Method for obtaining Ti3Al-based alloy with specific O phase content
By controlling the hot deformation parameters and heat treatment process, the problem of inaccurate O phase content in Ti3Al-based alloys was solved, and the preparation of alloys with high O phase content was realized, thus improving the overall performance of the alloys.
Patent Information
- Application Number
- CN202511705488.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-20
- Publication Date
- 2026-02-17
AI Technical Summary
The lack of a stable and reproducible method for preparing Ti3Al-based alloys with a specific O phase content in the existing technology has affected the optimization of the alloy's overall performance.
By quantitatively controlling hot deformation parameters, including deformation amount and strain rate, and adjusting the O phase content, combined with vacuum arc melting and heat treatment processes, the O phase content of Ti3Al-based alloys can be precisely controlled.
Stable preparation of Ti3Al-based alloys with high O phase content was achieved, significantly improving the mechanical properties and high-temperature creep properties of the alloys.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of high-temperature titanium alloy material preparation technology, specifically to a method for obtaining a Ti3Al-based alloy with a specific O phase content. Background Technology
[0002] Ti3Al-based alloys, also commonly known as α2-Ti3Al-based alloys, are a class of high-temperature structural materials with the intermetallic compound Ti3Al as the matrix. α2 contains ordered dopant. 19 Superlattice structure. Ti3Al alloys exhibit high-temperature oxidation resistance and strength (especially in the 650–700℃ temperature range) that titanium alloys cannot achieve. Ti3Al-based alloys are a class of engineering alloys with α2-Ti3Al phase as the main constituent phase (matrix phase) and alloyed by adding other alloying elements. The addition of these alloying elements aims to improve their intrinsic brittleness, oxidation resistance, and high-temperature strength.
[0003] Traditional Ti3Al-based alloys exhibit significant room-temperature brittleness, making them difficult to process and form. To overcome this drawback, researchers have developed second-generation Ti3Al-based alloys, represented by Ti-24Al-11Nb (at%), by adding alloying elements such as Nb, V, and Mo. In these alloys, the microstructure typically consists of the α2 phase (Ti3Al), the B2 / βo phase (the β phase has a body-centered cubic structure, belongs to the high-temperature phase, and has a significant effect on improving the plasticity of the alloy; the βo phase is its ordered phase at room temperature), and the O phase (Ti2AlNb, orthorhombic structure).
[0004] In Ti3Al-based alloys, the content of the oxygen phase is a crucial factor determining their overall performance. Recent studies have shown that a certain content of oxygen phase can effectively balance the strength and plasticity of the alloy, significantly improving its mechanical properties and high-temperature creep resistance. Therefore, obtaining a specific content and morphology of oxygen phase in Ti3Al-based alloys through precise process control has become a key technical issue for optimizing the properties of this type of alloy and promoting its engineering applications. Currently, there is a lack of existing technologies that can stably, accurately, and repeatedly obtain Ti3Al-based alloys with a specific oxygen phase content. Summary of the Invention
[0005] To address the technical challenge of precisely controlling the O phase content in existing Ti3Al-based alloy preparation methods, this invention innovatively achieves regulation of the O phase content by quantitatively controlling hot deformation parameters. This method reveals for the first time the strong correlation between deformation amount and O phase content.
[0006] Specifically, the present invention achieves the above-mentioned objectives through the following technical solutions.
[0007] According to one aspect of the present invention, a method for preparing a Ti3Al-based alloy with high O phase content is provided, comprising the following steps:
[0008] Step (1) Melting the target composition alloy ingot:
[0009] The raw materials used for smelting and casting ingots are sponge titanium (99.7 wt.%), high-purity aluminum particles (99.9 wt.%), and niobium-aluminum alloy (containing 72.63 wt.% niobium and 27.3 wt.% aluminum). These materials are mixed uniformly according to the target alloy ingot composition ratio. To prevent excessive volatilization of Al during smelting, an additional 3 wt.% Al is added during batching to compensate for potential elemental losses during smelting. The mixed raw materials are melted into ingots using, for example, but not limited to, a vacuum arc melting furnace (VAR). The melting process can be repeated up to seven times to obtain ingots with uniform composition. When using a vacuum arc melting furnace, the smelting vacuum level is below 0.1 Pa, and the smelting current is controlled within the range of 0.2 kA to 0.3 kA.
