Heat treatment method and application of Ti2AlNb alloy diffusion welding structural part

Abstract

The invention relates to the field of aerospace crafts, in particular to a heat treatment method and application of a Ti2AlNb alloy diffusion welding structural part. The method comprises the steps that the Ti2AlNb alloy diffusion welding structural part is subjected to first vacuum heat treatment and first gas quenching; carrying out second vacuum heat treatment and second gas quenching on the Ti2AlNb alloy diffusion welding structural part subjected to the first gas quenching; and the Ti2AlNb alloy diffusion welding structural part subjected to second gas quenching is subjected to heat preservation treatment and furnace cooling. By means of the method, performance recovery can be conducted on the Ti2AlNb alloy diffusion welding structural part subjected to diffusion bonding, the tensile strength of the alloy material and a welding joint under the conditions of the room temperature and the temperature of 750 DEG C is improved, meanwhile, it is guaranteed that the plasticity of the alloy material and the welding joint at the room temperature and the high temperature is not lower than 6%, other comprehensive mechanical properties meet the use requirements, and the use reliability of the Ti2AlNb alloy diffusion welding structural part is improved.

Description

Technical Field

[0001] The present invention relates to the field of aerospace vehicles, and in particular to a heat treatment method and application of a Ti2AlNb alloy diffusion-welded structural component. Background Art

[0002] With the design requirements of aerospace vehicles being faster, higher and lighter, aircraft and engines have put forward requirements for structural materials to be lighter and more resistant to high temperatures. Lightweight high-temperature materials and lightweight structural design have become the main development trend of structural materials. Ti2AlNb alloy has low density (5.3g / cm 3 ), higher high temperature yield strength and creep resistance, good flame retardant properties, high specific modulus, low thermal expansion coefficient and non-magnetic properties. The long-term use temperature is 600-750℃, and the short-term use temperature can reach 800-1000℃. It has become one of the new lightweight and high-temperature resistant materials preferred in the aerospace field to replace nickel-based high-temperature alloys.

[0003] The structure is mainly based on lightweight design of thin walls and hollow cavities. However, due to the complex structure of parts in the aerospace field, the same or different materials are usually required to be connected. As an intermetallic compound, Ti2AlNb has a long-range ordered atomic structure, and the atoms are bonded by a mixed bond of metallic bonds and covalent bonds. This bonding method makes it have excellent high-temperature performance while also having intrinsic brittleness. The reliability of the performance of the welded joint is a problem. At the same time, due to the structural characteristics of the hollow cavity and thin wall, deformation is prone to occur during welding. During the welding process, air can easily enter the cavity of the hollow structure, which will cause oxidation problems. This requires that the performance recovery heat treatment after welding requires vacuum. Therefore, achieving reliable connection of Ti2AlNb alloy hollow thin-walled structural parts will become a key issue in the promotion and application of such materials.

[0004] With the development of solid-phase diffusion bonding technology in recent years, the problem of connecting the same materials of Ti2AlNb alloy has been effectively solved. As a precise connection method, diffusion bonding relies on the local plastic deformation of the material surface at high temperature to form a close contact between the contact surfaces. Through the diffusion on the surface layer of the material, it produces a bond at the atomic level to form an integral joint. The deformation of the specimen after welding is small, which becomes an effective method for connecting the same materials of hollow thin-walled structural parts of Ti2AlNb alloy. However, due to the high Nb content of Ti2AlNb alloy, the welding temperature is relatively high, generally at 960℃~1020℃, in the near β phase region of the material, so as to ensure the diffusion between atoms at the contact interface. In addition, due to the hollow structure of the inner cavity, vacuum diffusion welding must be used to prevent oxidation of the welding interface and the hollow cavity; at the same time, in order to reduce the deformation of the structure, a sufficiently low cooling rate must be used. In actual production, furnace cooling is generally used. Due to the high temperature treatment and low cooling rate, the room temperature and high temperature strength of the base material and joint after welding are much lower than the material strength before welding, especially the tensile strength performance at the service temperature of 750℃ is much lower than the requirements of design and material selection.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] Aiming at the problem of performance attenuation after welding of Ti2AlNb alloy hollow structure diffusion welding structural parts for aerospace aircraft components, the present invention provides a heat treatment method and application of Ti2AlNb alloy diffusion welding structural parts. The heat treatment method can restore the performance of the structural parts after diffusion connection, and improve the comprehensive mechanical properties of the Ti2AlNb alloy diffusion welding structural parts.

