Single-phase beta-NiAl bonding layer and preparation method thereof
阅读说明：本技术 一种单相β-NiAl粘结层及其制备方法 (Single-phase beta-NiAl bonding layer and preparation method thereof ) 是由 张恒 张皓博 刘原 宫声凯 于 2021-07-14 设计创作，主要内容包括：本发明属于热障涂层技术领域,具体涉及一种单相β-NiAl粘结层及其制备方法。本发明提供的单相β-NiAl粘结层的制备方法,包括以下步骤：提供含有活性元素的β-γ’双相镍铝合金；将所述含有活性元素的β-γ’双相镍铝合金在基体表面制备双相γ’-β粘结层；对所述双相γ’-β粘结层进行渗铝处理,得到单相β-NiAl粘结层。本发明提供的制备方法无需熔炼制备单相β-NiAl合金,在基体表面制备双相γ’-β粘结层后通过渗铝处理的方式得到单相β-NiAl粘结层,本发明提供的制备方法大大提高了制备单相β-NiAl粘结层的成功率。(The invention belongs to the technical field of thermal barrier coatings, and particularly relates to a single-phase beta-NiAl bonding layer and a preparation method thereof. The preparation method of the single-phase beta-NiAl bonding layer provided by the invention comprises the following steps: providing a beta-gamma' -biphase nickel-aluminum alloy containing active elements; preparing a two-phase gamma '-beta bonding layer on the surface of a substrate by using the beta-gamma' -two-phase nickel-aluminum alloy containing the active elements; and carrying out aluminizing treatment on the two-phase gamma' -beta bonding layer to obtain the single-phase beta-NiAl bonding layer. The preparation method provided by the invention does not need to prepare the single-phase beta-NiAl alloy by smelting, and the single-phase beta-NiAl bonding layer is obtained by an aluminizing treatment mode after the double-phase gamma' -beta bonding layer is prepared on the surface of the matrix.)
1. A preparation method of a single-phase beta-NiAl bonding layer comprises the following steps:
providing a beta-gamma' -biphase nickel-aluminum alloy containing active elements;
preparing a two-phase gamma '-beta bonding layer on the surface of a substrate by using the beta-gamma' -two-phase nickel-aluminum alloy containing the active elements;
and carrying out aluminizing treatment on the two-phase gamma' -beta bonding layer to obtain the single-phase beta-NiAl bonding layer.
2. The preparation method according to claim 1, wherein the aluminizing treatment is chemical vapor deposition, and the temperature of the aluminizing treatment is 950-1050 ℃; the time is 3-10 h.
3. The method of claim 1, wherein the beta-gamma' -duplex nickel-aluminum alloy containing the active element is prepared by the method comprising the steps of:
smelting the active elements, a nickel source and an aluminum source, and then casting to obtain a cast ingot;
and annealing the cast ingot to obtain the beta-gamma' -biphase nickel-aluminum alloy containing the active elements.
4. The method according to claim 3, wherein the annealing treatment is carried out at 1200-1400 ℃ for 22-26 hours.
5. The method of claim 1, wherein the dual phase γ' - β bonding layer is formed by multi-arc ion plating or physical vapor deposition.
6. The method according to claim 5, wherein the arc current of the multi-arc ion plating is 160 to 200A, the bias voltage is 10 to 30V, and the degree of vacuum is 1X 10-3～9×10-3Pa, and the temperature of the matrix in the multi-arc ion plating process is 300-500 ℃.
7. The method according to claim 5, wherein the physical vapor deposition conditions are: the vacuum degree of the deposition chamber is 1 × 10-5～1×10-3Pa; the rotation rate of the substrate is 8-10 r/min, and the temperature of the substrate is 700-800 ℃; the electron beam current is 1.2-1.5A, and the electron beam voltage is 17-19 kV.
8. The method of claim 1, wherein the substrate comprises N5, IC21, DD6, or IC31 nickel-based single-crystal superalloys.
9. The single-phase beta-NiAl bonding layer prepared by the preparation method of any one of claims 1 to 8, which is characterized by comprising the following components in percentage by atom:
Al 30～60at.％；
0.02-0.26 at.% of active elements;
the balance of Ni.
