Single-phase beta phase bond alloy for high-temperature alloy and application thereof

Abstract

The application discloses a single-phase beta-phase adhesive layer alloy for high-temperature alloy and application thereof, and belongs to the technical field of material surface modification and coating. The single-phase beta-phase adhesive layer alloy is characterized by the following chemical components and mass percentages: 19.5-19.0 two percent of Al, 10.5-10.0 wt% of Co, 7.4-6.9 wt% of Cr, 1.0-0.8 wt% of Ta, 0.3-0.2 wt% of Ti, and the rest of Ni. The adhesive layer alloy is composed of single-phase beta phase at 800 DEG C. The application is based on a nickel-based high-temperature alloy, and the content of Al elements in the alloy is increased on the premise that the element composition of the beta phase is determined, and finally the composition of the single-phase beta-phase adhesive layer is determined. The beta phase is based on the NiAl phase and contains a large amount of Al elements, which can provide sufficient Al elements for generating an Al2O3 film on the surface of the adhesive layer.

Description

Technical Field

[0001] This invention belongs to the field of material surface modification and coating preparation technology, specifically relating to a single-phase β-phase binder alloy for high-temperature alloys and its application. Background Technology

[0002] The new generation of gas turbines boasts higher power and greater thrust, causing the turbine blades in the hot-end components to withstand higher temperatures of thermal flux. Thermal barrier coating technology can effectively increase the heat resistance of the substrate material in the hot-end components by approximately 150°C, demonstrating significant results.

[0003] Thermal barrier coatings (TBCs) primarily consist of a two-layer structure: a top ceramic layer and a bottom adhesive layer. The ceramic layer, with its unique porous structure, exhibits low thermal conductivity, thus providing insulation. The adhesive layer plays three main roles in the TBC system: mitigating the thermal expansion mismatch between the top ceramic layer and the substrate alloy; strengthening the bond with the top ceramic layer; and acting as a substrate barrier against oxidation and corrosion. Common adhesive layer systems include NiAl and MCrAlY. MCrAlY has become the most widely used adhesive layer system in recent years, where M typically represents Ni, Co, or Ni-Co. In MCrAlY, Cr enhances the adhesive layer's resistance to oxidation and sulfidation, while Al forms a dense Al2O3 film on the coating surface, preventing further oxidation. The addition of a small amount of Y promotes Al2O3 film formation and improves its bonding strength.

[0004] However, the adhesive layer can encounter problems during use, ultimately leading to coating failure or even peeling. The lack of Al in the adhesive layer prevents the formation of a dense, single Al2O3 film on the coating surface. Other elements also participate in the formation of the oxide film, eventually forming a composite oxide film composed of Cr2O3, NiO, and spinel-like metal oxides. The formation and rapid thickening of this composite oxide film generates significant internal stress within the coating, ultimately causing cracking and failure. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a single-phase β-phase adhesive layer alloy for high-temperature alloys and its application, so as to solve the technical problem that the absence of Al element leads to the formation of composite oxide films with other compositions, resulting in large internal stress and cracking in the coating.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] This invention discloses a single-phase β-phase binder alloy for high-temperature alloys, the chemical composition of which, by mass percentage, includes: 19.0%-19.5% Al, 10.0%-10.5% Co, 6.9%-7.4% Cr, 0.8%-1.0% Ta, 0.2%-0.3% Ti, and the balance being Ni.

[0008] Preferably, the oxide film on the surface of the single-phase β-phase adhesive layer alloy is composed of a single Al2O3 film.

[0009] Preferably, after oxidation at 800℃ for 100 hours, the average oxidation rate of the single-phase β-phase binder alloy is 0.035 - 0.039 g·m⁻². -2 ·h -1 .

[0010] Preferably, in the process of smelting the high-temperature alloy using a single-phase β-phase binder alloy, the raw materials are placed into the reaction equipment and a vacuum is drawn to 10°C. -3 The pressure is below 0.5 MPa, and then argon gas is introduced to maintain the pressure inside the reaction equipment at around 0.5 MPa. After melting and cooling, an alloy ingot is obtained, which is a single-phase β-phase binder alloy for high-temperature alloys.