[0007] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0008] One aspect of the present invention relates to a heat treatment method for a Ti2AlNb alloy diffusion welded structural part, comprising the following steps:

[0009] (a) subjecting a Ti2AlNb alloy diffusion welded structure to a first vacuum heat treatment and a first gas quenching;

[0010] (b) subjecting the Ti2AlNb alloy diffusion-welded structural component that has undergone the first gas quenching to a second vacuum heat treatment and a second gas quenching;

[0011] (c) subjecting the Ti2AlNb alloy diffusion-welded structural component that has undergone the second gas quenching to a heat preservation treatment and a furnace cooling.

[0012] The heat treatment method for the Ti2AlNb alloy diffusion welding structural component can restore the performance of the Ti2AlNb alloy diffusion welding structural component after diffusion connection, improve the tensile strength of the alloy material and the welded joint at room temperature and 750°C, and at the same time ensure that its room temperature and high temperature plasticity is not less than 6%, and other comprehensive mechanical properties meet the use requirements, thereby improving the reliability of the Ti2AlNb alloy diffusion welding structural component.

[0013] Another aspect of the present invention also relates to a method for preparing a Ti2AlNb alloy diffusion-welded structural component, including a heat treatment method for the Ti2AlNb alloy diffusion-welded structural component.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The heat treatment method for Ti2AlNb alloy diffusion welding structural parts provided by the present invention can restore the performance of Ti2AlNb alloy diffusion welding structural parts after diffusion connection through three-step vacuum annealing heat treatment, improve the tensile strength of the alloy material and the welded joint under room temperature and 750°C conditions, and at the same time ensure that its room temperature and high temperature plasticity is not less than 6%, and other comprehensive mechanical properties meet the use requirements, thereby improving the reliability of the Ti2AlNb alloy diffusion welding structural parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 This is the initial microstructure morphology of the Ti2AlNb alloy diffusion welded structure;

[0018] Figure 2 This is the microstructure morphology of the Ti2AlNb alloy diffusion welded structural component after heat treatment. DETAILED DESCRIPTION

[0019] The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0020] One aspect of the present invention relates to a heat treatment method for a Ti2AlNb alloy diffusion welded structural part, comprising the following steps:

[0021] (a) subjecting a Ti2AlNb alloy diffusion welded structure to a first vacuum heat treatment and a first gas quenching;

[0022] (b) subjecting the Ti2AlNb alloy diffusion-welded structural component that has undergone the first gas quenching to a second vacuum heat treatment and a second gas quenching;

[0023] (c) subjecting the Ti2AlNb alloy diffusion-welded structural component that has undergone the second gas quenching to a heat preservation treatment and a furnace cooling.

[0024] The heat treatment method for Ti2AlNb alloy diffusion welding structural parts can restore the performance of Ti2AlNb alloy diffusion welding structural parts after diffusion connection through three-step vacuum annealing heat treatment, improve the tensile strength of the alloy material and the welded joint under room temperature and 750°C conditions, and at the same time ensure that its room temperature and high temperature plasticity is not less than 6%, and other comprehensive mechanical properties meet the use requirements, thereby improving the reliability of Ti2AlNb alloy diffusion welding structural parts.

[0025] The first vacuum heat treatment and the first gas quenching of the Ti2AlNb alloy diffusion welded structure can ensure the shape and quantity of the primary strips. The second vacuum heat treatment and the second gas quenching of the Ti2AlNb alloy diffusion welded structure after the first gas quenching can ensure the shape and quantity of the secondary strips.

[0026] Furthermore, the vacuum degree of the first vacuum heat treatment is less than 1×10 -1 Pa.

