Preparation method of high-performance Ti2AlNb alloy forging stock
By optimizing multi-stage forging and heat treatment, the problems of cracking and uneven microstructure in the forging process of Ti2AlNb alloy were solved, and the preparation of high-performance forging billets was realized, which met the requirements of high thrust-to-weight ratio and mechanical properties of aero-engine components.
Patent Information
- Application Number
- CN202511520387.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-23
- Publication Date
- 2026-01-23
AI Technical Summary
The existing Ti2AlNb alloy is prone to cracking and uneven microstructure during forging, making it difficult to meet the requirements of high thrust-to-weight ratio and excellent mechanical properties of aero-engines.
By using multi-stage forging, bar forging, and biscuit forging, combined with appropriate heating temperature and deformation, the heat treatment process is optimized to refine and homogenize the grains and control the microstructure and distribution.
It improves the comprehensive mechanical properties and microstructure uniformity of Ti2AlNb alloy forgings, meeting the high-performance requirements of aero-engine components, and has high production efficiency and simple operation.
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Figure CN121373255A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of non-ferrous metal processing methods, and particularly relates to a preparation method of high-performance Ti2AlNb alloy forged blanks. BACKGROUND
[0002] Ti2AlNb alloy is an intermetallic compound alloy based on ordered orthorhombic structure O phase, has high specific strength and good creep resistance and oxidation resistance, and the density is relatively low compared with nickel-based high-temperature materials. Ti2AlNb alloy is mainly used for manufacturing key components such as turbine disks, casings and blisks of aero-engines, and is considered as an ideal light specific gravity high-temperature structural material for helping aero-engines to realize performance improvement through structural weight reduction.
[0003] With the continuous development of China's aerospace industry, higher requirements are put forward for the mechanical properties of Ti2AlNb alloy. However, Ti2AlNb alloy belongs to a ternary system, which is composed of complex β / B2, α2 and O phase structures, and the phase transition relationship is complex, and the microstructure and mechanical properties are sensitive to thermal mechanical processing.
[0004] In the conventional forging method of Ti2AlNb alloy, the blank is usually placed in the furnace for heating and then placed in a die much smaller than the blank temperature for forging deformation. However, in this forging process, the blank temperature rapidly decreases, the deformation resistance continuously rises, the plasticity of the forged piece decreases, and the internal stress sharply increases, which easily causes cracking, resulting in uneven deformation of the forged piece.
[0005] Therefore, in order to meet the requirements of high thrust-to-weight ratio and excellent mechanical properties of turbine disk of aero-engine in China, it is of great practical significance to invent a preparation method of high-performance Ti2AlNb alloy forged blanks. SUMMARY
[0006] In view of the above shortcomings of the prior art, the application provides a preparation method of high-performance Ti2AlNb alloy forged blanks, which optimizes the basic process parameters of alloy thermal deformation by designing the best deformation and microstructure control conditions of Ti2AlNb alloy, and finally optimizes the blank heating method, heating temperature, forging deformation and heat treatment system after forming, effectively solves the problems of cracking and uneven microstructure of the alloy during forging, reduces the anisotropy of the forged blank, and improves the comprehensive mechanical properties of the forged blank.
