Method for preparing ti2aln alloy with preferentially oriented o-phase

Abstract

The present application relates to a method for preparing Ti2AlNb alloy with precipitated O phase having preferred orientation, comprising: (1) heat treatment: performing solid solution treatment to adjust the structure to contain alpha2 / O phase or alpha2 phase particles in B2 matrix; (2) wire cutting: cutting compression sample; (3) constant stress treatment: heat preservation in B2+O two-phase region. Wherein, (1) is carried out at 980-1060 DEG C; (3) is 780-860 DEG C with constant stress of 150-550 MPa for 30 min, the alloy contains 18-25% Al and 18-25% Nb in atomic percentage, the precipitated O phase has two orientations, and the included angle is 60 DEG. The present application solves the problem that the O phase in the Ti2AlNb alloy obtained by the traditional heat treatment mode is randomly distributed and has no preferred orientation, and the O phase in the obtained Ti2AlNb has preferred orientation, and the included angle between the two orientations is 60 DEG.

Description

TECHNICAL FIELD

[0001] The present application relates to TiAl intermetallic compounds, in particular to a method for preparing Ti2AlNb alloy with preferentially oriented O phase. BACKGROUND

[0002] TiAl alloy has a series of advantages such as low density, high specific strength, high specific stiffness, good oxidation resistance, good high temperature creep resistance, etc., and has broad application prospects in the field of aerospace. Ti2AlNb alloy containing Nb has recently become a research hotspot. Compared with low Nb content TiAl alloy, Ti2AlNb alloy with higher Nb content has better room temperature plasticity, room temperature fracture toughness and better heat resistance. These excellent properties make Ti2AlNb-based alloy one of the most promising lightweight high-temperature structural materials, which has broad application prospects in the field of aviation and aerospace.

[0003] Ti2AlNb-based alloy is usually composed of B2, α2 and O phase. O phase has an ordered orthorhombic crystal structure and is the main strengthening phase in Ti2AlNb-based alloy. The morphology of O phase has a significant impact on the mechanical properties of Ti2AlNb alloy. O phase can be directly precipitated from B2 matrix or α2 phase, or can be generated by the peritectic reaction of α2 phase and B2 matrix.

[0004] The microstructure and morphology of Ti2AlNb-based alloy are closely related to its mechanical properties. Different preparation methods and different heat treatment processes will significantly change the microstructure of the alloy, thereby affecting the performance of the alloy and affecting the application of the alloy. After different processing conditions, the O phase precipitated in the B2 matrix has needle-like, lath-like, equiaxed, etc. The precipitated O phase is randomly distributed on the B2 matrix without any preferential orientation, or the O phase in a small local area has preferential orientation.

[0005] Zheng Youping et al. found that after Ti-22Al-25Nb alloy was deformed by 50% at a rate of 10 s -1 -1 at 1100℃, and then kept at 900℃ for 5min, the microstructure observed in the local area had parallel O phase laths, but they did not realize how to precisely control the O phase in Ti2AlNb alloy to form preferential orientation, especially how to realize the O phase with a certain preferential orientation and a target angle between two orientations, thereby precisely controlling the O phase in Ti2AlNb alloy. SUMMARY

[0006] In view of the fact that although the O phase can be generated in the existing Ti2AlNb alloy, the precipitated O phase is randomly distributed without any preferred orientation, the inventors of the present application have designed a method to realize the preferred orientation of the precipitated O phase in the Ti2AlNb alloy, so that the precipitated O phase in the obtained Ti2AlNb alloy has two orientations, and the included angle between the two orientations is controlled to be 60°.

[0007] Specifically, the present application realizes the above-mentioned application purposes through the following technical solutions.

[0008] According to the present application, a method for preparing a Ti2AlNb alloy with a precipitated O phase having a preferred orientation is provided, which comprises the following steps:

[0009] Step (1) heat treatment: the Ti2AlNb alloy is subjected to solid solution treatment to adjust the microstructure of the Ti2AlNb alloy to contain α2 / O phase or α2 phase particles in the B2 matrix;

[0010] Step (2) wire cutting: a cylindrical compression sample is cut from the center part of the Ti2AlNb alloy ingot by a numerical control wire cutting machine tool;

[0011] Step (3) constant stress treatment: the cut compression sample is subjected to heat preservation in the B2+O two-phase region of the Ti2AlNb alloy, and a constant stress is applied during the heat preservation process for 30 min.

