A Surface AlCr Slurry Penetrant for Nickel-Based Superalloys and Its Preparation Method

Abstract

The present invention discloses an AlCr slurry penetrant for a nickel-based superalloy surface and a preparation method thereof, which includes component A, component B and component C. Among them, component A is a liquid, including 5-20% of MgO, 5-10% of MgCl2, 1-5% of AlCl3 and 10-35% of H3PO4; component B is a liquid, including 2-15% of CrCl3, 3-9% of ammonia water and 10-20% of H3PO4; component C is a solid powder, including 35-55% of AlCr powder and 2-10% of Cr powder, and the balance is Al powder. The aluminizing agent of the present invention is applied to the blades of aerospace engines, greatly improving the service life of the blades of aerospace aircraft engines, and solving the problem of nodulation in the slurry diffusion stage, greatly increasing economic benefits and reducing the occurrence of reject rates.

Description

Technical Field

[0001] The present invention belongs to the technical field of surface treatment of metal materials, and particularly relates to an AlCr slurry penetrant for a nickel-based superalloy surface and a preparation method thereof. Background Art

[0002] With the development of the aerospace field, the working environment of aero-engine turbine blades has become increasingly harsh. When the engine rotates at high speed during operation, the turbine blades bear huge centripetal forces, and the operation of the turbine engine causes the temperature of the turbine blades to reach thousands of degrees Celsius. The average inlet temperature of the turbines of foreign advanced fourth-generation fighter jets in service has reached 1600 °C. Nowadays, only through the composition design of superalloys and advanced cooling technologies can no longer meet the current requirements for turbine engine blades. Surface treatment of superalloys can effectively increase the working temperature and protect the superalloys from high-temperature oxidation.

[0003] Oxidation and corrosion are key factors restricting superalloy materials. Therefore, the influence of high-temperature coatings on the mechanical properties and high-temperature properties of superalloys has become a hot research point. It is very necessary to find a protective coating with excellent high-temperature oxidation resistance and high-temperature corrosion resistance.

[0004] Thermal barrier coatings and cladding coatings are two types of coatings developed in recent years, but they have high production costs, high requirements for equipment, and limited application ranges. Thermal diffusion coatings are the most widely used high-temperature alloy protective coatings with relatively low production costs. Currently, the commonly used methods for preparing diffusion aluminide coatings for nickel-based high-temperature engine blades mainly include solid penetrants and slurry penetrant methods. Among them, solid penetrants are prone to environmental pollution, difficult to control the uniformity of the penetrated layer, easy to produce nodules, local aluminum enrichment, and other disadvantages. Liquid slurries can achieve local aluminization, but traditional aluminizing slurry formulations have the following problems: (1) The coatings prepared by traditional AlNi slurry penetrants have insufficient high-temperature oxidation resistance and corrosion resistance; (2) The viscosity and pH value of traditional slurries are not appropriate, resulting in local non-uniformity, nodules, and other problems after drying on the surfaces of parts such as high-temperature alloy blades. Summary of the Invention

[0005] The purpose of this part is to outline some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this part, as well as in the abstract and title of the present application, to avoid obscuring the purpose of this part, the abstract, and the title. However, such simplifications or omissions shall not be used to limit the scope of the present invention.

[0006] In view of the above and / or problems existing in the prior art, the present invention is proposed.

[0007] Therefore, one object of the present invention is to provide an AlCr powder penetrant with oxidation resistance and corrosion resistance, as well as a new slurry with more uniform coating properties.

[0008] To solve the above technical problems, the present invention provides the following technical solutions: A nickel-based superalloy surface AlCr slurry penetrant, wherein the nickel-based superalloy surface AlCr slurry penetrant includes component A, component B, and component C. Among them, component A is a liquid, including 5-20% of MgO, 5-10% of MgCl 2 , 1-5% of AlCl 3 , and 10-35% of H 3 PO 4 ; Component B is a liquid, including 2-15% of CrCl 3 , 3-9% of ammonia water, and 10-20% of H 3 PO 4 ; Component C is a solid powder, including 35-55% of AlCr powder and 2-10% of Cr powder, with the balance being Al powder.

[0009] As a preferred embodiment of the nickel-based superalloy surface AlCr slurry penetrant of the present invention, wherein: the content of Cr in the AlCr powder is 20-50%.

