A method of determining the texture of a titanium alloy

Abstract

The application relates to a method for measuring the texture of a titanium alloy, comprising the following steps: preparing a sample; obtaining a Debye ring, deriving Debye ring data and drawing a diffraction intensity-azimuth angle graph; analyzing a main texture preferred orientation; combining a solid solution alpha p -> beta transformation, most of the equiaxed alpha phase is dissolved in a matrix phase; aging a beta -> alpha s transformation, acicular secondary alpha phase is precipitated from the matrix phase, and the change trend of the solid solution aging texture is compared and analyzed. In addition, the application also relates to a method for heat treatment of a titanium alloy obtained according to the above analysis method, which comprises the following steps: solid solution treatment; low-temperature aging treatment, aging the titanium alloy after the solid solution treatment at 250-350 DEG C for 3-5 h, and then air cooling to room temperature; high-temperature aging treatment, aging the titanium alloy subjected to the low-temperature aging treatment at 500-550 DEG C for 5-7 h, and then air cooling to room temperature.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to the research and development of titanium alloys, and in particular to analyzing the microstructural evolution of titanium alloys for the research and development of new titanium alloys, and more particularly to a research method for determining the texture of titanium alloys to analyze the microstructural evolution of titanium alloys during heat treatment. Furthermore, the present disclosure also relates to a titanium alloy heat treatment process formulated by the method of determining the texture of titanium alloys. BACKGROUND

[0002] Titanium alloys have high specific strength, good corrosion resistance, excellent high and low temperature resistance, good biocompatibility, and other advantages, and are widely used in aerospace, medical devices, consumer electronics, chemical and metallurgical industries, etc.

[0003] The main phase composition of titanium alloys can be divided into three categories: alpha phase, beta phase and alpha+beta phase. Among them, metastable beta titanium alloys have high heat treatment strengthening effect, and solid solution aging treatment can significantly improve the strength and plasticity of the alloy, so they have broad application prospects in high demand fields such as aerospace.

[0004] The two-phase structure of metastable beta titanium alloys is mainly composed of beta phase and alpha phase. The beta phase usually has a body-centered cubic (bcc) crystal structure, while the alpha phase has a hexagonal close-packed (hcp) crystal structure. The microstructure of metastable beta titanium alloys usually includes alpha phase precipitates and stable beta matrix. The production often strengthens the alloy by generating fine and dispersed secondary nanometer alpha phase (alpha s However, due to the influence of forging, drawing and other processing history, there are inevitably uneven orientations in the interior of metastable beta titanium alloys, resulting in anisotropy of alloy performance. During solid solution aging, these textures have complex development trends with changes in heat treatment parameters and phase composition of the alloy, which limits the application of the alloy.

[0005] The processing history of metastable beta titanium alloy materials causes preferred orientation in the interior of the alloy. During the solid solution aging strengthening process, these preferred orientation textures have complex evolution. Therefore, studying different texture evolution mechanisms, reasonably explaining the texture types and evolution processes, and clarifying the changes in texture types and strength of metastable beta titanium alloys during solid solution aging have become an important way to research and develop metastable beta titanium alloys. For example, Zhang Junsong et al. studied two different texture evolution mechanisms of Ti3Sn / TiNi eutectic soft and hard dual-phase composite materials during compression, and reasonably explained the texture types and evolution processes.

[0006] Synchronous radiation HEXRD method is a powerful tool for studying metal and alloy with high angular resolution and strong penetration ability, and the Debye ring obtained contains not only the diffraction angle and the diffraction peak information of the corresponding crystal face, but also the diffraction intensity information of a certain diffraction ring on the macroscopic orientation angle of the sample. When the intensity fluctuation is observed, the existence of texture can be easily judged. Through data extraction of the corresponding ring, a one-dimensional diffraction intensity curve changing with the orientation angle 0°-360° can be drawn, and the texture is oriented and divided according to the relationship between the curve and the extrusion direction (AD) and the radial direction (RD) of the cylinder. For multi-texture or texture before and after turning, the micro-crystal coordinate system and the macro-sample coordinate system are connected, and the information of one texture and the corresponding two coordinate systems are used to deduce the orientation of other textures relative to it.

[0007] In addition, titanium alloy is treated by heat treatment such as solid solution treatment and aging treatment, which is an important method to eliminate internal stress of titanium alloy after machining such as extrusion and improve the comprehensive performance of titanium alloy. The titanium alloy heat treatment process is prepared by the method for measuring the texture of titanium alloy.

