A titanium alloy with adjustable adiabatic omega phase point lattice structure and preparation and quantitative control method thereof

Abstract

This invention discloses a titanium alloy with a tunable adiabatic ω-phase lattice structure and its preparation and quantitative control method, belonging to the field of metastable β-titanium alloy phase transformation technology. The aforementioned titanium alloy is a Ti-12Mo-xSn alloy, where 0 < x ≤ 3. This invention prepares the alloy by doping Ti-12Mo alloy with Sn. Through Sn doping, the ω-phase structure is effectively reduced without altering the stability of the Ti-12Mo alloy β matrix. ath The lattice collapse amplitude Z value of the phase enables this alloy to possess both high strength and low modulus, solving the problem of existing ω ath The invention addresses the technical problem that phase modulation methods are not conducive to improving the strength and toughness of metastable β titanium alloys. At the same time, it also provides a quantitative control method for the Z value of the alloy, which provides an important reference for the design of high strength and toughness titanium alloys. On the other hand, it can design titanium alloys with specific performance characteristics for different application scenarios, making it more applicable.

Description

Technical Field

[0001] This invention relates to the field of metastable β-titanium alloy phase transformation technology, specifically to a titanium alloy with an adjustable adiabatic ω-phase lattice structure and its preparation and quantitative control method. Background Technology

[0002] adiabatic ω(ω ath The ω phase is widely present in metastable β-titanium alloys. As a diffusionless shear precipitate, it possesses high strength and high modulus, significantly influencing the alloy's mechanical properties. The effect of ω on mechanical properties is usually manifested in its influence on deformation products. In existing research, isothermal ω(ω) iso α'' phase particles are generally considered to be an obstacle to the long-range propagation of the α'' martensite phase transformation, and can split the β matrix to achieve fine-grained strengthening. Besides strength, ω iso The self-hardening effect caused by changes in the phase lattice collapse amplitude Z can also gradually transform the deformation mechanism of materials from deformation twinning to single dislocation slip. This transformation is usually accompanied by a decrease in the plasticity of the alloy. Current research results mostly focus on ω. iso The effect of this phase on the alloy is usually manifested as hardening and embrittlement. The ω phase formed during cooling... ath This phase is also noteworthy, as it can enhance the superelastic triggering stress and elastic modulus of the alloy.

[0003] ω ath The interaction between phases and dislocations typically manifests as two mechanisms: cut-through and bypass. The cut-through mechanism restricts dislocations to {112}. <111> β Within the slip system, the bypass mechanism is not specific to the slip system; however, the transition between the two mechanisms and ω ath The phase collapse amplitude Z is closely related; ω ath The collapse amplitude Z during the phase collapse process is a measure of ω. ath An important parameter for the degree of phase formation, a decrease in the Z value usually means ω ath The decrease in phase lattice stability and the deformation-induced α'' martensite, as one of the sources of alloy strength and toughness, also have nucleation characteristics related to ω. ath The collapse amplitude Z of the phase is related to the phase collapse amplitude, specifically, changes in the Z value will alter ω. ath The lattice stability of the phase and {11-20} ω Shear modulus of a crystal plane.

[0004] With ω iso Different phases, ω ath The formation of the phase is not accompanied by solute diffusion; it is mainly caused by adjacent {111} β Atoms on the crystal surface along <111> β The collapse of crystal orientations, a process typically stemming from the lattice instability of the β phase, is therefore a focus of existing research on ω. athPhase regulation mostly starts with the stability of the β matrix. Element Fe and Cr, as eutectoid β-strong stabilizing elements, can significantly suppress ω. ath Phase precipitation occurs, but it also inhibits the formation of mechanical twins and deformation-induced α'' martensitic phase transformation. Element Sn, as a neutral β-stable element, only introduces a stress field through atomic occupancy to hinder dislocation movement, thereby hindering dislocation movement and ω... ath The nucleation of the phase does not significantly affect other deformation mechanisms; therefore, it remains to be seen whether the nucleation of ω can be achieved through the element Sn. ath Quantitative control of the phase collapse amplitude Z value is one of the important breakthroughs in improving the strength and toughness of metastable β titanium alloys. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a titanium alloy with a controllable adiabatic ω-phase lattice structure and its preparation and quantitative control method, thereby solving the problems of existing ω-phase lattice structures. ath The way the phase is controlled will simultaneously affect the occurrence of other phase transformations, which is not conducive to improving the strength and toughness of metastable β titanium alloys.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: In a first aspect, the present invention provides a titanium alloy with an adjustable adiabatic ω-phase lattice structure, wherein the titanium alloy is a Ti-12Mo-xSn alloy, and 0<x≤3.

[0007] The beneficial effects of this invention are as follows: By adding Sn to Ti-12Mo alloy, this invention obtains a metastable β-type Ti-12Mo-xSn (0<x≤3) alloy. Sn, as a neutral β-stable element, only introduces a stress field through atomic occupancy to hinder dislocation movement, thereby suppressing ω. ath Phase nucleation: Through this method, the Sn element doping used in this invention does not significantly affect other deformation mechanisms, and effectively reduces ω without changing the stability of the Ti-12Mo alloy β matrix. ath The lattice collapse amplitude Z value of the phase, thus enabling the alloy to possess both high strength and low modulus to a certain extent.

[0008] Furthermore, the titanium alloy is a Ti-12Mo-xSn alloy, where x = 1~3.