[0010] Step (2) Heat treatment:
[0011] The target composition alloy ingot is heated to 950-1200℃, then held at that temperature for 2-10 hours and air-cooled to room temperature (about 20℃). It is then heated again to 700-900℃, held at that temperature for 50-150 hours and water-cooled to obtain a single-phase α2 alloy.
[0012] Step (3) Cut the sample:
[0013] A cylindrical compression specimen with a size of Φ5 is cut from the center of the alloy ingot of the target composition, for example, but not limited to wire cutting. 10mm;
[0014] Step (4) Heat deformation treatment:
[0015] The alloy was hot-deformed at a temperature of 900–1200℃ with a strain rate of 0.0005–0.03 s⁻¹. -1 .
[0016] According to one embodiment of the present invention, preferably, the Ti3Al-based alloy composition is a Ti(20-25)Al(3-6)Nb alloy, wherein the numbers represent atomic percentages and the balance is Ti and unavoidable impurities.
[0017] According to one embodiment of the present invention, more preferably, the Ti3Al-based alloy composition is Ti(21-23)Al5Nb alloy.
[0018] According to one embodiment of the present invention, and even more preferably, the Ti3Al-based alloy composition is a Ti22Al5Nb alloy.
[0019] According to an embodiment of the present invention, preferably, in the heat treatment of step (2), the temperature is raised to 1100-1200°C at a heating rate of 15-20°C / s, held for 2-5 hours and then air-cooled to room temperature, and then raised to 750-850°C at a heating rate of 20°C / s, held for 80-130 hours and then water-cooled to obtain a single-phase α2 alloy.
[0020] According to an embodiment of the present invention, preferably, in the heat treatment of step (2), the temperature is raised to 1150°C at a heating rate of 20°C / s, held at that temperature for 3 hours, and then air-cooled to room temperature. Then, the temperature is raised again to 800°C at a rate of 20°C / s, held at 800°C for 100 hours, and then water-cooled to obtain a single-phase α2 alloy.
[0021] According to an embodiment of the present invention, preferably, in step (4), the heat deformation is heat compression and the heat deformation temperature is 1050°C.
[0022] According to an embodiment of the present invention, preferably, in step (4), the deformation amount of the heat deformation treatment is 5% to 35%, and the strain rate is 0.0005 s⁻¹. -1 0.0008 s -1 0.001 s -1 0.002 s -1 0.003 s -1 0.004 s -1 0.005 s -1 0.010 s -1 0.012 s -1 0.015 s -1 0.020 s -1 0.025 s -1 0.030 s -1 Any of them.
[0023] According to one embodiment of the present invention, preferably, in step (4), the deformation amount of the heat deformation treatment is 10% to 30%, for example 10%, 20%, or 30%, and the strain rate is 0.01 s⁻¹. -1 .
[0024] According to one aspect of the present invention, a high O-phase content Ti3Al-based alloy was prepared by using the method for preparing a high O-phase content Ti3Al-based alloy as described in any one of the preceding claims, wherein the O-phase content in the high O-phase content Ti3Al-based alloy exceeds 5%, even more preferably, exceeds 10%, even more preferably, exceeds 15%, even more preferably, exceeds 20%, even more preferably, exceeds 25%, even more preferably, exceeds 30%. Attached Figure Description
[0025] The above and other objects, features, and advantages of this disclosure will become more apparent from the more detailed description of the embodiments thereof in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the disclosure and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.
