A Hf6Ta2O 17 Abradable seal coat and method of making same

Abstract

Hf6Ta2O 17 A kind of Hf6Ta2O 17 The ceramic layer, the raw material of the ceramic layer includes Hf6Ta2O 17 Ceramic powder: pore-forming agent: lubricating phase=(88~92) :(3~5) :(3~7);The preparation method is: preparation ceramic layer sprayable powder, preparation nickel-based superalloy base-transition layer, use supersonic speed atmospheric plasma spraying technology and be sprayed in the surface of nickel-based superalloy base-transition layer ceramic layer, obtain nickel-based superalloy base-transition layer-ceramic layer, until the thickness of ceramic layer is 200 μm above, complete Hf6Ta2O 17 Preparation of the nickel-based abradable seal coating, the present application has the characteristics of high service temperature, coating is not easy to crack and fall off, simple preparation process, small wear, good thermal shock resistance.

Description

Technical Field

[0001] This invention relates to the field of high-temperature thermal coating technology, specifically to an Hf6Ta2O 17 Abrasion-resistant sealing coating and its preparation method. Background Technology

[0002] Around 2000, Metco proposed a high-temperature sealing ceramic coating using yttrium-stabilized zirconia (YSZ) and polystyrene. YSZ served as the main material to withstand temperatures up to 1150°C, while polystyrene acted as a pore-forming agent to increase the porosity of the YSZ sealing coating and improve its abrasion resistance. However, in practical applications, it was found that zirconia particles almost completely melted in the plasma spraying flame, forming a dense ceramic layer structure during coating formation. Polystyrene could only form macropores with relatively large pores. Although this could partially reduce the coating hardness, its improvement in abrasion resistance was limited. When turbine blade tips contacted the casing, the scraping between the blade tip and the dense ceramic layer led to tip wear. Furthermore, at service temperatures above 1150°C, the YSZ coating transformed from a metastable tetragonal phase to a monoclinic or cubic phase. This phase transformation, accompanied by a 4-5% volume change, increased internal stress in the coating, raising the risk of cracking and spalling. Overall, most high-temperature sealing coatings are not yet mature, and their safety and reliability are poor.

[0003] High-temperature wear-resistant sealing coatings are applied to the inner wall of the turbine casing in aero-engines to protect the blades, reduce fuel consumption, and improve engine efficiency. The operating temperature at the inlet of the high-pressure turbine in next-generation aero-engines exceeds 1700℃, and the service temperature of wear-resistant sealing coatings will approach 1350℃, far exceeding the melting point of metallic materials. Traditional metal-based and YSZ ceramic-based wear-resistant sealing coating systems can no longer meet these service requirements.

[0004] Existing YSZ ceramic materials experience a sharp decline in service life when the service temperature exceeds 1200℃. With the continuous increase in thrust ratio of aero-engines, the service temperature of high-temperature abrasive sealing coatings is also constantly rising. Under higher service temperature conditions, the YSZ coating will peel off in large pieces, severely limiting the improvement of aero-engine temperature.

[0005] Patent application [CN104561881A] entitled "A Method for Preparing a High-Temperature Abrasive Sealing Coating" describes a method for preparing a high-temperature brazing filler layer using a supersonic flame spraying method. A transition layer is then prepared on the surface of the high-temperature brazing filler layer. The transition layer is obtained by high-energy ball milling of high-temperature brazing filler and MCrAlY spray coating, each comprising 50 wt% of the total content of the transition layer. The mixture is then held at 1000℃-1150℃ under vacuum conditions for 12-17 minutes. A dense MCrAlY layer is then prepared on the surface of the transition layer. A porous wearable sealing coating containing a pore-forming agent is prepared on the surface of the layer. The raw material composition of the porous wearable sealing coating containing the pore-forming agent includes a pore-forming agent and MCrAlY spraying material, with the pore-forming agent content being 2wt%-5wt%. The pore-forming agent is removed to form a porous wearable sealing coating, resulting in a high-temperature wearable sealing coating. The service temperature is much lower than the actual temperature of existing engines. Due to the low melting point of the alloy material, the actual temperature of the engine far exceeds the maximum temperature that the alloy itself can withstand, thus exhibiting the disadvantage of insufficient service conditions. Summary of the Invention

[0006] In order to overcome the shortcomings of the prior art, the present invention aims to provide an Hf6Ta2O 17 Abrasion-resistant sealing coating and its preparation method: Hf6Ta2O was prepared by high-temperature solid-state reaction. 17 Powder is then used to spray a transition layer onto a nickel-based superalloy substrate using supersonic atmospheric plasma spraying technology, resulting in a nickel-based superalloy substrate-transition layer. Finally, a ceramic layer is sprayed onto the nickel-based superalloy substrate-transition layer to complete the Hf6Ta2O process. 17 The preparation of abrasive sealing coatings has the characteristics of high service temperature, coating is not easy to crack and peel off, simple preparation process, low wear amount and good thermal shock resistance.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A type of Hf6Ta2O 17 The wear-resistant sealing coating comprises a nickel-based superalloy substrate, a transition layer, and a ceramic layer, all stacked together. The ceramic layer is made from Hf6Ta2O. 17 Ceramic powder, pore-forming agent, and lubricating phase, by mass ratio, Hf6Ta2O 17 Ceramic powder: pore-forming agent: lubricating phase = (88-92): (3-5): (3-7).

