g., 0.45mm, 0.50mm, 0.55mm, 0.60mm, 0.65mm, 0.70mm, 0.75mm, or 0.79mm).

[0050] The protective coating of this invention is particularly suitable for protecting substrates formed of tungsten-copper materials. These tungsten-copper materials can be conventional tungsten-copper alloys that are resistant to high temperatures and ablation, have high strength, and are used in aerospace, machinery, and electronics fields. Preferably, the tungsten-copper material comprises a modified tungsten framework and copper distributed in the pores of the modified tungsten framework. A detailed description of this tungsten-copper material can be found in the description of the substrate material in the second aspect of the workpiece, and will not be repeated here.

[0051] A second aspect of the present invention provides a workpiece resistant to ultra-high temperature and ablation, the workpiece comprising a substrate and an ultra-high temperature thermal protection coating as described in the first aspect disposed on the surface of the substrate.

[0052] As one possible implementation, the matrix in the workpiece is a tungsten-copper material, which can be a conventional tungsten-copper alloy that is resistant to high temperatures, ablation, and has high strength and is used in aerospace, machinery, electronics and other fields.

[0053] To further improve the overall workpiece's resistance to high-temperature ablation and its high-temperature mechanical properties, the tungsten-copper material includes a modified tungsten skeleton and copper distributed in the pores of the modified tungsten skeleton. The modified tungsten skeleton is made by sintering tungsten powder, ceramic powder, and metal powder. The ceramic powder accounts for 1.2-4.5% (e.g., 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%) by mass percentage, the metal powder accounts for 0-10% (e.g., 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%), and the balance is tungsten powder. The ceramic powder is one or more of tantalum, titanium, niobium, zirconium and hafnium borides, carbides or oxides; The metal powder is one or both of molybdenum powder and rhenium powder.

[0054] If the proportion of ceramic powder is too high or too low, it will not significantly improve the ablation resistance and high-temperature mechanical properties of the material. Moreover, if the ceramic powder content is too high, it will increase the brittleness of the material, reduce its thermal conductivity, thermal shock resistance and other properties, and reduce its high-temperature performance.

[0055] The ceramic powder of this invention is preferably a boride of tantalum, titanium, niobium, zirconium, and hafnium. In particular, the inventors discovered that when the ceramic powder is a boride, the final material contains new phases such as WB and W2B. The formation and dispersion of these new phases can further improve the overall mechanical properties and ablation resistance of the material, producing unexpected effects. However, when the ceramic powder is a carbide or oxide of tantalum, titanium, niobium, zirconium, and hafnium, the final tungsten-copper material does not contain these new phases. Figure 7 .

[0056] The addition of appropriate amounts of molybdenum or rhenium metal powder can further improve the mechanical properties and ablation resistance of materials. However, the amount of molybdenum or rhenium metal powder added should not be too high. For example, excessive molybdenum content will result in a continuous molybdenum phase in the material skeleton, reducing the material's ablation resistance and high-temperature mechanical properties; at the same time, the molybdenum content should not be too low, as it will not have a strengthening effect.

[0057] As one possible implementation, the copper content in the copper-tungsten material is 6~12 wt% (e.g., 7 wt%, 8 wt%, 9 wt%, 10 wt%, 11 wt%).

[0058] The tungsten-copper material has an ablation time of ≥210s at 2810℃, preferably 210-330s (e.g., 230s, 250s, 270s, 290s, 310s); and a mass ablation rate of ≤0.25g / s, preferably 0.10-0.21g / s (e.g., 0.3g / s, 0.5g / s, 0.7g / s, 0.9g / s, 1.1g / s, 1.3g / s, 1.5g / s, 1.7g / s, 1.9g / s).

[0059] This invention modifies tungsten copper materials by adding ceramic powder and metal powder to tungsten powder, thereby obtaining novel tungsten copper materials. Adding appropriate ceramic powder can improve the ablation resistance and high-temperature mechanical properties of the material; adding appropriate metal powder can improve the tensile strength and reduce the brittleness of the material.

[0060] A third aspect of the present invention provides a method for preparing the above-mentioned workpiece, comprising a substrate preparation step and an ultra-high temperature thermal protective coating preparation step, wherein, The preparation steps of the ultra-high temperature thermal protective coating include: substrate sandblasting, adhesive layer spraying, transition layer spraying, and protective layer spraying; all spraying is carried out by plasma spraying.

[0061] Substrate sandblasting is a pretreatment process performed on the surface of a substrate before spraying a coating. It is used to clean, roughen, or strengthen the surface of the substrate. For example, high-speed jetting of abrasive particles can be used to impact the surface of a metal substrate. As an optional implementation, the process parameters of substrate sandblasting are: sandblasting pressure of 0.4-0.6 MPa (e.g., 0.45 MPa, 0.5 MPa, 0.55 MPa). Plasma spraying is preferred for the bonding layer, transition layer, and protective layer. As one possible implementation method, the spraying process parameters for each layer are as follows: The process parameters for adhesive layer spraying are as follows: spraying current is 780-820A (e.g., 790A, 800A, 810A), argon flow rate is 44-48L / min (e.g., 45L / min, 46L / min, 47L / min), and spraying power is 20-24KW (e.g., 21KW, 22KW, 23KW).

[0062] The process parameters for the transition layer spraying are as follows: spraying current is 820-850A (e.g., 830 A, 840 A, 845 A), argon flow rate is 40-43 L / min (e.g., 41 L / min, 42 L / min, 42.5 L / min), and spraying power is 23-25 ​​KW (e.g., 23.5 KW, 24 KW, 24.5 KW).