10. The single phase β -NiAl bonding layer of claim 9, wherein the reactive element comprises one or more of a rare earth element, Hf, Zr, and Ti.
Technical Field
The invention belongs to the technical field of thermal barrier coatings, and particularly relates to a single-phase beta-NiAl bonding layer and a preparation method thereof.
Background
Thermal barrier coatings are mainly used for hot end components of aircraft engines and generally consist of two parts: a ceramic layer for insulating the alloy component and a bonding layer for resisting high-temperature oxidation corrosion. The bonding layer is positioned between the metal substrate and the ceramic layer, so that the thermal expansion difference between the coating and the substrate is improved, the thermal stress of a system is relieved, and the oxidation of oxygen to the substrate is hindered.
beta-NiAl is a long-range ordered intermetallic compound, and due to the characteristic of coexistence of metallic bonds and covalent bonds, the melting point Tm of Ni50Al50 is 1638 ℃, which has the prerequisite for preparing the bonding layer of the ultrahigh-temperature thermal barrier coating. Furthermore, Ni50Al50 has a relatively low density (5.9 g/cm)3) And a high young's modulus (240GPa), and therefore has been attracting attention as a material to be used as a material for high-temperature devices for a long time. beta-NiAl has excellent high temperature oxidation resistance, and the high temperature oxidation resistance is mainly based on the capability of forming single complete alpha-Al with low growth rate2O3And (5) oxidizing the film. The bonding layer of the beta-NiAl system is expected to be in a higher temperature environment (>1150 ℃ C.). However, the beta-NiAl directly used as the bonding layer has some defects, a beta-NiAl coating forms a large number of cavities during high-temperature oxidation, the cavities limit the contact between metal and a film at the interface of the metal and an oxide film, and the interface cavities are important factors influencing the adhesion. Therefore, the NiAl coating needs to be modified to prepare a novel thermal barrier coating bonding layer material.
The addition of a suitable amount of active elements (all rare earth elements and 20 elements of Hf, Zr, and Ti) to β -NiAl improves the adhesion of the oxide film and reduces the growth rate of the oxide film by preventing the internal diffusion of O elements and the external diffusion of Al elements during the high-temperature oxidation process, reducing interfacial voids, and the like, which is called the active element effect (REE).
At present, the preparation of the NiAl bonding layer doped with the active element usually adopts the method of directly depositing the single-phase beta-NiAl bonding layer containing the active element on an alloy substrate, but because the method needs to use the single-phase beta-NiAl alloy containing the active element as a target material for physical vapor deposition or multi-arc ion plating, the single-phase beta-NiAl alloy containing the active element is very brittle and difficult to melt, and is easy to break off in the machining process, and the preparation success rate is low.
Disclosure of Invention
In view of the above, the invention provides a preparation method of a single-phase beta-NiAl bonding layer, and the preparation method provided by the invention does not need to prepare a single-phase beta-NiAl alloy in advance, so that the success rate of preparing the single-phase beta-NiAl bonding layer is greatly improved.
In order to solve the technical problem, the invention provides a preparation method of a single-phase beta-NiAl bonding layer, which comprises the following steps:
providing a beta-gamma' -biphase nickel-aluminum alloy containing active elements;
preparing a two-phase gamma '-beta bonding layer on the surface of a substrate by using the beta-gamma' -two-phase nickel-aluminum alloy containing the active elements;
and carrying out aluminizing treatment on the two-phase gamma' -beta bonding layer to obtain the single-phase beta-NiAl bonding layer.
Preferably, the aluminizing treatment mode is chemical vapor deposition, and the temperature of the aluminizing treatment is 950-1050 ℃; the time is 3-10 h.
Preferably, the preparation method of the beta-gamma' -dual-phase nickel-aluminum alloy containing the active elements comprises the following steps:
smelting the active elements, a nickel source and an aluminum source, and then casting to obtain a cast ingot;
and annealing the cast ingot to obtain the beta-gamma' -biphase nickel-aluminum alloy containing the active elements.
Preferably, the annealing treatment temperature is 1200-1400 ℃, and the time is 22-26 h.