[0009] The Hf6Ta2O 17 The ceramic powder contains hafnium oxide powder and tantalum oxide powder, with a mass ratio of hafnium oxide powder to tantalum oxide powder of 1:(0.35-1.05).

[0010] The pore-forming agent is a material that is easily removed at high temperatures and will not negatively affect the coating performance, specifically polystyrene, carbon powder, or starch.

[0011] The lubricating phase is a high-temperature lubricating material, specifically hexagonal boron nitride, bentonite, or diatomaceous earth.

[0012] The transition layer is made of NiCrAlY powder or PtAl alloy powder.

[0013] A type of Hf6Ta2O 17 The method for preparing a wear-resistant sealing coating includes the following steps:

[0014] Step 1: Ball mill hafnium oxide powder and tantalum oxide powder at a speed of 250-350 r / min for 8-10 h to obtain a uniformly mixed powder mixture. Stir the mixture at a speed of 700-1200 r / min and a temperature of 180-220℃ until it becomes a gel. Place it in an oven and dry at 75-100℃ for 8-10 h to obtain a uniformly mixed powder to be sintered. Sinter the powder at the following temperatures: below 300℃ at room temperature, heating rate of 8-10℃ / min; 300-950℃, heating rate of 6-8℃ / min, holding at 950℃ for 1-1.5 h; 900-1250℃, heating rate of 4-6℃ / min, holding at 1250℃ for 8-10 h to obtain Hf6Ta2O. 17 Ceramic powder; based on the raw material mass ratio, hafnium oxide powder: tantalum oxide powder = 1:(0.35-1.05);

[0015] Step 2: The Hf6Ta2O prepared in Step 1... 17 Ceramic powder was ball-milled with pore-forming agent, lubricating phase, binder, deionized water, and anhydrous ethanol at a speed of 60–90 r / min for 4–6 h. The resulting mixture, by mass ratio, contained Hf6Ta2O. 17 Ceramic powder: pore-forming agent: lubricating phase: binder: deionized water: anhydrous ethanol = (88-92): (3-5): (3-7): (94-104): (15-25): (15-25) to obtain Hf6Ta2O 17 Ceramic-based multiphase mixtures;

[0016] Step 3: The Hf6Ta2O prepared in step 2... 17 A ceramic-based multiphase mixture is granulated and dried to obtain a ceramic layer that can be sprayed with powder.

[0017] Step 4: Use supersonic atmospheric plasma spraying technology to spray the transition layer onto the pretreated nickel-based superalloy substrate until the thickness of the transition layer is 80-120μm, thus obtaining the nickel-based superalloy substrate---transition layer; the spraying power is 30-40kW, the flow rate of argon gas used in the spraying process is 65-70slpm, and the flow rate of hydrogen gas is 2-5slpm;

[0018] Step 5: Using supersonic atmospheric plasma spraying technology, the sprayable powder of the ceramic layer prepared in step 3 is sprayed onto the surface of the nickel-based superalloy substrate-transition layer prepared in step 4 to obtain the nickel-based superalloy substrate-transition layer-ceramic layer; the spraying power is 35-45kW, the argon flow rate is 65-70slpm and the hydrogen flow rate is 2-5slpm during the spraying process;

[0019] Step 6: Repeat step 5 continuously until the ceramic layer thickness is greater than 200 μm, completing the Hf6Ta2O process. 17 Preparation of wear-resistant sealing coating.

[0020] The pretreated nickel-based superalloy substrate in step 4 is a nickel-based superalloy substrate with a certain roughness obtained by sandblasting and aluminizing.

[0021] The binder in step 2 is a polyvinyl alcohol solution, a modified ethylene polymer, or sodium carboxymethyl cellulose.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. Due to Hf6Ta2O 17 The phase transition temperature is around 2250℃, so there is no obvious phase transition point at 1350℃ and no volume change caused by phase transition. The service temperature can be 1350℃, which is far higher than the melting point of alloy materials. Compared with traditional metal-based and YSZ ceramic-based wearable sealing coating systems, the service temperature is significantly improved.

[0024] 2. Compared with existing YSZ ceramic-based wear-resistant sealing coatings, Hf6Ta2O 17 The wear-resistant sealing coating has a low coefficient of thermal expansion, thus it has a significant advantage in service environments up to 1350°C, and it does not show significant peeling at 1350°C, exhibiting good thermal shock resistance.

[0025] 3. This invention prepares Hf6Ta2O via a high-temperature solid-state reaction. 17 The required Hf6Ta2O powder can be prepared using only two raw materials. 17 Since it is made of powder, it has the advantages of simple preparation process and mass production.

[0026] 5. This invention requires only polyvinyl alcohol as a binder to complete granulation, and deionized water and anhydrous ethanol as dispersants to prepare Hf6Ta2O using a solid-state sintering method. 17 Ceramic powders, therefore, have the advantage of simple preparation processes.