[0008] The appearance of texture will affect the uniformity and isotropy of titanium alloy, and then negatively affect the mechanical properties. Therefore, the inventors of the present application consider that the combination application of the synchronous radiation HEXRD method in the existing development technology of titanium alloy for studying the texture of titanium alloy and the heat treatment process of titanium alloy is rarely seen, and think about how to apply it to analyze the texture of titanium alloy to develop a new type of titanium alloy or improve the processing technology of titanium alloy, especially the heat treatment process. That is, the present application considers that the existing technology does not obtain titanium alloy with target performance by analyzing the influence of heat treatment process on the change trend of texture, and further thinks that the heat treatment process for obtaining target titanium alloy texture can be analyzed by analyzing the influence of heat treatment process on the texture of titanium alloy, so as to develop the heat treatment process of titanium alloy with target performance. SUMMARY

[0009] The inventors of the present application believe that the solid solution aging treatment significantly enhances the texture intensity of the alpha s phase, so that the alpha s phase with certain orientation is preferentially precipitated during phase transition, and therefore it is proposed to have two-phase structure, which is equiaxed alpha pMetastable β-titanium alloys, consisting of a β-matrix phase and a β-matrix phase, were subjected to solution treatment in the two-phase region followed by aging treatment with different parameters. The evolution of the internal texture of each phase exhibited unique characteristics. Synchrotron radiation technology, combined with analysis of grain micro-orientation and macroscopic azimuth angles of the samples, allowed for the differentiation of textures between different phases. Furthermore, it enabled the determination of texture types, strength information, and transformations before and after heat treatment during solution aging. This improved processing method for metastable β-titanium alloys, utilizing the high heat treatment strengthening effect and employing solution aging treatment to significantly enhance the alloy's strength and plasticity, holds broad application prospects in demanding fields such as aerospace.

[0010] According to a specific embodiment of the present invention, a method for determining the texture of titanium alloys is provided, comprising the following steps:

[0011] Step 1: Sample Preparation

[0012] Cylindrical samples are cut from the center of a forged or extruded titanium alloy forging using a CNC wire cutting machine. These samples are then divided into several groups, such as, but not limited to, three, four, or five groups.

[0013] The cylindrical samples were preferably subjected to solution treatment. Then, the first group of samples was subjected to high-temperature aging treatment, the second group of samples was subjected to low-temperature aging treatment, and the third group of samples was subjected to low-temperature aging and high-temperature aging treatment in sequence. After aging, each group of cylindrical samples was air-cooled to room temperature. The three groups of cylindrical samples are given only as examples and do not constitute any limitation on the present invention.

[0014] Step 2: Obtain the Debye ring and export the Debye ring data.

[0015] Synchrotron radiation high-energy X-ray diffraction (HEXRD) experiments were conducted on samples that had undergone different treatments and cooled to room temperature. The diffraction intensities of β(110), β(200), and α(0002) in the Debye ring of the samples, which showed significant changes with azimuth angle, were extracted. The diffraction ring data were collected and plotted as a diffraction intensity-azimuth relationship diagram.

[0016] Step 3: Analyze the main texture preference orientation

[0017] Based on the angle and intensity information in the diffraction intensity-azimuth angle, the preferred orientation of the main texture is analyzed;

[0018] Step 4: Analyze and obtain the trend of texture changes.

[0019] α-solution occurs p →β transformation occurs, with most of the equiaxed α phase dissolved in the matrix phase; aging results in β→α. s The transformation involved the precipitation of needle-like secondary α-phase from the matrix phase, and a comparative analysis was conducted on the changing trends of the solution-aged texture.

[0020] Preferably, the titanium alloy adopts a metastable β titanium alloy in a solid solution state. Further preferably, the metastable β titanium alloy contains 3-5 at.% of Al, 5-7 at.% of V, 4-6 at.% of Al, 2-4 at.% of Cr, 3-5 at.% of Al, 0-2 at.% of Zr, and the balance of Ti and inevitable impurities. Still further preferably, the titanium alloy is Ti-4Al-6V-5Mo-3Cr-1Zr.

[0021] Preferably, the solid solution treatment is to subject the alloy to solid solution treatment at 780-800 ℃ for 0.5-1 h and then air cool to room temperature, the low-temperature aging treatment is to age the titanium alloy at 250-350 ℃ for 3-5 h and then air cool to room temperature, and the high-temperature aging treatment is to age the titanium alloy at 500-550 ℃ for 5-7 h and then air cool to room temperature.

[0022] Further preferably, in the solid solution treatment, the titanium alloy is subjected to solid solution treatment at 795 ℃ for 0.5 h and then air cool to room temperature; in the low-temperature aging, the titanium alloy is aged at 300 ℃ for 4 h and then air cool to room temperature; and in the high-temperature aging, the titanium alloy is aged at 520 ℃ for 6 h and then air cool to room temperature.

[0023] According to one specific embodiment of the present application, a method for titanium alloy heat treatment process is provided by determining the texture of the titanium alloy by the method as described above,

[0024] First, the samples are subjected to different heat treatment processes, the texture is analyzed, the sample corresponding to the heat treatment process with the highest target texture proportion is found, and then the corresponding heat treatment process is determined, which specifically includes the following steps:

[0025] Step one, preparing samples

[0026] From the titanium alloy forgings formed by forging extrusion, cylindrical samples are cut from the center part by a numerical control wire cutting machine tool, and the cylindrical samples are divided into several groups, for example but not limited to three groups, four groups, five groups of samples.

