High-temperature-resistant SiC thermal spraying material, coating and preparation method and application of high-temperature-resistant SiC thermal spraying material
By depositing Ir on the surface of SiC powder and optimizing the spraying process, high-purity high-temperature resistant SiC thermal spraying materials were prepared, which solved the problem of insufficient high-temperature resistance of the existing SiC coating in high-temperature environments, and achieved an environment of 1800 to 2000℃. High performance and stability under the hood are suitable for key components such as missile shells.
Patent Information
- Application Number
- CN202411564100.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-05
- Publication Date
- 2025-02-11
AI Technical Summary
The existing SiC thermal spray coating cannot meet the high temperature resistance performance requirements of the missile shell under a high temperature oxidation environment above 1800°C, and the traditional process has defects in insufficient purity, process complexity and high temperature resistance stability.
High-purity high-temperature resistant SiC thermal spray material was prepared by ball milling and mixing Ir powder and depositing Ir on the surface of SiC powder using plasma spraying technology. The process includes optimizing spray parameters such as power, cooling air flow, spray distance and powder feed rate to ensure uniformity and denseness of the coating.
It significantly improves the high temperature resistance and stability of the coating, can maintain good mechanical properties and thermal stability in an environment of 1800 to 2000°C, meets the demand for ultra-high temperature conditions in the aerospace field, and reduces production costs.
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Figure CN119411061A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of new materials, and in particular to a high-temperature resistant SiC thermal spraying material, a coating, and a preparation method and application thereof. Background Art
[0002] In the field of high-end aerospace equipment manufacturing, key components such as missile casings have reached a very high level of attention in terms of high temperature resistance and wear resistance. These properties are absolutely necessary to ensure their functional stability and reliable operation. Silicon carbide (SiC) has excellent ablation resistance in extreme high temperature environments, especially in the range of 1800 to 2000°C, due to its high melting point, excellent hardness, and strong resistance to corrosion and oxidation. It also has excellent high-temperature thermal stability under high temperature conditions. Therefore, people have been committed to exploring the industrial application of SiC thermal spray coatings in the aerospace field.
[0003] However, in the coating industry, the thermal spray coating formed by SiC as the hard phase can only reach a maximum heat resistance of 1350℃, which cannot meet the high temperature resistance required by the missile shell in a high temperature oxidation environment above 1800℃. This limitation is due to the lack of purity of traditional SiC coatings when prepared by plasma thermal spraying technology, and the argon protection must be relied on in the process flow. These lead to many problems in the complexity of the production process, the purity of the coating, and the high temperature stability of the prepared coating, which cannot meet the design requirements under high temperature service conditions.
[0004] Therefore, it is urgent to start from the spraying powder raw materials and combine the characteristics of the thermal spraying process itself to carry out research and development of high-purity SiC coatings. Summary of the invention
[0005] In the process of preparing coatings by thermal spraying technology, silicon carbide (SiC) as a ceramic hard phase must be used in combination with a binder. Commonly used binders include cobalt (Co) and nickel (Ni) materials, but these materials are prone to introduce contaminants during the thermal spraying process, resulting in reduced high-temperature thermal stability of the coating. According to relevant reports, high-temperature sealing coatings are currently prepared by thermal spraying SiC+Si+BN composite powders, with a maximum operating temperature of up to 1350°C, which is suitable for aircraft engines and gas turbines (authorized patent number CN20201810200025.4). However, this technology has the limitations of high cost, cumbersome process, easy introduction of impurities, and low service temperature, so it cannot meet the requirements of ultra-high temperature conditions of 1800-2000°C. Under long-term extreme service conditions, traditional SiC coating materials may have problems with local surface damage, which is mainly due to their inability to withstand extremely high service temperatures. Therefore, improving the purity of SiC coatings and their stability in high temperature environments has become a technical problem that urgently needs to be solved.
[0006] In view of this, the present invention proposes an ultra-high temperature wear-resistant coating material and a coating preparation method thereof, which is suitable for environments with temperatures reaching 1800 to 2000°C. The present invention solves many problems existing in the prior art, and can meet the stringent requirements of the aerospace high-end equipment manufacturing field for key components such as missile casings by improving the high temperature resistance and stability of the coating.