[0027] In summary, this invention prepares Hf6Ta2O via a high-temperature solid-state reaction. 17 Powder is then used to spray a transition layer onto a nickel-based superalloy substrate using supersonic atmospheric plasma spraying technology, resulting in a nickel-based superalloy substrate-transition layer. Finally, a ceramic layer is sprayed onto the nickel-based superalloy substrate-transition layer to complete the Hf6Ta2O process. 17 The preparation of wear-resistant sealing coatings has the characteristics of high service temperature, coating that is not easy to crack and peel off, simple preparation process, small wear amount, and good thermal shock resistance. Attached Figure Description

[0028] Figure 1 Hf6Ta2O prepared according to this invention 17 Schematic diagram of the wear-resistant sealing coating structure.

[0029] Figure 2 Hf6Ta2O prepared according to this invention 17 Microscopic morphology of abrasive sealant coating granulated powder.

[0030] Figure 3 Hf6Ta2O prepared according to this invention 17 Microscopic morphology of the surface of the wear-resistant sealing coating.

[0031] Figure 4 Hf6Ta2O prepared according to this invention 17 Microscopic morphology of the abrasion-resistant sealing coating in optical cross section.

[0032] Figure 5 Hf6Ta2O prepared according to this invention 17 Microscopic morphology of the worn surface after abrasion-resistant sealing coating wear test; among which... Figure 5 (a) is Hf6Ta2O prepared according to the present invention. 17 Microscopic morphology of the worn surface after abrasion test of the wear-resistant sealing coating Figure 5 (b) is the Hf6Ta2O prepared according to the present invention. 17 Microscopic morphology of the worn surface after abrasion test of the wear-resistant sealing coating.

[0033] Figure 6 Hf6Ta2O prepared according to this invention 17 The wear output results of the wear-resistant sealing coating after the wear test.

[0034] Figure 7Hf6Ta2O prepared according to this invention 17 Macroscopic image of the wear-resistant sealing coating after 30 thermal cycles at 1300℃. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings.

[0036] Example 1

[0037] See Figure 1 A type of Hf6Ta2O 17 The wear-resistant sealing coating comprises a nickel-based superalloy substrate, a transition layer, and a ceramic layer stacked together; the transition layer material is NiCrAlY alloy powder; the ceramic layer comprises 92g of Hf6Ta2O. 17 Ceramic powder, 3g polystyrene powder, 5g hexagonal boron nitride powder; the Hf6Ta2O 17 The ceramic powder consists of 74g of hafnium oxide powder and 26g of tantalum oxide powder.

[0038] A type of Hf6Ta2O 17 The method for preparing a wear-resistant sealing coating includes the following steps:

[0039] Step 1: Add 74g of hafnium oxide powder and 26g of tantalum oxide powder to anhydrous ethanol as the ball milling medium. The amount of anhydrous ethanol added should completely cover the ball milling balls. Ball mill at 250 r / min for 8 hours to obtain a uniformly mixed powder mixture. Magnetically stir the uniformly mixed powder mixture and dry it at 700 r / min and 180℃ until the powder mixture becomes gel-like. Place it in an oven at 75℃ and dry for 10 hours to obtain a uniformly mixed powder to be sintered. Sinter the powder to be sintered at the following temperatures: below 300℃ at room temperature, heating rate of 10℃ / min; 300–950℃, heating rate of 8℃ / min, holding at 950℃ for 1 hour; 900–1250℃, heating rate of 5℃ / min, holding at 1250℃ for 10 hours to obtain Hf6Ta2O. 17 Ceramic powder;

[0040] Step 2: Take 92g of Hf6Ta2O prepared in Step 1 17 Ceramic powder, 3g polyphenylene ester powder, 5g hexagonal boron nitride powder, 94g modified ethylene polymer solution, 25g deionized water, and 25g anhydrous ethanol were ball-milled in a roller mill at a speed of 60 r / min for 4 hours to obtain Hf6Ta2O. 17 Ceramic-based multiphase mixtures;

[0041] Step 3: The Hf6Ta2O prepared in step 2... 17The ceramic-based multiphase mixture was granulated and dried using a spray granulator to obtain a product containing Hf6Ta2O. 17 Multiphase granulated powder; the inlet temperature of the spray granulator is 300℃, the outlet temperature is 100℃, the nozzle speed is 35rpm, and the peristaltic pump speed is 13rpm;

[0042] Step 4: Using supersonic atmospheric plasma spraying technology, NiCrAlY alloy powder is sprayed onto the pretreated nickel-based superalloy substrate until the transition layer thickness is 80μm, thus obtaining the nickel-based superalloy substrate---NiCrAlY alloy transition layer; the spraying power is 30kW, and the flow rate of argon gas used in the spraying process is 65slpm and the flow rate of hydrogen gas is 2slpm; the pretreated nickel-based superalloy substrate is a nickel-based superalloy substrate with a certain roughness obtained by sandblasting alumina.