[0027] Taking the case of dividing the samples into three groups for example, first, each group of samples is subjected to solid solution treatment, then the first group of samples is subjected to high-temperature aging treatment, i.e., it is subjected to solid solution treatment + high-temperature aging treatment; the second group of samples is subjected to low-temperature aging treatment, i.e., it is subjected to solid solution treatment + low-temperature aging treatment; and the third group of samples is subjected to low-temperature aging and high-temperature aging in turn, i.e., it is subjected to solid solution treatment + low-temperature aging + high-temperature aging treatment, and the three groups of cylindrical samples are all air cooled to room temperature after the above aging.

[0028] Step two, obtaining Debye ring and deriving Debye ring data

[0029] The room temperature samples in different states are subjected to HEXRD (high energy X-ray diffraction) experiment, and the β(110), β(200), α(0002), β(1100), β(2200) and α(0004) in the Debye ring of the sample are extracted, which are significantly changed with the azimuth angle, The diffraction ring data are plotted into the diffraction intensity-azimuth angle graph;

[0030] Step three, analysis of the main texture preferred orientation

[0031] According to the angle and intensity information in the diffraction intensity-azimuth angle, the preferred orientation of the main texture is analyzed;

[0032] Step four, analysis of the texture change trend

[0033] Combining the α p →β transition, most of the equiaxed α phase is dissolved in the matrix phase; the β→α s transition occurs during aging, and acicular secondary α phase is precipitated from the matrix phase. The change trend of the solution and aging textures is compared and analyzed.

[0034] Step five, development of heat treatment process

[0035] The types and intensities of the textures in the plurality of cylindrical samples are compared, and the group with the least texture is found. According to the heat treatment process it has undergone, a perfect heat treatment process for obtaining a titanium alloy with uniform structure and isotropic is developed.

[0036] Preferably, the solution treatment is that the alloy is solution treated at 780-800°C for 0.5-1h and then air cooled to room temperature.

[0037] Preferably, the low-temperature aging treatment is that the titanium alloy is aged at 250-350°C for 3-5h and then air cooled to room temperature.

[0038] Preferably, the high-temperature aging treatment is that the titanium alloy is aged at 500-550°C for 5-7h and then air cooled to room temperature.

[0039] Further preferably, in the solution treatment, the titanium alloy is solution treated at 795°C for 0.5h and then air cooled to room temperature; in the low-temperature aging, the titanium alloy is aged at 300°C for 4h and then air cooled to room temperature; in the high-temperature aging, the titanium alloy is aged at 520°C for 6h and then air cooled to room temperature.

[0040] Further preferably, the titanium alloy is a metastable beta titanium alloy containing 3-5 at.% Al, 5-7 at.% V, 4-6 at.% Al, 2-4 at.% Cr, 3-5 at.% Al, 0-2 at.% Zr, and the balance Ti and inevitable impurities. Still further preferably, the titanium alloy is Ti-4Al-6V-5Mo-3Cr-1Zr.

[0041] Compared with the prior art, the present application has the advantages and beneficial effects that:

[0042] 1. Traditional texture analysis is mainly carried out by the information in pole figure and inverse pole figure output by EBSD test, and usually only the crystal structure and orientation information of a local area can be obtained, and the texture characteristics of the whole sample cannot be comprehensively reflected. The selection of technical parameters such as step size and image calibration will affect the accuracy of grain or cell size calculation. In the present method, the hard X-ray generated by synchrotron radiation has high energy and deep penetration ability, and the diffraction information of the whole volume can be quickly obtained without damaging the sample.

[0043] 2. Compared with the traditional analysis method, the present method can accurately express the macroscopic preferred orientation of the whole sample and accurately reflect the complex orientation relationship inside the crystal.

[0044] 3. The present application finds the group with the least texture by comparing the types and intensities of textures in the plurality of cylindrical samples, and formulates a perfect heat treatment process for obtaining a titanium alloy with uniform structure and isotropy according to the heat treatment process it has undergone. BRIEF DESCRIPTION OF DRAWINGS

[0045] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout the figures. The accompanying drawings are intended to provide a further understanding of embodiments of the present disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and serve to explain the present disclosure, and do not constitute a limitation of the present disclosure. In the drawings, like reference numerals refer to like parts throughout the various figures.

[0046] Figure 1 A diffraction intensity-azimuth angle relationship diagram obtained according to Embodiment 1 of the present disclosure is shown;

[0047] Figure 2 In FIG. 2, a), b) show Figure 1 In FIG. 2, a), b) show

[0048] Figure 3 In FIG. 3, a) shows the crystal cell orientation of the beta phase and alpha phase corresponding to the strongest group of preferred orientations in FIG. 2; Figure 2the preferred orientation position of the displayed secondary texture after the beta phase unit cell of a) is rotated 30° clockwise around the X axis of the sphere, b), c) show the preferred orientation position of the displayed secondary texture after the alpha phase unit cell of b) is rotated 15° counterclockwise and 45° clockwise around the X axis of the sphere, respectively; Figure 2 the preferred orientation position of the displayed secondary texture after the alpha phase unit cell of b) is rotated 15° counterclockwise and 45° clockwise around the X axis of the sphere, respectively;