[0007] In order to achieve the above-mentioned application purposes, the application provides the following technical solutions: The application provides a preparation method of high-performance Ti2AlNb alloy forged blanks, comprising the following steps: S1, cogging forging; the Ti2AlNb alloy ingot is subjected to multi-pass cogging forging, first subjected to 1-3 passes of forging deformation, the forging deformation amount of each pass is 38%-42%; then subjected to 4-6 passes of forging deformation, the forging deformation amount of each pass is 35%-40%, the upsetting and drawing ratio of each time is 2.3-2.5; S2, bar forging; the cogged material after the cogging forging is subjected to multi-pass multi-directional forging deformation, first subjected to 4-6 passes of upsetting and drawing deformation, the deformation amount of each pass is 28%-33%, the upsetting and drawing ratio of each time is 1.8-2.0, to obtain an approximately octagonal blank; then the approximately octagonal blank is subjected to 2-4 passes of flat square upsetting and drawing deformation, the deformation amount of each pass is 35%-40%, and size surface interchanging deformation elongation is performed, to obtain an octagonal blank; the octagonal blank is heated to 900℃ for 60min, then heated to 980℃ for 180min, and then subjected to chamfering and roundness breaking to obtain a Ti2AlNb alloy bar or a Ti2AlNb alloy cake; S3, cake processing; the Ti2AlNb alloy cake is subjected to multi-pass isothermal forging deformation, first subjected to 1-3 passes of isothermal forging deformation, the forging deformation amount of each pass is 35%-40%, the holding time is 170min, then subjected to 2-4 passes of isothermal forging deformation, the forging deformation amount of each pass is 40%-45%, the holding time is 150min-240min; S4, the Ti2AlNb alloy cake after the Ti2AlNb alloy bar or cake processing is subjected to solid solution and aging treatment in an electric furnace to obtain a high-performance Ti2AlNb alloy blank, the solid solution temperature is 930 C°±10℃, the solid solution time is 2h, the cooling mode is water cooling; the aging temperature is 730 C°±10℃, the aging time is 24h, and the cooling mode is air cooling.
[0008] Preferably, in step S1, during each pass of cogging forging, the Ti2AlNb alloy ingot is placed in the furnace at a temperature of 850℃, held for 90min, then the furnace temperature is raised to 1000-1200℃, and held for 150-180min.
[0009] Preferably, in step S2, during each pass of forging deformation, the cogged material after the cogging forging is placed in the furnace at a temperature of 900℃, held for 60min, then the furnace temperature is raised to 985℃, and held for 160min.
[0010] Preferably, in step S3, the multi-pass isothermal forging deformation is performed on a die forging machine, the Ti2AlNb alloy cake is placed in the furnace at a temperature of 900℃, held for 60min, then heated to 980℃, and subjected to multi-pass forging deformation at 980℃, the final temperature is ≥870℃.
[0011] Preferably, in step S3, in the isothermal forging deformation process of 1-3 times, the reduction rate in each isothermal forging deformation process is 2mm / s, and the holding time is 1-200min after the material reduction reaches the preset deformation amount.
[0012] Preferably, in step S3, in the isothermal forging deformation process of 2-4 times, the hot material time in each isothermal forging deformation process is 60min-120min, and the reduction rate is 0.5mm / s.
[0013] Preferably, in step S4, before the solid solution and aging treatment, the Ti2AlNb alloy forging bar or the Ti2AlNb alloy forging cake after processing is machined to remove the surface oxide layer and the forging defects.
[0014] Compared with the prior art, the present application has the following beneficial technical effects: The present application has the following beneficial technical effects: The present application has the following beneficial technical effects:
[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly described below, and it should be known that the drawings described below only relate to some embodiments of the present disclosure, not limit the present disclosure, wherein: Figure 1 is the preparation method flow chart of the high-performance Ti2AlNb alloy forging cake provided by the present application.
[0016] Figure 2 is a comparison chart of room temperature tensile properties of Ti2AlNb alloy under different solid solution and aging treatments provided by the present application, wherein (a) is a comparison chart of room temperature strength, and (b) is a comparison chart of room temperature plasticity.
[0017] Figure 3are microstructure diagrams of Ti2AlNb alloy provided by the embodiment 1 and the comparative examples 4~6 of the present application, wherein (a) is a microstructure diagram of the embodiment 1, (b) is a microstructure diagram of the comparative example 4, (c) is a microstructure diagram of the comparative example 5, and (d) is a microstructure diagram of the comparative example 6.
[0018] Figure 4 are physical diagrams of the isothermal forging process of the pancake of the embodiment 2 of the present application, wherein (a) and (b) are physical diagrams after the first fire forging, (c) and (d) are physical diagrams after the second fire forging, and (e) and (f) are physical diagrams after the third fire forging.
[0019] Figure 5 is a physical diagram of the cracked forging blank in the open-die forging process of the Ti2AlNb alloy provided by the comparative example 1 of the present application.
[0020] Figure 6 is a physical diagram of the cracked forging blank in the open-die forging process of the Ti2AlNb alloy provided by the comparative example 2 of the present application.
[0021] Figure 7 is a physical diagram of the cracked forging blank in the open-die forging process of the Ti2AlNb alloy provided by the comparative example 3 of the present application.