Preferably, the manner of preparing the dual phase γ' - β bonding layer comprises multi-arc ion plating or physical vapor deposition.
Preferably, the arc current of the multi-arc ion plating is 160-200A, the bias voltage is 10-30V, and the vacuum degree is 1 multiplied by 10-3～9×10-3Pa, wherein the temperature of the matrix in the multi-arc ion plating process is 300-500 ℃;
preferably, the physical vapor deposition conditions are as follows: the vacuum degree of the deposition chamber is 1 × 10-5～1×10-3Pa; the rotation rate of the substrate is 8-10 r/min, and the temperature of the substrate is 700-800 ℃; the electron beam current is 1.2-1.5A, and the electron beam voltage is 17-19 kV.
Preferably, the substrate comprises N5 nickel-based single crystal superalloy, IC21 nickel-based single crystal superalloy, DD6 nickel-based single crystal superalloy, or IC31 nickel-based single crystal superalloy.
The invention also provides a single-phase beta-NiAl bonding layer prepared by the preparation method in the technical scheme, and the single-phase beta-NiA bonding layer comprises the following components in atomic percentage:
Al 30～60at.％；
0.02-0.26 at.% of active elements;
the balance of Ni.
Preferably, the active element comprises one or more of rare earth elements, Hf, Zr and Ti.
The invention provides a preparation method of a single-phase beta-NiAl bonding layer, which comprises the following steps: providing a beta-gamma' -biphase nickel-aluminum alloy containing active elements; preparing a two-phase gamma '-beta bonding layer on the surface of a substrate by using the beta-gamma' -two-phase nickel-aluminum alloy containing the active elements; and carrying out aluminizing treatment on the two-phase gamma' -beta bonding layer to obtain the single-phase beta-NiAl bonding layer. The preparation method provided by the invention does not need to prepare the single-phase beta-NiAl alloy by smelting, and the single-phase beta-NiAl bonding layer is obtained by an aluminizing treatment mode after the double-phase gamma' -beta bonding layer is prepared on the surface of the matrix.
Drawings
FIG. 1 is a diagram of a sample object containing a single phase β -NiAl bonding layer;
FIG. 2 is an SEM image of a dual phase gamma' -beta bonding layer prepared in example 1;
FIG. 3 is an SEM image of a single phase beta-NiAl bond layer prepared in example 1;
FIG. 4 is a plot of the mass change points for different oxidation treatment times for samples containing single phase β -NiAl bond layers prepared in example 1.
Detailed Description
The invention provides a preparation method of a single-phase beta-NiAl bonding layer, which comprises the following steps:
providing a beta-gamma' -biphase nickel-aluminum alloy containing active elements;
preparing a two-phase gamma '-beta bonding layer on the surface of a substrate by using the beta-gamma' -two-phase nickel-aluminum alloy containing the active elements;
and carrying out aluminizing treatment on the two-phase gamma' -beta bonding layer to obtain the single-phase beta-NiAl bonding layer.
The invention provides a beta-gamma' -biphase nickel-aluminum alloy containing active elements. In the present invention, the active element preferably includes one or more of rare earth elements, Hf, Zr, and Ti, more preferably Hf and Zr. When the active elements comprise more than two specific substances, the atomic ratio of the specific substances is not particularly limited, and any ratio can be adopted; in the embodiment of the invention, the active elements are Hf and Zr, and the atomic ratio of the Hf to the Zr is 1: 1. In the present invention, the active element is preferably provided in the form of a simple metal.
In the present invention, the method for preparing the beta-gamma' -biphase nickel-aluminum alloy containing the active element preferably comprises the following steps:
smelting the active elements, a nickel source and an aluminum source, and then casting to obtain a cast ingot;
and annealing the cast ingot to obtain the beta-gamma' -biphase nickel-aluminum alloy containing the active elements.
According to the invention, the active elements, the nickel source and the aluminum source are smelted and cast to obtain the ingot.
In the present invention, the nickel source is preferably a nickel block, and the aluminum source is preferably an aluminum block. In the invention, the atomic percentage of the active element in the ingot is preferably 0.04 to 0.24 at.%, and more preferably 0.05 to 0.15 at.%. In the invention, the aluminum source accounts for 25 to 45 at% of the ingot, preferably 30 to 40 at%.