[0043] Step 5: Apply supersonic atmospheric plasma spraying technology to the Hf6Ta2O-containing material prepared in Step 3. 17 The multiphase granulated powder is sprayed onto the surface of the transition layer prepared in step 4 to obtain a nickel-based superalloy substrate---NiCrAlY alloy transition layer---Hf6Ta2O 17 Multiphase ceramic layer; the spraying power is 35kW, the flow rate of argon gas used in the spraying process is 68slpm, and the flow rate of hydrogen gas is 3slpm;

[0044] Step 6: Repeat step 5 continuously until Hf6Ta2O is reached. 17 The thickness of the multiphase ceramic layer is 300 μm, and Hf6Ta2O is completed. 17 Preparation of wear-resistant sealing coating.

[0045] Example 2

[0046] A type of Hf6Ta2O 17 The wear-resistant sealing coating comprises a nickel-based superalloy substrate, a transition layer, and a ceramic layer stacked together; the transition layer material is NiCrAlY alloy powder; the ceramic layer contains 88g of Hf6Ta2O as its raw material. 17 Ceramic powder, 5g polystyrene powder, 7g hexagonal boron nitride powder; the Hf6Ta2O 17 The ceramic powder consists of 59g of hafnium oxide powder and 41g of tantalum oxide powder.

[0047] A type of Hf6Ta2O 17 The method for preparing a wear-resistant sealing coating includes the following steps:

[0048] Step 1: Add 59g of hafnium oxide powder and 41g of tantalum oxide powder to anhydrous ethanol as the ball milling medium. The amount of anhydrous ethanol added should completely cover the ball milling balls. Ball mill at 300 r / min for 9 hours to obtain a uniformly mixed powder mixture. Magnetically stir the uniformly mixed powder mixture to dry it at 900 r / min and 200℃ until the powder mixture becomes gel-like. Place it in an oven at 85℃ and dry for 9 hours to obtain a uniformly mixed powder to be sintered. Sinter the powder to be sintered at the following temperatures: below 300℃ at room temperature, heating rate of 9℃ / min; 300–950℃, heating rate of 7℃ / min, holding at 950℃ for 1 hour; 900–1250℃, heating rate of 4℃ / min, holding at 1250℃ for 9 hours to obtain Hf6Ta2O. 17 Ceramic powder;

[0049] Step 2: Take 88g of Hf6Ta2O prepared in Step 1 17 Ceramic powder, 5g polystyrene powder, 7g hexagonal boron nitride powder, 100g polyvinyl alcohol solution, 15g deionized water, and 15g anhydrous ethanol were ball-milled for 4 hours at 75 r / min to obtain Hf6Ta2O. 17 Ceramic-based multiphase mixtures;

[0050] Step 3: The Hf6Ta2O prepared in step 2... 17 The ceramic-based multiphase mixture was granulated and dried using a spray granulator to obtain a product containing Hf6Ta2O. 17 Multiphase granulated powder; the inlet temperature of the spray granulator is 300℃, the outlet temperature is 100℃, the nozzle speed is 35rpm, and the peristaltic pump speed is 13rpm;

[0051] Step 4: Using supersonic atmospheric plasma spraying technology, NiCrAlY alloy powder is sprayed onto the pretreated nickel-based superalloy substrate until the transition layer thickness is 100μm; thus obtaining the nickel-based superalloy substrate---NiCrAlY alloy transition layer; the spraying power is 35kW, and the flow rate of argon gas used in the spraying process is 68slpm and the flow rate of hydrogen gas is 3slpm; the pretreated nickel-based superalloy substrate is a nickel-based superalloy substrate with a certain roughness obtained by sandblasting alumina.

[0052] Step 5: Use a supersonic atmospheric plasma spraying device to spray the Hf6Ta2O-containing material prepared in step 3. 17 The multiphase granulated powder is sprayed onto the surface of the transition layer prepared in step 4 to obtain a nickel-based superalloy substrate---NiCrAlY alloy transition layer---Hf6Ta2O 17Multiphase ceramic layer; the spraying power is 40kW, the argon flow rate is 67slpm and the hydrogen flow rate is 5slpm during the spraying process;

[0053] Step 6: Repeat step 5 continuously until Hf6Ta2O is reached. 17 The thickness of the multiphase ceramic layer is 500 μm, and Hf6Ta2O is completed. 17 Preparation of wear-resistant sealing coating.

[0054] Example 3

[0055] A type of Hf6Ta2O 17 The wear-resistant sealing coating comprises a nickel-based superalloy substrate, a transition layer, and a ceramic layer stacked together; the transition layer is made of PtAl alloy powder; the ceramic layer comprises 91g of Hf6Ta2O. 17 Ceramic powder, 4g polyphenylene ester powder, 5g diatomaceous earth powder; the Hf6Ta2O 17 The ceramic powder consists of 49g of hafnium oxide powder and 51g of tantalum oxide powder.