[0022] Figure 8 is a microstructure diagram of the Ti2AlNb alloy provided by the embodiment 2 of the present application. DETAILED DESCRIPTION
[0023] In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by a person of ordinary skill in the art without creative effort also belong to the protection scope of the present disclosure.
[0024] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this present subject matter belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0025] Reference to“an embodiment” herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase“in an embodiment” in various places in the specification are not necessarily referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will understand that embodiments described herein can be combined with other embodiments.
[0026] The application provides a preparation method of a high-performance Ti2AlNb alloy forging blank, comprising the following steps: S1, open forging; the Ti2AlNb alloy ingot is subjected to multi-pass open forging, preferably 1-3 passes of forging deformation, for example, 1 pass, 2 passes, or 3 passes, and the deformation amount of each pass is preferably 38%-42%, for example, 38%, 39%, 40%, 41%, or 42%; and preferably 4-6 passes of forging deformation, for example, 4 passes, 5 passes, or 6 passes, and the deformation amount of each pass is preferably 35%-40%, for example, 35%, 36%, 37%, 37.5%, 38%, 39%, or 40%; and the upsetting and drawing ratio of each pass is preferably 2.3-2.5, for example, 2.3, 2.4, or 2.5; Specifically, the forging process is carried out on a 1600T oil press forging machine, and in each pass of open forging in step S1, the blank is placed in the furnace at a temperature of 850℃, and after 90min of heat preservation, the furnace temperature is preferably increased to 1000-1200℃, for example, 1000℃, 1020℃, 1050℃, 1080℃, 1100℃, 1150℃, or 1200℃, and the heat preservation time is preferably 150-180min, for example, 150min, 160min, 170min, or 180min, and after each pass, the ingot is subjected to forging deformation.
[0027] Specifically, in the forging process, the hot material is reheated for half the time, after the heat preservation process is completed, the heat preservation cotton is covered, and after 60min of reheating and heat preservation, the material is quickly transferred from the furnace to the oil press forging machine, and if the heat preservation time is extended by 30min due to unexpected sliding, etc. during the forging process, the material is reheated and heat preserved for 30min, and then taken out for forging, and the final temperature is not lower than 870℃.
[0028] S2, forging bar forging; the billet after the blooming forging is deformed by multiple heating times and multiple directions, preferably 4-6 heating times of upsetting and drawing deformation, for example, it can be 4 heating times, 5 heating times, 6 heating times, the deformation amount of each heating time is 28%-33%, and the upsetting and drawing ratio of each time is preferably 1.8-2.0, for example, it can be 1.8, 1.9, 2.0, to obtain an approximate octagonal billet; then the approximate octagonal billet is preferably deformed by 2-4 heating times of flat square upsetting and drawing, for example, it can be 2 heating times, 3 heating times, 4 heating times, the deformation amount of each heating time is 35%-40%, and the size surface interchanging deformation is elongated to obtain an octagonal billet; the octagonal billet is heated to 900°C in the furnace for 60 min, then heated to 980°C for 180 min, and then obtained by chamfering and rounding to obtain a Ti2AlNb alloy forging bar or a Ti2AlNb alloy forging cake; Specifically, in step S2, during the forging deformation process of each heating time, the billet after the blooming forging is placed in the furnace at a temperature of 900°C, heated to 985°C after 60 min of heat preservation, and heat preserved for 160 min.
[0029] Specifically, the rolling process of the Ti2AlNb alloy forging bar obtained by chamfering and rounding allows multiple re-furnace.