[0007] The present invention provides a method for preparing a high temperature resistant SiC thermal spraying material, comprising:
[0008] After ball-milling the Ir powder and the SiC powder, Ir is deposited on the surface of the SiC powder by plasma spraying technology to obtain the high temperature resistant SiC thermal spraying material;
[0009] The parameters of the plasma spraying technology include: power 55-60kW, cooling air flow 8-15lpm, spraying distance 70-110mm, and powder feeding rate 25-35g / min.
[0010] Preferably, the Ir powder is pure Ir powder; the purity of the Ir powder and the SiC powder is not less than 99%.
[0011] Preferably, the ball milling time for mixing Ir powder and SiC powder is 3-5 hours, the ball mill tank and grinding balls are made of silicon carbide, and the purity of the ball mill tank and grinding balls is not less than 99%.
[0012] Preferably, Ir is deposited on the surface of SiC powder by plasma spraying technology to form a composite structure powder.
[0013] Preferably, the requirements for the ball mill tank include: the inner wall of the tank and the ball mill beads are both made of SiC material with a purity of 99%.
[0014] Preferably, during the plasma spraying process, the Ir powder and the SiC powder are deposited and coated on the surface of SiC to form a composite powder.
[0015] Preferably, after Ir is deposited on the surface of SiC powder by plasma spraying technology, the powder is screened by high-speed rotation of a collecting tank; the rotation rate of the collecting tank is 1000-2000 rpm, and the particle size range of the screened powder is 30-80 μm.
[0016] The present invention also provides a high temperature resistant SiC thermal spraying material, which is prepared according to the above-mentioned method for preparing the high temperature resistant SiC thermal spraying material.
[0017] The present invention also proposes a method for preparing a high temperature resistant SiC thermal spray coating, comprising:
[0018] After drying the high temperature resistant SiC thermal spraying material according to claim 6, the high temperature resistant SiC thermal spraying material is sprayed onto the surface of the substrate using plasma technology to obtain the high temperature resistant SiC thermal spraying coating.
[0019] Preferably, when the plasma technology is used to spray the high temperature resistant SiC thermal spray material onto the surface of the substrate, the method comprises:
[0020] The substrate is mounted on a spraying device and placed in a plasma spraying cabin;
[0021] The plasma spraying chamber is first vacuumed until the pressure drops to 30 mbar, then backfilled with argon gas to 50 mbar, and then plasma spraying is performed;
[0022] The parameters of the plasma spraying are: power 28-35kW, cooling gas flow 80-100lpm, spraying distance 80-110mm, powder feeding rate 30-40g / min, coating thickness 250-300μm; the cooling gas includes argon, hydrogen and helium;
[0023] During plasma spraying, the substrate temperature does not exceed 150°C.
[0024] The present invention also provides a high temperature resistant SiC thermal spray coating, which is prepared according to the above-mentioned preparation method of the high temperature resistant SiC thermal spray coating.
[0025] The present invention also proposes an application of the high-temperature resistant SiC thermal spraying material or the high-temperature resistant SiC thermal spraying coating in the preparation of high-temperature resistant materials.
[0026] Compared with the prior art, the present invention has the following beneficial effects:
[0027] 1. By depositing Ir on the surface of SiC powder, the high temperature resistance and stability of the coating are significantly improved. Ir has excellent high temperature oxidation resistance and corrosion resistance, and can effectively protect the SiC coating from chemical reactions in extreme high temperature environments, thereby extending the service life of the coating.
[0028] 2. The plasma spraying technology parameters used in the present invention are optimized to ensure the uniformity and density of the coating, thereby improving the mechanical properties and thermal stability of the coating. The optimized parameters include power, cooling air flow, spraying distance and powder feeding rate. The precise control of these parameters helps to reduce pores and cracks in the coating and improve the overall quality of the coating.
