A Ta 12 High-Temperature Antioxidant Coating Material for W Alloy and Its Preparation Method

Abstract

This invention provides a Ta 12 This invention relates to a high-temperature anti-oxidation coating material for tantalum alloys and its preparation method, aiming to address the insufficient protective capability of existing tantalum alloy coating technologies under extreme high-temperature environments. Through carefully designed material ratios and preparation processes, this invention successfully develops a coating material that can significantly improve the protective capability of Ta alloys under extreme high-temperature environments. 12 This invention presents a high-temperature oxidation-resistant coating for W alloy, exhibiting superior oxidation resistance, thermal shock stability, and erosion resistance under high-temperature conditions. The coating material primarily consists of Mo, Cr and their compounds, Ta₂O₅, Hf and its compounds, MoSi₂, Ti, ZrO₂, Y₂O₃, Sc₂O₃, and Si. All components exist in powder form and are prepared through grinding, mixing, coating, and sintering processes. This coating technology is not only applicable to the aerospace industry but can also be widely used in high-temperature industrial equipment and the chemical industry, possessing broad market prospects and significant economic benefits.

Description

Technical Field

[0001] This invention relates to the field of coating materials technology, specifically to a Ta 12 The invention relates to a high-temperature anti-oxidation protective coating material for W alloy and its preparation method, aiming to provide a coating material with excellent high-temperature oxidation resistance, thermal shock resistance and good adhesion between the coating and the substrate. Background Technology

[0002] In current research and application of tantalum alloys, mainstream technologies primarily employ coating formulations based on Si-Cr-Ti-Zr, Si-Ti-Hf-Mo, and composite materials using MoSi2+Zr+TiB2 as the base layer and Si+W+Hf as the top layer. These formulations utilize various preparation techniques, including slurry coating, spraying, magnetron sputtering, and infiltration, aiming to significantly improve the high-temperature oxidation resistance of tantalum alloys and maintain their mechanical properties at high temperatures through surface treatment. Specifically, Ta... 10 After coating treatment, W alloy is widely used in aerospace combustion chambers, missile engine nose cones, fasteners, exhaust pipes and other key high-temperature components. Its high-temperature oxidation resistance has achieved remarkable results, maintaining 25 hours at 1800℃ and 5 hours at 1900℃, and it has been put into practical use in the market.

[0003] However, regarding Ta 12 Research on high-temperature oxidation-resistant coatings for tantalum alloys is only reported in one domestic paper, "Preparation of High-Temperature Oxidation-Resistant Iridium Coating for Tantalum Alloys." This study utilizes magnetron sputtering to coat tantalum alloys with iridium coatings. 12 A metallic Ni transition layer was first prepared on the surface of the W alloy, followed by an iridium coating applied by electroplating. The aim was to explore its high-temperature oxidation resistance at 1700℃ for 15 minutes. Although this provides a basis for Ta 12 The research and development of high-temperature anti-oxidation coatings for W alloys has made preliminary progress, but there have been no related publications in the patent field.

[0004] To address this technological gap, this invention proposes a Ta 12 The high-temperature anti-oxidation protective coating material for W alloy and its preparation method aim to meet the working requirements of the alloy under extreme high-temperature conditions and further extend its service life. The coating of this invention not only has a dense surface structure and good adhesion to the substrate, but also exhibits an anti-oxidation coating lifespan exceeding 2 hours under extreme conditions of 1900℃ and exceeding 18 hours at 1800℃. Furthermore, under air-cooled thermal shock conditions of 800–1800℃, the coating lifespan exceeds 200 cycles.