[0030] S3, forging cake processing; the Ti2AlNb alloy forging cake is deformed by multiple heating times of isothermal forging, preferably 1-3 heating times of isothermal forging deformation, for example, it can be 1 heating time, 2 heating times, 3 heating times, the deformation amount of each heating time is preferably 35%-40%, for example, it can be 35%, 36%, 37%, 38%, 39%, 40%, the heat preservation time is 170 min, then preferably 2-4 heating times of isothermal forging deformation, for example, it can be 2 heating times, 3 heating times, 4 heating times, the deformation amount of each heating time is 40%-45%, and the heat preservation time is preferably 150 min-240 min, for example, it can be 150 min, 170 min, 200 min, 220 min, 240 min, the billet is taken out of the furnace after the heat preservation time, re-heated and preserved for 60 min, then forged, and the heat preservation time is allowed to be extended by 30 min. When unexpected sliding occurs during the billet forging process, the billet is re-heated and preserved for 30 min, then forged, and the final temperature is not lower than 870°C; Specifically, in step S3, the multi-pass isothermal forging deformation is performed on a 100MN / 200MN die forging machine, and an isothermal lower die is selected as the die, the die temperature is 980℃, the Ti2AlNb alloy forging pancake is placed in the furnace at a temperature of 900℃, and after being kept for 60min, the temperature is raised to 980℃, and the multi-pass forging deformation is performed at 980℃; in the process of 1~3-pass isothermal forging deformation, the reduction rate in each pass of isothermal forging deformation is 2mm / s, and when the material reduction reaches the preset deformation, pressure holding is performed, the pressure holding time is 1~200min, after the pressure holding is completed, the forging ram is raised; in the process of 2~4-pass isothermal forging deformation, the hot material time in each pass of isothermal forging deformation is preferably 60min~120min, for example, it can be 60min, 70min, 80min, 90min, 100min, 110min, 120min, and the reduction rate is 0.5mm / s.
[0031] S4, after the Ti2AlNb alloy forging bar or the Ti2AlNb alloy forging pancake after processing is subjected to solid solution and aging treatment in an electric furnace, a high-performance Ti2AlNb alloy forging blank is obtained, the solid solution temperature is 930 C°±10℃, the solid solution time is 2h, the cooling mode is water cooling; the aging temperature is 730 C°±10℃, the aging time is 24h, and the cooling mode is air cooling; Specifically, before the solid solution and aging treatment, the Ti2AlNb alloy forging bar or the Ti2AlNb alloy forging pancake after processing is subjected to mechanical processing to remove the surface oxide layer and forging defects.
[0032] The following will be specifically described by examples.
[0033] Example 1 The nominal composition of the Ti2AlNb alloy ingot used is Ti-22Al-25Nb (at. %), the raw material is subjected to vacuum consumable arc melting (VAR) to obtain the used Φ260×916mm alloy ingot, and then wire cutting is adopted to obtain an ingot with a size of Φ260×396, and the forging process is performed on a 1600T oil press forging machine. The billet heating temperature and holding time are according to the requirement of each pass, the hot material reheat time is halved, after the end of the holding process, the holding cotton is covered, and after reheat for 60min, it is quickly transferred from the furnace to the oil press forging, and the reheat time is extended by 30min in case of unexpected sliding and other situations during the forging process, at this time, the reheat time is extended by 30min, and the forging is performed after the billet is taken out, and the final temperature is not lower than 870℃.
[0034] First heating, billet 850℃ into the furnace, holding time 90min, temperature rise to 1150℃, holding time 170min; The second fire heating, the blank 850℃ into the furnace, the holding time 90min, the temperature rising to 1100℃, the holding time 150min; The third fire heating, the blank 850℃ into the furnace, the holding time 90min, the temperature rising to 1080℃, the holding time 150min; The fourth fire heating, the blank 850℃ into the furnace, the holding time 90min, the temperature rising to 1020℃, the holding time 150min; The sixth fire heating, the blank 900℃ into the furnace, the holding time 60min, the temperature rising to 985℃, the holding time 160min; The eleventh fire heating, the blank 900℃ into the furnace, the holding time 60min, the temperature rising to 980℃, the holding time 180min.
[0035] The specific forging scheme is shown in Table 1: Table 1 Forging process scheme of the forged bar
[0036] After the blank forging is completed, sampling is carried out for solid solution and aging treatment, 930 C° solid solution holding for 2h, water quenching and then aging at 730 C° for 24h, air cooling; According to the room temperature tensile property test results of Fig. 2, the microstructure and performance of the Ti2AlNb alloy forged blank prepared by using the embodiment are uniform, and the mechanical properties are obviously superior to the mechanical properties of the forged blank obtained by using the traditional forging process, and the microstructure under the solid solution and aging heat treatment state in the embodiment is as shown in Fig. Figure 3 (a).