[0010] As a preferred embodiment of the nickel-based superalloy surface AlCr slurry penetrant of the present invention, wherein: the nickel-based superalloy surface AlCr slurry penetrant, by mass fraction, includes 40-50% of component A, 15-22% of component B, and the balance of component C.

[0011] As a preferred embodiment of the nickel-based superalloy surface AlCr slurry penetrant of the present invention, wherein: the nickel-based superalloy surface AlCr slurry penetrant, by mass fraction, includes 46% of component A, 19% of component B, and 35% of component C.

[0012] As a preferred embodiment of the nickel-based superalloy surface AlCr slurry penetrant of the present invention, wherein: component A includes 11% of MgO, 5% of MgCl 2 , 2.5% of AlCl 3 , and 26% of H 3 PO 4 ; Component B includes 7% of CrCl 3 , 6% of ammonia water, and 16% of H 3 PO 4 ; Component C includes 43% of AlCr powder, 5% of Cr powder, and 52% of Al powder.

[0013] As a preferred embodiment of the nickel-based superalloy surface AlCr slurry penetrant of the present invention, wherein: the content of Cr in the AlCr powder is 30%.

[0014] The present invention also discloses a preparation method of an AlCr slurry penetrant for a nickel-based superalloy surface, including:

[0015] Prepare component A: Mix the MgO, MgCl 2 , AlCl 3 , H 3 PO 4 and dilute with distilled water;

[0016] Prepare component B: Mix the CrCl 3 , ammonia water, H 3 PO 4 and dilute with distilled water;

[0017] Prepare component C: Mix the AlCr powder, Cr powder and Al powder;

[0018] Stir and dry: Mix component A, component B and component C evenly, and finally dry to obtain the AlCr slurry penetrant for the nickel-based superalloy surface of the present invention.

[0019] As a preferred embodiment of the preparation method of the AlCr slurry penetrant for the nickel-based superalloy surface of the present invention, wherein: for the preparation of component A, the dilution includes controlling the chlorine element concentration to be lower than 10 -3 mol / L, controlling the component density to be 1.1 - 1.5 g / cm 3 , the pH value to be 0.8 - 2.6 and the viscosity to be 3 - 15×10 -3 Pas.

[0020] As a preferred embodiment of the preparation method of the AlCr slurry penetrant for the nickel-based superalloy surface of the present invention, wherein: for the preparation of component B, after mixing the CrCl 3 , ammonia water, H 3 PO 4 , let it stand for more than 72 h, control the component density to be 1.0 - 1.4 g / cm 3 , the pH value to be 0.1 - 1.2 and the viscosity to be 5 - 12×10 -3 Pas.

[0021] As a preferred embodiment of the preparation method of the AlCr slurry penetrant for the nickel-based superalloy surface of the present invention, wherein: the step of mixing component A, component B and component C evenly includes mixing component A and component B evenly first, then adding component C and mixing, and diluting with ultrapure water in a ratio of 1:10.

[0022] As a preferred embodiment of the preparation method of the AlCr slurry penetrant for the nickel-based superalloy surface of the present invention, wherein: for the drying, the temperature is 40 - 80 °C and the time is 20 - 60 h.

[0023] As a preferred embodiment of the preparation method of the AlCr slurry penetrant on the surface of the nickel-based superalloy of the present invention, wherein: the drying includes drying in a vacuum drying oven at a temperature of 50°C for 50 hours.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The aluminum-chromium slurry prepared by the present invention solves the defects of uneven coating thickness, surface nodulation, local aluminum enrichment, etc. in the preparation of traditional aluminum penetrants in the past. Among them, MgCl 2 and AlCl 3 are added, and their function is to act as a dispersant. At the same time, this formulation is added in three components, which has a good dispersion effect during the high-temperature diffusion stage of the slurry, eliminating surface nodules; at the same time, the prepared aluminum-chromium coating has greatly improved sulfur corrosion resistance, oxidation corrosion resistance, thermal stability and coating life. The aluminizing agent of the present invention is applied to the blades of aerospace engines, greatly improving the service life of the blades of aerospace aircraft engines, and solving the problem of nodules during the slurry diffusion stage, greatly increasing economic benefits and reducing the occurrence of waste products. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. Among them:

[0027] Figure 1 It is a macroscopic view of the component after spraying the slurry penetrant in Embodiment 1 of the present invention;