[0005] Meanwhile, other similar patents have provided valuable references for the field. For example, Chinese patent application CN201710489407.9 discloses a method for preparing a Si-BY coating on the surface of tantalum and tantalum alloys. This method emphasizes the pretreatment of the sample surface, the ball milling refinement of the infiltrator, and the heating, holding, and cooling treatments in a high-temperature furnace, which can significantly improve the high-temperature oxidation resistance of the base alloy while also taking into account its corrosion and wear resistance. In addition, patent documents CN201510216664.6.9 and CN201811618657.9 demonstrate different formulations and preparation methods for anti-oxidation coatings of tantalum-tungsten alloys, providing protective solutions for tantalum-tungsten alloys in high-temperature environments.

[0006] By comparison, it can be seen that although existing technologies have achieved certain results in improving the high-temperature oxidation resistance of tantalum alloys, there are still shortcomings regarding Ta... 12 The development of specific high-temperature anti-oxidation coatings for W alloys is still in the preliminary exploratory stage. This invention aims to provide a simplified preparation process and low-cost implementation method for Ta... 12 This provides more efficient and reliable high-temperature protective coating solutions for W alloys and similar high-temperature applications, filling technological gaps and promoting the development and application of related technologies. Summary of the Invention

[0007] This invention aims to address the limitations of existing tantalum alloy coating technologies in terms of extreme high temperatures, long-term durability, and erosion resistance, and proposes a novel Ta... 12 High-temperature anti-oxidation coating material for W alloy and its preparation method. This technology not only improves the high-temperature oxidation resistance and thermal shock resistance of the coating, but also optimizes the adhesion between the coating and the substrate, ensuring the long-term stability and crack resistance of the coating.

[0008] The technical solution adopted in this invention is as follows:

[0009] A Ta 12 The W alloy high-temperature anti-oxidation coating material comprises, by mass percentage: 4-5 wt% molybdenum, 4-5 wt% chromium and its compounds, 2-3 wt% tantalum oxide, 1-2 wt% hafnium boride, 2-3 wt% molybdenum disilicide, 1-2 wt% titanium, 3-4 wt% zirconium dioxide, 0.5-1.2 wt% yttrium oxide, 0.5-1 wt% scandium oxide, and 73.8-82 wt% silicon.

[0010] Specifically, all components of the material exist in the form of powder with a mesh size of 300 or less.

[0011] The Ta 12 The preparation method of W alloy high-temperature anti-oxidation coating material includes the following steps:

[0012] a) Mix the aforementioned components with polyethylene glycol to form a mixture, wherein the polyethylene glycol accounts for 1 to 2% of the total mass of the mixture;

[0013] b) Add anhydrous ethanol as an additive to the mixture, wherein the amount added accounts for 30-40% of the total mass after mixing;

[0014] c) Grind the mixture for 5-8 hours to prepare a coating slurry;

[0015] d) Spraying or dipping the coating slurry onto Ta 12 On a W alloy matrix;

[0016] e) The coated alloy substrate is placed in a vacuum furnace and sintered at 1530–1600°C for 40–60 minutes to form a high-temperature anti-oxidation coating, wherein the vacuum degree is better than 1.0 × 10⁻⁶. -3 Pa.

[0017] Preferably, the thickness of the prepared high-temperature antioxidant coating is 100–140 μm.

[0018] The present invention also provides a Ta coating material using the aforementioned coating material. 12 W alloy component, the surface of which is covered with a high-temperature anti-oxidation coating prepared according to the aforementioned method, the coating can maintain high-temperature anti-oxidation performance for more than 2 hours at a high temperature of 1900°C, and maintain anti-oxidation performance for more than 18 hours at a high temperature of 1800°C.

[0019] The component has a thermal shock life of more than 200 cycles in a temperature range of 800 to 1800°C.

[0020] Through the above solutions, the present invention also provides a Ta coating material using the aforementioned coating material. 12 W alloy components are used in aviation, aerospace vehicles, high-temperature industrial equipment, and the chemical industry. The high-temperature anti-oxidation coating on the surface of these components provides excellent high-temperature oxidation resistance, thermal shock stability, and erosion resistance, meeting the application requirements in high-temperature environments.