[0063] The process parameters for protective layer spraying are as follows: spraying current is 850-900A (e.g., 860A, 870A, 880A, 890A, 900A), argon flow rate is 40-46L / min (e.g., 41 L / min, 42 L / min, 43 L / min, 45 L / min), and spraying power is 26-30KW (e.g., 27KW, 28KW, 29KW, 30KW).

[0064] The preferred tungsten-copper material of this invention comprises a modified tungsten framework and copper distributed in the pores of the modified tungsten framework as a matrix, and its preparation steps include: Powder processing: First, tungsten-metal powder is prepared by co-reduction, and then it is mechanically mixed with ceramic powder to obtain a uniformly mixed raw material powder; or, the tungsten powder, metal powder and ceramic powder are directly mixed by mechanical mixing to obtain the raw material powder. Forming: The raw material powder is pressed into shape, and the pressed blank is shaped. Sintering: The shaped compact is sintered to obtain a modified tungsten framework; Copper infiltration: The modified tungsten skeleton is subjected to copper infiltration treatment.

[0065] In the preparation of the matrix, the purpose of shaping is to make the blank after pressing, such as cold isostatic pressing, have a smooth appearance, uniform thickness, and symmetrical spatial dimensions, which is beneficial to uniform shrinkage during subsequent sintering.

[0066] Furthermore, the ceramic powder is preferably a fine powder with a D50 of 0.1~3μm; Furthermore, when directly using the mechanical mixing method for mixing, the ceramic powder and tungsten powder are mixed first, and then metal powder is added and mixed. The total mixing time is 2 to 8 hours. Furthermore, the pressing and forming is cold isostatic pressing or molding, with a pressure of 180~250MPa (e.g., 200MPa, 220MPa, 240MPa) and a holding time of 10~60min (e.g., 20min, 30min, 40min, 50min). The cold isostatic pressing process involves loading the dried powder into a rubber sleeve, then into a pressing mold with a core, and immersing it in an oil cylinder to obtain a pressed blank. After cold isostatic pressing, the mold and other tooling are removed, and the pressed blank is shaped. Furthermore, the sintering conditions are as follows: atmospheric pressure sintering, sintering atmosphere is either hydrogen or argon, sintering temperature range is 1800~2400℃ (1900℃, 2000℃, 2100℃, 2200℃, 2300℃), and holding time is 2.5~6h (e.g., 3h, 4h, 5h).

[0067] The copper infiltration is carried out by placing the obtained sintered billet on a hanger or in a graphite boat, using a hanging infiltration or stacking infiltration method.

[0068] Furthermore, the copper diffusion conditions are H2 atmospheric pressure copper diffusion, vacuum copper diffusion, or pressure copper diffusion in a nitrogen atmosphere; Furthermore, the copper is high-purity oxygen-free copper powder, copper wire, or copper foil; Furthermore, the temperature of the copper infiltration treatment is 1350~1550℃ (e.g., 1400℃, 1450℃, 1500℃), and the holding time is 1.5~6h (e.g., 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h).

[0069] When using the suspended copper infiltration process, the following steps can be taken: First, suspend the workpiece with molybdenum wire, calculate the required copper content and add it to the crucible, then suspend the workpiece into the copper infiltration furnace and fire it in a high-purity hydrogen atmosphere. The high-temperature zone temperature is 1350~1550℃ (e.g., 1400℃, 1450℃, 1500℃), and the holding time is 1.5~4.5h (e.g., 2h, 2.5h, 3h, 3.5h, 4h). When using the copper infiltration method, the following steps can also be taken: First, evacuate the workpiece to remove the gas. Then, heat the workpiece to 1350~1550℃ (e.g., 1400℃, 1450℃, 1500℃) to melt the copper and soak it in copper. Then, perform pressure-based copper immersion to achieve uniform pressure immersion of the copper liquid in all directions. The pressure and temperature holding time is 1.5~6h (e.g., 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h). After the copper immersion is completed, perform pressure-based cooling.

[0070] The present invention will now be described in further detail with reference to specific embodiments and comparative examples.

[0071] Examples 1-7 and Comparative Examples 1-4 below are preparation examples and comparative examples of setting an adhesive layer and a protective coating on a tungsten copper material (commercially available W-7Cu) substrate.

[0072] Example 1 1.1 Preparation of Ultra-High Temperature Resistant Ceramic Composite Powder 1) Slurry preparation: Ytterbium oxide powder, hafnium oxide powder, deionized water, and PVA adhesive are prepared into a slurry in a certain proportion. The specific preparation proportions are shown in the table below.

[0073] Table 1 Ingredients list for Example 1 2) Slurry preparation: The prepared slurry is homogenized using ball milling. Ball milling process parameters: ball-to-material ratio 3:1; ball mill speed: 300 rpm; ball milling time: 2 hours.

[0074] 3) Spray granulation: The prepared slurry is processed into ultra-high temperature ceramic composite powder using spray granulation. The inlet temperature is 240℃~260℃; the outlet temperature is 100~110℃.

[0075] 4) Drying: The prepared spray-granulated powder is heated in an oven to remove moisture and impurities. The oven temperature is 100℃, and the time is 1.0h~1.5h.

[0076] 5) Densification and homogenization treatment: Plasma spheroidization is used to treat the spray-dried powder to obtain powder with good solid solubility, smooth surface, and uniform composition. Current: 600~650 A; Main gas: 35~45 L / min; Power: >24KW; Carrier gas: 7~10 L / min; Powder feed rate: 20~30 g / min.

[0077] 6) Drying: Place the powder in an oven and dry it. The oven temperature is 100℃ and the time is 1.0h~1.5h.

[0078] 7) Sieving: Sieving out ultra-high temperature ceramic composite powders that meet the particle size requirements, such as... Figure 1 As shown.