[0028] Figure 2 It is a scanning electron microscope image of the coating cross-section corresponding to (a), (b), (c) and (d) in Embodiments 1 to 4 of the present invention respectively;

[0029] Figure 3 It is a graph of the oxidation test results of Embodiments 1 to 6 of the present invention;

[0030] Figure 4 It is a graph of the oxidation test results of Embodiments 1, 7, and 8 of the present invention;

[0031] Figure 5 It is a graph of the oxidation test results of Embodiments 1, 9, and 10 of the present invention;

[0032] Figure 6 It is a graph of the oxidation test results of Embodiments 1, 11, and 12 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0033] To make the above objects, features and advantages of the present invention more obvious and understandable, the following describes in detail the specific implementation manners of the present invention in combination with the embodiments of the specification.

[0034] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar promotions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0035] Secondly, the so-called "one embodiment" or "embodiment" herein refers to a specific feature, structure or characteristic that can be included in at least one implementation manner of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it an embodiment that is separate or selectively mutually exclusive with other embodiments.

[0036] Example 1

[0037] (1) Prepare a nickel-based superalloy surface AlCr slurry penetrant with 46% of component A, 19% of component B, and 35% of component C by mass fraction;

[0038] Among them, component A includes 11% of MgO, 5% of MgCl 2 , 2.5% of AlCl 3 , 26% of H 3 PO 4 ; component B includes 7% of CrCl 3 , 6% ammonia water, 16% of H 3 PO 4 ; component C includes 43% of AlCr powder, 5% of Cr powder, and the balance is spherical Al powder, where the content of Cr in the AlCr powder is 30%;

[0039] (2) After fully mixing the above component A, dilute it with distilled water and titrate it. After dilution, the concentration of chlorine element is lower than 10 - 3 mol / L, the component density is 1.2 g / cm 3 , the pH value is 1.1, and the viscosity is 6×10 -3 Pas;

[0040] (3) After fully mixing the above component B, dilute it with distilled water and titrate it, and let it stand for 80 h. The component density is 1.2 g / cm 3 , the pH value is 0.25, and the viscosity is 7×10 -3 Pas;

[0041] (4) Mix the above component C with a ball mill;

[0042] (5) Mix component A, component B and component C evenly by stirring.

[0043] (6) Dilute the above-mentioned evenly mixed slurry with ultrapure water at a ratio of 1:10.

[0044] (7) Put the above-mentioned evenly mixed slurry into a vacuum drying oven for drying at a temperature of 50 °C and aging for 50 h to obtain AlCr slurry penetrant sample 1.

[0045] Spray the above sample 1 onto the blades of a nickel-based superalloy aircraft engine by a conventional method. After spraying, the coating thickness of the component is uniform, and there are no defective nodules on the surface after high-temperature diffusion. The rejection rate in factory application is only 1-2%, which is three percentage points lower than the 5-6% of the existing slurry formula. The components after spraying are as Figure 1 shown; its coating cross-section is as Figure 2 (a) shown, and the thickness of the penetration layer is 60-80 μm.

[0046] Example 2

[0047] (1) Prepare an AlCr slurry penetrant for the surface of a nickel-based superalloy containing 46% of component A, 19% of component B, and 35% of component C by mass fraction.

[0048] Among them, component A includes 13% of MgO, 7% of MgCl 2 , 2.5% of AlCl 3 , 22% of H 3 PO 4 ; component B includes 9% of CrCl 3 , 7% of ammonia water, 12% of H 3 PO 4 ; component C includes 39% of AlCr powder, 7% of Cr powder, and the balance is spherical Al powder, where the content of Cr in the AlCr powder is 30%;

[0049] (2) After fully mixing the above component A, dilute it with distilled water and titrate it. The concentration of chlorine element after dilution is lower than 10 - 3 mol / L, the density of the component is 1.2 g / cm 3 , the pH value is 1.1, and the viscosity is 6×10 -3 Pas;

[0050] Repeat steps (2), (3), (4), (5), (6), (7) of Example 1 to obtain AlCr slurry penetrant sample 2.

[0051] The above sample 2 was sprayed onto the blades of a nickel-based superalloy aircraft engine by a conventional method. After spraying, the coating thickness of the components was uniform, and there were no defective nodules on the surface after high-temperature diffusion. The rejection rate in factory applications was only 2-3%, a reduction of two percentage points compared to the existing slurry formulation with a rejection rate of 5-6%; its coating cross-section is as shown in Figure 2 (b), and the thickness of the infiltration layer is 60-70 μm.