[0037] Example 2 The nominal composition of the ingot is Ti-22Al-25Nb (at. %), and the raw material is subjected to vacuum consumable arc melting to obtain the alloy ingot. Subsequently, a wire cutting is adopted to obtain an ingot with a size of Φ260x520. The forging process is carried out on a 1600T oil press forging machine, the blank heating temperature and holding time are according to the requirements of each fire, the hot material reheat time is halved, after the holding process is completed, the holding cotton is covered, and after 60min of reheat, it is quickly transferred from the furnace to the oil press forging, and the holding time is allowed to be extended by 30min. In the case of unexpected sliding and other situations, the blank is reheat for 30min, and then it is forged out of the furnace, and the final temperature is not lower than 870℃.
[0038] The first fire heating, the blank 850℃ into the furnace, the holding time 90min, the temperature rising to 1150℃, the holding time 170min; The second fire heating, the blank 850℃ into the furnace, the holding time 90min, the temperature rising to 1100℃, the holding time 150min; The third fire heating, billet 850℃ into the furnace, holding time 90min, heating to 1080℃, holding time 150min; The fourth and fifth fire heating, billet 850℃ into the furnace, holding time 90min, heating to 1020℃, holding time 150min; The sixth to tenth fire heating, billet 900℃ into the furnace, holding time 60min, heating to 985℃, holding time 160min; The eleventh fire heating, billet 900℃ into the furnace, holding time 60min, heating to 980℃, holding time 180min.
[0039] The specific forging scheme is shown in Table 2: Table 2 Forging scheme of forging cake
[0040] After the rod after forging is polished and treated, such as cleaning, isothermal forging is carried out on the 100MN / 200MN die forging machine, and the selected die is isothermal lower die, and the die temperature is 980℃. The forging process is that the billet is 900℃ into the furnace, the holding time is 60min, the temperature is raised to 980℃, the first fire holding time is 170min, the second fire is 245min (hot material 123min), and the third fire is 154min (hot material 77min). After the holding time, the furnace is taken out and the holding cotton is preserved, the furnace is reheated for 60min, and the furnace is taken out for forging, and the holding time is allowed to be extended by 30min. When the billet is forged and unexpected sliding occurs, the furnace is reheated for 30min, and the furnace is taken out for forging, and the final temperature is not lower than 870℃. The specific forging process is shown in Table 3, and the forging process is shown in Figure 4 .
[0041] Table 3 Isothermal forging process scheme of forging cake
[0042] After the forging cake is forged, sampling is carried out for microstructure analysis, and the organization form is shown in Figure 8 As shown in the figure, the gray lamellar O phase and the needle-like O phase are dispersedly distributed in the B2 matrix, and the volume fraction is relatively large, and it can be seen that the forging cake organization obtained through the forging process is uniform and has good performance.
[0043] Comparative Example 1 The nominal composition of the ingot used is Ti-22Al-25Nb (at. %), and the raw material is obtained by vacuum arc remelting. Then, a wire cutting is used to obtain an ingot with a size of Φ260x520. The forging process is carried out on a 1600T oil press forging machine. The heating temperature and holding time of the blank are required according to each fire, the hot material is reheated for half the time, after the holding process is over, the holding cotton is covered, and after 60 minutes of holding, it is quickly transferred from the furnace to the oil press forging, and the holding time is allowed to be extended by 30 minutes. In the case of unexpected sliding and other situations during the forging process, the blank needs to be reheated for 30 minutes and then forged out of the furnace, and the final temperature is not lower than 870℃.
[0044] The first fire heating, the blank is heated to 850℃, the holding time is 90min, the temperature is raised to 1150℃, and the holding time is 170min; The second fire heating, the blank is heated to 850℃, the holding time is 90min, the temperature is raised to 1100℃, and the holding time is 150min; The third fire heating, the blank is heated to 850℃, the holding time is 90min, the temperature is raised to 1080℃, and the holding time is 150min; The fourth and fifth fire heating, the blank is heated to 850℃, the holding time is 90min, the temperature is raised to 1020℃, and the holding time is 150min; In the first fire, the deformation amount is 40%, and in the second to fifth fires, the deformation amount is 47.5%. Compared with examples 1 and 2, in the comparative example 1, the deformation amount of the second to fifth fires is increased to 47.5%, which is obviously higher than the set 35%-40%. Due to the large deformation amount in the forging process, the blank cracks, as shown in Figure 5 .