[0079] 1.2 Coating Preparation A bonding layer and a protective layer were sequentially sprayed onto the surface of a tungsten-copper substrate using a plasma spraying method. The powder used to prepare the bonding layer was pure tungsten powder, and the material for the protective layer was the ultra-high temperature ceramic composite powder prepared in step 1.1 of this embodiment, with a particle size range of 10~70μm.

[0080] First, the substrate was sandblasted at a pressure of 0.5 ± 0.1 MPa. Then, a pure tungsten bonding layer was prepared on the sandblasted tungsten-copper substrate surface using plasma spraying. The process parameters were: spraying current 820 A, argon flow rate 44 L / min, and spraying power 24 kW. Next, plasma spraying was performed according to the following parameters: spraying current 880 A, argon flow rate 42 L / min, and spraying power 27 kW. The bonding layer thickness was 0.15 mm, the protective layer thickness was 0.85 mm, and the total coating thickness was 1.0 mm.

[0081] Coating effect test: The prepared coating was subjected to a plasma ablation test. At 2810℃ for 563 seconds, the coating burned through, exposing the substrate. The test was then stopped. The sample after ablation... Figure 2 As shown.

[0082] Example 2 2.1 Preparation of Ultra-High Temperature Resistant Ceramic Composite Powder 1) Slurry Preparation: Lutene oxide powder, hafnium oxide powder, deionized water, and PVA adhesive are mixed in a specific ratio to form a slurry. The specific ratios are shown in the table below. Table 2 Ingredients list for Example 2 2) Slurry preparation, 3) Spray granulation, 4) Drying, 5) Densification and homogenization treatment, 6) Drying, 7) Sieving steps are the same as in Example 1.

[0083] 2.2 Coating Preparation Using the same method as in 1.2 of Example 1, an adhesive layer was first sprayed onto the same substrate as in Example 1 using the adhesive layer material of Example 1 as the raw material, and then a protective layer was sprayed onto the adhesive layer using the composite powder prepared in this example as the raw material for the protective layer, to prepare a coating with an adhesive layer thickness of 0.15 mm, a protective layer thickness of 0.85 mm, and a total coating thickness of 1.0 mm.

[0084] Coating effect test: The prepared coating was subjected to a plasma ablation test. The coating was ablated at 2810℃ for 532 seconds, and the coating was burned through to expose the substrate. The test was then stopped.

[0085] Example 3 3.1 Preparation of Ultra-High Temperature Resistant Ceramic Composite Powder 1) Slurry preparation: Mix rare earth oxides ytterbium oxide and lutetium oxide powder, hafnium oxide powder, deionized water, and PVA adhesive in a certain proportion to form a slurry. The specific proportions are shown in the table below: Table 3 Ingredients list for Example 3 2) Slurry preparation, 3) Spray granulation, 4) Drying, 5) Densification and homogenization treatment, 6) Drying, 7) Sieving steps are the same as in Example 1.

[0086] 3.2 Coating Preparation Using the same method as in 1.2 of Example 1, an adhesive layer was first sprayed onto the same substrate as in Example 1 using the adhesive layer material of Example 1 as the raw material, and then a protective layer was sprayed onto the adhesive layer using the composite powder prepared in this example as the raw material, to prepare a coating with an adhesive layer thickness of 0.15 mm, a protective layer thickness of 0.85 mm, and a total coating thickness of 1.0 mm.

[0087] Coating effect test: The prepared coating was subjected to a plasma ablation test. The coating did not burn through after 690 seconds of ablation at 2810℃. The test was then stopped. The sample after ablation showed... Figure 3 As shown.

[0088] Example 4 4.1 Preparation of Ultra-High Temperature Resistant Ceramic Composite Powder 1) Slurry preparation: Mix rare earth oxides ytterbium oxide and lutetium oxide powder, hafnium oxide powder, deionized water, and PVA adhesive in a certain proportion to form a slurry. The specific proportions are shown in the table below.

[0089] Table 4 Ingredients list for Example 4 2) Slurry preparation, 3) Spray granulation, 4) Drying, 5) Densification and homogenization treatment, 6) Drying, 7) Sieving steps are the same as in Example 1.

[0090] 4.2 Coating Preparation Using the same method as in 1.2 of Example 1, an adhesive layer was first sprayed onto the same substrate as in Example 1 using the adhesive layer material of Example 1 as the raw material, and then a protective layer was sprayed onto the adhesive layer using the composite powder prepared in this example as the raw material for the protective layer, to prepare a coating with an adhesive layer thickness of 0.15 mm, a protective layer thickness of 0.85 mm, and a total coating thickness of 1.0 mm.

[0091] Coating effect test: The prepared coating was subjected to a plasma ablation test. The coating was ablated at 2810℃ for 360 seconds, and the coating was burned through to expose the substrate. The test was then stopped.

[0092] Example 5 5.1 Preparation of Ultra-High Temperature Resistant Ceramic Composite Powder 1) Slurry preparation: Mix rare earth oxides ytterbium oxide and lutetium oxide powder, hafnium oxide powder, deionized water, and PVA adhesive in a certain proportion to form a slurry. The specific proportions are shown in the table below.

[0093] Table 5 Ingredients list for Example 5 2) Slurry preparation, 3) Spray granulation, 4) Drying, 5) Densification and homogenization treatment, 6) Drying, 7) Sieving steps are the same as in Example 1.

[0094] 5.2 Coating Preparation Using the same method as in 1.2 of Example 1, an adhesive layer was first sprayed onto the same substrate as in Example 1 using the adhesive layer material of Example 1 as the raw material, and then a protective layer was sprayed onto the adhesive layer using the composite powder prepared in this example as the raw material for the protective layer, to prepare a coating with an adhesive layer thickness of 0.15 mm, a protective layer thickness of 0.85 mm, and a total coating thickness of 1.0 mm.