[0052] Example 3

[0053] (1) Prepare a nickel-based superalloy surface AlCr slurry penetrant with 46% of component A, 19% of component B, and 35% of component C by mass fraction;

[0054] Among them, component A includes 15% of MgO, 9% of MgCl 2 , 3.5% of AlCl 3 , 22% of H 3 PO 4 ; component B includes 11% of CrCl 3 , 8% ammonia water, 12% of H 3 PO 4 ; component C includes 39% of AlCr powder, 9% of Cr powder, and the balance is spherical Al powder, where the Cr content in the AlCr powder is 30%;

[0055] Repeat steps (2), (3), (4), (5), (6), and (7) of Example 1 to obtain AlCr slurry penetrant sample 3.

[0056] The above sample 3 was sprayed onto the blades of a nickel-based superalloy aircraft engine by a conventional method. After spraying, the coating thickness of the components was uniform, and there were no defective nodules on the surface after high-temperature diffusion. The rejection rate in factory applications was only 1-2%, a reduction of three percentage points compared to the existing slurry formulation with a rejection rate of 5-6%; its coating cross-section is as shown in Figure 2 (c), and the thickness of the infiltration layer is 70-80 μm.

[0057] Example 4

[0058] (1) Prepare a nickel-based superalloy surface AlCr slurry penetrant with 40% of component A, 22% of component B, and 38% of component C by mass fraction;

[0059] Among them, component A includes 11% of MgO, 5% of MgCl 2 , 2.5% of AlCl3, 26% of H 3 PO 4 ; component B includes 7% of CrCl 3 , 6% ammonia water, 16% of H 3 PO 4; Component C includes 43% AlCr powder, 5% Cr powder, and the balance is spherical Al powder, where the Cr content in the AlCr powder is 30%;

[0060] Repeat steps (2), (3), (4), (5), (6), and (7) of Example 1 to obtain the AlCr slurry penetrant sample 4.

[0061] Spray the above slurry onto the blades of a nickel-based superalloy high-temperature aircraft engine by a conventional method. After spraying, the coating thickness of the component is uniform, and there are no defective nodules on the surface after high-temperature diffusion. The defective rate in factory applications is almost close to 1%, and there are no nodules on the surface of the blades with defective rates either; the cross-section of its coating is as Figure 2 (d) shown, and the thickness of the penetration layer is 70 - 80 μm.

[0062] Example 5

[0063] (1) Prepare a nickel-based superalloy surface AlCr slurry penetrant with 50% of Component A, 15% of Component B, and 35% of Component C by mass fraction;

[0064] Among them, Component A includes 11% MgO, 5% MgCl 2 , 2.5% AlCl 3 , 26% H 3 PO 4 ; Component B includes 7% CrCl 3 , 6% ammonia water, 16% H 3 PO 4 ; Component C includes 43% AlCr powder, 5% Cr powder, and the balance is spherical Al powder, where the Cr content in the AlCr powder is 30%;

[0065] Repeat steps (2), (3), (4), (5), (6), and (7) of Example 1 to obtain the AlCr slurry penetrant sample 5.

[0066] Spray the above sample 5 onto the blades of a nickel-based superalloy high-temperature aircraft engine by a conventional method. After spraying, the coating thickness of the component is uniform, and there are no defective nodules on the surface after high-temperature diffusion.

[0067] Example 6

[0068] (1) Weigh Component A' and Component B' respectively by mass fraction; Component A' includes 28% Al 2 O 3 , 26% CrCl 2 , 1.3% Ni, 1.3% NH 4 Cl, 3% H 3 PO 4 ; Component B' includes 3% H3 PO 4 、 11% Al, 22% Cr 2 O 3 。

[0069] (2) Mix the above component A thoroughly, dilute it with distilled water and filter it to control the chlorine element concentration below 10 - 3 mol / L. Let component B stand for 72 h after mixing evenly.

[0070] (3) Mix the above qualified component A and component B evenly.

[0071] (4) Dilute the above evenly mixed slurry with ultrapure water at a ratio of 1:10.

[0072] (5) Put the above evenly mixed slurry into a vacuum drying oven at 50 °C for 50 h of aging to obtain the AlNi slurry infiltrant sample 6. Spray sample 6 onto the blades of a nickel-based high-temperature aircraft engine according to the conventional method.