[0056] A type of Hf6Ta2O 17 The method for preparing a wear-resistant sealing coating includes the following steps:

[0057] Step 1: Add 49g of hafnium oxide powder and 51g of tantalum oxide powder to anhydrous ethanol as the ball milling medium. The amount of anhydrous ethanol added should completely cover the milling balls. Ball mill for 10 hours at 350 rpm to obtain a uniformly mixed powder mixture. Magnetically stir the mixture to dry it at 1200 rpm and 220°C until it becomes a gel. Place it in an oven at 100°C and dry for 8 hours to obtain a uniformly mixed powder to be sintered. Sinter the powder at the following temperatures: below 300°C at room temperature, heating rate of 8°C / min; 300–950°C, heating rate of 6°C / min, holding at 950°C for 1.5 hours; 900–1250°C, heating rate of 6°C / min, holding at 1250°C for 8 hours to obtain Hf6Ta2O. 17 Ceramic powder;

[0058] Step 2: Take 91g of Hf6Ta2O prepared in Step 1 17 Ceramic powder, 4g polyphenylene ester powder, 5g diatomaceous earth powder, 104g sodium carboxymethyl cellulose solution, 20g deionized water, and 20g anhydrous ethanol were ball-milled in a roller mill at 90 r / min for 6 h to obtain Hf6Ta2O. 17 Ceramic-based multiphase mixtures;

[0059] Step 3: The Hf6Ta2O prepared in step 2... 17 The ceramic-based multiphase mixture was granulated and dried using a spray granulator to obtain a product containing Hf6Ta2O. 17 Multiphase granulated powder; the inlet temperature of the spray granulator is 300℃, the outlet temperature is 100℃, the nozzle speed is 35rpm, and the peristaltic pump speed is 13rpm;

[0060] Step 4: Using supersonic atmospheric plasma spraying technology, PtAl alloy powder is sprayed onto the pretreated nickel-based superalloy substrate until the transition layer thickness is 100μm, thus obtaining the nickel-based superalloy substrate---PtAl alloy transition layer; the spraying power is 40kW, the flow rate of argon gas used in the spraying process is 70slpm, and the flow rate of hydrogen gas is 5slpm; the pretreated nickel-based superalloy substrate is a nickel-based superalloy substrate with a certain roughness obtained by sandblasting alumina.

[0061] Step 5: Use a supersonic atmospheric plasma spraying device to spray the Hf6Ta2O-containing material prepared in step 3. 17 The multiphase granulated powder is sprayed onto the surface of the transition layer prepared in step 4 to obtain a nickel-based superalloy substrate---NiCrAlY alloy transition layer---Hf6Ta2O 17 Multiphase ceramic layer; the spraying power is 45kW, and the flow rate of argon gas used in the spraying process is 70slpm and the flow rate of hydrogen gas is 2slpm.

[0062] Step 6: Repeat step 5 continuously, Hf6Ta2O 17 The multiphase ceramic layer is 1000 μm thick, and Hf6Ta2O is completed. 17 Preparation of wear-resistant sealing coating.

[0063] Example 4

[0064] A type of Hf6Ta2O 17 The wear-resistant sealing coating comprises a nickel-based high-temperature alloy substrate, a transition layer, and a ceramic layer stacked together; the transition layer material is PtAl alloy powder; the ceramic layer contains 90g of Hf6Ta2O as its raw material. 17 Ceramic powder, 3g carbon powder, 7g diatomaceous earth powder; the Hf6Ta2O 17 The ceramic powder consists of 49g of hafnium oxide powder and 51g of tantalum oxide powder.

[0065] A type of Hf6Ta2O 17 The method for preparing a wear-resistant sealing coating includes the following steps:

[0066] Step 1: Add 49g of hafnium oxide powder and 51g of tantalum oxide powder to anhydrous ethanol as the ball milling medium. The amount of anhydrous ethanol added should completely cover the ball milling balls. Ball mill for 10 hours at 350 rpm to obtain a uniformly mixed powder mixture. Magnetically stir the uniformly mixed powder mixture at 1200 rpm and 220°C until the powder mixture becomes gel-like. Place it in an oven at 100°C and dry for 8 hours to obtain a uniformly mixed powder to be sintered. Sinter the powder to be sintered at the following temperatures: below 300°C at room temperature, heating rate of 8°C / min; 300–950°C, heating rate of 6°C / min, holding at 950°C for 1.5 hours; 900–1250°C, heating rate of 6°C / min, holding at 1250°C for 8 hours to obtain Hf6Ta2O. 17 Ceramic powder;

[0067] Step 2: Take 90g of Hf6Ta2O prepared in Step 1 17 Ceramic powder, 3g carbon powder, 7g diatomaceous earth powder, 100g sodium carboxymethyl cellulose solution, 25g deionized water, and 20g anhydrous ethanol were ball-milled in a roller mill at 90 r / min for 6 hours to obtain Hf6Ta2O. 17 Ceramic-based multiphase mixtures;

[0068] Step 3: The Hf6Ta2O prepared in step 2... 17 The ceramic-based multiphase mixture was granulated and dried using a spray granulator to obtain a product containing Hf6Ta2O. 17 Multiphase granulated powder; the inlet temperature of the spray granulator is 300℃, the outlet temperature is 100℃, the nozzle speed is 35rpm, and the peristaltic pump speed is 13rpm;

[0069] Step 4: Using supersonic atmospheric plasma spraying technology, PtAl alloy powder is sprayed onto the pretreated nickel-based superalloy substrate until the transition layer thickness is 100μm, thus obtaining the nickel-based superalloy substrate---PtAl alloy transition layer; the spraying power is 35kW, the flow rate of argon gas used in the spraying process is 70slpm, and the flow rate of hydrogen gas is 5slpm; the pretreated nickel-based superalloy substrate is a nickel-based superalloy substrate with a certain roughness obtained by sandblasting alumina.