[0049] Figure 4 a diffraction intensity-azimuthal angle relationship diagram of Example 2 of the present disclosure is shown;

[0050] Figure 5 a diffraction intensity-azimuthal angle relationship diagram of Example 3 of the present disclosure is shown;

[0051] Figure 6 a texture preferred orientation diagram of Example 3 of the present disclosure is shown, wherein a), b) show the preferred orientation diagram of the alpha phase texture in the solid solution state, c), d) show the preferred orientation position of the texture after the alpha phase unit cell in a), b) is rotated 35° clockwise around the X axis of the Ewald sphere; Figure 6 the preferred orientation position of the displayed secondary texture after the alpha phase unit cell of b) is rotated 15° counterclockwise and 45° clockwise around the X axis of the sphere, respectively;

[0052] Figure 7 a diffraction intensity-azimuthal angle relationship diagram obtained according to Example 4 of the present disclosure is shown;

[0053] Figure 8 a diffraction intensity-azimuthal angle relationship diagram obtained according to Example 4 of the present disclosure is shown. DETAILED DESCRIPTION

[0054] 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 a part of the embodiments of the present disclosure, rather than all the embodiments of the present disclosure, and it should be understood that the present disclosure is not limited to the example embodiments described herein.

[0055] The inventors of the present application propose to use the texture research method applied in the above-mentioned synchrotron HEXRD method, and to perform the following steps:

[0056] (1) A titanium alloy is prepared, and synchrotron HEXRD detection is performed after several different heat treatments. The axial direction (AD) of the cylindrical sample used in the experiment is the extrusion direction, and the sample is placed horizontally perpendicular to the incident beam. The two radial directions (RD) are perpendicular and parallel to the incident beam, respectively. The azimuthal angles of the axial direction and the radial direction perpendicular to the incident beam correspond to 0° and 90° in the Debye ring, respectively. Fit2D, Origin, and other software are used to process the obtained synchrotron data. Through the changes of the preferred orientation intensity and the azimuthal angle in the image, combined with the two-phase crystal structure information, the relative positions among the multiple organizations in the gold, the orientation change of the main texture in each phase under different heat treatment states, and the strength change of the texture before and after heat treatment are quantitatively described.

[0057] (2) After obtaining the Debye ring of the sample, a diffraction ring with obvious change in diffraction intensity at different azimuth angles, i.e. a diffraction ring with preferred orientation, is selected, and one-dimensional diffraction data of the selected diffraction ring changing in azimuth angle is derived.

[0058] (3) The preferred orientation angle and intensity information in different states are compared, the texture type in a single sample and the change of texture between different samples are summarized, and reasonable explanation is given in combination with the microstructure and phase change.

[0059] (4) According to the preferred orientation information of a microstructure, a crystal cell meeting the condition is placed at the center of the Ewald sphere, and by rotating the crystal cell around the sphere, texture positions meeting other preferred orientations are obtained.

[0060] Embodiment

[0061] The present application will be further described below in combination with the embodiment of material texture characterization, but the present application is not limited to the following embodiment.

[0062] Embodiment 1

[0063] This embodiment is directed to texture analysis of a metastable β titanium alloy Ti-4Al-6V-5Mo-3Cr-1Zr (the numbers represent the atomic percentage in the alloy, the same below, the balance is Ti and unavoidable impurities). The analysis is realized by the following steps:

[0064] (1) Preparation of sample

[0065] The ingot of the above titanium alloy is first subjected to forging at 850-950℃, air-cooled to room temperature after unloading, and then extruded into a cylindrical sample with a size of 10mm x 10mm x 100mm at a temperature above the β phase transition temperature, and then the cylindrical sample is polished.

[0066] (2) Derivation of Debye ring data

[0067] The sample is subjected to HEXRD detection of synchrotron radiation, the cylindrical sample is placed horizontally with the axis direction (AD) being the extrusion direction and perpendicular to the incident beam, and the two radial directions (RD) are perpendicular and parallel to the incident beam, respectively, and the axis direction and the radial direction perpendicular to the incident beam correspond to the azimuth angles of 0° and 90° in the Debye ring, respectively. The obtained synchrotron radiation data is processed by using software such as Fit2D and Origin, and thus the Debye ring of the sample is obtained.

[0068] ​In Fit2D software, the radius range of the target diffraction ring is selected using the tools "INNER RADIUS" and "OUTER RADIUS". The data within the selected ring is then integrated using the "INTEGRATE" operation to extract the diffraction intensity β(110), β(200), and α(0002) in the Debye ring of the sample, which show significant changes with azimuth angle. Diffraction ring data, and plotted as follows: Figure 1 .

[0069] (3) Main texture preference

[0070] according to Figure 1 The diffraction intensity-azimuth relationship diagram is used to distinguish and summarize the preferred orientation of the main textures.

[0071] (4) Draw the Ewald sphere

[0072] Based on the preferred orientation information of the main filamentary textures of the β and α phases, a unit cell meeting the conditions is drawn as follows: Figure 2 As shown in a) and b), after placing the unit cell at the center of the Ewald sphere, the relative positions of the preferred orientations of the two phases within the sphere are as follows: Figure 2 As shown in c) and d).