[0095] Coating effect test: The prepared coating was subjected to a plasma ablation test. The coating was ablated at 2810℃ for 488 seconds, and the coating was burned through to expose the substrate. The test was then stopped.

[0096] Example 6 6.1 Preparation of Ultra-High Temperature Resistant Ceramic Composite Powder 1) Slurry preparation: Mix rare earth oxides ytterbium oxide and lutetium oxide powder, hafnium oxide powder, deionized water, and PVA adhesive in a certain proportion to form a slurry. The specific proportions are shown in the table below: Table 6 Ingredients list for Example 6 2) Slurry preparation, 3) Spray granulation, 4) Drying, 5) Densification and homogenization treatment, 6) Drying, 7) Sieving steps are the same as in Example 1.

[0097] 6.2 Coating Preparation Using the same method as in 1.2 of Example 1, an adhesive layer was first sprayed onto the same substrate as in Example 1 using the adhesive layer material of Example 1 as the raw material, and then a protective layer was sprayed onto the adhesive layer using the composite powder prepared in this example as the raw material for the protective layer, to prepare a coating with an adhesive layer thickness of 0.15 mm, a protective layer thickness of 0.85 mm, and a total coating thickness of 1.0 mm.

[0098] Coating effect test: The prepared coating was subjected to a plasma ablation test. The coating was ablated at 2810℃ for 645 seconds, and the coating was burned through to expose the substrate. The test was then stopped.

[0099] Example 7 7.1 Preparation of Ultra-High Temperature Resistant Ceramic Composite Powder 1) Slurry preparation: Mix rare earth oxides ytterbium oxide and lutetium oxide powder, hafnium oxide powder, deionized water, and PVA adhesive in a certain proportion to form a slurry. The specific proportions are shown in the table below: Table 7 Ingredients list for Example 7 2) Slurry preparation, 3) Spray granulation, 4) Drying, 5) Densification and homogenization treatment, 6) Drying, 7) Sieving steps are the same as in Example 1.

[0100] 7.2 Coating Preparation Using the same method as in 1.2 of Example 1, an adhesive layer was first sprayed onto the same substrate as in Example 1 using the adhesive layer material of Example 1 as the raw material, and then a protective layer was sprayed onto the adhesive layer using the composite powder prepared in this example as the raw material for the protective layer, to prepare a coating with an adhesive layer thickness of 0.15 mm, a protective layer thickness of 0.85 mm, and a total coating thickness of 1.0 mm.

[0101] Coating effect test: The prepared coating was subjected to a plasma ablation test. The coating was ablated at 2810℃ for 610 seconds, and the coating was burned through to expose the substrate. The test was then stopped.

[0102] Comparative Example 1 1.1 Preparation of composite powders 1) Slurry preparation: Mix rare earth oxides ytterbium oxide and hafnium oxide powder, along with deionized water and PVA adhesive in a certain proportion to form a slurry. The specific proportions are shown in the table below: Table 8. Ingredients list for Comparative Example 1 2) Slurry preparation, 3) Spray granulation, 4) Drying, 5) Densification and homogenization treatment, 6) Drying, 7) Sieving steps are the same as in Example 1.

[0103] 1.2 Coating Preparation Using the same method as in 1.2 of Example 1, an adhesive layer was first sprayed onto the same substrate as in Example 1 using the adhesive layer material of Example 1 as the raw material, and then a protective layer was sprayed onto the adhesive layer using the composite powder prepared in this comparative example as the raw material for the protective layer, to prepare a coating with an adhesive layer thickness of 0.15 mm, a protective layer thickness of 0.85 mm, and a total coating thickness of 1.0 mm.

[0104] Coating effect test: The prepared coating was subjected to a plasma ablation test. The coating was ablated at 2810℃ for 141 seconds, and the coating was burned through to expose the substrate. The test was then stopped.

[0105] Comparative Example 2 2.1 Preparation of composite powders 1) Slurry Preparation: Lutene oxide powder, hafnium oxide powder, deionized water, and PVA adhesive are mixed in a specific ratio to form a slurry. The specific ratios are shown in the table below. Table 9. Ingredients list for Comparative Example 2 2) Slurry preparation, 3) Spray granulation, 4) Drying, 5) Densification and homogenization treatment, 6) Drying, 7) Sieving steps are the same as in Example 1.

[0106] 2.2 Coating Preparation Using the same method as in 1.2 of Example 1, an adhesive layer was first sprayed onto the same substrate as in Example 1 using the adhesive layer material of Example 1 as the raw material, and then a protective layer was sprayed onto the adhesive layer using the composite powder prepared in this comparative example as the raw material for the protective layer, to prepare a coating with an adhesive layer thickness of 0.15 mm, a protective layer thickness of 0.85 mm, and a total coating thickness of 1.0 mm.

[0107] Coating effect test: The prepared coating was subjected to a plasma ablation test. The coating was ablated at 2810℃ for 126 seconds, and the coating was burned through to expose the substrate. The test was then stopped.

[0108] Comparative Example 3 3.1 Preparation of composite powders 1) Slurry preparation: Mix rare earth oxides ytterbium oxide and lutetium oxide powder, hafnium oxide powder, deionized water, and PVA adhesive in a certain proportion to form a slurry. The specific proportions are shown in the table below: Table 10 Comparative Example 3 Ingredient List 2) Slurry preparation, 3) Spray granulation, 4) Drying, 5) Densification and homogenization treatment, 6) Drying, 7) Sieving steps are the same as in Example 1.

[0109] 3.2 Coating Preparation Using the same method as in 1.2 of Example 1, an adhesive layer was first sprayed onto the same substrate as in Example 1 using the adhesive layer material of Example 1 as the raw material, and then a protective layer was sprayed onto the adhesive layer using the composite powder prepared in this comparative example as the raw material for the protective layer, to prepare a coating with an adhesive layer thickness of 0.15 mm, a protective layer thickness of 0.85 mm, and a total coating thickness of 1.0 mm.

