Refractory metal-ceramic composite environmental barrier coating bonding layer material

Abstract

The invention discloses a refractory metal-ceramic composite environmental barrier coating bonding layer material, which is prepared by mechanically crushing and uniformly mixing HfO2 and Nb, and the bonding layer material comprises the following components in percentage by mass: 60-90% of HfO2 and 10-40% of elementary substance Nb. The novel composite environment barrier bonding layer material is simple in raw material composition, good in uniformity and high in use temperature, and the service life of an environment barrier coating is effectively prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic coating material preparation, and in particular to a refractory metal-ceramic composite environmental barrier coating bonding layer material and a preparation method thereof. Background Art

[0002] In recent years, with the continuous development of the aviation industry, the gas temperature in gas turbines has reached 1500-1700℃, and ceramic matrix composites (CMCs) have replaced nickel-based high-temperature alloys to become a new type of high-temperature structural material. At the same time, the long-term service temperature of hot end components has exceeded 1400℃, and environmental barrier coatings (EBCs) must be applied to protect them. In order to enhance the adhesion between EBCs and the substrate and reduce the thermal expansion mismatch between the substrate and the environmental barrier coating, a bonding layer must be used between the environmental barrier coating and the ceramic matrix composite. Therefore, the bonding layer material of the environmental barrier coating and its preparation method have become one of the research hotspots of high-temperature thermal protection materials today.

[0003] The existing environmental barrier coating bonding layer materials are mainly pure Si bonding layers and Si-containing composite bonding layers, such as Si-HfO2 series materials, Yb-Gd-Si ternary alloy series materials, etc. By reasonably selecting components and ratios, bonding layer materials with matching thermal expansion coefficients can be obtained.

[0004] As the engine operating temperature increases, the turbine front inlet temperature will exceed the melting point of Si. The operating temperature exceeding the melting point of Si will cause Si to penetrate into the substrate, causing the bonding layer to disappear, and then the coating to fail, which is not conducive to protecting the substrate. Summary of the invention

[0005] Based on the above deficiencies of the prior art, the technical problem solved by the present invention is to provide an environmental barrier coating bonding layer material which does not contain Si, has a thermal expansion coefficient matching that of a substrate and has an operating temperature exceeding 1400°C.

[0006] In order to solve the above technical problems, the present invention provides a method for preparing a new type of refractory metal-ceramic composite ceramic block product material, which is characterized by comprising the following steps:

[0007] (1) drying HfO2 and metal Nb and mixing them, ball milling to obtain a uniform slurry, and then passing the slurry into a spray granulation tower for spray drying to obtain a mixed powder;

[0008] (2) The mixed powder is placed in a plasma sintering furnace and a composite synthetic block is obtained by rapid sintering.

[0009] As a preferred embodiment of the above technical solution, the refractory metal-ceramic novel composite ceramic block product material provided by the present invention further includes part or all of the following technical features:

[0010] As an improvement of the above technical solution, in terms of mass percentage, the HfO2 is 60% to 90%, and the metal Nb is 10% to 40%.

[0011] As a preferred embodiment of the above technical solution, the sintering temperature is 1300-1500° C. and the holding pressure is 40 MPa.

[0012] The present invention also includes a method for preparing a refractory metal-ceramic composite environmental barrier coating bonding layer material, comprising the following steps:

[0013] (1) adding deionized water and a binder to the mixed powder to prepare a slurry and then ball milling, then passing the slurry into a spray granulation tower for spray granulation, and obtaining a spherical powder after screening;

[0014] (2) The screened spherical powder is sprayed onto the surface of a pretreated SiC ceramic sheet, SiC / SiCf composite material or other substrate using plasma spraying technology to obtain a coating with a high melting point.

[0015] As a preferred embodiment of the above technical solution, the particle size of the spherical powder after screening is 32 to 125 μm.

[0016] The present invention also provides a Si-free, high-melting-point refractory metal-ceramic new composite environmental barrier bonding layer material, wherein the refractory metal-ceramic new composite environmental barrier bonding layer material is made by mixing two base materials through mechanical crushing; the base materials include HfO2 and metal Nb.

[0017] As a preferred embodiment of the above technical solution, the HfO2 is 60% to 90% and the metal Nb is 10% to 40% by mass.

[0018] As a preferred embodiment of the above technical solution, the Si-free, high-melting-point refractory metal-ceramic new composite environmental barrier bonding layer material is prepared by any of the above methods.

[0019] As a preferred embodiment of the above technical solution, the new refractory metal-ceramic composite environmental barrier bonding layer material that does not contain Si and has a high melting point, as described above, since the melting point of HfO2 is 2758°C and the melting point of Nb is 2477°C, the melting point of the doped mixture of the two is generally between the two, so the operating temperature of the new refractory metal-ceramic composite environmental barrier bonding layer material is ≥1400°C.

[0020] The present invention also requires the use of a new Si-free, high-melting-point refractory metal-ceramic composite environmental barrier bonding layer material, wherein the new Si-free, high-melting-point refractory metal-ceramic composite environmental barrier bonding layer material is used as a coating for thermal protection of aerospace components.