[0027] Furthermore, the temperature of the first vacuum heat treatment is 940-960° C., including but not limited to any point value of 940° C., 945° C., 950° C., 955° C. or 960° C. or a range value between any two of them. If the temperature of the first vacuum heat treatment is too high, the plasticity of the structural part will be reduced; if the temperature is too low, the strength of the structural part will be reduced.

[0028] Furthermore, the time of the first vacuum heat treatment is 0.5 to 1.5 h, including but not limited to any one of 0.5 h, 0.7 h, 0.9 h, 1.1 h, 1.3 h or 1.5 h or a range between any two of them.

[0029] Furthermore, the heating rate of the first vacuum heat treatment is 2-4°C / min, including but not limited to any one of 2°C / min, 2.5°C / min, 3°C / min, 3.5°C / min or 4°C / min or a range between any two of them.

[0030] Furthermore, the pressure of the first gas quenching is 0.5-1 bar, including but not limited to any point value of 0.5 bar, 0.6 bar, 0.7 bar, 0.8 bar, 0.9 bar or 1 bar or any range value between two of them. By limiting the pressure of the gas quenching to a certain range, the cooling rate of the gas quenching can be reasonably controlled.

[0031] Further, the Ti2AlNb alloy diffusion welded structural component is cooled to a furnace temperature of 100°C or less (for example, but not limited to, any point value of 99°C, 90°C, 80°C, 70°C, 60°C, 50°C, 40°C, 30°C or 20°C or a range value between any two of them) to end the first gas quenching. Ending the first gas quenching at a furnace temperature below 100°C can ensure that the residual stress of the structural component is as small as possible to prevent deformation or cracking.

[0032] Furthermore, the vacuum degree of the second vacuum heat treatment is less than 1×10 -1 Pa.

[0033] Further, the temperature of the second vacuum heat treatment is 780-800° C., including but not limited to any point value of 780° C., 785° C., 790° C., 795° C. or 800° C. or a range value between any two of them. The temperature of the second vacuum heat treatment is the aging temperature. If the temperature is too high, the strength will be reduced, and if the temperature is too low, the plasticity will be insufficient.

[0034] Furthermore, the time of the second vacuum heat treatment is 6 to 10 hours, including but not limited to any one of 6 hours, 7 hours, 8 hours, 9 hours or 10 hours or a range between any two of them.

[0035] Furthermore, the heating rate of the second vacuum heat treatment is 2 to 4°C / min, including but not limited to any one of 2°C / min, 2.5°C / min, 3°C / min, 3.5°C / min or 4°C / min or a range between any two of them.

[0036] Furthermore, the pressure of the second gas quenching is 0.5-1 bar, including but not limited to any point value of 0.5 bar, 0.6 bar, 0.7 bar, 0.8 bar, 0.9 bar or 1 bar or any range value between two of them. By limiting the pressure of the gas quenching to a certain range, the cooling rate of the gas quenching can be reasonably controlled.

[0037] Further, the Ti2AlNb alloy diffusion welded structure is cooled to a furnace temperature of 400°C or less (for example, but not limited to, any one of 399°C, 350°C, 300°C, 250°C, 200°C, 150°C or 100°C or a range between any two of them) to end the second gas quenching. Ending the second gas quenching at a furnace temperature below 400°C can release a certain amount of residual stress.

[0038] Furthermore, the temperature of the heat preservation treatment is 350-400° C., including but not limited to any point value of 350° C., 360° C., 370° C., 380° C., 390° C. or 400° C. or any range value between two thereof. If the temperature of the heat preservation treatment is too high, the microstructure transformation will be affected, and if the temperature is too low, the stress relief effect will not be obvious.

[0039] Furthermore, the heat preservation treatment time is 6 to 10 hours, including but not limited to any one of 6 hours, 7 hours, 8 hours, 9 hours or 10 hours or a range between any two of them.