[0012] Preferably, in the step (1), the solid solution treatment is cooled after being heat preserved at 980-1060℃ for 1-3h. And further preferably, in the step (1), the alloy is placed in a heat treatment furnace at 980℃ for 1h and then taken out and water cooled to room temperature.

[0013] Preferably, in the step (3), the constant stress treatment is 780-860℃ with a constant stress of 150-550MPa for 30min. And further preferably, in the step (3), the cut sample is subjected to constant stress treatment on a Gleeble thermal simulation experiment machine, the sample temperature is raised to 780℃, a constant stress of 150MPa is applied, and the constant stress is maintained for 30min, and then water cooled to room temperature.

[0014] Preferably, the Ti2AlNb alloy contains 18-25% Al and 18-25% Nb in atomic percentage, and the balance is Ti and unavoidable impurities. And further preferably, the Ti2AlNb alloy contains 22% Al and 25% Nb in atomic percentage, and the balance is Ti and unavoidable impurities.

[0015] Preferably, the precipitated O phase has two orientations, and the included angle is 60°.

[0016] Generally, the present application relates to a preparation method of preferentially oriented O phase in Ti2AlNb alloy, especially Ti2AlNb alloy with specific composition of Ti-22Al-25Nb. The alloy ingot sample is firstly solid-solution treated at 980-1060℃ for 1h and then water-cooled to room temperature, and then treated at 780-860℃ for 30min under constant stress of 150-550MPa and then water-cooled to room temperature. The obtained alloy has a structure of B2+α2+O three phases or B2+α2 two phases after solid-solution treatment for 1h. After constant stress treatment, the alloy has a structure of B2+α2+O three phases, and the O phase is precipitated in the form of lath in the B2 matrix, and the O phase has two preferential orientations with an included angle of 60°. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:

[0018] Figure 1 Scanning electron microscope (BSE-SEM) microstructure of Ti2AlNb alloy according to Example 1 of the present application after 980℃ / 1h heat treatment + 780℃ / 150MPa / 30min constant pressure treatment, wherein the white matrix is B2 phase, the black particles are α2 / O phase, and the gray phase is O phase.

[0019] Figure 2 Scanning electron microscope (BSE-SEM) microstructure of Ti2AlNb alloy according to Comparative Example 1 of the present application after 980℃ / 1h heat treatment + 780℃ / 30min heat treatment.

[0020] Figure 3 Scanning electron microscope (BSE-SEM) microstructure of Ti2AlNb alloy according to Example 2 of the present application after 1060℃ / 1h heat treatment + 820℃ / 350MPa / 30min constant pressure treatment, wherein the white matrix is B2 phase, and the gray phase is O phase.

[0021] Figure 4 Scanning electron microscope (BSE-SEM) microstructure of Ti2AlNb alloy according to Comparative Example 2 of the present application after 1060℃ / 1h heat treatment + 820℃ / 30min heat treatment.

[0022] Figure 5The scanning electron microscope (BSE-SEM) microstructure of the Ti2AlNb alloy according to the Example 3 of the present application after being subjected to a heat treatment at 1020℃ / 1h + a constant pressure treatment at 780℃ / 350MPa / 30min, wherein the white matrix is B2 phase and the gray phase is O phase.

[0023] Figure 6 The scanning electron microscope (BSE-SEM) microstructure of the Ti2AlNb alloy according to the Comparative Example 3 of the present application after being subjected to a heat treatment at 1020℃ / 1h + a constant pressure treatment at 780℃ / 30min.

[0024] Figure 7 The scanning electron microscope (BSE-SEM) microstructure of the Ti2AlNb alloy according to the Example 4 of the present application after being subjected to a heat treatment at 1060℃ / 1h + a constant pressure treatment at 860℃ / 350MPa / 30min, wherein the white matrix is B2 phase and the gray phase is O phase.