[0021] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0022] (1) The novel refractory metal-ceramic composite environmental barrier bonding layer material of the present invention has a simple raw material composition, a simple and easy-to-control preparation method, and is prepared by mixing HfO2 and Nb in a certain proportion.

[0023] (2) The present invention utilizes two high melting point materials to form a new type of refractory metal-ceramic composite environmental barrier bonding layer, which can effectively increase the service temperature of the environmental barrier coating. The coating is widely used in thermal protection of aerospace components.

[0024] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following is a detailed description in combination with the preferred embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings of the embodiment are briefly introduced below.

[0026] Figure 1 It is a structural diagram of the bonding layer of the bonding layer material of the refractory metal-ceramic composite environmental barrier coating of the present invention.

[0027] Figure 2 The thermal expansion coefficient curves of the HfO2-Nb coating prepared in Example 1 and the bulk materials prepared in Examples 4 and 5 in the temperature range of 200-1400°C. DETAILED DESCRIPTION

[0028] The specific implementation modes of the present invention are described in detail below, which is a part of this specification. The principles of the present invention are explained through examples. Other aspects, features and advantages of the present invention will become clear through the detailed description.

[0029] The technical solution of the present invention is as follows:

[0030] A refractory metal-ceramic composite environmental barrier coating bonding layer material, the material composition includes simple substance Nb and HfO2; in terms of mass percentage, the HfO2 is 60% to 90%, and the simple substance Nb is 10% to 40%.

[0031] The second object of the present invention is to provide a method for preparing a refractory metal-ceramic composite ceramic block product, the preparation method comprising the following steps:

[0032] (1) The material powders are mixed in a certain proportion, ball-milled for 72 hours to obtain a uniformly mixed slurry, spray-granulated in a spray granulation tower, and sieved to obtain a mixed powder.

[0033] (2) Rapid sintering is performed in a plasma sintering furnace at a sintering temperature of 1350°C and a holding pressure of 40 MPa to obtain a composite block product.

[0034] The third object of the present invention is to provide a method for preparing a refractory metal-ceramic composite environmental barrier bonding layer coating material, the preparation method comprising the following steps:

[0035] (1) Adding the insoluble metal-ceramic composite powder to deionized water, a binder, etc. in proportion, and then ball milling, spray granulation, and sieving to obtain a composite powder material.

[0036] (2) The spherical composite powder prepared above is sprayed on the pretreated SiC ceramic sheet, SiC / SiC f A new type of refractory metal-ceramic composite environmental barrier bonding layer is prepared on the surface of a substrate such as a composite material.

[0037] Example 1

[0038] A novel refractory metal-ceramic composite environmental barrier bonding layer is composed of 90wt.% HfO2 and 10wt.% single substance Nb.

[0039] The above-mentioned bonding layer preparation process is as follows:

[0040] (1) Take the mixed powder in the above proportion, add a certain amount of deionized water, zirconium balls and an appropriate amount of binder into a ball mill, and then place the ball mill in a ball mill at a speed of 36 r / min for 72 hours.

[0041] (2) The ball-milled slurry was filtered through a 200-mesh screen and passed into a spray granulation tower for granulation. The spray granulation tower parameters were set as follows: the air inlet temperature was 220°C, the air outlet temperature was 110°C, and the atomizer frequency was 22 Hz.

[0042] (3) The granulated dry powder is sieved to obtain a bonding layer powder of 32-125 μm.

[0043] According to the test, in the temperature range of 200-1400°C, the average thermal expansion coefficient of the novel refractory metal-ceramic composite environmental barrier bonding layer of this embodiment is 6.48×10 -6 K -1 .

[0044] Example 2

[0045] A novel refractory metal-ceramic composite environmental barrier bonding layer is composed of 80wt.% HfO2 and 20wt.% single substance Nb.

[0046] The above-mentioned bonding layer preparation process is as follows:

[0047] (1) Take the mixed powder in the above proportion, add a certain amount of deionized water, zirconium balls and an appropriate amount of binder into a ball mill, and then place the ball mill in a ball mill at a speed of 36 r / min for 72 hours.

[0048] (2) The ball-milled slurry was filtered through a 200-mesh screen and passed into a spray granulation tower for granulation. The spray granulation tower parameters were set as follows: the air inlet temperature was 220°C, the air outlet temperature was 110°C, and the atomizer frequency was 22 Hz.

[0049] (3) The granulated dry powder is sieved to obtain a bonding layer powder of 32-125 μm.

[0050] Example 3

[0051] A novel refractory metal-ceramic composite environmental barrier bonding layer is composed of 70wt.% HfO2 and 30wt.% single substance Nb.

[0052] The above-mentioned bonding layer preparation process is as follows:

[0053] (1) Take the mixed powder in the above proportion, add a certain amount of deionized water, zirconium balls and an appropriate amount of binder into a ball mill, and then place the ball mill in a ball mill at a speed of 36 r / min for 72 hours.

[0054] (2) The ball-milled slurry was filtered through a 200-mesh screen and passed into a spray granulation tower for granulation. The spray granulation tower parameters were set as follows: the air inlet temperature was 220°C, the air outlet temperature was 110°C, and the atomizer frequency was 22 Hz.