[0040] Further, the Ti2AlNb alloy diffusion welded structural component is cooled to a furnace temperature of 100°C or less (for example, but not limited to, any point value of 99°C, 90°C, 80°C, 70°C, 60°C, 50°C, 40°C, 30°C or 20°C or a range value between any two of them) to end the furnace cooling. Ending the furnace cooling at a furnace temperature of less than 100°C can ensure that the residual stress of the structural component is as small as possible to prevent deformation or cracking.

[0041] The main purpose of heat preservation treatment and furnace cooling is to eliminate the residual stress during high temperature gas quenching.

[0042] Furthermore, the Ti2AlNb alloy diffusion welding structural part includes but is not limited to: a Ti2AlNb alloy hollow structure diffusion welding structural part.

[0043] Furthermore, the Ti2AlNb alloy diffusion welding structure is placed on a flat ceramic sheet for the first vacuum heat treatment and the second vacuum heat treatment. The ceramic sheet is used to prevent the metal from reacting with the steel base and to provide a plane for the workpiece to ensure uniform stress on the structure.

[0044] The diffusion welded structural part mentioned in the present invention refers to a welded structural part obtained by diffusion-welding two Ti2AlNb alloy parts to be welded of the same composition by using a vacuum diffusion bonding process and then cooling them in a furnace under vacuum.

[0045] The gas quenching mentioned in the present invention is a metal heat treatment process, which refers to the process of heating a metal material such as steel to a certain temperature and then rapidly cooling it with high-pressure gas.

[0046] The furnace cooling mentioned in the present invention refers to a method in which after the material or workpiece is heated and kept warm in a heat treatment furnace, the furnace energy is cut off to allow the material or workpiece to cool along with the furnace.

[0047] The present invention adopts a vacuum heat treatment furnace with a gas quenching function to perform performance recovery heat treatment on the structural parts after diffusion bonding.

[0048] Another aspect of the present invention also relates to a method for preparing a Ti2AlNb alloy diffusion-welded structural component, including a heat treatment method for the Ti2AlNb alloy diffusion-welded structural component.

[0049] The embodiments of the present invention will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. If no specific conditions are specified in the examples, the conditions are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be obtained commercially.

[0050] Example 1

[0051] The heat treatment method of the Ti2AlNb alloy diffusion welding structural part provided in this embodiment includes the following steps:

[0052] The first step of solution annealing heat treatment: the Ti2AlNb alloy diffusion welding structure is placed in a vacuum heat treatment furnace for the first vacuum heat treatment. The Ti2AlNb alloy diffusion welding structure is placed on a flat ceramic sheet and vacuum is started. The vacuum degree reaches 1×10 -1 Pa or less; apply electric heating, the workpiece heats up with the furnace, the heating rate is controlled at 3℃ / min, heats to 945℃, and keeps warm for 1h; after the insulation, the first gas quenching is carried out at a pressure of 1bar, the cooling rate is 50℃ / min, and the workpiece is cooled to below 100℃ and taken out of the furnace;

[0053] The second step is aging annealing heat treatment: the Ti2AlNb alloy diffusion welding structure is placed in a vacuum heat treatment furnace for the second vacuum heat treatment. The Ti2AlNb alloy diffusion welding structure is placed on a flat ceramic sheet and the vacuum degree reaches 1×10 -1 Start electric heating below Pa, control the heating rate at 3℃ / min, heat to 780℃, and keep it warm for 6h; after the end of the heat preservation, carry out the second gas quenching at a pressure of 1bar, maintain the cooling rate at about 50℃ / min, and cool to below 400℃;

[0054] The third step is stress relief annealing heat treatment: keep at 400℃ for 6h, cool the furnace to below 100℃ and take out of the furnace.

[0055] Figure 1 This is the initial microstructure morphology of the Ti2AlNb alloy diffusion-welded structural component in this embodiment without heat treatment. Figure 2 This is a microstructure image of the embodiment after heat treatment to restore performance. Figure 1 and Figure 2 It can be seen that the microstructure of the Ti2AlNb alloy diffusion welding structure has changed before and after the heat treatment. The microstructure obtained by the three-step heat treatment in this embodiment is a double lath structure composed of α2+O+B2 phases, the size of the primary lath is 5-8μm, and the size of the secondary lath is about 0.5μm. Figure 2 .