[0026] Figure 1 The Ti22Al5Nb alloy (the figures are atomic percentages, i.e., 22 at.% aluminum, 5 at.% niobium, and the balance being Ti and unavoidable impurities) was deformed at 1050℃ at a rate of 0.01 s⁻¹. -1 Stress-strain curves were obtained by hot compression of the alloy with different deformation amounts (10%, 20%, 30%).
[0027] Figure 2 The deformation rate of the Ti22Al5Nb alloy at 1050℃ was 0.01 s⁻¹. -1 The change in O phase content obtained through synchrotron radiation under compression with a deformation of 30%.
[0028] Figure 3 The deformation rate of the Ti22Al5Nb alloy at 1050℃ was 0.01 s⁻¹. -1 The 2D high-energy X-ray diffraction (2D-HEXRD) pattern and electron backscatter diffraction (EBSD) phase distribution diagram after conditional compression with a deformation of 10% are shown. The α2 phase content is 87.7%, and the O phase content is 8.1%.
[0029] Figure 4 The deformation rate of the Ti22Al5Nb alloy at 1050℃ was 0.01 s⁻¹. -1 The 2D high-energy X-ray diffraction (2D-HEXRD) pattern and electron backscatter diffraction (EBSD) phase distribution diagram after conditional compression with a deformation of 20% are shown. The α2 phase content is 63.6%, and the O phase content is 32.1%.
[0030] Figure 5The deformation rate of the Ti22Al5Nb alloy at 1050℃ was 0.01 s⁻¹. -1 The 2D high-energy X-ray diffraction (2D-HEXRD) pattern and electron backscatter diffraction (EBSD) phase distribution diagram after conditional compression with a deformation of 30% are shown. The α2 phase content is 93.5%, and the O phase content is 6.3%. Detailed Implementation
[0031] Hereinafter, exemplary embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present disclosure, and not all embodiments of the present disclosure, and it should be understood that the present disclosure is not limited to the exemplary embodiments described herein.
[0032] Example 1
[0033] Step (1) Melting the target composition alloy ingot:
[0034] The target alloy composition was Ti22Al5Nb (the numbers represent atomic percentages, i.e., the alloy contains 22 at.% Al, 5 at.% Nb, and the balance being Ti and unavoidable impurities). The raw materials used for smelting and casting the ingot were sponge titanium (99.7 wt.%), high-purity aluminum particles (99.9 wt.%), and niobium-aluminum alloy (containing 72.63 wt.% niobium and 27.3 wt.% aluminum). These materials were mixed uniformly according to the target alloy ingot composition ratio. To prevent excessive Al volatilization during smelting, an additional 3 wt.% Al was added during batching to compensate for potential elemental losses during smelting. The mixed raw materials were melted into ingots using a vacuum arc remelting furnace (VAR), and the smelting process was repeated up to seven times to obtain ingots with uniform composition. The smelting vacuum was below 0.1 Pa, and the smelting current was controlled within the range of 0.2 kA to 0.3 kA.
[0035] Step (2) Heat treatment:
[0036] The temperature was increased to 1150℃ at a heating rate of 20℃ / s, held at 1150℃ for 3 hours and then air-cooled to room temperature. Then the temperature was increased to 800℃ at a heating rate of 20℃ / s, held at 800℃ for 100 hours and then water-cooled to obtain a single-phase α2 alloy.
[0037] Step (3) Cut the sample:
[0038] A cylindrical compression specimen with a size of Φ5 was cut from the center of the alloy ingot of the target composition. 10mm;
[0039] Step (4) Heat deformation treatment:
[0040] The alloy was hot deformed at a temperature of 1050℃ with a strain rate of 0.01 s⁻¹.-1 The alloy was subjected to hot compression with deformation amounts of 10%, 20%, and 30%, respectively.