[0025] Figure 8 The scanning electron microscope (BSE-SEM) microstructure of the Ti2AlNb alloy according to the Comparative Example 4 of the present application after being subjected to a heat treatment at 1060℃ / 1h + a constant pressure treatment at 860℃ / 30min. DETAILED DESCRIPTION

[0026] Hereinafter, example embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only disclosed as examples, and not all embodiments of the present disclosure, and it should be understood that the present disclosure is not limited to the example embodiments described here.

[0027] In order to make subsequent processing can precipitate a large number of O phase, the Ti2AlNb alloy is first subjected to a solution treatment at 980℃-1060℃, and the alloy microstructure after the solution treatment is B2 matrix containing a small amount of α2 / O phase or α2 phase particles. The alloy after the solution treatment is cut into a size suitable for compression by wire cutting process. Then, a constant stress treatment at 780℃-860℃ and 150MPa-550MPa for 30min, and a large number of O phase with preferred orientation is precipitated in the B2 matrix of the alloy after the constant stress treatment.

[0028] The preparation method of the TiAl alloy applied in the above experimental method is carried out according to the following steps:

[0029] (1) Heat treatment: the Ti2AlNb alloy is first subjected to a solution treatment, and the alloy is adjusted to contain α2 / O phase or α2 phase particles in the B2 matrix by heat treatment;

[0030] (2) Wire cutting: a cylinder is cut from the center part of the above ingot by a numerical control wire cutting machine tool;

[0031] (3) Constant stress treatment: the cut compression sample is kept in B2+O two-phase region, and a constant stress is applied during the keeping process, and the time is 30 min.

[0032] Compared with the prior art, the application has the advantages and beneficial effects that:

[0033] 1. After traditional solid solution and aging treatment, the O phase precipitated in the Ti2AlNb alloy is randomly distributed and has no preferred orientation, and the O phase precipitated in the B2 matrix of the Ti2AlNb alloy in the application is regularly arranged and has preferred orientation, and the O phase has two orientations, and the included angle of the two different orientations of the O phase is 60°.

[0034] 2. Compared with the traditional solid solution and aging treatment, the O phase precipitated in the alloy is in the form of lath, and the O phase is more densely distributed.

[0035] The application will be further described below in combination with the characterization examples of the material properties, but the application is not limited to the following examples. Example 1

[0036] This embodiment is a preparation method of a Ti2AlNb alloy with preferred orientation O phase, and the atomic percentage of the Ti2AlNb alloy used in the experiment is: Ti-22Al-25Nb, and the balance is Ti and unavoidable impurities.

[0037] The preparation of the Ti2AlNb alloy with preferred orientation O phase is realized by the following steps:

[0038] (1) Heat treatment: the alloy is placed in a heat treatment furnace at 980 DEG C for 1 h and then taken out and water-cooled to room temperature;

[0039] (2) Wire cutting: the sample is cut from the center part of the alloy after heat treatment in step 1 by a numerical control wire cutting machine. The sample is a cylinder with a size of Φ5*10mm;

[0040] (3) Constant stress treatment: the cut sample is subjected to constant stress treatment on a Gleeble thermal simulation experiment machine, the sample temperature is raised to 780 DEG C, a constant stress of 150 MPa is applied, and the stress is maintained for 30 min, and then water-cooled to room temperature;

[0041] (4) Microstructure observation: the sample after constant stress treatment is cut parallel to the direction of applied stress, the sample is mechanically polished until the surface is mirror-like and free of scratches, and the structure is observed using a scanning electron microscope.

[0042] For example, Figure 1It can be seen that the microstructure of the Ti2AlNb alloy after constant stress treatment is composed of B2, α2 and O phases. A large number of lath-shaped O phases are precipitated in the B2 matrix of the alloy, and the precipitated O phases have preferred orientation, mainly two orientations, and the included angle between the O phases with different orientations is 60°.