[0073] (5) β phase texture relationship

[0074] exist Figure 1 In the middle, the β phase, besides... Figure 2 The silk texture shown in c) also has some relatively weak silk textures at other angles, by... Figure 2 c) The β-phase unit cell is obtained by rotating it 30° clockwise around the X-axis of the sphere. Figure 3 a) It can be seen that the texture orientation after rotation is... Figure 1 The orientation of the relatively weak texture in the middle β phase is basically consistent.

[0075] (6) α phase texture relationship

[0076] exist Figure 1 In the middle, the α phase, besides... Figure 2 The filamentary texture shown in d) also exhibits some relatively weaker filamentary textures at other angles. For the secondary textures in the α phase, such as... Figure 3 As shown in b) and c), by Figure 2 d) After rotating the α-phase unit cell counterclockwise by 15° and clockwise by 45° around the X-axis of the sphere, the resulting new preferred orientation direction is... Figure 1 The orientation of the relatively weak texture in the α phase is basically consistent.

[0077] from Figure 1 as well as Figure 2From a), c), it can be seen that the main filament texture in the β phase is β<110> with an angle of 45° to the AD and RD of the cylindrical sample and β<200> located near the AD and RD directions. From Figure 1 and Figure 2 From b), d), it can be seen that the main filament texture in the α phase is α<0002> with an angle of 45° to the AD and RD and By rotating the Ewald sphere, from Figure 3 a), it can be seen that the two texture directions in the β phase of the alloy are at an angle of 30° to each other, and from Figure 3 b), c), it can be seen that the three texture directions in the α phase are at an angle of 0°, 45° and 60° to the axial direction AD, respectively.

[0078] Example 2

[0079] This example is directed to texture analysis of the metastable β titanium alloy Ti-4Al-6V-5Mo-3Cr-1Zr in the solid solution state, and the analysis results are achieved by the following steps:

[0080] (1) Sample preparation

[0081] The titanium alloy is first subjected to forging and extrusion as in Example 1, and then subjected to a solid solution treatment at 795°C for 0.5h, air-cooled to room temperature, cut into samples with a size of and polished.

[0082] (2) Derivation of Debye ring data:

[0083] The sample is subjected to HEXRD detection of synchrotron radiation, the axial direction (AD) of the cylindrical sample is the extrusion direction, and the sample is placed horizontally perpendicular to the incident beam, and the two radial directions (RD) are perpendicular and parallel to the incident beam, respectively, and the axial direction and the radial direction perpendicular to the incident beam correspond to the azimuthal angles of 0° and 90° in the Debye ring, respectively. The obtained synchrotron radiation data is processed using software such as Fit2D and Origin, and thus the Debye ring of the sample is obtained.

[0084] In the Fit2D software, the radius range in which the target diffraction ring is located is selected by using the tools "INNER RADIUS" and "OUTER RADIUS", and the data in the selected annulus is integrated by the "INTEGRATE" operation, and the β(110), β(200), α(0002), α(1010) and α(1120) in the Debye ring of the sample which change significantly with the azimuthal angle are extracted. The diffraction ring data is plotted into a diffraction intensity-azimuthal angle relationship diagram as shown in Figure 4 .

[0085] (3) Main texture preferred orientation:

[0086] According toFigure 4 the angle and intensity information in the Debye ring, the preferred orientation of the main texture is analyzed.

[0087] (4) Analysis of the trend of the texture change of the β phase and the α phase:

[0088] Combining the α p solid solution with the β to α transformation, most of the equiaxed α phase is dissolved in the matrix phase, and the orientation and intensity change trend of the alloy texture before and after the solid solution treatment are compared and analyzed.

[0089] From the Figure 4 it can be seen that the texture orientation information before and after the solid solution remains basically unchanged, and the texture intensity of the alloy generally presents the trend of increasing the β phase and decreasing the α phase. The main silk texture in the β phase is β <110> with a 45° angle between the cylindrical sample AD and RD, and β <200> near the AD and RD directions. The main silk texture in the α phase is α <0002> with a 45° angle between the AD and RD, and β(110) and β(200) main texture intensity increases to 161.7% and 155.8% of the original, respectively.

[0090] Example 3

[0091] This example is directed to the texture analysis of the metastable β titanium alloy Ti-4Al-6V-5Mo-3Cr-1Zr, and the analysis result is realized by the following steps:

[0092] (1) Preparation of the sample

[0093] Solid solution aging treatment: the above titanium alloy is first subjected to forging and extrusion as in Example 1, the alloy is subjected to solid solution treatment at 795℃ for 0.5h, then air cooling to room temperature, followed by high temperature aging at 520℃ for 6h, air cooling to room temperature, the titanium alloy subjected to solid solution treatment and high temperature aging treatment is cut into samples with a size of and polished.