[0041] The results are shown in the figure. Figure 1 The stress-strain curves of the target alloy Ti22Al5Nb were obtained by hot compression of the alloy at 1050℃ and a deformation rate of 0.01 with different deformation amounts (10%, 20%, 30%). Figure 1 It can be seen that the mechanical properties are generally poor when the deformation is 10%, while the deformation is relatively close when it is 20% or 30%.
[0042] Figure 2 The target alloy, Ti22Al5Nb, was subjected to a deformation rate of 0.01 s⁻¹ at 1050 °C. -1 The change in O phase content obtained through synchrotron radiation under compression with a deformation of 30%.
[0043] Figure 3 The target alloy, Ti22Al5Nb, was subjected to a deformation rate of 0.01 s⁻¹ at 1050 °C. -1 The 2D high-energy X-ray diffraction (2D-HEXRD) pattern and electron backscatter diffraction (EBSD) phase distribution diagram after conditional compression with a deformation of 10% are shown. The α2 phase content is 87.7%, and the O phase content is 8.1%.
[0044] Figure 4 The target alloy, Ti22Al5Nb, was subjected to a deformation rate of 0.01 s⁻¹ at 1050 °C. -1 The 2D high-energy X-ray diffraction (2D-HEXRD) pattern and electron backscatter diffraction (EBSD) phase distribution diagram after conditional compression with a deformation of 20% are shown. The α2 phase content is 63.6%, and the O phase content is 32.1%.
[0045] Figure 5 The target alloy, Ti22Al5Nb, was subjected to a deformation rate of 0.01 s⁻¹ at 1050 °C. -1 The 2D high-energy X-ray diffraction (2D-HEXRD) pattern and electron backscatter diffraction (EBSD) phase distribution diagram after conditional compression with a deformation of 30% are shown. The α2 phase content is 93.5%, and the O phase content is 6.3%.
[0046] comprehensive Figure 3-5 It is understood that the method of the present invention for preparing Ti3Al-based alloys with high O phase content can obtain Ti3Al-based alloys with high O phase content exceeding 5%, and particularly preferably, the deformation rate is 0.01 s at 1050°C. -1 Under the condition of 20% deformation, the O phase content exceeded 30%.
[0047] Example 2
[0048] Using the same alloy composition as in Example 1, the alloy was processed with the specific processing parameters listed in Table 1 below, including hot compression temperature, strain rate, and strain. The remaining processing procedures, such as melting, sample cutting, and X-ray diffraction observation, were the same as in Example 1. The O phase content is shown in Table 1, and the resulting alloy has a high O phase content.
[0049] Example 3
[0050] Using the same alloy composition as in Example 1, the alloy was processed with the specific processing parameters listed in Table 1 below, including hot compression temperature, strain rate, and strain. The remaining processing procedures, such as melting, sample cutting, and X-ray diffraction observation, were the same as in Example 1. The O phase content is shown in Table 1, and the resulting alloy has a high O phase content.
[0051] Comparative Example
[0052] Comparative Example 1
[0053] Using alloy compositions different from those in Example 1 as shown in Table 1, the alloys were subjected to the same treatments as in Example 1, including hot compression temperature, strain rate, and strain. The remaining treatments, such as melting, sample cutting, and X-ray diffraction observation, were the same as those in Example 1. The O phase content is shown in Table 1, and the O phase content in the resulting alloy is significantly lower.
[0054] Comparative Example 2
[0055] The alloy composition used is different from that in Example 1, as shown in Table 1 below. The specific processing parameters, such as hot compression temperature, strain rate, and strain, are different. The other processing procedures, such as melting, sample cutting, and X-ray diffraction observation, are the same as those in Example 1. The O phase content is shown in Table 1. The O phase content in the obtained alloy is significantly lower.
[0056] Comparative Example 3
[0057] Using the same alloy composition as in Example 1, the alloy was processed with the specific processing parameters listed in Table 1 below, including hot compression temperature, strain rate, and strain. The remaining processing procedures, such as melting, sample cutting, and X-ray diffraction observation, were the same as in Example 1. The O phase content is shown in Table 1, and the O phase content in the resulting alloy is very low.