[0043] The inventors observed the microstructure of the Ti2AlNb alloy after constant stress treatment, and found that the microstructure of the Ti2AlNb alloy after constant stress treatment is composed of B2, α2 and O phases. A large number of lath-shaped O phases are precipitated in the B2 matrix of the alloy, and the precipitated O phases have preferred orientation, mainly two orientations, and the included angle between the O phases with different orientations is 60°. Figure 1

[0044] The alloy composition, treatment method and specific processing steps and observation method used in Comparative Example 1 are similar to those of Example 1, and the only difference is that in the constant stress treatment of step (3) of Example 1, the cut sample is only heat treated on the Gleeble thermal simulation testing machine, that is, the sample temperature is raised to 780℃, kept for 30 min, and then water cooled to room temperature, without applying a constant stress of 150 MPa.

[0045] The microstructure of Comparative Example 1 is observed as follows: It can be seen that the microstructure of the Ti2AlNb alloy after constant stress treatment is composed of B2, α2 and O phases. Basically no lath-shaped O phase is precipitated in the B2 matrix of the alloy, although O phase is precipitated, but the precipitated O phase does not have preferred orientation.

[0046] Figure 2 The inventors observed the microstructure of the Ti2AlNb alloy after constant stress treatment, and found that the microstructure of the Ti2AlNb alloy after constant stress treatment is composed of B2, α2 and O phases. A large number of lath-shaped O phases are precipitated in the B2 matrix of the alloy, and the precipitated O phases have preferred orientation, mainly two orientations, and the included angle between the O phases with different orientations is 60°.

[0047] The inventors observed the microstructure of the Ti2AlNb alloy after constant stress treatment, and found that the microstructure of the Ti2AlNb alloy after constant stress treatment is composed of B2, α2 and O phases. A large number of lath-shaped O phases are precipitated in the B2 matrix of the alloy, and the precipitated O phases have preferred orientation, mainly two orientations, and the included angle between the O phases with different orientations is 60°. Figure 2 Comparing Comparative Example 1 and Example 1, it can be seen that the O phase lath structure with preferred orientation is obtained by the method of the present application.

[0048] Example Two The present example is a preparation method of a Ti2AlNb alloy with preferred orientation O phase, and the atomic percentage of the Ti2AlNb alloy used in the experiment is: Ti-22Al-25Nb, and the balance is Ti and unavoidable impurities.

[0049] The preparation of the Ti2AlNb alloy is realized by the following steps:

[0050] (1) Heat treatment: the alloy is placed in a heat treatment furnace at 1060℃ for 1h and then taken out and water cooled to room temperature;

[0051]

[0052] ​​(2) Wire cutting: cutting the sample from the center of the alloy after heat treatment in step 1 by a numerical control wire cutting machine, the sample is a cylinder with a size of Φ5*10mm;

[0053] (3) Constant stress treatment: treating the cut sample on a Gleeble thermal simulation experiment machine, the sample temperature is raised to 820℃, a constant stress of 350MPa is applied, and maintained for 30min, and then water cooled to room temperature,

[0054] (4) Microstructure observation: cutting the sample after constant stress treatment in parallel to the direction of applied stress, mechanically polishing the sample until the surface is mirror-like and free of scratches, and observing the microstructure using a scanning electron microscope.

[0055] As shown in Figure 3 It can be seen that the Ti2AlNb alloy after constant stress treatment is observed, and the microstructure is composed of B2, α2 and O phase. A large amount of lath-shaped O phase is precipitated in the B2 matrix of the alloy. These precipitated O phases have preferred orientation, mainly two orientations, and the included angle between the O phases with different orientations is 60°.

[0056] The inventors counted the volume area content of each phase in Figure 3 The B2 phase is 23.16%, and the O phase lath is 76.84%.

[0057] Comparative Example 2

[0058] The alloy composition, treatment method, specific processing steps and observation method used in Comparative Example 2 are similar to those of Example 2, the only difference is that in the constant stress treatment of step (3) of Example 2, the cut sample in this comparative example 2 is only heat treated on the Gleeble thermal simulation experiment machine, i.e. the sample temperature is raised to 820℃, maintained for 30min, and then water cooled to room temperature, without applying a constant stress of 350MPa.