[0045] Comparative example 2 The nominal composition of the Ti2AlNb alloy ingot used is Ti-22Al-25Nb (at. %), and the raw material is obtained by vacuum arc remelting (VAR) to obtain one Φ260x916mm alloy ingot, and then a wire cutting is used to obtain an ingot with a size of Φ260x396. The forging process is carried out on a 1600T oil press forging machine. The heating temperature and holding time of the blank are required according to each fire, the hot material is reheated for half the time, after the holding process is over, the holding cotton is covered, and after 60 minutes of holding, it is quickly transferred from the furnace to the oil press forging, and the holding time is allowed to be extended by 30 minutes. In the case of unexpected sliding and other situations during the forging process, the blank needs to be reheated for 30 minutes and then forged out of the furnace, and the final temperature is not lower than 870℃.
[0046] The first fire heating, the blank is heated to 850℃, the holding time is 90min, the temperature is raised to 1150℃, and the holding time is 170min; The second fire heating, billet 850℃ into the furnace, holding time 90min, heating to 1100℃, holding time 150min; The third fire heating, billet 850℃ into the furnace, holding time 90min, heating to 1080℃, holding time 150min; The fourth and fifth fire heating, billet 900℃ into the furnace, holding time 60min, heating to 985℃, holding time 160min; The sixth fire heating, billet 900℃ into the furnace, holding time 60min, heating to 980℃, holding time 180min.
[0047] In which the first fire deformation is 40%, the second and third fire deformation is 37.5%, the fourth and fifth fire deformation is 30%, and the sixth fire deformation is 37%. Compared with Example 1 and Example 2, the number of fires in the process of cogging and forging rod of the present comparative example is 3, which makes the residual stress large in the process of forging, and the billet cracks, as shown in Figure 6 .
[0048] Comparative Example 3 In the process of forging rod forging of the fifth to eighth fire of the present comparative example, the upsetting and drawing ratio of each time is the same as that in the process of cogging forging, that is, the process scheme in the fifth to eighth fire is 210 × 210 × 470 → upsetting to 295 → elongation to 210 × 210 × 470; the remaining steps are the same as those of Example 1.
[0049] In the present comparative example, fixed large forging ratio is used in the process of cogging and forging rod, which leads to cracking of the billet in the later stage, as shown in Figure 7 .
[0050] Comparative Example 4 The solid solution and aging treatment scheme of the present comparative example is 950 C° solid solution for 2h, water quenching, and aging at 730 C° for 24h, air cooling; the remaining steps are the same as those of Example 1.
[0051] Comparative Example 5 The solid solution and aging treatment scheme of the present comparative example is 950 C° solid solution for 2h, water quenching, and aging at 770 C° for 24h, air cooling; the remaining steps are the same as those of Example 1.
[0052] Comparative Example 6 The solid solution and aging treatment scheme of the present comparative example is 940 C° solid solution for 2h, water quenching, and aging at 790 C° for 24h, air cooling; the remaining steps are the same as those of Example 1.
[0053] Figure 2 is a chart of the results of the room temperature tensile property test of Example 1 and Comparative Examples 4-6, wherein in the abscissa of Figure 2 (a) and Figure 2 (b), 1 represents the test results of Example 1, 2 represents the test results of Comparative Example 4, 3 represents the test results of Comparative Example 5, and 4 represents the test results of Comparative Example 6. By comprehensively comparing and analyzing the yield strength, tensile strength and elongation of the prepared blank, it can be seen that the comprehensive mechanical property of Example 1 is the best.
[0054] Figure 3 Figure 3 is a microstructure chart of the forging blank of Example 1 and Comparative Examples 4-6, wherein, Figure 3 (a) is the microstructure chart of Example 1, Figure 3 (b) is the microstructure chart of Comparative Example 4, Figure 3 (c) is the microstructure chart of Comparative Example 5, Figure 3 (d) is the microstructure chart of Comparative Example 6. It can be seen from the chart that the internal organization of Comparative Examples 4-6 is relatively dispersed and uneven, and the internal organization of Example 1 is the most uniform. A large number of lath are dispersedly distributed in the matrix of Example 1, so that the alloy has high strength, and blocky and elliptical O phase exist.