[0056] Example 2

[0057] The heat treatment method of the Ti2AlNb alloy diffusion welding structural part provided in this embodiment includes the following steps:

[0058] The first step of solution annealing heat treatment: the Ti2AlNb alloy diffusion welding structure is placed in a vacuum heat treatment furnace for the first vacuum heat treatment. The Ti2AlNb alloy diffusion welding structure is placed on a flat ceramic sheet and vacuum is started. The vacuum degree reaches 1×10 -1 Pa or less; apply electric heating, the workpiece heats up with the furnace, the heating rate is controlled at 2℃ / min, heats to 940℃, and keeps warm for 0.5h; after the insulation, perform the first gas quenching at a pressure of 0.5bar, cool to below 100℃ and take out of the furnace;

[0059] The second step is aging annealing heat treatment: the Ti2AlNb alloy diffusion welding structure is placed in a vacuum heat treatment furnace for the second vacuum heat treatment. The Ti2AlNb alloy diffusion welding structure is placed on a flat ceramic sheet and the vacuum degree reaches 1×10 -1 Start electric heating below Pa, control the heating rate at 2℃ / min, heat to 780℃, and keep it warm for 10h; after the end of the heat preservation, perform the second gas quenching at a pressure of 0.5bar and cool to below 400℃;

[0060] The third step is stress relief annealing heat treatment: keep at 350℃ for 10h, cool the furnace to below 100℃ and take out of the furnace.

[0061] Example 3

[0062] The heat treatment method of the Ti2AlNb alloy diffusion welding structural part provided in this embodiment includes the following steps:

[0063] The first step of solution annealing heat treatment: the Ti2AlNb alloy diffusion welding structure is placed in a vacuum heat treatment furnace for the first vacuum heat treatment. The Ti2AlNb alloy diffusion welding structure is placed on a flat ceramic sheet and vacuum is started. The vacuum degree reaches 1×10 -1 Pa or less; apply electric heating, the workpiece heats up with the furnace, the heating rate is controlled at 4℃ / min, heats to 960℃, and keeps warm for 1.5h; after the insulation, perform the first gas quenching at a pressure of 0.8bar, cool to below 100℃ and take out of the furnace;

[0064] The second step is aging annealing heat treatment: the Ti2AlNb alloy diffusion welding structure is placed in a vacuum heat treatment furnace for the second vacuum heat treatment. The Ti2AlNb alloy diffusion welding structure is placed on a flat ceramic sheet and the vacuum degree reaches 1×10 -1 Pa, start electric heating, control the heating rate at 4℃ / min, heat to 800℃, and keep it warm for 6h; after the end of the heat preservation, carry out the second gas quenching at a pressure of 0.8bar and cool it to below 400℃;

[0065] The third step is stress relief annealing heat treatment: keep at 380℃ for 8h, cool the furnace to below 100℃ and take out of the furnace.

[0066] Comparative Example 1

[0067] The only difference between this comparative example and Example 1 is that the temperature of the first vacuum heat treatment is 1000°C.

[0068] Comparative Example 2

[0069] The only difference between this comparative example and Example 1 is that the pressure of the first gas quench is 1.5 bar.

[0070] Comparative Example 3

[0071] The only difference between this comparative example and Example 1 is that the temperature of the second vacuum heat treatment is 850°C.

[0072] Comparative Example 4

[0073] The only difference between this comparative example and Example 1 is that the pressure of the second gas quench is 1.5 bar.

[0074] Experimental example

[0075] The properties of Ti2AlNb alloy diffusion welded structural parts before welding, after welding and after performance recovery heat treatment are shown in Tables 1 and 2.