[0059] The microstructure observation of Comparative Example 2 is as shown in Figure 4 It can be seen that the Ti2AlNb alloy after constant stress treatment is observed, and the microstructure is composed of B2, α2 and O phase. No obvious lath-shaped O phase is observed to precipitate in the B2 matrix of the alloy, although O phase is precipitated, but no preferred orientation of the precipitated O phase is observed.

[0060] The inventors counted the volume area content of each phase in Figure 4 The B2 phase is 27.08%, and the O phase is 72.92%.

[0061] Comparing Comparative Example 2 and Example 2, it can be seen that the O phase lath structure with a significantly preferred orientation is obtained by the method of the present application.

[0062] Comparing Example 1 and 2, it can be seen that higher pressure and temperature treatment further promotes the formation of O-phase lath structure with preferred orientation. Example Three

[0063] This example is a method for preparing a Ti2AlNb alloy with preferred orientation O-phase. The atomic percentage of the Ti2AlNb alloy used in the experiment is: Ti-22Al-25Nb, with the balance being Ti and unavoidable impurities.

[0064] The preparation of the Ti2AlNb alloy is achieved by the following steps:

[0065] (1) Heat treatment: place the alloy in a heat treatment furnace at 1020°C for 1 hour, then take it out and water cool to room temperature;

[0066] (2) Wire cutting: cut a sample from the center of the alloy after heat treatment in step 1 using a numerical control wire cutting machine. The sample is a cylinder with dimensions of Φ5*10mm;

[0067] (3) Constant stress treatment: perform constant stress treatment on the cut sample on a Gleeble thermal simulation experiment machine. The sample temperature is raised to 780°C, a constant stress of 350MPa is applied, and maintained for 30 minutes, then water cooled to room temperature,

[0068] (4) Microstructure observation: cut the constant stress treated sample parallel to the direction of applied stress, mechanically polish the sample until the surface is mirror-like and free of scratches, and use a scanning electron microscope to observe the microstructure.

[0069] As Figure 5 It can be seen that the microstructure of the Ti2AlNb alloy after constant stress treatment is composed of B2, α2 and O-phase. A large number of lath-shaped O-phase is precipitated in the B2 matrix of the alloy. These precipitated O-phase has preferred orientation, mainly two orientations, and the angle between O-phase of different orientations is 60°.

[0070] The inventors counted the volume area content of each phase in Figure 5 The volume area content of each phase in Example 3 is as follows: B2 phase 18.01%, O-phase lath 77.62%, α2 / O-phase particles 4.37%.

[0071] Comparative Example 3

[0072] The alloy composition, treatment method, specific processing steps and observation method used in Comparative Example 3 are similar to those of Example 3, the only difference being that in the constant stress treatment of step (3) of Example 3, the sample is only heat treated on the Gleeble thermal simulation experiment machine, i.e. the sample temperature is raised to 780°C, maintained for 30 minutes, then water cooled to room temperature, without applying a constant stress of 350MPa.

[0073] Microstructure observation was carried out on the Ti2AlNb alloy after the constant stress treatment as in Comparative Example 3, and the microstructure thereof was composed of B2, a2 and O phases. No obvious lath-shaped O phase was observed to be precipitated from the B2 matrix of the alloy, and although the O phase was precipitated, no precipitated O phase having a preferred orientation was observed. Figure 6 As can be seen, the microstructure of the Ti2AlNb alloy after the constant stress treatment is composed of B2, a2 and O phases. No obvious lath-shaped O phase is observed to be precipitated from the B2 matrix of the alloy, and although the O phase is precipitated, no precipitated O phase having a preferred orientation is observed.

[0074] The inventors carried out microstructure observation on the Ti2AlNb alloy after the constant stress treatment as in Example 3, and the microstructure thereof was composed of B2, a2 and O phases. Figure 6 The volume area content of each phase in Example 3 was counted as follows: B2 phase 21.43%; O phase 72.12%; a2 / O phase particle 6.45%.

[0075] Comparing Comparative Example 3 and Example 3, it can be seen that the O phase lath structure having a significantly preferred orientation is obtained by the method of the present application.