In the present invention, the method further preferably comprises, before the melting: and sequentially cleaning and drying the active elements, the nickel source and the aluminum source. In the present invention, the cleaning is preferably ultrasonic cleaning, and the solvent for ultrasonic cleaning is preferably acetone; the ultrasonic cleaning time is preferably 25-35 min, and more preferably 30 min; the power of the ultrasound is not specially limited, and the ultrasound can be cleaned. In the present invention, the temperature and time for the drying are not particularly limited as long as the solvent on the surfaces of the active element, the nickel source and the aluminum source can be removed.
In the present invention, the melting is preferably vacuum melting, and the degree of vacuum of the vacuum melting is preferably 1 × 10-5～1×10-4Pa, more preferably 0.51X 10-4～0.81×10-4Pa. The temperature and time of the vacuum melting are not particularly limited, as long as the melting can be achieved. In the smelting process, the turning is preferably performed, and the number of the turning is preferably 4-8 times, and more preferably 5-6 times. The invention can ensure that the components in the ingot are uniformly distributed through the turning. The vacuum melting device is not particularly limited, and the vacuum melting device can be a conventional device in the field, and an arc melting furnace is adopted for vacuum melting in the embodiment of the invention.
In the invention, the annealing treatment temperature is preferably 1200-1400 ℃, and more preferably 1250-1300 ℃; the time is preferably 22 to 26 hours, and more preferably 24 to 25 hours. In the present invention, the annealing treatment preferably further includes: and cooling the product subjected to the annealing treatment to room temperature, wherein the room temperature is preferably 20-35 ℃, and more preferably 25-30 ℃.
The beta-gamma '-biphase nickel-aluminum l alloy containing the active elements is used for preparing a biphase gamma' -beta bonding layer on the surface of a matrix. In the present invention, the substrate preferably comprises N5 nickel-based single crystal superalloy, IC21 nickel-based single crystal superalloy, DD6 nickel-based single crystal superalloy, or IC31 nickel-based single crystal superalloy, and more preferably, IC21 nickel-based single crystal superalloy. The shape and size of the substrate are not particularly limited, and can be set as required.
In the present invention, the manner of preparing the bi-phase γ' - β l bonding layer preferably includes multi-arc ion plating or physical vapor deposition, more preferably multi-arc ion plating. In the invention, the arc current of the multi-arc ion plating is preferably 160-200A, and more preferably 180-190A; the bias voltage is preferably 10-30V, more preferably 20-25V; the degree of vacuum is preferably 1X 10-3～9×10-3Pa, more preferably 5X 10-3Pa; the temperature of the substrate in the multi-arc ion plating process is preferably 300-500 ℃, and more preferably 400-450 ℃.
Before the invention adopts multi-arc ion plating to prepare the double-phase gamma' -beta bonding layer, the invention also preferably comprises the following steps: and carrying out sand blasting pretreatment on the surface of the matrix and then machining to enable the shape of the matrix to adapt to physical vapor deposition equipment. In the present invention, the grit for the blast pretreatment is preferably 20 mesh; the pressure of the sand blasting treatment is preferably 0.1-0.5 MPa, and more preferably 0.2-0.4 MPa. In the present invention, the machining preferably further includes: and sequentially polishing and chamfering the machined substrate. In the present invention, the roughness of the substrate surface after the polishing treatment is preferably Ra <0.8, and the polishing mode is not particularly limited as long as the roughness can be achieved. The chamfering treatment of the present invention is not particularly limited, and may be performed in a manner conventional in the art. The invention performs the chamfering process to avoid the occurrence of edge effect.
In the present invention, it is preferable that the chamfering process further includes: and cleaning the chamfered basal body. In the invention, the cleaning is preferably carried out by ultrasonic cleaning in absolute ethyl alcohol and acetone in sequence, and the time of ultrasonic cleaning in absolute ethyl alcohol and the time of ultrasonic cleaning in acetone are independent, preferably 13-20 min, and more preferably 15-18 min. In the present invention, the cleaning preferably further comprises: and drying the cleaned matrix. In the invention, the drying temperature is preferably 70-200 ℃, and more preferably 80-150 ℃; the time is preferably 1 to 2 hours, and more preferably 1.5 to 1.8 hours.