[0029] 3. The purity of the SiC powder used in the present invention is not less than 99%, which ensures the high purity of the coating, thereby reducing the negative impact of impurities and improving the high temperature resistance and stability of the coating.
[0030] 4. The high temperature resistant SiC thermal spraying material and coating of the present invention are suitable for environments with temperatures reaching 1800 to 2000°C, meeting the requirements of the aerospace field for ultra-high temperature working conditions. This enables the coating to maintain good mechanical properties and thermal stability in extremely high temperature environments, and is suitable for key components such as missile casings and engine combustion chambers.
[0031] 5. The preparation method of the present invention is simple and easy to implement, with relatively low cost, and is easy to promote and apply in industrial production. By optimizing the ball milling mixing time and using a ball mill body and grinding balls made of silicon carbide, the mixing efficiency and the uniformity of the powder are improved, thereby reducing the production cost.
[0032] 6. The application of the high temperature resistant SiC thermal spraying material and coating of the present invention in the preparation of high temperature resistant materials can significantly improve the performance and service life of the materials, and provide a new solution for the field of high-end aerospace equipment manufacturing.
[0033] In summary, the present invention successfully prepares a high-temperature resistant SiC thermal spray material and coating suitable for ultra-high temperature environments by optimizing material composition and spraying process parameters, which solves many problems existing in the prior art and has significant technical advantages and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0034] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:
[0035] Figure 1 This is a schematic diagram of the preparation of the high temperature resistant SiC thermal spraying material of the present invention;
[0036] Figure 2 The invention provides a method for preparing a high temperature resistant SiC thermal spray coating;
[0037] Figure 3 This is a microscopic morphology of the surface of the high temperature resistant SiC thermal spray coating of Example 1;
[0038] Figure 4 The microscopic morphology and XRD test results of the high temperature resistant coating powder of Example 1;
[0039] Figure 5 The XPS analysis results of Ir in the high temperature resistant coating powder of Example 1;
[0040] Figure 6 This is a microscopic morphology of the high temperature resistant coating powder of Example 2;
[0041] Figure 7 The XPS analysis results of Ir in the high temperature resistant coating powder of Example 2;
[0042] Figure 8 The nanoindentation test curve results of the coatings of Example 3 and Example 4;
[0043] Fig. 9 The thermal shock test results of the coatings of Example 3 and Example 4 are shown in FIG. DETAILED DESCRIPTION
[0044] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features described in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.
[0045] Example 1
[0046] Figure 1-2 They are respectively a schematic diagram of preparing the high temperature resistant SiC thermal spraying material of the present invention and a flow chart of the preparing method.
[0047] Pure Ir powder and SiC powder with a purity of not less than 99% are ball-milled to ensure uniform mixing. During the ball milling process, the ball mill tank and grinding balls are made of 99% pure silicon carbide, and the ball milling time is controlled within 4 hours. To ensure the purity of the powder, the inner wall of the ball mill tank and the grinding balls used are made of 99% pure silicon carbide.
[0048] By plasma spraying technology, metal Ir is deposited on the surface of SiC particles to form a protective coating. This process relies on the heat generated during spraying, and the spraying parameters are set as follows to ensure appropriate heat input, considering that the melting point of metal iridium is 2410°C: the power is set to 55kW, the argon cooling gas flow is 15lpm, the spray distance is 70mm, and the powder feeding rate is 35g / min.
[0049] After spraying is completed, the obtained powder is cooled, collected, screened and dried to prepare a high temperature resistant coating powder suitable for thermal spraying for subsequent use.
[0050] The obtained high temperature resistant coating powder was subjected to scanning electron microscopy (SEM) experiment to obtain its microscopic morphology ( Figure 3-Figure 4 ),Depend on Figure 4 It can be seen that the particle sphericity reaches 99%, the particle size range is between 50-80μm, and the size uniformity is good.
[0051] In order to further understand the composition of the coating powder, XRD phase analysis was performed ( Figure 4 ), and obtain the energy spectrum analysis diagram, by Figure 4 It can be seen that Ir and SiC in the coating powder each form a separate phase without any chemical reaction.