[0110] Coating effect test: The prepared coating was subjected to a plasma ablation test. The coating was ablated at 2810℃ for 230 seconds, and the coating was burned through to expose the substrate. The test was then stopped.

[0111] Comparative Example 4 4.1 Preparation of composite powders The process steps are 1) slurry preparation, 2) slurry preparation, 3) spray granulation, 4) sintering, and 5) sieving. Among them, 1) slurry preparation, 2) slurry preparation, and 3) spray granulation are the same as in Example 1, and 5) sieving is the same as in 7) of Example 1.

[0112] 4) The sintering step is as follows: The spray-granulated powder is sintered in a sintering furnace to obtain powder with a certain strength. The sintering temperature is 1600℃, and the holding time is 3 hours.

[0113] 4.2 Coating Preparation Using the same method as in 1.2 of Example 1, an adhesive layer was first sprayed onto the same substrate as in Example 1 using the adhesive layer material of Example 1 as the raw material, and then a protective layer was sprayed onto the adhesive layer using the composite powder prepared in this comparative example as the raw material for the protective layer, to prepare a coating with an adhesive layer thickness of 0.15 mm, a protective layer thickness of 0.85 mm, and a total coating thickness of 1.0 mm.

[0114] Coating effect test: The prepared coating was subjected to a plasma ablation test. The coating was ablated at 2810℃ for 70 seconds, and the coating was burned through to expose the substrate. The test was then stopped.

[0115] Examples 8-10 and Comparative Examples 5-6 below are preparation examples of sequentially setting an adhesive layer, a transition layer and a protective layer on a substrate tungsten copper material (W-7Cu).

[0116] Example 8 The substrate material of the ultra-high temperature thermal protective coating prepared in this embodiment is W-7Cu tungsten copper material, the adhesive layer material is pure tungsten powder, the transition layer material consists of 50wt% tungsten powder + 50wt% ultra-high temperature resistant ceramic composite powder prepared in Example 3, and the protective layer material is ultra-high temperature resistant ceramic composite powder prepared in Example 3.

[0117] The thickness of the adhesive layer in the composite coating is 0.15 mm, the thickness of the transition layer is 0.2 mm, and the thickness of the protective layer is 0.65 mm.

[0118] The coating is achieved by plasma spraying, and the preparation method includes the following steps: (1) Sandblasting was performed using the same sandblasting process as in 1.2 of Example 1; (2) A pure tungsten bonding layer was prepared on the tungsten-copper alloy substrate treated in step (1) using plasma spraying process. The process parameters were: spraying current of 820A, argon flow rate of 44L / min, and spraying power of 24KW. (3) A transition layer is sprayed onto the pure tungsten bonding layer prepared in step (2) using plasma spraying process. The process parameters are: spraying current is 850A, argon flow rate is 40L / min, and spraying power is 25KW. (4) A protective layer is sprayed onto the surface of the transition layer prepared in step (3) using plasma spraying process. The process parameters are: spraying current is 880A, argon flow rate is 42L / min, and spraying power is 27KW.

[0119] The coating prepared by this method showed no obvious ablation damage under plasma simulated ablation conditions of 2810℃ and 690s.

[0120] Comparative Example 5 Based on Example 8, the adhesive layer and transition layer are omitted, and everything else is the same as in Example 8.

[0121] The coating prepared in this comparative example detached from the substrate after 35 seconds of simulated plasma ablation at 2810℃, exposing the substrate, at which point the experiment was stopped. This comparative example lacked both an adhesive layer and a transition layer, consisting only of a protective layer, and the coating detached from the substrate very quickly. The adhesive layer serves two purposes: improving bonding strength and providing thermal stress matching during heating. Designing the transition layer with a combination of different components can further enhance thermal matching.

[0122] Comparative Example 6 Based on Example 8, the adhesive layer is omitted, and everything else is the same as in Example 8.

[0123] The coating prepared in this comparative example was ablated for 316 seconds under plasma simulation ablation conditions of 2810℃, at which point the coating detached, exposing the substrate, and the experiment was stopped.

[0124] Example 9 The substrate material of the ultra-high temperature thermal protective coating prepared in this embodiment is W-7Cu tungsten copper material, the adhesive layer material is pure molybdenum powder, the transition layer is 50wt% molybdenum powder + 50wt% ultra-high temperature resistant ceramic composite powder prepared in Example 3, and the protective layer material is ultra-high temperature resistant ceramic composite powder prepared in Example 3.

[0125] The thickness of the adhesive layer in the composite coating is 0.15 mm, the thickness of the transition layer is 0.2 mm, and the thickness of the protective layer is 0.65 mm.

[0126] The spraying process parameters for the adhesive layer are: spraying current of 780A, argon flow rate of 48L / min, and spraying power of 20KW; the spraying process parameters for the transition layer are: spraying current of 820A, argon flow rate of 43L / min, and spraying power of 23KW; the preparation process for the protective layer is the same as in Example 8.

[0127] The coating prepared by this method was subjected to plasma ablation at 2810°C for 596 seconds, during which the coating burned through and exposed the substrate, at which point the experiment was stopped. In this example, the binder material was molybdenum, and the transition layer also contained molybdenum. Since the melting point of molybdenum is slightly lower than that of tungsten, the ablation resistance of the coating in this example is slightly worse than that in Example 8.

[0128] Example 10 The substrate material of the ultra-high temperature thermal protective coating prepared in this embodiment is W-7Cu tungsten copper material, the binder layer material consists of 50wt% tungsten powder + 50wt% molybdenum powder, the transition layer material consists of 50wt% binder layer material + 50wt% ultra-high temperature resistant ceramic composite powder prepared in Example 3, and the protective layer material is the ultra-high temperature resistant ceramic composite powder prepared in Example 3.