[0073] Conduct high-temperature oxidation tests on samples 1-6. Clean the sprayed blade specimens of the above samples 1-6 with alcohol, dry them, weigh the weight before oxidation with a four-digit electronic balance, then put them into a muffle furnace and heat to 1000 °C. After 50 h, 100 h, 150 h and 200 h respectively, weigh the mass change and divide it by the surface area of the sample to calculate the mass change per unit area.

[0074] The test results are as Figure 3 shown. The AlCr slurry infiltrant of the present invention has greatly improved oxidation resistance compared with the aluminized agent prepared by the traditional method. As Figure 3 can be seen, after 50 h of oxidation, the mass changes of samples 1 to 6 are: 0.3259 g / cm 2 、 0.3624 g / cm 2 、 0.3358 g / cm 2 、 0.3874 g / cm 2 、 0.3546 g / cm 2 、 0.6584 g / cm 2 ; after 100 h of oxidation, the mass changes are: 0.3789 g / cm 2 、 0.4112 g / cm 2 、 0.3568 g / cm 2 、 0.4102 g / cm 2 、 0.3895 g / cm 2 、 0.6851 g / cm 2 ; after 150 h of oxidation, the mass changes are: 0.4025 g / cm2 、0.4902 g / cm 2 、0.4582 g / cm 2 、0.4656 g / cm 2 、0.4123 g / cm 2 、0.7845 g / cm 2 ; The mass changes after 200 h of oxidation are respectively: 0.5228 g / cm 2 、0.5344 g / cm 2 、0.5001 g / cm 2 、0.5508 g / cm 2 、0.4894 g / cm 2 、0.8825 g / cm 2 .

[0075] It can be seen from the above experimental results that the oxidation resistance of the AlCr slurry penetrant of the present invention is significantly improved, and the maximum oxidation resistance is more than doubled compared with the AlNi slurry penetrant.

[0076] Electrochemical corrosion tests were carried out on samples 1 - 6, and the results are shown in Table 1.

[0077] Table 1

[0078]

[0079] It can be seen from the data in Table 1 that the corrosion resistance of the AlCr slurry penetrant of the present invention is significantly improved compared with the AlNi slurry penetrant, and the corrosion resistance of sample 1 is the strongest.

[0080] Example 7

[0081] (1) Prepare an AlCr slurry penetrant for the surface of a nickel-based superalloy with 46% of component A, 19% of component B, and 35% of component C by mass fraction;

[0082] Among them, component A includes 5% of MgO, 5% of MgCl 2 、1% of AlCl 3 、35% of H 3 PO 4 ; Component B includes 7% of CrCl 3 、6% ammonia water, 16% of H 3 PO 4 ; Component C includes 43% of AlCr powder, 5% of Cr powder, and the balance is spherical Al powder, where the content of Cr in the AlCr powder is 30%;

[0083] Repeat the steps (2), (3), (4), (5), (6), and (7) of Example 1 to obtain an AlCr slurry penetrant sample 7, and spray the sample 7 onto the blades of a nickel-based superalloy aircraft engine by a conventional method.

[0084] Example 8

[0085] (1) Prepare a nickel-based superalloy surface AlCr slurry penetrant with 46% of component A, 19% of component B, and 35% of component C by mass fraction;

[0086] Among them, component A includes 20% of MgO, 10% of MgCl 2 , 5% of AlCl 3 , 10% of H 3 PO 4 ; component B includes 7% of CrCl 3 , 6% of ammonia water, 16% of H 3 PO 4 ; component C includes 43% of AlCr powder, 5% of Cr powder, and the balance is spherical Al powder, where the content of Cr in the AlCr powder is 30%;

[0087] Repeat the steps (2), (3), (4), (5), (6), and (7) of Example 1 to obtain an AlCr slurry penetrant sample 8, and spray the sample 8 onto the blades of a nickel-based superalloy aircraft engine by a conventional method.

[0088] Conduct high-temperature oxidation tests on samples 7 and 8, and compare the test results with those of sample 1. The results are as Figure 4 shown. It can be seen that after 50 h of oxidation, the mass changes of samples 1, 7, and 8 are 0.3259 g / cm 2 , 0.4868 g / cm 2 , and 0.5563 g / cm 2 respectively; after 100 h of oxidation, the mass changes are 0.3789 g / cm 2 , 0.5025 g / cm 2 , and 0.6958 g / cm 2 respectively; after 150 h of oxidation, the mass changes are 0.4025 g / cm 2 , 0.6598 g / cm 2 , and 0.8272 g / cm 2 respectively; after 200 h of oxidation, the mass changes are 0.5228 g / cm 2 , 0.7999 g / cm 2 , and 0.9251 g / cm 2 .