[0011] More preferably, the smelting raw materials are placed into the reaction equipment in order of decreasing melting point.

[0012] More preferably, the smelting raw materials are pure metals Al, Co, Cr, Ta, Ti and Ni in descending order of melting point.

[0013] More preferably, the reaction equipment is a vacuum induction suspension melting equipment.

[0014] The present invention also discloses the application of the above-mentioned single-phase β-phase binder alloy for high-temperature alloys as a thermal barrier coating.

[0015] The present invention also discloses the application of the above-mentioned high-temperature alloy single-phase β-phase binder layer alloy in the preparation of hot-end components of gas turbines.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The single-phase β-phase binder alloy for high-temperature alloys disclosed in this invention is based on nickel-based high-temperature alloys. By increasing the Al content in the alloy and determining the elemental composition of the β-phase, the single-phase β-phase is ultimately determined to be based on the NiAl phase. On the one hand, this invention, based on nickel-based high-temperature alloys, ensures that the binder alloy and the matrix have similar elemental composition to the greatest extent possible. On the other hand, it contains a relatively large amount of Al. The single-phase β-phase binder alloy designed in this invention consists of a single β-phase and does not contain brittle or harmful phases. The β-phase can provide sufficient Al to generate an Al2O3 film on the surface of the binder, ensuring that the binder has resistance to high-temperature oxidation. Therefore, it can effectively avoid the formation of composite oxide films due to the lack of Al, which would otherwise lead to the formation of other oxides. In other words, the oxide film on the surface of the alloy of this invention consists only of a single Al2O3 film, without internal oxidation or composite oxides. Therefore, it will not cause large internal stress within the coating, leading to coating cracking and failure. Attached Figure Description

[0018] Figure 1 The oxidation kinetics curve of the alloy prepared in Example 1 after oxidation at 800°C for 100 hours is shown.

[0019] Figure 2 The oxidation kinetics curve of the alloy prepared in Example 2 after oxidation at 800°C for 100 hours is shown.

[0020] Figure 3 The oxidation kinetics curve of the alloy prepared in Example 3 after oxidation at 800°C for 100 hours is shown.

[0021] Figure 4 The oxidation kinetics curve of the alloy prepared in Example 4 after oxidation at 800°C for 100 hours is shown.

[0022] Figure 5 The oxidation kinetics curve of the alloy prepared in Example 5 after oxidation at 800°C for 100 h is shown. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0025] This invention discloses a single-phase β-phase binder alloy for high-temperature alloys, with the following chemical composition and mass percentages: Al 19.5-19.0 wt%, Co 10.5-10.0 wt%, Cr 7.4-6.9 wt%, Ta 1.0-0.8 wt%, Ti 0.3-0.2 wt%, and the remainder Ni. The binder alloy at 800℃ consists of a single-phase β-phase.

[0026] The present invention will now be described in further detail with reference to the accompanying drawings:

[0027] Example 1

[0028] The chemical composition and weight percentage of the single-phase β-phase binder alloy for high-temperature alloys in this embodiment are as follows: Al is 19.5 wt%, Co is 10.5 wt%, Cr is 7.4 wt%, Ta is 1.0 wt%, Ti is 0.3 wt%, and the remainder is Ni.

[0029] The method for preparing the single-phase β-phase binder layer alloy for high-temperature alloys of the present invention is as follows: The alloy is prepared using a vacuum induction suspension melting method. First, the pure metal raw materials Al, Co, Cr, Ta, Ti, and Ni are placed sequentially into a water-cooled copper crucible for vacuum induction suspension melting in order of their melting points from high to low. Then, a vacuum pump is used to evacuate the melting furnace to 10 °C. - 3 The pressure is below 0.5 MPa, and then argon gas is introduced to maintain the furnace pressure at around 0.5 MPa. Then, melting and cooling are carried out to obtain an alloy ingot, namely a single-phase β-phase binder alloy for high-temperature alloys.