[0094] (2) Derivation of Debye ring data:

[0095] The sample is subjected to HEXRD detection of synchrotron radiation, the axial direction (AD) of the cylindrical sample is the extrusion direction, and is placed horizontally perpendicular to the incident beam, the two radial directions (RD) are perpendicular and parallel to the incident beam, respectively, the azimuthal angles of the axial direction and the radial direction perpendicular to the incident beam in the Debye ring are 0° and 90°, respectively, the obtained synchrotron radiation data is processed using software such as Fit2D and Origin, and thus the Debye ring of the sample is obtained.

[0096] In the Fit2D software, the target diffraction ring is selected by using the tools "INNER RADIUS" and "OUTER RADIUS", and the data in the selected annulus is integrated by the "INTEGRATE" operation to extract the diffraction intensity of the sample Debye ring which changes significantly with the azimuth angle of β(110), β(200), α(0002), diffraction ring data, and draw the diffraction intensity-azimuth angle relationship diagram as shown in Figure 5 .

[0097] (3) Draw the Ewald sphere

[0098] observation Figure 5 The preferred orientation angle of the α phase is found to be different from that of the α phase in the solid solution state without high-temperature aging in Example 2. In order to explore the preferred orientation relationship of the α phase before and after high-temperature aging, the Ewald sphere of the α phase solid solution texture is drawn according to the conclusion in Example 2 as shown in Figure 6 a) and b) are the textures with angles of 45° and 60° with AD, respectively, and the rotation operation is performed to obtain Figure 6 c) and d), which are basically consistent with the preferred orientation angle of the α phase in Figure 5

[0099] (4) Analyze the texture change trend of the β phase and the α phase and the β→α s transformation and α s phase precipitation during high-temperature aging. According to the angle and intensity information in Figure 5 , the orientation and intensity change trend of the alloy texture before and after high-temperature aging are compared and analyzed. As shown in Figure 5 , compared with the solid solution state, the texture intensity of β(110) and β(200) is reduced by more than 80%, mainly distributed in the AD direction. The α(0002) orientation is closer to the AD and RD directions, and the texture intensity is enhanced by 119.2% and 584.2%, respectively. The α phase solid solution texture Figure 6 a) and b) are shown, and after rotating the unit cell in the Ewald sphere X axis clockwise by 35°, as shown in Figure 6 c) and d), it can be seen that the texture is turned to the direction with an angle of about 80° and 25° with AD, which indicates that the texture of the α s phase is about 30° relative to the α p phase.

[0100] Example 4

[0101] In this example, the metastable β titanium alloy Ti-4Al-6V-5Mo-3Cr-1Zr is subjected to texture analysis, and the analysis results are realized by the following steps: ​

[0102] (1) Preparation of the sample:

[0103] The above titanium alloy was first subjected to forging and extrusion as in Example 1, and the titanium alloy was solution treated, and the alloy was solution treated at 795°C for 0.5h and then air cooled to room temperature; then the titanium alloy was subjected to low-temperature aging treatment, and was kept at 300°C for 4h; after the low-temperature aging treatment, the titanium alloy cooled to room temperature was cut into a sample with a size of (2) Debye ring data is derived:

[0104] The sample was subjected to synchrotron HEXRD detection, the cylindrical sample axis (AD) was the extrusion direction, and was placed horizontally perpendicular to the incident beam, and the two radial directions (RD) were perpendicular and parallel to the incident beam, respectively, and the azimuthal angles of the axial direction and the radial direction perpendicular to the incident beam corresponded to 0° and 90° in the Debye ring, respectively, and the synchrotron data obtained was processed using software such as Fit2D and Origin, and thus the Debye ring of the sample was obtained.

[0105] In the Fit2D software, the radius range in which the target diffraction ring was located was selected by using the tools “INNER RADIUS” and “OUTER RADIUS”, and the data in the selected annulus was integrated by the “INTEGRATE” operation to obtain the Debye ring of the sample, and the β(110), β(200), α(0002), diffraction ring data in the Debye ring of the sample were extracted, and were plotted into a diffraction intensity-azimuthal angle relationship graph as shown in Figure 7 .

[0106] (3) Analysis of the change trend of the β phase and the α phase texture

[0107] According to the angle and intensity information in Figure 7 , the change trend of the orientation and intensity of the alloy texture before and after the low-temperature aging was compared. It was observed that the preferred orientation degree of the β phase and the α phase in Figure 7 was greatly enhanced. As can be seen from Figure 7 , it was found that the texture orientation information before and after the low-temperature aging basically remained unchanged. The main wire texture in the β phase was β<110> at an angle of 45° with the AD and RD of the cylindrical sample and β<200> near the AD and RD directions. The main wire texture in the α phase was α<0002> at an angle of 45° with the AD and RD and Compared with the solution state, β(110) was enhanced by 518.5% in the direction at an angle of 45° with the AD and RD; β(200) was enhanced by 298.1% in the direction near the RD. α(0002), was enhanced by 325.2% in the direction at an angle of 45° with the AD and RD.