[0021] Ta prepared by this invention 12 The W alloy high-temperature anti-oxidation coating not only provides excellent high-temperature anti-oxidation performance but also possesses superior thermal shock stability and strong adhesion to the substrate, enabling it to withstand extreme temperatures up to 1900℃. Against the backdrop of rapid technological advancements in fields such as aerospace and aviation, the development of this coating not only provides… 12 W alloys and their applications offer enhanced performance assurance and broaden their application prospects in high-temperature industrial equipment and the chemical industry.

[0022] The high-temperature antioxidant coating material of this invention, compared to uncoated Ta... 12 The W alloy substrate exhibited significantly improved performance characteristics. This unique coating not only ensured performance stability under extreme high-temperature environments but also effectively prevented coating cracking and significantly enhanced the material's high-temperature oxidation resistance. In comparative analysis, the original Ta... 12 Without any protective treatment, the oxidation resistance of W alloy is limited to 30 minutes at 1200°C. However, after applying the technology of this invention, the coating material not only makes Ta... 12 The oxidation resistance life of W alloy was extended to 18 hours at a high temperature of 1800℃, and it maintained its oxidation resistance for 2 hours under extreme high temperature conditions of 1900℃, with the test piece remaining intact. Attached Figure Description

[0023] Figure 1 This is a process flow diagram of the present invention.

[0024] Figure 2 This is a morphological image of sample A# after oxidation during static performance testing at 1800℃ in Example 1 of this invention.

[0025] Figure 3 The appearance morphology of sample C# after oxidation during static performance testing at 1900℃ in Example 1 of this invention.

[0026] Figure 4 The appearance morphology of sample E# after oxidation in the thermal shock performance test at 800-1800℃ in Example 1 of this invention.

[0027] Figure 5 The appearance morphology of sample G# after oxidation during static performance testing at 1800℃ in Example 2 of this invention.

[0028] Figure 6 The appearance morphology of sample I# after oxidation during static performance testing at 1900℃ in Example 2 of this invention.

[0029] Figure 7 The appearance morphology of sample K# after oxidation in the thermal shock performance test at 800-1800℃ in Example 2 of this invention. Detailed Implementation

[0030] The following specific embodiments and accompanying drawings further illustrate the details and applications of the present invention. However, it should be understood that these embodiments are intended to illustrate, not limit, the broad scope of application of the present invention. After becoming familiar with the basic principles of the present invention, those skilled in the art can make various reasonable adjustments and variations based on these principles, and such adjustments and variations still fall within the scope of the claims of this patent application.

[0031] Example 1

[0032] In this embodiment, the specific proportions of the raw material powder for preparing the high-temperature antioxidant coating are as follows: molybdenum (Mo) accounts for 4 wt%, chromium disilicide (CrSi2) for 4 wt%, tantalum oxide (Ta2O5) for 2 wt%, hafnium boride (HfB2) for 1 wt%, molybdenum disilicide (MoSi2) for 2 wt%, titanium (Ti) for 1 wt%, zirconium dioxide (ZrO2) for 3 wt%, yttrium oxide (Y2O3) for 0.5 wt%, scandium oxide (Sc2O3) for 0.5 wt%, and silicon (Si) accounts for 82 wt% of the total weight. According to... Figure 1 As shown in the steps, after uniformly mixing these components, we added 2% polyethylene glycol as a binder, and then added 30% anhydrous ethanol as a solvent. This mixture was then ball-milled in a planetary ball mill for 6 hours to obtain a homogeneous coating slurry.

[0033] Next, in Ta 12 The slurry was uniformly coated onto a W alloy substrate using a dip-coating method. The coated substrate was then subjected to a melting treatment in a furnace at 1530°C for 40 minutes under a vacuum better than 1.0 × 10⁻³ Pa. Through this series of meticulously designed preparation steps, we successfully prepared specimens numbered A to F, each with a coating thickness between 101 and 10⁹ micrometers (μm).