In the present invention, the physical vapor deposition conditions are preferably: the vacuum degree of the deposition chamber is preferably 1 × 10-5～1×10-3Pa, more preferably 0.5X 10-4～1×10-4Pa; the rotation rate of the substrate is preferably 8 to 10r/min, and more preferably 9 r/min; the substrate temperature is preferably 700-800 ℃, and more preferably 750-780 ℃; the electron beam current is preferably 1.2-1.5A, and more preferably 1.3-1.4A; the electron beam voltage is preferably 17 to 19kV, and more preferably 17.5 to 18 kV. In the present invention, the substrate is a vapor deposited sample.
Before the preparation of the biphase gamma' -beta bonding layer by adopting physical vapor deposition, the invention also preferably comprises the following steps: and machining the substrate to enable the shape of the substrate to be suitable for physical vapor deposition equipment. In the invention, the thickness of the prepared biphase gamma' -beta bonding layer is preferably 30-100 μm, and more preferably 45-70 μm.
After the biphase gamma '-beta bonding layer is obtained, the biphase gamma' -beta bonding layer is aluminized to obtain the single-phase beta-NiAl bonding layer. In the invention, the preferred mode of aluminizing treatment is chemical vapor deposition, and the preferred temperature of aluminizing treatment is 950-1050 ℃, and more preferably 1000 ℃; the time is preferably 3 to 10 hours, and more preferably 6 to 8 hours. In the present invention, the raw materials for chemical vapor deposition preferably include an aluminum source, a filler and an activator, and the aluminum source preferably includes aluminum powder or an aluminum alloy; the aluminum alloy includes a NiAl alloy, a CoAl alloy, or a CrAl alloy, and more preferably a NiAl alloy.
The invention also provides a single-phase beta-NiAl bonding layer prepared by the preparation method in the technical scheme, and the single-phase beta-NiA bonding layer comprises the following components in atomic percentage:
Al 30～60at.at.％；
0.02-0.26 at.% of active elements;
the balance of Ni.
In the invention, the single-phase beta-NiA bonding layer comprises 30-60 at.% Al, preferably 30-40 at.%, in terms of atomic percentage.
In the invention, the single-phase beta-NiA bonding layer comprises 0.05 to 2.00 at.% of active component, preferably 0.05 to 0.15 at.%, calculated by atomic percentage. In the present invention, the active component preferably includes one or more of rare earth elements, Hf, Zr, and Ti, more preferably one or more of Hf, Zr, and Ti; hf and Zr are more preferable. When the rare earth elements comprise more than two of the specific substances, the atomic ratio of the specific substances is not particularly limited, and any ratio can be adopted. In the invention, when the active elements are Hf and Zr, the atomic percentage content of Hf is preferably 0.025 to 1 at.%, more preferably 0.05 to 0.08 at.%; the content of Zr in atomic percentage is preferably 0.025-1 at.%, and more preferably 0.05-0.08 at.%.
In the present invention, the single-phase β -NiA bonding layer further includes the balance Ni in atomic percentage.
In the invention, the thickness of the single-phase beta-NiAl bonding layer is preferably 30-60 μm, and more preferably 40-50 μm.
The single-phase beta-NiA bonding layer provided by the invention has a flat and compact surface, an oxidation film generated on the surface of the bonding layer is straight, and the oxidation resistance of the bonding layer can reach the complete oxidation resistance standard in GB/T13303.91 (method for measuring the oxidation resistance of steel) and HB5258-2000 (method for measuring and testing the oxidation resistance of steel and high-temperature alloy).
In order to further illustrate the present invention, the following embodiments are described in detail, but they should not be construed as limiting the scope of the present invention.