[0055] (3) The granulated dry powder is sieved to obtain a bonding layer powder of 32-125 μm.

[0056] Example 4

[0057] A new type of refractory metal-ceramic composite ceramic block product material, the block material consists of 70% HfO2 and 30% metal Nb.

[0058] The process flow of preparing the above block material is as follows:

[0059] The above raw materials were mixed in different mass percentages, then ball-milled for 72 hours, dried and ground to obtain mixed powder. Then, Nb-HfO2 ceramic blocks were prepared by spark plasma sintering. The spark plasma sintering experimental parameters were as follows: room temperature -600°C, heating rate 150°C, pressure 40MPa; 600-1200°C, heating rate 100°C, pressure 40MPa; 1200-1400°C, heating rate 50°C, pressure 40MPa.

[0060] According to the test, within the temperature range of 200-1400°C, the average thermal expansion coefficient of the novel refractory metal-ceramic composite ceramic block of this embodiment is 7.40×10 -6 K -1 .

[0061] Example 5

[0062] A new type of refractory metal-ceramic composite ceramic block product material, the block material consists of 80% HfO2 and 20% metal Nb.

[0063] The process flow of preparing the above block material is as follows:

[0064] The above raw materials were mixed in different mass percentages, then ball-milled for 72 hours, dried and ground to obtain mixed powder. Then, Nb-HfO2 ceramic blocks were prepared by spark plasma sintering. The spark plasma sintering experimental parameters were as follows: room temperature -600°C, heating rate 150°C, pressure 40MPa; 600-1200°C, heating rate 100°C, pressure 40MPa; 1200-1400°C, heating rate 50°C, pressure 40MPa.

[0065] According to the test, within the temperature range of 200-1400°C, the average thermal expansion coefficient of the novel refractory metal-ceramic composite ceramic block of this embodiment is 6.94×10 -6 K -1 .

[0066] The raw materials listed in the present invention, as well as the upper and lower limits and interval values ​​of the raw materials of the present invention, and the upper and lower limits and interval values ​​of the process parameters (such as temperature, time, etc.) can all realize the present invention, and the embodiments are not listed one by one here.

[0067] The above is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and changes can be made without departing from the principle of the present invention, and these improvements and changes are also regarded as the protection scope of the present invention.

Claims

1. A method for preparing a new type of refractory metal-ceramic composite ceramic block product material, characterized in that: The following steps are included: (1) drying HfO2 and metal Nb and mixing them, ball milling to obtain a uniform slurry, and then passing the slurry into a spray granulation tower for spray drying to obtain a mixed powder; (2) The mixed powder is placed in a plasma sintering furnace and a composite synthetic block is obtained by rapid sintering.

2. The method for preparing the novel refractory metal-ceramic composite ceramic block product material according to claim 1, characterized in that: In terms of mass percentage, the HfO2 is 60% to 90%, and the metal Nb is 10% to 40%.

3. The method for preparing the novel refractory metal-ceramic composite ceramic block product material according to claim 1, characterized in that: The sintering temperature is 1300-1500° C., and the holding pressure is 40 MPa.

4. A method for preparing a refractory metal-ceramic composite environmental barrier coating bonding layer material, characterized in that: The steps include: (1) adding deionized water and a binder to the mixed powder to prepare a slurry and then ball milling, then passing the slurry into a spray granulation tower for spray granulation, and obtaining a spherical powder after screening; (2) The screened spherical powder is sprayed onto the surface of a pretreated SiC ceramic sheet, SiC / SiCf composite material or other substrate using plasma spraying technology to obtain a coating with a high melting point.

5. The method for preparing the refractory metal-ceramic composite environmental barrier coating bonding layer material according to claim 4, characterized in that: The particle size of the spherical powder after screening is 32-125 μm.

6. A new type of Si-free, high-melting-point refractory metal-ceramic composite environmental barrier bonding layer material, characterized in that: The novel refractory metal-ceramic composite environmental barrier bonding layer material is prepared by mixing two base materials through mechanical crushing; the base materials include HfO2 and metal Nb.

7. The Si-free, high-melting-point refractory metal-ceramic novel composite environmental barrier bonding layer material according to claim 6, characterized in that: In terms of mass percentage, the HfO2 is 60% to 90%, and the metal Nb is 10% to 40%.

8. The Si-free, high-melting-point refractory metal-ceramic novel composite environmental barrier bonding layer material according to claim 6, characterized in that: The Si-free, high-melting-point refractory metal-ceramic novel composite environmental barrier bonding layer material is prepared by any method of claims 1-5.

9. The Si-free, high-melting-point refractory metal-ceramic novel composite environmental barrier bonding layer material according to any one of claims 4 to 8, characterized in that: The use temperature of the new refractory metal-ceramic composite environmental barrier bonding layer material is ≥1400°C.

10. Application of a new type of Si-free, high-melting-point refractory metal-ceramic composite environmental barrier bonding layer material, characterized in that: The Si-free, high-melting-point refractory metal-ceramic novel composite environmental barrier bonding layer material is used as a coating for thermal protection of aerospace components.

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