[0070] Step 5: Use a supersonic atmospheric plasma spraying device to spray the Hf6Ta2O-containing material prepared in step 3. 17 The multiphase granulated powder is sprayed onto the surface of the transition layer prepared in step 4 to obtain a nickel-based superalloy substrate---NiCrAlY alloy transition layer---Hf6Ta2O 17Multiphase ceramic layer; the spraying power is 45kW, and the flow rate of argon gas used in the spraying process is 68slpm and the flow rate of hydrogen gas is 3slpm.

[0071] Step 6: Repeat step 5 continuously, Hf6Ta2O 17 The multiphase ceramic layer is 900 μm thick, and Hf6Ta2O is completed. 17 Preparation of wear-resistant sealing coating.

[0072] Example 5

[0073] A type of Hf6Ta2O 17 The wear-resistant sealing coating comprises a nickel-based superalloy substrate, a transition layer, and a ceramic layer stacked together; the transition layer material is NiCrAlY alloy powder; the ceramic layer contains 91g of Hf6Ta2O as its raw material. 17 Ceramic powder, 4g starch, 5g bentonite powder; Hf6Ta2O 17 The ceramic powder consists of 70g of hafnium oxide powder and 30g of tantalum oxide powder.

[0074] A type of Hf6Ta2O 17 The method for preparing a wear-resistant sealing coating includes the following steps:

[0075] Step 1: Add 70g of hafnium oxide powder and 30g of tantalum oxide powder to anhydrous ethanol as the ball milling medium. The amount of anhydrous ethanol added should completely cover the ball milling balls. Ball mill for 10 hours at 350 rpm to obtain a uniformly mixed powder mixture. Magnetically stir the uniformly mixed powder mixture and dry it at 1200 rpm and 210℃ until the powder mixture becomes gel-like. Place it in an oven at 90℃ and dry for 8 hours to obtain a uniformly mixed powder to be sintered. Sinter the powder to be sintered at the following temperatures: below 300℃ at room temperature, heating rate of 10℃ / min; 300~950℃, heating rate of 7℃ / min, holding at 950℃ for 1 hour; 900~1250℃, heating rate of 6℃ / min, holding at 1250℃ for 8 hours to obtain Hf6Ta2O. 17 Ceramic powder;

[0076] Step 2: Take 91g of Hf6Ta2O prepared in Step 1 17 Ceramic powder, 4g starch, 5g bentonite powder, 104g polyvinyl alcohol solution, 20g deionized water, and 25g anhydrous ethanol were ball-milled in a roller mill at 90 r / min for 6 hours to obtain Hf6Ta2O. 17 Ceramic-based multiphase mixtures;

[0077] Step 3: The Hf6Ta2O prepared in step 2... 17 The ceramic-based multiphase mixture was granulated and dried using a spray granulator to obtain a product containing Hf6Ta2O. 17 Multiphase granulated powder; the inlet temperature of the spray granulator is 300℃, the outlet temperature is 100℃, the nozzle speed is 35rpm, and the peristaltic pump speed is 13rpm;

[0078] Step 4: Using supersonic atmospheric plasma spraying technology, PtAl alloy powder is sprayed onto the pretreated nickel-based superalloy substrate until the transition layer thickness is 100μm, thus obtaining the nickel-based superalloy substrate---PtAl alloy transition layer; the spraying power is 40kW, the flow rate of argon gas used in the spraying process is 65slpm, and the flow rate of hydrogen gas is 3slpm; the pretreated nickel-based superalloy substrate is a nickel-based superalloy substrate with a certain roughness obtained by sandblasting alumina.

[0079] Step 5: Use a supersonic atmospheric plasma spraying device to spray the Hf6Ta2O-containing material prepared in step 3. 17 The multiphase granulated powder is sprayed onto the surface of the transition layer prepared in step 4 to obtain a nickel-based superalloy substrate---NiCrAlY alloy transition layer---Hf6Ta2O 17 Multiphase ceramic layer; the spraying power is 45kW, and the flow rate of argon gas used in the spraying process is 70slpm and the flow rate of hydrogen gas is 2slpm.

[0080] Step 6: Repeat step 5 continuously, Hf6Ta2O 17 The thickness of the multiphase ceramic layer is 500 μm, and Hf6Ta2O is completed. 17 Preparation of wear-resistant sealing coating.

[0081] Figure 2 Hf6Ta2O prepared for this invention 17 The microstructure of the abrasive sealant coating granulated powder shows that Hf6Ta2O 17 Abrasive sealant granulation powder is a mixed powder with a good spherical shape, and therefore can be used as a good spray powder.