[0089] From the above experimental results, it can be seen that in sample 7, the contents of MgO, MgCl 2 , AlCl 3 in component A are reduced compared with sample 1, resulting in lower antioxidant properties than sample 1. This is attributed to the fact that Al element is the main element in the slurry, and the reduction of Al and Mg elements leads to a decrease in antioxidant ability; while in sample 8, the contents of MgO, MgCl 2 , AlCl 3 in component A are increased compared with sample 1, resulting in lower antioxidant properties than sample 1. This is attributed to the fact that the element content is too high during the slurry penetration stage, and the defects increase.

[0090] Electrochemical corrosion tests were carried out on samples 1, 7, and 8, and the results are shown in Table 2.

[0091] Table 2

[0092]

[0093] It can be seen from the data in Table 2 that the corrosion resistance of samples 7 and 8 has decreased to varying degrees. This may be due to the fact that the Mg element content is too high or too low, resulting in a decrease in the surface corrosion potential and corrosion resistance.

[0094] Example 9

[0095] (1) Prepare an AlCr slurry penetrant for nickel-based superalloy surface with 46% of component A, 19% of component B, and 35% of component C by mass fraction;

[0096] Among them, component A includes 11% of MgO, 5% of MgCl 2 , 2.5% of AlCl 3 , 26% of H 3 PO 4 ; component B includes 2% of CrCl 3 , 3% of ammonia water, 10% of H 3 PO 4 ; component C includes 43% of AlCr powder, 5% of Cr powder, and the balance is spherical Al powder, and the content of Cr in the AlCr powder is 30%;

[0097] Repeat steps (2), (3), (4), (5), (6), and (7) of Example 1 to obtain AlCr slurry penetrant sample 9.

[0098] Example 10

[0099] (1) Prepare an AlCr slurry penetrant for nickel-based superalloy surface with 46% of component A, 19% of component B, and 35% of component C by mass fraction;

[0100] Among them, component A includes 11% of MgO, 5% of MgCl 2 , 2.5% of AlCl 3 , 26% of H 3 PO 4 ; component B includes 15% of CrCl 3 , 9% of ammonia water, 20% of H 3 PO 4 ; component C includes 43% of AlCr powder, 5% of Cr powder, and the balance is spherical Al powder, where the content of Cr in the AlCr powder is 30%;

[0101] Repeat steps (2), (3), (4), (5), (6), and (7) of Example 1 to obtain 10 samples of AlCr slurry penetrant.

[0102] Perform high-temperature oxidation tests on samples 9 and 10, and compare the test results with those of sample 1. The results are as Figure 5 shown. It can be seen that after 50 hours of oxidation, the mass changes of samples 1, 9, and 10 are respectively: 0.3259 g / cm 2 , 0.5982 g / cm 2 , 0.4025 g / cm 2 ; after 100 hours of oxidation, the mass changes are respectively: 0.3789 g / cm 2 , 0.7956 g / cm 2 , 0.5256 g / cm 2 ; after 150 hours of oxidation, the mass changes are respectively: 0.4025 g / cm 2 , 0.8835 g / cm 2 , 0.6998 g / cm 2 ; after 200 hours of oxidation, the mass changes are respectively: 0.5228 g / cm 2 , 1.0002 g / cm 2 , 0.8425 g / cm 2 .

[0103] From the above experimental results, it can be seen that in sample 9, the contents of CrCl 3 and ammonia water in component B are reduced compared with those in sample 1, resulting in inferior antioxidant properties to those of sample 1. This is attributed to the fact that ammonia water is mainly used to adjust the acidity and alkalinity, and too low or too high levels cannot ensure the stability of the slurry acidity and alkalinity. Thus, in sample 10, the contents of CrCl 3 and ammonia water in component B are increased compared with those in sample 1, also resulting in inferior antioxidant properties to those of sample 1.

[0104] Perform electrochemical corrosion tests on samples 1, 9, and 10, and the results are shown in Table 3.