[0076] Table 1 Tensile properties of Ti2AlNb alloy diffusion welded structural parts before and after welding

[0077]

[0078] Table 2 Comparison of tensile properties of Ti2AlNb alloy diffusion welded structural parts before performance recovery and after heat treatment

[0079]

[0080] The heat treatment method of the Ti2AlNb alloy diffusion welding structural part provided by the present invention adopts a three-step vacuum annealing heat treatment process to solve the problem of tensile strength attenuation of the diffusion welding structural part with a hollow cavity after welding, so that the performance of the welded structural part is restored to 90% of the material standard before welding (room temperature tensile strength ≥900MPa, yield strength ≥760MPa, room temperature plasticity ≥6%; 750℃ room temperature tensile strength ≥540MPa, yield strength ≥405MPa, room temperature plasticity ≥9%). The present invention effectively improves the margin of the tensile strength of the Ti2AlNb alloy diffusion welding structural part and improves the reliability of the component. The present invention is simple to operate, short in process, high in stability, and suitable for industrial production.

[0081] Although the present invention has been illustrated and described with specific embodiments, it should be appreciated that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Those skilled in the art should understand that the technical solutions described in the above embodiments may be modified, or some or all of the technical features thereof may be replaced by equivalents without departing from the spirit and scope of the present invention. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. Therefore, this means that all such replacements and modifications within the scope of the present invention are included in the appended claims.

Claims

1. A heat treatment method for a Ti2AlNb alloy diffusion welded structural part, characterized in that: The following steps are involved: (a) subjecting a Ti2AlNb alloy diffusion welded structure to a first vacuum heat treatment and a first gas quenching; (b) subjecting the Ti2AlNb alloy diffusion-welded structural component that has undergone the first gas quenching to a second vacuum heat treatment and a second gas quenching; (c) subjecting the Ti2AlNb alloy diffusion-welded structural component that has undergone the second gas quenching to a heat preservation treatment and a furnace cooling.

2. The heat treatment method of Ti2AlNb alloy diffusion welding structural parts according to claim 1, characterized in that: The temperature of the first vacuum heat treatment is 940-960°C; And / or, the time of the first vacuum heat treatment is 0.5 to 1.5 hours.

3. The heat treatment method of the Ti2AlNb alloy diffusion welding structural part according to claim 1, characterized in that: The vacuum degree of the first vacuum heat treatment is less than 1×10 -1 Pa; And / or, the heating rate of the first vacuum heat treatment is 2-4°C / min.

4. The heat treatment method of Ti2AlNb alloy diffusion welding structural parts according to claim 1, characterized in that: Includes at least one of the following technical features: (1) The pressure of the first gas quenching is 0.5 to 1 bar; (2) The Ti2AlNb alloy diffusion-welded structure is cooled to a furnace temperature below 100° C. to terminate the first gas quenching.

5. The heat treatment method of Ti2AlNb alloy diffusion welding structural parts according to claim 1, characterized in that: The temperature of the second vacuum heat treatment is 780-800°C; And / or, the second vacuum heat treatment is performed for 6 to 10 hours.

6. The heat treatment method of Ti2AlNb alloy diffusion welding structural parts according to claim 1, characterized in that: The vacuum degree of the second vacuum heat treatment is less than 1×10 -1 Pa; And / or, the heating rate of the second vacuum heat treatment is 2-4°C / min.

7. The heat treatment method of Ti2AlNb alloy diffusion welding structural parts according to claim 1, characterized in that: Includes at least one of the following technical features: (1) The pressure of the second gas quenching is 0.5 to 1 bar; (2) The Ti2AlNb alloy diffusion-welded structure is cooled to a furnace temperature below 400° C. to terminate the second gas quenching.

8. The heat treatment method of Ti2AlNb alloy diffusion welding structural parts according to claim 1, characterized in that: The temperature of the heat preservation treatment is 350-400°C; And / or, the heat preservation treatment time is 6 to 10 hours.

9. The heat treatment method of Ti2AlNb alloy diffusion welding structural parts according to claim 1, characterized in that: The Ti2AlNb alloy diffusion-welded structural component is cooled to a furnace temperature below 100° C. and the furnace cooling is terminated.

10. A method for preparing a Ti2AlNb alloy diffusion-welded structural component, characterized in that: A heat treatment method for a Ti2AlNb alloy diffusion welded structural component comprising the method described in any one of claims 1 to 9.

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