[0055] The above only describes the preferred embodiments of the present application. It should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.
Claims
1. A method for preparing high-performance Ti2AlNb alloy forging blanks, characterized in that, The method comprises the following steps: S1, cogging forging; the Ti2AlNb alloy ingot is subjected to multi-pass cogging forging, first 1-3 passes of forging deformation, each pass of which is 38%-42% of the forging deformation amount; then 4-6 passes of forging deformation, each pass of which is 35%-40% of the forging deformation amount, and the upsetting and drawing ratio is 2.3-2.5; S2, bar forging; the cogged blank is subjected to multi-pass multi-directional forging deformation, first 4-6 passes of upsetting and drawing deformation, each pass of which is 28%-33% of the deformation amount, and the upsetting and drawing ratio is 1.8-2.0, to obtain an approximately octagonal blank; then the approximately octagonal blank is subjected to 2-4 passes of flat square upsetting and drawing deformation, each pass of which is 35%-40% of the deformation amount, and the large and small surface interchanging deformation is performed to elongate, to obtain an octagonal blank; the octagonal blank is heated to 900℃ for 60min, then heated to 980℃ for 180min, and then subjected to edge turning and roundness breaking to obtain a Ti2AlNb alloy bar or a Ti2AlNb alloy cake; S3, cake processing; the Ti2AlNb alloy cake is subjected to multi-pass isothermal forging deformation, first 1-3 passes of isothermal forging deformation, each pass of which is 35%-40% of the forging deformation amount, and the holding time is 170min, and then 2-4 passes of isothermal forging deformation, each pass of which is 40%-45% of the forging deformation amount, and the holding time is 150-240min; S4, the Ti2AlNb alloy cake after the Ti2AlNb alloy bar or cake processing is subjected to solid solution and aging treatment in an electric furnace to obtain a high-performance Ti2AlNb alloy forging blank, the solid solution temperature is 930 C°±10℃, the solid solution time is 2h, the cooling mode is water cooling, the aging temperature is 730 C°±10℃, the aging time is 24h, and the cooling mode is air cooling.
2. The method according to claim 1, wherein the high-performance Ti2AlNb alloy forging blank is prepared by the following steps: In step S1, during each pass of cogging forging, the Ti2AlNb alloy ingot is placed in the furnace at a temperature of 850℃, held for 90min, then the furnace temperature is raised to 1000-1200℃, and held for 150-180min. 3. The method for preparing a high-performance Ti2AlNb alloy forging billet according to claim 1, characterized in that, In step S2, during each pass of forging deformation, the cogged blank is placed in the furnace at a temperature of 900℃, held for 60min, then the furnace temperature is raised to 985℃, and held for 160min.
4. The method for preparing a high-performance Ti2AlNb alloy forging billet according to claim 1, characterized in that, In step S3, the multi-pass isothermal forging deformation is performed on a die forging machine, the Ti2AlNb alloy cake is placed in the furnace at a temperature of 900℃, held for 60min, then heated to 980℃, and subjected to multi-pass forging deformation at 980℃, and the final temperature is ≥870℃.
5. The method for preparing a high-performance Ti2AlNb alloy forging billet according to claim 1, characterized in that, In step S3, during each pass of isothermal forging deformation, the pressing speed is 2mm / s, and when the material pressing amount reaches the preset deformation amount, pressure holding is performed, the pressure holding time is 1-200min, and then the forging press head is raised.
6. The method for preparing a high-performance Ti2AlNb alloy forging billet according to claim 1, characterized in that, In step S3, during each pass of isothermal forging deformation, the hot material time is 60-120min, and the pressing speed is 0.5mm / s.
7. The method for preparing a high-performance Ti2AlNb alloy forging billet according to claim 1, characterized in that, In step S4, the Ti2AlNb alloy forged bar or the Ti2AlNb alloy forged cake after processing is machined to remove the surface oxidation layer and the forging defects before solid solution and aging treatment is performed.