[0129] The adhesive layer has a thickness of 0.15 mm, the transition layer has a thickness of 0.2 mm, and the protective layer has a thickness of 0.65 mm.

[0130] The spraying process parameters for the adhesive layer are: spraying current of 800A, argon flow rate of 46L / min, and spraying power of 22KW; the spraying process parameters for the transition layer are: spraying current of 840A, argon flow rate of 43L / min, and spraying power of 24KW; the preparation of the protective layer is the same as in Example 8.

[0131] The coating prepared by this method was subjected to plasma ablation at 2810°C for 684 seconds, during which the coating burned through and exposed the substrate, at which point the experiment was stopped. In this example, the binder material was a mixture of molybdenum and tungsten powder, so the coating in this example had slightly worse ablation resistance than that in Example 8 but better than that in Example 9.

[0132] Examples 11-20 and Comparative Examples 7-10 below are examples and comparative examples of different tungsten-copper material matrix preparations.

[0133] The particle sizes of the raw material powders used in the following matrix material examples and comparative examples are as follows: Tungsten powder: Fisher particle size 6.5μm; HfB2 powder: Laser-etched particle size distribution exhibits a unimodal distribution (D50): 2.5~3.5μm. HfC: Laser particle size distribution exhibits a unimodal distribution; D50: 2.5~3.5μm. TaC: Laser-induced particle size distribution exhibits a unimodal distribution; D50: 2.5~3.5μm. Re powder: Laser particle size distribution D50: 15-16μm, Example 11 The preparation method of W-2HfB2-3Re-Cu in this embodiment includes the following steps: (1) Preparation of raw material powder: Weigh 47.5 kg of tungsten powder, 1 kg of HfB2 powder and 1.5 kg of Re powder, mix the tungsten powder, ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is loaded into the sintering furnace and held at 2200℃ for 270 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact with a room temperature tensile strength of 310 MPa and a 1000℃ tensile strength of 220 MPa. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0134] Example 12 The preparation method of W-2HfB2-Cu in this embodiment includes the following steps: (1) Preparation of raw material powder: Weigh 49 kg of tungsten powder and 1 kg of HfB2 powder, and mix the tungsten powder and ceramic powder on a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 20min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2080℃ for 360 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact with a room temperature tensile strength of 280 MPa and a 1000℃ tensile strength of 190 MPa. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0135] Example 13 The preparation method of W-1.2TaC-5Re-Cu in this embodiment includes the following steps: (1) Preparation of raw material powder: Weigh 46.9 kg of tungsten powder, 0.6 kg of TaC powder and 2.5 kg of Re powder, and mix the tungsten powder, ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 15min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2100℃ for 360 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the material placement platform and place it in the copper infiltration furnace. After vacuuming, heat it to 1200°C. After the copper melts, immerse the workpiece in it and then pressurize it with N2. After the pressure reaches 5MPa, keep it at the temperature for 120 minutes. After cooling to room temperature, release the pressure and remove it from the furnace.

[0136] Example 14 The preparation method of W-1.2HfC-5Re-Cu in this embodiment includes the following steps: (1) Preparation of raw material powder: Weigh 46.9 kg of tungsten powder, 0.6 kg of HfC powder and 2.5 kg of Re powder, and mix the tungsten powder, ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2100℃ for 300 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: The obtained sintered billet is placed on a hanger, and the workpiece is suspended by a molybdenum wire and then suspended into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by suspension. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0137] Example 15 The preparation method of W-2HfC-3Re-Cu in this embodiment (1) Preparation of raw material powder: Weigh 47.5 kg of tungsten powder, 1 kg of HfC powder, and 1.5 kg of Re powder. Mix the tungsten powder, ceramic powder, and rhenium powder in a three-dimensional mixer for 6 hours to obtain a uniformly mixed raw material powder. (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2700℃ for 300 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact; its room temperature tensile strength is 320 MPa and its 1000℃ tensile strength is 250 MPa. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0138] Example 16 The preparation method of W-2HfO2-3Re-Cu in this embodiment is as follows: (1) Preparation of raw material powder: Weigh 47.5 kg of tungsten powder, 1 kg of HfO2 powder, and 1.5 kg of Re powder. Mix the tungsten powder, ceramic powder, and rhenium powder in a three-dimensional mixer for 6 hours to obtain a uniformly mixed raw material powder. (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2100℃ for 270 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0139] Example 17 The preparation method of W-4HfB2-3Re-Cu in this embodiment is as follows: (1) Preparation of raw material powder: Weigh 46.5 kg of tungsten powder, 2 kg of HfB2 powder and 1.5 kg of Re powder, mix the tungsten powder, ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2000℃ for 270 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0140] Example 18 The preparation method of W-3TiB2-7Re-Cu in this embodiment is as follows: (1) Preparation of raw material powder: Weigh 45kg of tungsten powder, 1.5kg of TiB2 powder and 3.5kg of Re powder, and mix the tungsten powder, ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2100℃ for 200 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0141] Example 19 The preparation method of W-3NbB2-7Mo-Cu in this embodiment is as follows: (1) Preparation of raw material powder: Weigh 45 kg of tungsten powder, 1.5 kg of NbB2 powder and 3.5 kg of Mo powder, mix the tungsten powder, ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2200℃ for 300 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0142] Example 20 The preparation method of W-3ZrB2-7Re-Cu in this embodiment is as follows: (1) Preparation of raw material powder: Weigh 45kg of tungsten powder, 1.5kg of ZrB2 powder and 3.5kg of Re powder, and mix the tungsten powder, ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2200℃ for 200 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: Place the sintered billet obtained in step (3) on the hanger, hang the workpiece with molybdenum wire and then hang the workpiece into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by hanging infiltration. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0143] Comparative Example 7 The preparation method of this comparative example W-Cu includes the following steps: (1) Take 100 kg of tungsten powder and put it into a vacuum dryer for drying. Control the drying temperature at 150℃, the holding time at 100 min, and the vacuum degree ≥10. -2 Pa; (2) Forming: The cold isostatic pressing process is adopted. The dried tungsten powder is put into a rubber sleeve, then into a pressing mold with a core, and immersed in an oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. (3) Sintering: The pressed blank obtained in step (2) is loaded into the sintering furnace and held at 2000℃ for 300 min in a high-purity hydrogen atmosphere to obtain a tungsten skeleton sintered blank; (4) Copper infiltration: The obtained sintered billet is placed on a hanger, and the workpiece is suspended by a molybdenum wire and then suspended into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by suspension. The copper infiltration temperature is maintained at 1500℃ and the holding time is 90min.