[0082] See Figure 3 The Hf6Ta2O prepared by this invention 17 The abrasive sealing coating is composed of a large number of molten granulated powders, which are spread out in a flat manner. It has partially molten particles and good porosity, and has the characteristics of high deposition efficiency and mass production capability.

[0083] See Figure 4 The Hf6Ta2O prepared by this invention 17The wearable sealing coating has a transition layer thickness of 100μm and a ceramic layer thickness of about 400μm. It can be seen that it has a controllable thickness and a simple preparation process.

[0084] See Figure 5 Figure (a) shows the Hf6Ta2O prepared in this invention. 17 The microstructure of the wear-resistant sealing coating after wear is shown in Figure (b), which is a magnified view of the wear area. As can be seen from the figure, the wear area mainly exhibits plow marks, indicating that the Hf6Ta2O prepared in this invention... 17 Abrasion-resistant sealing coatings are characterized by low wear and resistance to cracking and peeling.

[0085] See Figure 6 The Hf6Ta2O prepared by this invention 17 The wear output results of the abrasion-resistant sealing coating show that it has the characteristics of low wear and resistance to cracking and peeling. In the abrasion test, Hf6Ta2O 17 The base seal coating exhibits minimal wear after wear, and no issues such as coating adhesion or blade tip damage occur.

[0086] See Figure 7 Hf6Ta2O prepared in this invention 17 The macroscopic thermal cycling diagram of the base sealing coating shows that after 30 cycles at 1350℃, no peeling occurred. However, numerous closed-loop cracks appeared on the coating surface, indicating stress release and delayed peeling. This demonstrates the effectiveness of the Hf6Ta2O prepared in this invention. 17 Abrasive sealing coatings have the characteristics of good thermal shock resistance and high service temperature, and can be used as abrasive coatings for high-temperature stators in the turbine section of aero-engines.

[0087] As can be seen from the examples, compared with the prior art, the present invention uses a high-temperature solid-state reaction to prepare Hf6Ta2O. 17 Powder is then used to spray a transition layer onto a nickel-based superalloy substrate using supersonic atmospheric plasma spraying technology, resulting in a nickel-based superalloy substrate-transition layer. Finally, a ceramic layer is sprayed onto the nickel-based superalloy substrate-transition layer to complete the Hf6Ta2O process. 17 The preparation of wear-resistant sealing coatings has the characteristics of high service temperature, coating that is not easy to crack and peel off, simple preparation process, small wear amount, and good thermal shock resistance.

Claims

1. A type of Hf6Ta2O 17 A wear-resistant sealing coating comprising a nickel-based superalloy substrate, a transition layer, and a ceramic layer stacked together, characterized in that... The ceramic layer is made from Hf6Ta2O. 17 Ceramic powder, pore-forming agent, and lubricating phase, by mass ratio, Hf6Ta2O 17 Ceramic powder: pore-forming agent: lubricating phase = (88~92): (3~5): (3~7); The Hf6Ta2O 17 The ceramic powder, whose raw materials include hafnium oxide powder and tantalum oxide powder, is in the following mass ratio: hafnium oxide powder : tantalum oxide powder = 1 : (0.35-1.05). The pore-forming agent is polystyrene, carbon powder, or starch; The lubricating phase is hexagonal boron nitride, bentonite, or diatomaceous earth; The Hf6Ta2O 17 The method for preparing a wear-resistant sealing coating includes the following steps: Step 1: Ball mill hafnium oxide powder and tantalum oxide powder at a speed of 250-350 r / min for 8-10 h to obtain a homogeneous powder mixture. Stir the homogeneous powder mixture at a speed of 700-1200 r / min and a temperature of 180-220℃ until the powder mixture becomes gel-like. Place it in an oven and dry at 75-100℃ for 8-10 h to obtain a homogeneous powder to be sintered. Sinter the powder to be sintered at the following temperatures: below 300℃ at room temperature, heating rate of 8-10℃ / min; 300-950℃, heating rate of 6-8℃ / min, holding at 950℃ for 1-1.5 h; 950-1250℃, heating rate of 4-6℃ / min, holding at 1250℃ for 8-10 h to obtain Hf6Ta2O. 17 Ceramic powder; based on the raw material mass ratio, hafnium oxide powder : tantalum oxide powder = 1 : (0.35-1.05); Step 2: The Hf6Ta2O prepared in Step 1... 17 Ceramic powder was ball-milled with pore-forming agent, lubricating phase, binder, deionized water, and anhydrous ethanol at a speed of 60–90 r / min for 4–6 h. The resulting mixture, by mass ratio, contained Hf6Ta2O. 17 Ceramic powder: pore-forming agent: lubricating phase: binder: deionized water: anhydrous ethanol = (88~92): (3~5): (3~7): (94~104): (15~25): (15~25) to obtain Hf6Ta2O 17 Ceramic-based multiphase mixtures; Step 3: The Hf6Ta2O prepared in step 2... 17 A ceramic-based multiphase mixture is granulated and dried to obtain a ceramic layer that can be sprayed with powder. Step 4: Use supersonic atmospheric plasma spraying technology to spray the transition layer onto the pretreated nickel-based superalloy substrate until the thickness of the transition layer is 80-120μm, thus obtaining the nickel-based superalloy substrate---transition layer; the spraying power is 30-40kW, the flow rate of argon gas used in the spraying process is 65-70slpm, and the flow rate of hydrogen gas is 2-5slpm; Step 5: Using supersonic atmospheric plasma spraying technology, the sprayable powder of the ceramic layer prepared in step 3 is sprayed onto the surface of the nickel-based superalloy substrate-transition layer prepared in step 4 to obtain the nickel-based superalloy substrate-transition layer-ceramic layer; the spraying power is 35-45kW, the argon flow rate is 65-70slpm and the hydrogen flow rate is 2-5slpm during the spraying process; Step 6: Repeat step 5 continuously until the ceramic layer thickness is greater than 200 μm, completing the Hf6Ta2O process. 17 Preparation of wear-resistant sealing coating.