[0030] The single-phase β-phase binder alloy was subjected to high-temperature oxidation experiments in an atmospheric muffle furnace. The results are shown below. Figure 1 The figure shows the oxidation kinetics curve of the single-phase β-phase binder alloy for high-temperature alloys prepared in this embodiment after oxidation at 800°C for 100 hours. After oxidation at 800°C for 100 hours, the average oxidation rate of the alloy is... The oxide film on the alloy surface consists of a single Al2O3 film, with no internal oxidation or composite oxides observed.

[0031] Example 2

[0032] The chemical composition and weight percentage of the single-phase β-phase binder alloy for high-temperature alloys in this embodiment are as follows: Al is 19.3 wt%, Co is 10.3 wt%, Cr is 7.4 wt%, Ta is 1.0 wt%, Ti is 0.28 wt%, and the remainder is Ni.

[0033] The method for preparing the single-phase β-phase binder layer alloy for high-temperature alloys of the present invention is as follows: The alloy is prepared using a vacuum induction suspension melting method. First, the pure metal raw materials Al, Co, Cr, Ta, Ti, and Ni are placed sequentially into a water-cooled copper crucible for vacuum induction suspension melting in order of their melting points from high to low. Then, a vacuum pump is used to evacuate the melting furnace to 10 °C. - 3 The pressure is below 0.5 MPa, then argon gas is introduced to maintain the furnace pressure at around 0.5 MPa; then melting is carried out, and finally the alloy ingot is obtained by cooling.

[0034] The single-phase β-phase binder alloy was subjected to high-temperature oxidation experiments in an atmospheric muffle furnace. The results are shown below. Figure 2 The figure shows the oxidation kinetics curve of the single-phase β-phase binder alloy for high-temperature alloys prepared in this embodiment after oxidation at 800°C for 100 hours. After oxidation at 800°C for 100 hours, the average oxidation rate of the alloy is... The oxide film on the alloy surface consists of a single Al2O3 film, with no internal oxidation or composite oxides observed.

[0035] Example 3

[0036] The chemical composition and weight percentage of the single-phase β-phase binder alloy for high-temperature alloys in this embodiment are as follows: Al is 19.4 wt%, Co is 10.4 wt%, Cr is 7.5 wt%, Ta is 0.8 wt%, Ti is 0.25 wt%, and the remainder is Ni.

[0037] The method for preparing the single-phase β-phase binder layer alloy for high-temperature alloys of the present invention is as follows: The alloy is prepared using a vacuum induction suspension melting method. First, the pure metal raw materials Al, Co, Cr, Ta, Ti, and Ni are placed sequentially into a water-cooled copper crucible for vacuum induction suspension melting in order of their melting points from high to low. Then, a vacuum pump is used to evacuate the melting furnace to 10 °C. - 3 The pressure is below 0.5 MPa, then argon gas is introduced to maintain the furnace pressure at around 0.5 MPa; then melting is carried out, and finally the alloy ingot is obtained by cooling.

[0038] The single-phase β-phase binder alloy was subjected to high-temperature oxidation experiments in an atmospheric muffle furnace. The results are shown below. Figure 3 The figure shows the oxidation kinetics curve of the single-phase β-phase binder alloy for high-temperature alloys prepared in this embodiment after oxidation at 800°C for 100 hours. After oxidation at 800°C for 100 hours, the average oxidation rate of the alloy is... The oxide film on the alloy surface consists of a single Al2O3 film, with no internal oxidation or composite oxides observed.

[0039] Example 4

[0040] The chemical composition and weight percentage of the single-phase β-phase binder alloy for high-temperature alloys in this embodiment are as follows: Al is 19.2 wt%, Co is 10.3 wt%, Cr is 7.6 wt%, Ta is 0.9 wt%, Ti is 0.28 wt%, and the remainder is Ni.

[0041] The method for preparing the single-phase β-phase binder layer alloy for high-temperature alloys of the present invention is as follows: The alloy is prepared using a vacuum induction suspension melting method. First, the pure metal raw materials Al, Co, Cr, Ta, Ti, and Ni are placed sequentially into a water-cooled copper crucible for vacuum induction suspension melting in order of their melting points from high to low. Then, a vacuum pump is used to evacuate the melting furnace to 10 °C. - 3 The pressure is below 0.5 MPa, then argon gas is introduced to maintain the furnace pressure at around 0.5 MPa; then melting is carried out, and finally the alloy ingot is obtained by cooling.