[0034] Table 1

[0035] Serial Number serial number Test temperature ℃ Test methods Coating lifespan 1 A 1800℃ static <![CDATA[18h 09 min]]> 2 B 1800℃ static <![CDATA[18h 07 min]]> 3 C 1900℃ static <![CDATA[2h 10 min]]> 4 D 1900℃ static <![CDATA[2h 16 min]]> 5 E 800-1800℃ air cooling thermal shock thermal shock 222 times 6 F 800-1800℃ air cooling thermal shock thermal shock 213 times

[0036] Figure 2 This is a morphological image of sample A# after oxidation during static performance testing at 1800℃ in this embodiment; Figure 3 This embodiment shows the appearance morphology of the C# sample after oxidation during static performance testing at 1900℃. Figure 4 This embodiment shows the appearance of sample E# after oxidation following thermal shock performance testing at 800–1800℃.

[0037] The data in Table 1 and Figures 2-4 It clearly demonstrates that it is applied to Ta 12The high-temperature anti-oxidation coating on the W alloy substrate exhibits superior protective performance. Specifically, the coating provides oxidation protection for over 18 hours at extreme high temperatures of 1800°C, maintaining the integrity of the specimen. Under even more demanding conditions of 1900°C, the coating also ensures substrate stability for at least 2 hours. Furthermore, in air-cooled thermal shock tests conducted within the 800–1800°C range, the coating's lifespan exceeded 200 cycles, further validating its excellent durability under repeated temperature changes. These results fully demonstrate the highly efficient protective capability and superior performance stability of the coating of this invention.

[0038] Example 2

[0039] In this embodiment, the specific proportions of the raw material powder for preparing the high-temperature anti-oxidation coating are as follows: molybdenum (Mo) content is 5 wt%, chromium disilicide (CrSi2) content is 5 wt%, tantalum oxide (Ta2O5) content is 3 wt%, hafnium boride (HfB2) content is 2 wt%, molybdenum disilicide (MoSi2) content is 3 wt%, titanium (Ti) content is 2 wt%, zirconium dioxide (ZrO2) content is 4 wt%, yttrium oxide (Y2O3) content is 1.2 wt%, scandium oxide (Sc2O3) content is 1 wt%, and silicon (Si) accounts for 73.8 wt%. Figure 1 The steps shown involve thoroughly mixing these components, then adding 2% polyethylene glycol by mass as a binder, followed by 30% anhydrous ethanol by mass. This pretreated mixture was then fed into a planetary ball mill for 6 hours of fine ball milling to prepare a homogeneous coating slurry.

[0040] Next, this coating slurry is uniformly applied to Ta using a dip-coating method. 12 The coating was applied to a W alloy substrate. The substrate, after coating, was then subjected to a vacuum level better than 1.0 × 10⁻⁶. -3 Sintering was carried out under conditions of Pa and a temperature of 1560°C for 45 minutes. In this embodiment, specimens numbered G to M were prepared by this method, wherein the coating thickness of each specimen was between 107 and 133 micrometers (μm).

[0041] Table 2

[0042] Serial Number serial number Test temperature ℃ Test methods Coating lifespan 1 G 1800℃ static <![CDATA[18h 11 min]]> 2 H 1800℃ static <![CDATA[18h 06 min]]> 3 I 1900℃ static <![CDATA[2h 10 min]]> 4 J 1900℃ static <![CDATA[2h 08 min]]> 5 K 800-1800℃ air cooling thermal shock thermal shock 242 times 6 M 800-1800℃ air cooling thermal shock thermal shock 228 times

[0043] Figure 5 The appearance morphology of sample G# after oxidation during static performance testing at 1800℃ in this embodiment; Figure 6 The appearance morphology of sample I# after oxidation during static performance testing at 1900℃ in this embodiment; Figure 7 This embodiment shows the appearance of sample K# after oxidation following thermal shock performance testing at 800–1800℃.