[0052] In order to further understand the state of metallic Ir in the coating powder, XPS elemental analysis was performed ( Figure 5 ), and obtained the XPS spectrum analysis diagram, by Figure 5 It can be seen that the metal Ir in the coating powder basically exists in the form of a single substance.
[0053] The trace impurities of the prepared high temperature resistant SiC coating material were measured by GDMS (glow discharge mass spectrometry), and it was found that the total amount of trace elements was 1.1 ppm.
[0054] Example 2
[0055] Pure Ir powder and SiC powder with a purity of not less than 99% are ball-milled to ensure uniform mixing. During the ball milling process, the ball mill tank and grinding balls are made of 99% pure silicon carbide, and the ball milling time is controlled within 4 hours. To ensure the purity of the powder, the inner wall of the ball mill tank and the grinding balls used are made of 99% pure silicon carbide.
[0056] By plasma spraying technology, metal Ir is deposited on the surface of SiC particles to form a protective coating. This process relies on the heat generated during spraying, and the spraying parameters are set as follows to ensure appropriate heat input, considering that the melting point of metal iridium is 2410°C: the power is set to 60kW, the argon cooling gas flow is 8lpm, the spraying distance is 110mm, and the powder feeding rate is 25g / min.
[0057] After spraying is completed, the obtained powder is cooled, collected, screened and dried to prepare a high temperature resistant coating powder suitable for thermal spraying for subsequent use.
[0058] The obtained high temperature resistant coating powder was subjected to scanning electron microscopy (SEM) experiment to obtain its microscopic morphology ( Figure 6 ),Depend on Figure 6 It can be seen that the particle sphericity reaches 99%, the particle size range is between 30-50μm, and the size uniformity is good.
[0059] In order to further understand the state of metallic Ir in the coating powder, XPS elemental analysis was performed ( Figure 7 ), and obtained the XPS spectrum analysis diagram, by Figure 7 It can be seen that the metal Ir in the coating powder basically exists in the form of a single substance.
[0060] The trace impurities of the prepared high temperature resistant SiC coating material were measured by GDMS (glow discharge mass spectrometry), and it was found that the total amount of trace elements was 1.5 ppm.
[0061] Example 3: Spraying high temperature resistant coating powder using supersonic plasma technology
[0062] The high temperature resistant coating powder prepared according to Example 1 was dried at 80°C for 1 hour and then prepared for subsequent processes. First, the surface of the substrate CoCrAlY was polished with high-purity SiC to achieve roughening, and then cleaned and dried with a solvent. The treated substrate was mounted on a spraying device and placed in a conventional plasma spraying chamber. The spraying chamber was first evacuated until the pressure dropped to 30mbar, and then backfilled to 50mbar with argon to achieve suitable spraying conditions. The spraying operation was performed according to the following parameters: the power was set to 28kW, the cooling gas argon flow rate was 100lpm, the spraying distance was set to 80mm, and the powder feeding rate was 30g / min.
[0063] The comprehensive performance of the coating was evaluated. The test results showed that the thickness of the high temperature resistant SiC coating was 250 μm; the bonding strength between the coating and the substrate was 23 MPa, and the nano-indentation hardness of the coating was 15.6 GPa ( Figure 8), the coating porosity is 3%, and in the 2000℃ thermal shock test, the number of thermal shock resistance is greater than 20 times ( Fig. 9 ), the coating has no cracks after thermal shock and has significant high temperature resistance and oxidation resistance.
[0064] Example 4: Spraying high temperature resistant coating powder using supersonic plasma technology
[0065] The high temperature resistant coating powder prepared according to Example 1 was dried at 80°C for 1 hour and then prepared for subsequent processes. First, the surface of the substrate CoCrAlY was polished with high-purity SiC to achieve roughening, and then cleaned and dried with a solvent. The treated substrate was mounted on a spraying device and placed in a conventional plasma spraying chamber. The spraying chamber was first evacuated until the pressure dropped to 30mbar, and then backfilled to 50mbar with argon to achieve suitable spraying conditions. The spraying operation was performed according to the following parameters: the power was set to 35kW, the cooling gas nitrogen flow rate was 80lpm, the spraying distance was set to 110mm, and the powder feeding rate was 40g / min.