[0108] Example 5

[0109] The metastable beta titanium alloy Ti-4Al-6V-5Mo-3Cr-1Zr was subjected to solution + double-stage aging (low temperature aging followed by high temperature aging) treatment, and the specific operation steps are as follows:

[0110] (1) Preparation of samples:

[0111] The titanium alloy was first subjected to forging and extrusion as in Example 1, and was subjected to solution treatment, and the alloy was subjected to solution treatment at 795°C for 0.5h and then air-cooled to room temperature; then the titanium alloy was subjected to low temperature aging treatment, and the titanium alloy after solution treatment was aged at 300°C for 4h and then air-cooled to room temperature; then the titanium alloy was subjected to high temperature aging treatment, and the titanium alloy subjected to low temperature aging treatment was aged at 520°C for 6h and then air-cooled to room temperature; the sample after solution + double-stage aging treatment was cut into a size of and polished.

[0112] (2) Derivation of Debye ring data:

[0113] The sample was subjected to synchrotron HEXRD detection, the axial direction (AD) of the cylindrical sample was the extrusion direction, and the sample was placed horizontally perpendicular to the incident beam, and the two radial directions (RD) were perpendicular and parallel to the incident beam, respectively, and the azimuthal angles of the axial direction and the radial direction perpendicular to the incident beam in the Debye ring were 0° and 90°, respectively. The obtained synchrotron data was processed using software such as Fit2D and Origin, and thus the Debye ring of the sample was obtained.

[0114] In the Fit2D software, the radius range of the target diffraction ring was selected by using the tools "INNER RADIUS" and "OUTER RADIUS", and the data in the selected annulus was integrated by "INTEGRATE" operation to obtain the Debye ring of the sample, and the diffraction intensity of the sample Debye ring which changed significantly with the azimuthal angle was extracted, and the β(110), β(200), α(0002), diffraction ring data, and plotted into a diffraction intensity-azimuthal angle relationship graph as shown in Figure 8 .

[0115] (3) Analysis of the change trend of beta phase and alpha phase texture

[0116] According to the angle and intensity information in Figure 8 , the orientation and intensity change trend of the alloy texture before and after double-stage aging was compared.

[0117] As shown in Figure 8 , compared with Figure 4In solid solution state, the texture intensity of β(110) and β(200) in AD, RD direction respectively decreased by 82.8%, 12.8%, mainly distributed in AD direction; the texture intensity of α(0002), increased by 64.0%, 302.3% respectively. In combination with the results of solid solution + high temperature aging in example 3, the texture intensity and preferred orientation position of α phase and β phase after double-stage aging treatment are similar to the experimental results after high temperature aging.

[0118] From the comparison of the above examples, by comparing the type and intensity of the texture contained in the samples in different states, the group with the least texture and the weakest intensity can be found, and according to the heat treatment process it has undergone, a good foundation is laid for formulating a perfect heat treatment process for obtaining a titanium alloy with uniform structure and isotropy.

[0119] For example, in order to obtain a titanium alloy with lower texture intensity of β(110) and β(200) of β phase in AD, RD direction compared with solid solution state, a solid solution treatment + high temperature aging heat treatment process can be designed, and more preferably as in the present application, the metastable β titanium alloy Ti-4Al-6V-5Mo-3Cr-1Zr is first subjected to forging and extrusion, and then subjected to solid solution treatment, the alloy is solid solution treated at 795℃ for 0.5h and then air cooled to room temperature; then the titanium alloy is subjected to high temperature aging treatment, and is kept at 520℃ for 6h; and then air cooled to room temperature, finally the texture intensity of β phase is reduced by more than 80%.

[0120] For another example, if a titanium alloy heat treatment process is required in which the texture intensity of β(110) and β(200) of β phase is significantly reduced and mainly distributed in AD direction, a heat treatment process as in the present application can be used, in which the metastable β titanium alloy Ti-4Al-6V-5Mo-3Cr-1Zr is first subjected to solid solution, and then subjected to low temperature aging and high temperature aging in sequence, and then air cooled to room temperature.

[0121] Based on the above examples 1-5, the present application has the following characteristics:

[0122] 1. The data for the study of titanium alloy texture is obtained from the HEXRD experiment of synchrotron radiation.

[0123] 2. The azimuthal angle-diffraction intensity curve of the diffraction ring is drawn, and the orientation and intensity change of the corresponding α phase and β phase texture is analyzed.

[0124] 3. According to the preferred orientation angle of the main texture, the unit cell is drawn, the crystal coordinate system is combined with the sample coordinate system, the orientation change of the unit cell located at the center of the Ewald sphere is driven by the rotation of the Ewald sphere, and it is matched with the secondary texture orientation, so as to reflect the multiple textures in single phase, and the orientation relative position of the texture before and after heat treatment.

[0125] The above describes the basic principles of the present disclosure in combination with specific embodiments, but it needs to be pointed out that the advantages, benefits, effects and the like mentioned in the present disclosure are only examples and are not limiting, and these advantages, benefits, effects and the like cannot be considered as necessary for each embodiment of the present disclosure. In addition, the above specific details of the disclosure are only for the purpose of example and for the purpose of understanding, and are not limiting, and the above details do not limit the present disclosure to be necessarily implemented with the above specific details.

[0126] 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, configuration as shown in the block diagram. As those skilled in the art will recognize, these devices, apparatuses, equipment, systems can be connected, arranged, configured in any manner. 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.