[0044] The results in Table 2 and Figures 5-7 It is clearly demonstrated that the coating prepared using this invention is effective on Ta 12 On W alloy substrates, this coating significantly enhances the substrate's durability under extreme conditions. Specifically, this coating maintains substrate integrity for over 18 hours at 1800°C and retains high-temperature oxidation resistance for at least 2 hours at the more severe 1900°C. Furthermore, in air-cooled thermal shock tests within the 800–1800°C range, the coating exhibits a lifespan exceeding 200 cycles, demonstrating its excellent thermal stability and durability. These data highlight the remarkable effectiveness of the coating in providing long-term high-temperature protection.

[0045] Table 3

[0046] Serial Number Equipment Name model factory 1 beaker 300ml Yangzhou Subo Glass Instrument Factory 2 muffle furnace G～13 Shenyang Energy-Saving Electric Furnace Factory 3 vacuum furnace ZS~420 Lanzhou Vacuum Electric Furnace Factory 4 Variable frequency planetary ball mill XQM~2L Nanjing Daran Technology Co., Ltd.

[0047] Table 3 lists some of the equipment models and their manufacturers used in the two embodiments described above.

[0048] The two embodiments described above represent only some practical applications of the present invention, and the innovative concepts of the present invention are not limited to these examples. Any non-essential changes made to the present invention based on these ideas will be considered an infringement of the rights of the present invention. Furthermore, any simple adjustments, modifications, or equivalent substitutions made to the embodiments without departing from the core technical principles of the present invention should be included within the scope of the technical solutions of the present invention.

Claims

1. A kind of Ta 12 W alloy high-temperature anti-oxidation coating material, characterized in that... The coating material comprises, by mass percentage: 4-5 wt% molybdenum, 4-5 wt% chromium and its compounds, 2-3 wt% tantalum oxide, 1-2 wt% hafnium boride, 2-3 wt% molybdenum disilicide, 1-2 wt% titanium, 3-4 wt% zirconium dioxide, 0.5-1.2 wt% yttrium oxide, 0.5-1 wt% scandium oxide, and 73.8-82 wt% silicon.

2. The Ta according to claim 1 12 W alloy high-temperature anti-oxidation coating material, characterized in that... All components of the material exist in the form of powder with a mesh size of less than 300.

3. A Ta 12 The method for preparing W alloy high-temperature anti-oxidation coating material is characterized by: Includes the following steps: a) A mixture is formed by combining the component as defined in claim 1 with polyethylene glycol, wherein the polyethylene glycol accounts for 1 to 2% of the total mass of the mixture; b) Add anhydrous ethanol as an additive to the mixture, wherein the amount added accounts for 30-40% of the total mass after mixing; c) Grind the mixture for 5-8 hours to prepare a coating slurry; d) Spraying or dipping the coating slurry onto Ta 12 On a W alloy matrix; e) Place the coated substrate in a vacuum furnace and sinter at 1530–1600°C for 40–60 minutes to form a high-temperature antioxidant coating, wherein the vacuum degree is better than 1.0 × 10⁻⁶. -3 Pa.

4. The method according to claim 3, characterized in that, The prepared high-temperature antioxidant coating has a thickness of 100–140 μm.

5. A Ta material using the material of claim 1 or 2 12 W alloy component, characterized in that The surface of the component is covered with a high-temperature antioxidant coating prepared according to the method of claim 3. The coating can maintain high-temperature antioxidant performance for more than 2 hours at a high temperature of 1900°C and maintain antioxidant performance for more than 18 hours at a high temperature of 1800°C.

6. The Ta according to claim 5 12 W alloy component, characterized in that The component has a thermal shock life of more than 200 cycles in a temperature range of 800 to 1800°C.

7. A Ta material using the material of claim 1 or 2 12 Applications of W alloy components in aviation, aerospace vehicles, high-temperature industrial equipment, and the chemical industry.

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