[0144] Comparative Example 8 The preparation method of this comparative example (W-5HfB2-3Re)-Cu includes the following steps: (1) Preparation of raw material powder: Weigh 46 kg of tungsten powder, 2.5 kg of HfB2 powder and 1.5 kg of Re powder, and mix the tungsten powder, modified ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder. (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2000℃ for 270 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: The obtained sintered billet is placed on a hanger, and the workpiece is suspended by a molybdenum wire and then suspended into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by suspension. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0145] Comparative Example 9 The preparation method of this comparative example (W-5HfB2-3Re)-Cu includes the following steps: (1) Preparation of raw material powder: Weigh 46 kg of tungsten powder, 2.5 kg of HfB2 powder and 1.5 kg of Re powder, and mix the tungsten powder, modified ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder. (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is placed into a sintering furnace and held at 2200℃ for 270 min in a high-purity hydrogen atmosphere to obtain a modified tungsten skeleton sintered compact. (4) Copper infiltration: The obtained sintered billet is placed on a hanger, and the workpiece is suspended by a molybdenum wire and then suspended into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by suspension. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0146] Comparative Example 10 The preparation method of this comparative example W-0.5HfC-3Re-Cu includes the following steps: (1) Preparation of raw material powder: Weigh 48.25 kg of tungsten powder, 0.25 kg of HfC powder and 1.5 kg of Re powder, and mix the tungsten powder, modified ceramic powder and rhenium powder in a three-dimensional mixer for 6 hours to obtain uniformly mixed raw material powder; (2) Forming: The cold isostatic pressing process is adopted. The raw material powder mixed evenly in (1) is put into the rubber sleeve, then into the pressing mold with the mold core, and immersed in the oil cylinder. The pressing pressure is 200MPa, and the holding time is 10min±1min to obtain the pressed blank. The pressed blank is then shaped. (3) Sintering: The shaped compact obtained in step (2) is loaded into the sintering furnace and held at 2100℃ for 300 min in a high-purity hydrogen atmosphere to obtain the modified tungsten skeleton compact. (4) Copper infiltration: The obtained sintered billet is placed on a hanger, and the workpiece is suspended by a molybdenum wire and then suspended into the copper infiltration furnace. Copper infiltration is carried out in a high-purity hydrogen atmosphere by suspension. The copper infiltration temperature is maintained at 1500℃ and the holding time is 120min.

[0147] Performance testing The materials obtained in Examples 11-20 and Comparative Examples 7-10 of this invention were subjected to copper content testing, tensile strength at 1600℃ and ablation resistance testing.

[0148] The copper content test adopts the national standard GJB2299; The tensile strength at 1600℃ conforms to the national standards GB / T228.2 and GJB2299. The ablation performance test was conducted using a plasma ablation device, see [link / reference]. Figure 6 The ablation performance of the material was tested at 2810℃. The ablation test method followed the requirements of GJB323A-96 standard, but the heat source was a plasma gun, which generated a plasma flame perpendicular to the circular surface of the specimen. The tip of the flame was aligned with the center of the specimen, and an infrared thermometer was used to measure the temperature throughout the experiment. The temperature was transmitted back to the temperature control system, which adjusted the distance between the plasma gun and the specimen to ensure that the temperature at the center of the specimen remained constant at the required experimental temperature. The specimen was ablated along its thickness, and the experiment stopped when the specimen burned through. The time taken from the specimen reaching the specified test temperature to burning through was recorded as "ablation time (t)". ​​The weights before and after the test were recorded as M1 and M2, respectively. The mass ablation rate can be expressed as (M1-M2) / t. The specimen for ablation resistance testing was a 5mm thick circular piece. The ablation test was conducted perpendicular to the thickness direction, and the ablation test ended when the specimen burned through.

[0149] Results data The performance test results are shown in Table 11: Table 11 As can be seen from the table above, compared with conventional tungsten copper infiltrated materials (Comparative Example 7), the novel tungsten copper infiltrated material prepared by this invention has significantly improved high-temperature strength, with a tensile strength of up to 268 MPa in a vacuum atmosphere at 1600℃; its ablation resistance is significantly improved, with an ablation time nearly doubled compared to conventional grade tungsten copper (W-7Cu), reaching 327 s; ablation mass loss is significantly reduced, with an ablation rate as low as 0.11 g / s.

[0150] Furthermore, a comparison between Comparative Examples 8-10 and Example 11 in the table above shows that adding too much or too little ceramic powder will have an adverse effect on the ablation resistance and mechanical properties of the material.

[0151] from Figure 5 As can be seen from the scanning electron microscope images of the novel tungsten copper-infiltrated material prepared in Example 11, the material has the typical structure of tungsten copper material, consisting of a framework and copper; the gray-contrast part is the framework, which is a granular or blocky structure, and these particles play a role in reinforcement and support in the material; the black-contrast part is the copper matrix surrounding the tungsten particles; the diffusely distributed dark gray part is the WB new phase.