The weighing means in the examples are electronic balances (model CPA225D, Sartorius, precision 10)-5g)。
Example 1
Preparing a matrix:
cutting the IC21 alloy into a cylindrical sample with the specification of 10mm in diameter and 3mm in thickness by using a wire cutting method, and respectively forming a hole with the diameter of 1mm at each end of the diameter of the sample so as to hang the sample on a bracket when preparing a coating; carrying out sand blasting pretreatment on the cut matrix sample (the mesh number of sand for sand blasting is 20 meshes, the pressure is 0.2MPa), and then sequentially polishing the matrix sample by using No. 320, No. 600 and No. 800 water-milled sand paper to ensure that the surface roughness Ra of the matrix sample is less than 0.8, and completely chamfering the edge into a fillet; ultrasonically cleaning the polished substrate sample for 15min by using absolute ethyl alcohol and acetone in sequence; drying the cleaned matrix sample for 2h at 80 ℃; obtaining a matrix;
preparing a target material:
respectively ultrasonically cleaning a nickel block, an aluminum block, a hafnium block and a zirconium block in acetone for 30min and then drying; putting the dried nickel block, aluminum block, hafnium block and zirconium block into an electric arc melting furnace for vacuum melting (the vacuum degree is 10)-4Pa), turning 4 times in the smelting process, wherein the atom percentage of the aluminum blocks is 30 at.%, the atom percentage of the hafnium blocks is 0.05 at.%, the atom percentage of the zirconium blocks is 0.05 at.%, and the atom percentage of the nickel blocks is 69.9 at.%; casting after vacuum melting to obtain a cast ingot;
annealing the cast ingot at 1300 ℃ for 24h, and cooling to 30 ℃ to obtain a beta-gamma' -biphase NiAlHfZr alloy; machining the beta-gamma' biphase NiAlHfZr alloy into a disc-shaped target material with the roughness of 0.5 so as to adapt to multi-arc ion plating equipment;
preparing a bonding layer:
the beta-gamma' biphase NiAlHfZr alloy is subjected to multi-arc ion plating (the current is 180A, the bias voltage is 25V, and the vacuum degree is 5 multiplied by 10) on the surface of a substrate at the temperature of 400 DEG C-3Pa) to obtain a biphasic gamma' -beta tie layer having an average thickness of 50 μm;
and (3) aluminizing the two-phase gamma' -beta bonding layer by adopting chemical vapor deposition (1000 ℃, 8h) to obtain the single-phase beta-NiAl bonding layer.
FIG. 1 is a diagram of a sample object containing a single phase β -NiAl bonding layer.
Scanning electron microscope detection is carried out on the prepared biphase gamma' -beta bonding layer to obtain an SEM picture as shown in figure 2. As can be seen from fig. 2, the thickness of the two-phase γ ' - β adhesive layer is 52.48 μm, and the two-phase γ ' - β adhesive layer contains two phases with different contrast, wherein the dark gray color is the γ ' phase and the light gray color is the β phase.
Scanning electron microscope detection is carried out on the prepared single-phase beta-NiAl bonding layer to obtain an SEM picture as shown in figure 3. From fig. 3, it can be seen that the thickness of the single-phase β -NiAl bonding layer is 48.15 μm, and the single-phase β -NiAl bonding layer contains a uniform contrast β single phase.
The prepared sample containing the single-phase beta-NiAl bonding layer is subjected to oxidation treatment at 1200 ℃ for 100h according to the oxidation resistance measurement test method of HB 5258-2000-steel and high-temperature alloy. The quality of the samples after different oxidation treatment times is given in table 1.
TABLE 1 quality of the samples after different oxidation treatment times
Time h of oxidation treatment
Sample weight g
0
3.66720
1
3.66800
4
3.66856
7
3.66896
10
3.66942
20
3.67012
30
3.67068
40
3.67116
50
3.67156
75
3.67180
100
3.67200
A dot line plot is plotted from the data in table 1, as shown in fig. 4.
It can be seen from Table 1 and FIG. 4 that the change in mass of the sample after oxidation treatment for 50 hours and 100 hours was 0.9348g/m2From HB5258-2000, it can be known that the single-phase beta-NiAl bonding layer prepared by the preparation method provided by the invention reaches the standard of complete oxidation resistance at 1200 ℃.
Although the present invention has been described in detail with reference to the above embodiments, it is only a part of the embodiments of the present invention, not all of the embodiments, and other embodiments can be obtained without inventive step according to the embodiments, and the embodiments are within the scope of the present invention.
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