[0058] The inventors further adjusted the alloy composition and processing coefficient in Examples 2-3 and Comparative Examples 1-3, and the specific parameters and results are summarized in Table 1 below:
[0059] Table 1:
[0060]
[0061] The results above show that both Al and Nb contents deviating from the composition range of this invention and heat deformation temperature deviating from the range of this invention can lead to a significant decrease in O phase content, or even the absence of O phase. Therefore, the processing technology of this invention, combined with alloy composition, is essential for achieving high O phase content Ti3Al-based alloys.
[0062] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.
[0063] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this disclosure to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations therein.
Claims
1. A method for producing a high O-phase content Ti3Al-based alloy, characterized by, The method comprises the following steps: Step (1) smelting: smelting a target component alloy ingot; Step (2) heat treatment: heating the target component alloy ingot to 950-1200℃, then keeping warm for 2-10h, air cooling to room temperature, heating again to 700-900℃, keeping warm for 50-150h, and then water cooling to obtain a single-phase α2 alloy; Step (3) cutting a sample: cutting a cylindrical compression sample from the center of the target component alloy ingot; Step (4) hot deformation treatment: hot deformation of the alloy at a hot deformation temperature of 900-1200 °C, strain rate of 0.0005-0.03 s -1 .
2. The method for preparing high-0-phase-content Ti3Al-based alloys according to claim 1, characterized by, The Ti3Al-based alloy component is Ti(20-25)Al(3-6)Nb alloy.
3. The method for preparing high-0-phase-containing Ti3Al-based alloys according to claim 1, characterized by, The Ti3Al-based alloy component is Ti(21-23)Al5Nb alloy.
4. The method for preparing high-0-phase-containing Ti3Al-based alloys according to claim 1, characterized by, The Ti3Al-based alloy component is Ti22Al5Nb alloy.
5. The method for preparing high-0-phase-containing Ti3Al-based alloys according to claim 1, characterized by, In the step (2) heat treatment, the temperature is raised to 1100-1200℃ at a temperature raising rate of 15-20℃ / s, kept warm for 2-5h, air cooled to room temperature, then raised to 750-850℃ at a temperature raising rate of 20℃ / s, kept warm for 80-130h, and then water cooled to obtain a single-phase α2 alloy.
6. The method for producing high-0-phase-content Ti3Al-based alloys according to claim 5, characterized by, In the step (2) heat treatment, the temperature is raised to 1150℃ at a temperature raising rate of 20℃ / s, kept warm for 3h, air cooled to room temperature, then raised to 800℃ at a temperature raising rate of 20℃ / s, kept warm for 100h at 800℃, and then water cooled to obtain a single-phase α2 alloy.
7. The method for producing high-0-phase-content Ti3Al-based alloys according to claim 1, characterized by, In the step (4), the heat deformation is hot compression, and the heat deformation temperature is 1050℃.
8. The method for producing high-0-phase-content Ti3Al-based alloys according to claim 1, characterized by, In the step (4), the deformation amount of the thermal deformation treatment is 5% to 35%, and the strain rate is any one of 0.0005 s -1 , 0.0008 s -1 , 0.001 s -1 , 0.002 s -1 , 0.003 s -1 , 0.004 s -1 , 0.005 s -1 , 0.010 s -1 , 0.012 s -1 , 0.015 s -1 , 0.020 s -1 , 0.025 s -1 , 0.030 s -1 .
9. The method for preparing high-0-phase-containing Ti3Al-based alloys according to claim 1, characterized by, In the step (4), the deformation amount of the thermal deformation treatment is 10% to 30%, and the strain rate is 0.01 s -1 .
10. High O-phase content Ti3Al-based alloy produced by the method for producing high O-phase content Ti3Al-based alloys according to any one of the preceding claims, characterized in that The high O phase content Ti3Al-based alloy has an O phase content of more than 5%.