[0076] Meanwhile, comparing Example 1 and 2 with the present example, it can be seen that higher pressure and temperature treatment has a certain further promoting effect on the O phase lath structure having a preferred orientation. Example Four

[0077] The present example is a method for preparing a Ti2AlNb alloy having an O phase with a preferred orientation. The atomic percentage of the Ti2AlNb alloy used in the experiment is: Ti-22Al-25Nb, and the balance is Ti and unavoidable impurities.

[0078] The preparation of the Ti2AlNb alloy is realized by the following steps:

[0079] (1) Heat treatment: the alloy is placed in a heat treatment furnace at 1060°C for 1 h and then taken out and water-cooled to room temperature;

[0080] (2) Wire cutting: a sample is cut from the center of the alloy after heat treatment in step 1 by a numerical control wire cutting machine, and the sample is a cylinder with a size of Φ5*10 mm;

[0081] (3) Constant stress treatment: the cut sample is subjected to constant stress treatment on a Gleeble thermal simulation experiment machine, the temperature of the sample is raised to 860°C, a constant stress of 350 MPa is applied, and the stress is maintained for 30 min, and then the sample is water-cooled to room temperature,

[0082] (4) Microstructure observation: the sample after constant stress treatment is cut parallel to the direction of applied stress, the sample is mechanically polished until the surface is mirror-like and free of scratches, and the microstructure is observed using a scanning electron microscope.

[0083] As can be seen in the microstructure observation of the sample after constant stress treatment in the present example, Figure 7It can be seen that the microstructure of the Ti2AlNb alloy after constant stress treatment is composed of B2, α2 and O phases. A large number of lath-shaped O phases are precipitated in the B2 matrix of the alloy, and the precipitated O phases have preferred orientation, mainly two orientations, and the angle between the O phases with different orientations is 60°.

[0084] The inventors statistically analyzed the volume area content of each phase in the alloy as follows: B2 phase 15.92%, O phase lath 84.08%. Figure 7

[0085] The alloy composition, treatment method and specific processing steps and observation method used in Comparative Example 4 are similar to those in Example 4, and the only difference is that in the constant pressure treatment in step (3) of Example 4, the cut sample in Comparative Example 4 is only heat treated, that is, the sample temperature is raised to 860℃, kept for 30 min, and then water cooled to room temperature, without applying a constant stress of 350 MPa.

[0086] The microstructure observation in Comparative Example 4 is as follows: It can be seen that the microstructure of the Ti2AlNb alloy after constant stress treatment is composed of B2, α2 and O phases. No obvious lath-shaped O phases are observed to be precipitated in the B2 matrix of the alloy, and although O phases are precipitated, no preferred orientation of the precipitated O phases is observed.

[0087] Figure 8 The inventors statistically analyzed the volume area content of each phase in the alloy as follows: B2 phase 31.26%, O phase 68.74%.

[0088] The alloy composition, treatment method and specific processing steps and observation method used in Comparative Example 4 are similar to those in Example 4, and the only difference is that in the constant pressure treatment in step (3) of Example 4, the cut sample in Comparative Example 4 is only heat treated, that is, the sample temperature is raised to 860℃, kept for 30 min, and then water cooled to room temperature, without applying a constant stress of 350 MPa. Figure 8 Comparing Comparative Example 4 and Example 4, it can be seen that the O phase lath structure with a significantly preferred orientation is obtained by the method of the present application.

[0089] Meanwhile, comparing the results of the above groups of examples and the present example, it can be seen that higher pressure and temperature treatment has a certain further promoting effect on the O phase lath structure with a preferred orientation.

[0090] In summary, by heat treating and constant pressure treating the Ti2AlNb alloy with an atomic percentage of Ti-22Al-25Nb, the Ti2AlNb alloy with a target orientation and an orientation angle is obtained, specifically:

[0091]

[0092] ​​Solution treatment is carried out in a B2+alpha2+O three-phase region or a B2+alpha2 two-phase region, and the sample after holding is quenched in water to regulate the microstructure of the alloy into B2 matrix with alpha2 / O phase or alpha2 phase particles, and the B2 matrix cannot have needle-shaped, lath-shaped and other morphologies of O phase; the temperature of the constant stress treatment is in a B2+O two-phase region, and a higher temperature is beneficial to the preferred orientation of the O phase.