[0042] The single-phase β-phase binder alloy was subjected to high-temperature oxidation experiments in an atmospheric muffle furnace. The results are shown below. Figure 4 The figure shows the oxidation kinetics curve of the single-phase β-phase binder alloy for high-temperature alloys prepared in this embodiment after oxidation at 800°C for 100 hours. After oxidation at 800°C for 100 hours, the average oxidation rate of the alloy is... The oxide film on the alloy surface consists of a single Al2O3 film, with no internal oxidation or composite oxides observed.

[0043] Example 5

[0044] The chemical composition and weight percentage of the single-phase β-phase binder alloy for high-temperature alloys in this embodiment are as follows: Al is 19.0 wt%, Co is 10.2 wt%, Cr is 7.4 wt%, Ta is 1.0 wt%, Ti is 0.29 wt%, and the remainder is Ni.

[0045] The method for preparing the single-phase β-phase binder layer alloy for high-temperature alloys of the present invention is as follows: The alloy is prepared using a vacuum induction suspension melting method. First, the pure metal raw materials Al, Co, Cr, Ta, Ti, and Ni are placed sequentially into a water-cooled copper crucible for vacuum induction suspension melting in order of their melting points from high to low. Then, a vacuum pump is used to evacuate the melting furnace to 10 °C. - 3 The pressure is below 0.5 MPa, then argon gas is introduced to maintain the furnace pressure at around 0.5 MPa; then melting is carried out, and finally the alloy ingot is obtained by cooling.

[0046] The single-phase β-phase binder alloy was subjected to high-temperature oxidation experiments in an atmospheric muffle furnace. The results are shown below. Figure 5 The figure shows the oxidation kinetics curve of the single-phase β-phase binder alloy for high-temperature alloys prepared in this embodiment after oxidation at 800°C for 100 hours. After oxidation at 800°C for 100 hours, the average oxidation rate of the alloy is... The oxide film on the alloy surface consists of a single Al2O3 film, with no internal oxidation or composite oxides observed.

[0047] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A single-phase β-phase binder alloy for high-temperature alloys, characterized in that, Its chemical composition, by mass percentage, includes: 19.0%-19.5% Al, 10.0%-10.5% Co, 6.9%-7.4% Cr, 0.8%-1.0% Ta, 0.2%-0.3% Ti, with the balance being Ni; After oxidation at 800℃ for 100 hours, the average oxidation rate of this single-phase β-phase binder alloy was 0.035-0.039 g·m⁻¹. -2 ·h -1 .

2. The single-phase β-phase binder alloy for high-temperature alloys according to claim 1, characterized in that, The oxide film on the surface of this single-phase β-phase adhesive layer alloy consists of a single Al2O3 film.

3. The single-phase β-phase binder alloy for high-temperature alloys according to claim 1, characterized in that, This high-temperature alloy uses a single-phase β-phase binder layer alloy. During smelting, the raw materials are placed into the reaction equipment, and a vacuum is drawn to 10. -3 The pressure is below 0.5 MPa, and then argon gas is introduced to maintain the pressure inside the reaction equipment at around 0.5 MPa. After melting and cooling, an alloy ingot is obtained, which is a single-phase β-phase binder alloy for high-temperature alloys.

4. The single-phase β-phase binder alloy for high-temperature alloys according to claim 3, characterized in that, The smelting raw materials are added to the reaction equipment in order of decreasing melting point.

5. The single-phase β-phase binder alloy for high-temperature alloys according to claim 4, characterized in that, The smelting raw materials are pure metals Ta, Cr, Ti, Co, Ni and Al, arranged in descending order of melting point.

6. The single-phase β-phase binder alloy for high-temperature alloys according to claim 3, characterized in that, The reaction equipment is a vacuum induction suspension melting equipment.

7. The application of the single-phase β-phase binder alloy for high-temperature alloys as described in any one of claims 1 to 6 as a thermal barrier coating.

8. The application of the high-temperature alloy single-phase β-phase binder layer alloy according to any one of claims 1 to 6 in the preparation of hot-end components of gas turbines.

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