[0127] It also needs to be pointed out 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 recombination should be considered as equivalent solutions of the present disclosure.

[0128] The above description of the disclosed aspects is provided so that any person skilled in the art can make or use the present disclosure. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the aspects shown herein, but rather is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

[0129] The above description has been given for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present disclosure to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain modifications, alterations, changes, additions and sub-combinations thereof.

Claims

1. A method for determining the texture of titanium alloys, comprising the following steps: Step 1: Sample Preparation Cylindrical specimens are cut from the center of the forged and extruded titanium alloy forgings, and the cylindrical specimens are divided into multiple groups and subjected to heat treatment respectively to obtain room temperature specimens for obtaining Debye rings. Step 2: Obtain the Debye ring and export the Debye ring data. The cylindrical sample obtained after the heat treatment at room temperature was subjected to synchrotron high-energy X-ray diffraction (HEXRD) experiments. The diffraction intensities of β(110), β(200), and α(0002) in the Debye ring of the sample, which showed significant changes with azimuth angle, were extracted. The diffraction ring data were collected and plotted as a diffraction intensity-azimuth relationship diagram. Step 3: Analyze the preferred orientation of main textures Based on the angle and intensity information in the diffraction intensity-azimuth angle, the preferred orientation of the main texture is analyzed; Step 4: Analyze and obtain the trend of texture changes. α-solution occurs p →β transformation occurs, with most of the equiaxed α phase dissolved in the matrix phase; aging results in β→α. s The transformation involves the precipitation of needle-like secondary α phases from the matrix phase, exhibiting a change in texture compared to titanium alloys that have undergone simple solid solution treatment.

2. The method according to claim 1, wherein, The titanium alloy is a metastable β titanium alloy in a solid solution state. The cylindrical samples are divided into three groups, which are subjected to solid solution treatment + high temperature aging treatment, solid solution treatment + low temperature aging treatment, and solid solution treatment + low temperature aging treatment + high temperature aging treatment, respectively. After aging, they are all air-cooled to room temperature.

3. The method according to claim 1 or 2, wherein, The titanium alloy is a metastable β-titanium alloy containing 3-5 at.% Al, 5-7 at.% V, 4-6 at.% Al, 2-4 at.% Cr, 3-5 at.% Al, 0-2 at.% Zr, with the balance being Ti and unavoidable impurities.

4. The method according to claim 3, wherein, The titanium alloy is Ti-4Al-6V-5Mo-3Cr-1Zr.

5. The method according to claim 2, wherein, The solution treatment involves treating the titanium alloy at 795°C for 0.5 hours and then air-cooling it to room temperature. The low-temperature aging treatment involves aging the solution-treated titanium alloy at 250–350°C for 3–5 hours, followed by air cooling to room temperature. The high-temperature aging treatment involves holding the titanium alloy that has undergone low-temperature aging treatment at 500–550°C for 5–7 hours, followed by air cooling to room temperature.

6. A method for developing a heat treatment process for titanium alloys, comprising the method for determining the texture of titanium alloys according to any one of claims 1 to 5. Its features are, Also includes: Step 5: Develop the heat treatment process By comparing the types and intensities of textures in the multiple groups of cylindrical samples, the group with the fewest textures is identified. Based on the heat treatment processes it has undergone, a comprehensive heat treatment process is developed to obtain titanium alloys with uniform and isotropic microstructures.

7. The method for formulating a heat treatment process for titanium alloys according to claim 6, Its features are, The cylindrical samples were divided into three groups, which were subjected to solution treatment + high temperature aging treatment, solution treatment + low temperature aging treatment, and solution treatment + low temperature aging treatment + high temperature aging treatment, respectively. After aging, all samples were air-cooled to room temperature.

8. The method for formulating a heat treatment process for titanium alloys according to claim 7, Its features are, The solution treatment involves treating the alloy at 780–800°C for 0.5–1 hour and then air-cooling it to room temperature. The low-temperature aging treatment involves aging the solution-treated titanium alloy at 250–350°C for 3–5 hours, followed by air cooling to room temperature. The high-temperature aging treatment involves holding the titanium alloy that has undergone low-temperature aging treatment at 500–550°C for 5–7 hours, followed by air cooling to room temperature.

9. The method for formulating a heat treatment process for titanium alloys according to claim 8, characterized in that, In the solution treatment, the titanium alloy was solution treated at 795°C for 0.5 hours, and then air-cooled to room temperature. In the aforementioned low-temperature aging process, the titanium alloy is aged at 300°C for 4 hours, and then air-cooled to room temperature. In the high-temperature aging process, the titanium alloy was held at 520°C for 6 hours and then air-cooled to room temperature.

10. The method for formulating a heat treatment process for titanium alloys according to claim 7 or 8, characterized in that, The titanium alloy is a metastable β-titanium alloy containing 3-5 at.% Al, 5-7 at.% V, 4-6 at.% Al, 2-4 at.% Cr, 3-5 at.% Al, 0-2 at.% Zr, with the balance being Ti and unavoidable impurities.

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