[0105] Table 3

[0106]

[0107] It can be seen from the data in Table 3 that the corrosion resistance of Sample 9 and Sample 10 has decreased to varying degrees. The reason is related to the content of Cr. The Cr element is the most important alloying element in corrosion resistance. Too low a content directly leads to a decrease in corrosion resistance, while too high a content will cause an increase in surface brittleness, form a Cr-rich region, and the surface properties are unstable.

[0108] Example 11

[0109] (1) Prepare an AlCr slurry penetrant for nickel-based superalloy surfaces with 46% of Component A, 19% of Component B, and 35% of Component C by mass fraction;

[0110] Among them, Component A includes 11% of MgO, 5% of MgCl 2 , 2.5% of AlCl 3 , 26% of H 3 PO 4 ; Component B includes 7% of CrCl 3 , 6% of ammonia water, 16% of H 3 PO 4 ; Component C includes 55% of AlCr powder, 2% of Cr powder, and the balance is spherical Al powder, where the content of Cr in the AlCr powder is 30%;

[0111] Repeat steps (2), (3), (4), (5), (6), and (7) of Example 1 to obtain Sample 11 of the AlCr slurry penetrant.

[0112] Example 12

[0113] (1) Prepare an AlCr slurry penetrant for nickel-based superalloy surfaces with 46% of Component A, 19% of Component B, and 35% of Component C by mass fraction;

[0114] Among them, Component A includes 11% of MgO, 5% of MgCl 2 , 2.5% of AlCl 3 , 26% of H 3 PO 4 ; Component B includes 7% of CrCl 3 , 6% of ammonia water, 16% of H 3 PO 4 ; Component C includes 35% of AlCr powder, 10% of Cr powder, and the balance is spherical Al powder, where the content of Cr in the AlCr powder is 30%;

[0115] Repeat the steps (2), (3), (4), (5), (6), and (7) of Example 1 to obtain the AlCr slurry penetrant sample 12.

[0116] Perform high-temperature oxidation tests on samples 11 and 12, and compare the test results with those of sample 1. The results are as Figure 6 shown. It can be seen that after 50 h of oxidation, the mass changes of samples 1, 11, and 12 are 0.3259 g / cm 2 , 0.5546 g / cm 2 , and 0.6956 g / cm 2 respectively; after 100 h of oxidation, the mass changes are 0.3789 g / cm 2 , 0.6474 g / cm 2 , and 0.7865 g / cm 2 respectively; after 150 h of oxidation, the mass changes are 0.4025 g / cm 2 , 0.7589 g / cm 2 , and 0.8568 g / cm 2 respectively; after 200 h of oxidation, the mass changes are 0.5228 g / cm 2 , 0.8124 g / cm 2 , and 0.9795 g / cm 2 .

[0117] From the above experimental results, it can be seen that in sample 11, the content of AlCr powder in component C increases compared with sample 1, and the content of Cr powder decreases compared with sample 1, resulting in worse oxidation resistance than sample 1, which is also related to the Cr content; in sample 10, the content of AlCr powder in component C decreases compared with sample 1, and the content of Cr powder increases compared with sample 1, resulting in worse oxidation resistance than sample 1.

[0118] Perform electrochemical corrosion tests on samples 1, 11, and 12, and the results are shown in Table 4.

[0119] Table 4

[0120]

[0121] It can be seen from the data in Table 3 that the change in the Cr content has led to a decrease in the corrosion resistance of samples 11 and 12 to varying degrees.

[0122] Example 13

[0123] Prepare a nickel-based superalloy surface AlCr slurry penetrant with 46% of component A, 19% of component B, and 35% of component C by mass fraction;

[0124] Among them, component A includes 11% of MgO, 5% of MgCl 2 , 2.5% of AlCl 3 , 26% of H 3 PO 4 ; component B includes 7% of CrCl 3 , 6% of ammonia water, 16% of H 3 PO 4 ; component C includes 43% of AlCr powder, 5% of Cr powder, and the balance is spherical Al powder, where the content of Cr in the AlCr powder is 30%;

[0125] (2) After fully mixing the above component A, dilute it with distilled water and titrate. After dilution, the concentration of chlorine element is lower than 10 - 3 mol / L, the density of the component is 1.0 g / cm 3 , the pH value is 1.2, and the viscosity is 7×10 -3 Pas;

[0126] (3) After fully mixing the above component B, dilute it with distilled water and titrate, and let it stand for 60 h. The density of the component is 1.0 g / cm 3 , the pH value is 1.1, and the viscosity is 11×10 -3 Pas;

[0127] (4) Mix the above component C with a ball mill;

[0128] (5) Mix and stir component A, component B, and component C evenly;

[0129] (6) Dilute the above evenly mixed slurry with ultrapure water in a ratio of 1:10;

[0130] (7) Put the above evenly mixed slurry into a vacuum drying oven for drying at a temperature of 40°C and aging for 20 h to obtain an AlCr slurry penetrant.