[0066] The comprehensive performance of the coating was evaluated. The test results showed that the thickness of the high temperature resistant SiC coating was 300 μm; the bonding strength between the coating and the substrate was 38 MPa, and the nano-indentation hardness of the coating was 12.3 GPa ( Figure 8 ), the coating porosity is 7%, and in the 2000℃ thermal shock test, the number of thermal shock resistance is more than 20 times ( Fig. 9 ), the coating has no cracks after thermal shock and has significant high temperature resistance and oxidation resistance.
[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.
Claims
1. A method for preparing a high temperature resistant SiC thermal spraying material, characterized in that: include: After ball-milling and mixing Ir powder and SiC powder, Ir is deposited on the surface of SiC powder by plasma spraying technology, and high-speed rotating screening is performed by a collecting tank to obtain the high-temperature resistant SiC thermal spray material; The parameters of the plasma spraying technology include: power 55-60kW, cooling air flow 8-15lpm, spraying distance 70-110mm, and powder feeding rate 25-35g / min.
2. The method for preparing a high temperature resistant SiC thermal spraying material according to claim 1, characterized in that: The Ir powder is pure Ir powder; The purity of the Ir powder and the SiC powder is not less than 99%.
3. The method for preparing a high temperature resistant SiC thermal spraying material according to claim 1, characterized in that: The ball milling time for mixing Ir powder and SiC powder is 3-5 hours. The ball mill tank and grinding balls are made of silicon carbide, and the purity of the ball mill tank and grinding balls is not less than 99%.
4. The method for preparing a high temperature resistant SiC thermal spraying material according to claim 1, characterized in that: Ir is deposited on the surface of SiC powder by plasma spraying technology to form a composite structure powder.
5. The method for preparing a high temperature resistant SiC thermal spraying material according to claim 1, characterized in that: After Ir is deposited on the surface of SiC powder by plasma spraying technology, it is screened by high-speed rotation of the collection tank; The rotation rate of the collecting tank is 1000-2000 rpm, and the particle size range of the sieved powder is 30-80 μm.
6. A high temperature resistant SiC thermal spraying material, characterized in that: The high temperature resistant SiC thermal spraying material is prepared according to the preparation method of any one of claims 1 to 5.
7. A method for preparing a high temperature resistant SiC thermal spray coating, characterized in that: include: After drying the high temperature resistant SiC thermal spraying material according to claim 6, the high temperature resistant SiC thermal spraying material is sprayed onto the surface of the substrate using plasma technology to obtain the high temperature resistant SiC thermal spraying coating.
8. The method for preparing a high temperature resistant SiC thermal spray coating according to claim 7, characterized in that: When the plasma technology is used to spray the high temperature resistant SiC thermal spray material onto the surface of the substrate, it includes: The substrate is mounted on a spraying device and placed in a plasma spraying cabin; The plasma spraying chamber is first vacuumed until the pressure drops to 30 mbar, then backfilled with argon gas to 50 mbar, and then plasma spraying is performed; The parameters of the plasma spraying are: power 28-35kW, cooling gas flow 80-100lpm, spraying distance 80-110mm, powder feeding rate 30-40g / min, coating thickness 250-300μm; the cooling gas includes argon, hydrogen and helium; During plasma spraying, the substrate temperature does not exceed 150°C.
9. A high temperature resistant SiC thermal spray coating, characterized in that: The high temperature resistant SiC thermal spray coating is prepared by the preparation method according to any one of claims 7-8, the nano-indentation hardness of the coating can reach 11-16GPa, the porosity of the coating is less than 6%, in a 2000°C thermal shock test, the thermal shock resistance number is 50 times, and the bonding property with the substrate is not less than 23MPa.
10. Use of the high temperature resistant SiC thermal spray material according to claim 6 or the high temperature resistant SiC thermal spray coating according to claim 9 in the preparation of high temperature resistant materials.