[0152] from Figure 4As can be seen, the novel tungsten-copper infiltrated material prepared in Example 15 has the typical structure of tungsten-copper materials, consisting of a framework and copper. The gray portion represents the framework, which is a granular or blocky structure. These particles play a reinforcing and supporting role in the material. The golden-yellow portion is a copper matrix surrounding the tungsten particles. The grain size of the tungsten framework is around level 10.

[0153] from Figure 7 The XRD patterns show that new phases, including WB and W2B, are formed in HfB2 and rhenium-modified tungsten copper materials (Example 11). These new phases enhance the mechanical properties and ablation resistance of the original composition and improve the stability of the material properties. In contrast, no new phases are formed in HfC and rhenium-modified materials (Example 14), and the stability of the material properties is poor.

[0154] from Figure 8 As can be seen, there are more black areas in Comparative Example 9. This is because the increased amount of hafnium boride produces too much WB phase, which leads to a certain degree of reduction in the material's resistance to ablation.

[0155] This invention does not provide separate examples of workpiece preparation. The workpiece preparation process is similar to that of Example 8. In the preferred workpiece preparation example, only the substrate W7Cu needs to be replaced with the tungsten copper material prepared in Examples 11-20. Since the high-temperature resistance, ablation resistance, and high-temperature mechanical properties of the tungsten copper material prepared in Examples 11-20 are superior to those of W7Cu, the high-temperature resistance and ablation resistance of the workpiece prepared from it are also superior to those of the workpiece prepared from W7Cu.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultra-high temperature thermal protection coating, wherein the coating is disposed on the surface of a substrate, characterized in that, The coating includes: a protective layer; The protective layer is made of ultra-high temperature resistant ceramic composite powder material, which is a solid solution composite material made of raw material hafnium oxide and rare earth oxides. The rare earth oxides are one or both of ytterbium oxide and lutetium oxide. The content of hafnium oxide in the raw material is 70%~90 mol.% and the content of rare earth oxides is 10~30 mol.% by molar percentage.

2. The ultra-high temperature thermal protection coating according to claim 1, characterized in that, The rare earth oxide is a mixture of ytterbium oxide and lutetium oxide. By molar percentage, the hafnium oxide content in the raw material is 75%~82 mol.%, and the rare earth oxide content is 18~25 mol.%. And / or, the ultra-high temperature resistant ceramic composite powder is a spherical powder obtained by granulation and plasma spheroidization of a mixture of raw materials hafnium oxide and rare earth oxides.

3. The ultra-high temperature thermal protection coating according to claim 2, characterized in that, In the rare earth oxide, the molar ratio of ytterbium oxide to lutetium oxide is (0.8~1.2):1; And / or, the content of ytterbium oxide in the raw material is 11 mol.%, and the content of lutetium oxide is 11 mol.%.

4. The ultra-high temperature thermal protection coating according to claim 2, characterized in that, The process before granulation also includes wet ball milling of the mixture; And / or, the particle size of the spherical powder is from 500 nm to 100 μm; And / or, the granulation is spray granulation.

5. The ultra-high temperature thermal protection coating according to claim 1, characterized in that, The coating further includes an adhesive layer disposed between the substrate surface and the protective layer, wherein the adhesive layer is composed of one or two of tungsten and molybdenum; and the substrate is a tungsten-copper material.

6. The ultra-high temperature thermal protection coating according to claim 5, characterized in that, The coating further includes a transition layer disposed between the adhesive layer and the protective layer, wherein the transition layer is composed of a composite material of 45-55% adhesive layer material and 45-55% protective layer material by mass; and the thickness of the transition layer is 0.20-0.50 mm. And / or, the thickness of the adhesive layer is 0.10~0.20 mm; And / or, the thickness of the protective layer is 0.40~0.80mm.

7. A workpiece resistant to ultra-high temperature and ablation, characterized in that, The workpiece includes a substrate and an ultra-high temperature thermal protection coating as described in claims 1 to 6 disposed on the surface of the substrate, wherein the substrate is a tungsten copper material.

8. The workpiece according to claim 7, characterized in that, The tungsten-copper material comprises a modified tungsten framework and copper distributed in the pores of the modified tungsten framework. The modified tungsten framework is made by sintering tungsten powder, ceramic powder, and metal powder. The ceramic powder accounts for 1.2-4.5% by mass, the metal powder accounts for 0-10%, and the remainder is tungsten powder. The ceramic powder is one or more of tantalum, titanium, niobium, zirconium, and hafnium borides, carbides, or oxides. The metal powder is one or two of molybdenum powder and rhenium powder. The copper content in the tungsten-copper material is 6~12wt%.

9. A method for preparing a workpiece as described in claim 7 or 8, characterized in that, include: The substrate preparation steps and the ultra-high temperature thermal protection coating preparation steps, among which, The preparation steps of the ultra-high temperature thermal protective coating include: substrate sandblasting, adhesive layer spraying, transition layer spraying, and protective layer spraying; all spraying is carried out by plasma spraying.

10. The method for preparing a workpiece according to claim 9, characterized in that, The matrix preparation steps include: S1. Powder processing: First, tungsten-metal powder is prepared by co-reduction, and then it is mechanically mixed with ceramic powder to obtain a uniformly mixed raw material powder; or, the tungsten powder, metal powder and ceramic powder are directly mixed by mechanical mixing to obtain the raw material powder. S2. Forming: The raw material powder obtained in step S1 is pressed into shape, and the pressed blank is shaped. S3. Sintering: The pressed blank obtained in step S2 is sintered to obtain a modified tungsten framework; S4. Copper infiltration: The modified tungsten skeleton is subjected to copper infiltration treatment.

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