2. The Hf6Ta2O according to claim 1 17 The wear-resistant sealing coating is characterized by, The transition layer is made of NiCrAlY powder or PtAl alloy powder.

3. The Hf6Ta2O according to claim 1 17 The wear-resistant sealing coating is characterized by, The pretreated nickel-based superalloy substrate in step 4 is a nickel-based superalloy substrate with a certain roughness obtained by sandblasting and aluminizing.

4. The Hf6Ta2O according to claim 1 17 The wear-resistant sealing coating is characterized by, The binder in step 2 is a polyvinyl alcohol solution, a modified ethylene polymer, or sodium carboxymethyl cellulose.

5. A type of Hf6Ta2O 17 A wear-resistant sealing coating comprising a nickel-based superalloy substrate, a transition layer, and a ceramic layer stacked together, characterized in that... The transition layer material is NiCrAlY alloy powder; the ceramic layer's raw material includes: 88g of Hf6Ta2O 17 Ceramic powder, 5g polystyrene powder, 7g hexagonal boron nitride powder; the Hf6Ta2O 17 The ceramic powder comprises 59g of hafnium oxide powder and 41g of tantalum oxide powder. The Hf6Ta2O 17 The method for preparing a wear-resistant sealing coating includes the following steps: Step 1: Add 59g of hafnium oxide powder and 41g of tantalum oxide powder to anhydrous ethanol as the ball milling medium. The amount of anhydrous ethanol added should completely cover the ball milling balls. Ball mill at 300 r / min for 9 hours to obtain a uniformly mixed powder mixture. Magnetically stir the uniformly mixed powder mixture at 900 r / min and 200℃ until the powder mixture becomes gel-like. Place it in an oven at 85℃ and dry for 9 hours to obtain a uniformly mixed powder to be sintered. Sinter the powder to be sintered at the following temperatures: below 300℃ at room temperature, heating rate of 9℃ / min; 300–950℃, heating rate of 7℃ / min, holding at 950℃ for 1 hour; 950–1250℃, heating rate of 4℃ / min, holding at 1250℃ for 9 hours to obtain Hf6Ta2O. 17 Ceramic powder; Step 2: Take 88g of Hf6Ta2O prepared in Step 1 17 Ceramic powder, 5g polystyrene powder, 7g hexagonal boron nitride powder, 100g polyvinyl alcohol solution, 15g deionized water, and 15g anhydrous ethanol were ball-milled for 4 hours at 75 r / min to obtain Hf6Ta2O. 17 Ceramic-based multiphase mixtures; Step 3: The Hf6Ta2O prepared in step 2... 17 The ceramic-based multiphase mixture was granulated and dried using a spray granulator to obtain a product containing Hf6Ta2O. 17 Multiphase granulated powder; the inlet temperature of the spray granulator is 300℃, the outlet temperature is 100℃, the nozzle speed is 35rpm, and the peristaltic pump speed is 13rpm; Step 4: Using supersonic atmospheric plasma spraying technology, NiCrAlY alloy powder is sprayed onto the pretreated nickel-based superalloy substrate until the transition layer thickness is 100μm; thus obtaining the nickel-based superalloy substrate---NiCrAlY alloy transition layer; the spraying power is 35kW, and the flow rate of argon gas used in the spraying process is 68slpm and the flow rate of hydrogen gas is 3slpm; the pretreated nickel-based superalloy substrate is a nickel-based superalloy substrate with a certain roughness obtained by sandblasting alumina. Step 5: Use a supersonic atmospheric plasma spraying device to spray the Hf6Ta2O-containing material prepared in step 3. 17 The multiphase granulated powder is sprayed onto the surface of the transition layer prepared in step 4 to obtain a nickel-based superalloy substrate---NiCrAlY alloy transition layer---Hf6Ta2O 17 Multiphase ceramic layer; the spraying power is 40kW, the argon flow rate is 67slpm and the hydrogen flow rate is 5slpm during the spraying process; Step 6: Repeat step 5 continuously until Hf6Ta2O is reached. 17 The thickness of the multiphase ceramic layer is 500 μm, and Hf6Ta2O is completed. 17 Preparation of wear-resistant sealing coating.

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