[0093] The above exploration of the present application finds that the combined treatment of heat treatment and constant pressure treatment on the Ti2AlNb alloy is an effective way to obtain the Ti2AlNb alloy with target orientation and orientation angle, and points out a clear way for designing the Ti2AlNb alloy according to the actual mechanical performance needs.

[0094] The basic principles of the present disclosure are described above in combination with specific embodiments, but it should be pointed out that the advantages, advantages, effects and the like mentioned in the present disclosure are only examples and cannot be considered as the must-have of each embodiment of the present disclosure. In addition, the specific details of the above disclosure are only for the purpose of example and for the purpose of understanding, and are not limited to the specific details described above.

[0095] The block diagrams of the devices, apparatuses, equipment, systems involved in the present disclosure are only illustrative examples and are not intended to require or imply the connection, arrangement and configuration shown in the block diagram. As those skilled in the art will recognize, these devices, apparatuses, equipment, systems can be connected, arranged and configured in any way. Words such as "include", "contain", "have" and the like are open-ended words, which mean "including but not limited to", and can be used interchangeably. The words "or" and "and" used herein mean the word "and / or", and can be used interchangeably unless the context clearly indicates otherwise. The word "such as" used herein means the phrase "such as but not limited to", and can be used interchangeably.

[0096] It should also be noted that in the devices, equipment and methods of the present disclosure, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be considered as equivalent solutions of the present disclosure.

[0097] In this document, adjectives such as "first", "second" and the like are not intended to emphasize order, positional relationship, importance, priority and the like, but to distinguish different elements / components / circuits / modules / devices / steps. In contrast, adjectives such as "first", "second" and the like can be used to emphasize the order, positional relationship, importance, priority and the like of different elements / components / circuits / modules / devices / steps.

[0098] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other aspects without departing from the scope of the disclosure. Thus, the present disclosure is not intended to be limited to the aspects shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0099] The above description has been presented to enable any person skilled in the art to make or use the disclosure. Furthermore, the purpose of the above description is not intended to limit the embodiments of the present disclosure to the form disclosed herein. Although various example aspects and embodiments have been discussed above, those of ordinary skill in the art will appreciate a variety of modifications, alternatives, permutations, additions, and sub-combinations of the described aspects and embodiments.

Claims

1. A method for preparing a Ti2AlNb alloy with preferentially oriented precipitated O phase, characterized in that, Includes the following steps: Step (1) Heat treatment: The Ti2AlNb alloy is subjected to solution treatment to adjust the microstructure of the Ti2AlNb alloy to contain α2 / O phase or α2 phase particles in the B2 matrix; Step (2) Wire cutting: A cylindrical compression sample is cut from the center of the Ti2AlNb alloy ingot using a CNC wire cutting machine. Step (3) Constant stress treatment: The cut compression sample is kept at 780℃-860℃ in the B2+O two-phase region of the Ti2AlNb alloy. During the heat preservation process, a constant stress of 150MPa-550MPa is applied for 30min.

2. The method as described in claim 1, characterized in that, In step (1), the solution treatment is carried out at 980℃-1060℃ for 1 to 3 hours and then cooled.

3. The method as described in claim 2, characterized in that, In step (1), the alloy is placed in a heat treatment furnace at 980°C and kept at that temperature for 1 hour before being taken out and cooled to room temperature with water.

4. The method as described in claim 1, characterized in that, In step (3), the cut sample is subjected to constant stress treatment on the Gleeble thermal simulation tester. The sample temperature is raised to 780°C, a constant stress of 150 MPa is applied and held for 30 minutes, and then cooled to room temperature with water.

5. The method as described in claim 1, characterized in that, The Ti2AlNb alloy contains 18-25% Al and 18-25% Nb by atomic percentage, with the balance being Ti and unavoidable impurities.

6. The method as described in claim 5, characterized in that, The Ti2AlNb alloy contains 22% Al and 25% Nb by atomic percentage, with the balance being Ti and unavoidable impurities.

7. The method as described in claim 1, characterized in that, The precipitated O phase has two orientations with an included angle of 60°.

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