[0131] Spray the above slurry onto the blades of a nickel-based superalloy aircraft engine by a conventional method. The defective rate is as low as 1%, no nodule phenomenon occurs, and the coating thickness is 80 - 90 μm.

[0132] The aluminizing agent prepared by the present invention solves the problems of easy nodule formation, uneven diffusion, and small black dots in the traditional penetrant during the high-temperature diffusion stage. At the same time, due to the addition of Cr element, the corrosion resistance and oxidation resistance of the coating are improved. The aluminizing agent of the present invention is applied to the blades of aerospace engines, greatly improving the service life of the blades of aerospace aircraft engines, reducing the defective rate, and greatly improving the economic efficiency and working efficiency.

[0133] 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 preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. An AlCr slurry penetrant for nickel-based superalloy surface Characterized in that: The AlCr slurry penetrant for nickel-based superalloy surface is composed of 40-50% of component A, 15-22% of component B and the balance of component C by mass fraction; Among them, the component A is a liquid, including 11-15% of MgO, 5-9% of MgCl 2 , 2.5-3.5% of AlCl 3 and 22-26% of H 3 PO 4 ; Component B is a liquid, including 7-11% of CrCl 3 , 6-8% of ammonia water and 12-16% of H 3 PO 4 ; Component C is a solid powder, including 39-43% of AlCr powder and 5-9% of Cr powder, and the balance is Al powder; the content of Cr in the AlCr powder is 30%.

2. The AlCr slurry penetrant for nickel-based superalloy surface according to claim 1 Characterized in that: The AlCr slurry penetrant for nickel-based superalloy surface, by mass fraction, includes 46% of component A, 19% of component B and 35% of component C.

3. The AlCr slurry penetrant for nickel-based superalloy surface according to claim 2 Characterized in that: The component A includes 11% of MgO, 5% of MgCl 2 , 2.5% of AlCl 3 and 26% of H 3 PO 4 ; the component B includes 7% of CrCl 3 , 6% of ammonia water and 16% of H 3 PO 4 ; the component C includes 43% of AlCr powder, 5% of Cr powder and 52% of Al powder.

4. A preparation method of the AlCr slurry penetrant for nickel-based superalloy surface according to any one of claims 1-3 Characterized in that: Including, Prepare Component A: Mix the MgO, MgCl 2 , AlCl 3 , H 3 PO 4 and dilute with distilled water; Prepare Component B: Mix the CrCl 3 , ammonia water, and H 3 PO 4 , and dilute with distilled water; Preparing component C: mixing the AlCr powder, Cr powder and Al powder; Stirring and drying: mixing component A, component B and component C evenly and finally drying to obtain the AlCr slurry penetrant for nickel-based superalloy surface of the present invention.

5. The preparation method of the AlCr slurry penetrant for nickel-based superalloy surface according to claim 4 Characterized in that: The formulated component A, the dilution, includes controlling the concentration of chlorine element to be lower than 10 -3 mol / L, controlling the density of the component to be 1.1~1.5 g / cm 3 , the pH value to be 0.8~2.6, and the viscosity to be 3~15×10 -3 Pas.

6. The preparation method of the AlCr slurry penetrant for nickel-based superalloy surface according to claim 4 Characterized in that: Regarding the formulated component B, mix the CrCl 3 , ammonia water, and H 3 PO 4 , and let it stand for more than 72 h. Control the density of the component to be 1.0 - 1.4 g / cm 3 , the pH value to be 0.1 - 1.2, and the viscosity to be 5 - 12×10 -3 Pas.

7. The preparation method of the AlCr slurry penetrant for nickel-based superalloy surface according to claim 4 Characterized in that: The step of mixing component A, component B and component C evenly includes mixing component A and component B evenly first, then adding component C and mixing, and diluting with ultrapure water in a ratio of 1:10.

Images