[0009] A second aspect of the present invention provides a method for preparing the above-described tunable adiabatic ω-phase lattice structure of a titanium alloy, comprising the following steps: S1. Weigh each alloy component according to the alloy ratio of Ti-12Mo-xSn, 0<x≤3, and then melt it to obtain the cast alloy. S2. The as-cast alloy obtained in S1 is subjected to solution quenching treatment to obtain a titanium alloy with an adjustable adiabatic ω-phase lattice structure.

[0010] The beneficial effects of this invention are as follows: The preparation method of this invention is simple. By designing the composition of the Ti-12Mo-xSn (0<x≤3) alloy and combining it with the heat treatment process, the ω content in the alloy microstructure is reduced to a certain extent. ath The phase lattice collapse amplitude Z value is reduced, which to some extent endows the alloy with excellent properties of high strength and low modulus.

[0011] Furthermore, the smelting process in S1 includes the following steps: first, the components are smelted to obtain a master alloy, then the master alloy is remelted 10 to 20 times, and finally, it is cast to obtain a cast alloy.

[0012] Preferably, it is remelted 16 times.

[0013] Furthermore, the melting method employs vacuum non-consumable arc melting.

[0014] Furthermore, the heat treatment temperature for solution quenching in S2 is 900~1000℃, and the time is 1~3 h.

[0015] Preferably, the solution quenching heat treatment temperature is 950℃ and the time is 2 h.

[0016] Furthermore, the heat treatment was performed at a vacuum level of 2×10⁻⁶. -4 ~4×10 -4 The experiment was conducted under the condition of Pa.

[0017] Preferably, the heat treatment is performed at a vacuum degree of 2.9 × 10⁻⁶. -4 Performed under Pa conditions Furthermore, in S2, solution quenching is performed by water quenching to room temperature.

[0018] A third aspect of the present invention provides a titanium alloy with an adjustable thermally insulating ω-phase lattice structure. ath A quantitative control method for the phase collapse amplitude Z value is achieved by adjusting the mass fraction of Sn in a titanium alloy with a controllable adiabatic ω-phase lattice structure to control the ω-phase collapse amplitude Z value. ath Quantitative control of the phase collapse amplitude Z value.

[0019] The beneficial effects of this invention are as follows: By adjusting the Sn component content in the alloy, this invention can achieve the desired ω content in titanium alloys. ath Quantitative control of the phase collapse amplitude Z value provides an important breakthrough for improving the strength and toughness of metastable β-type titanium alloys.

[0020] Furthermore, it includes the following steps: First, titanium alloys with tunable adiabatic ω-phase lattice structures of different composition ratios were prepared, and then the ω-phase of each titanium alloy was measured. ath The phase collapse amplitude Z value was used to finally establish ω. athA one-to-one mapping relationship between the phase collapse amplitude Z value and the Sn mass fraction in a titanium alloy with a tunable adiabatic ω-phase lattice structure is established to realize ω ath Quantitative control of the phase collapse amplitude Z value.

[0021] The beneficial effects of adopting the above-mentioned further technical solutions are as follows: This invention establishes ω ath The one-to-one mapping relationship between the phase collapse amplitude Z value and the Sn mass fraction in titanium alloys with tunable adiabatic ω-phase lattice structure enables precise quantitative control of the Z value, thereby enabling the preparation of titanium alloys with different performance characteristics to meet various application scenarios and has broad application prospects.

[0022] Furthermore, ω ath The phase collapse amplitude Z value is calculated using the following formula: 2Z+δ= d

[111] ; In the formula, Z is ω ath Phase collapse amplitude; δ represents titanium alloy ω ath The intensity deviation of atomic rows in a phase lattice structure; d

[111] For titanium alloy adjacent (111) β Interplanar spacing of crystal planes.

[0023] The present invention has the following beneficial effects: 1. This invention provides a Sn-doped metastable β-type titanium alloy, which effectively reduces ω by Sn doping without altering the stability of the Ti-12Mo alloy β matrix. ath The lattice collapse amplitude Z value of the phase enables this alloy to possess both high strength and low modulus, solving the problem of existing ω ath The technical problem that phase modulation methods are not conducive to improving the strength and toughness of metastable β-titanium alloys.

[0024] 2. The preparation method of this invention is simple. By combining titanium alloy composition design with heat treatment process, ω is effectively reduced. ath The lattice collapse amplitude Z value of the phase effectively improves the strength and toughness of titanium alloys.

[0025] 3. This invention establishes ω ath The one-to-one mapping relationship between the phase lattice collapse amplitude Z value and Sn mass fraction enables quantitative control of the Z value. On the one hand, it provides an important reference for the design of high strength and toughness titanium alloys, and on the other hand, it allows for the design of titanium alloys with specific performance characteristics for different application scenarios, making them more applicable. Attached Figure Description

[0026] Figure 1This invention relates to a cubic β-phase (Z=0) to a hexagonal ω-phase. ath A schematic diagram of the crystal structure of the phase (Z=1 / 6) transformation, where Z represents the β phase {110}. β crystal plane edge <111> β The collapse amplitude value in the direction, δ is ω ath The intensity deviation values ​​of the B and C atomic columns in the lattice structure of the phase. d

[111] For atoms A and D that are adjacent on the chain (111) β Interplanar spacing of crystal planes; Figure 2 The β matrix and ω of the Ti-12Mo-1Sn (wt.%) alloy sample in Example 1 ath Intensity distribution curves of the four atomic chains A, B, C, and D in the phase lattice structure; Figure 3 The Ti-12Mo-1Sn (wt.%) alloy single crystal in Example 1 <111> β Stress-strain curves of oriented nanopillar compression; Figure 4 The β matrix and ω of the Ti-12Mo-3Sn (wt.%) alloy sample in Example 2 ath Intensity distribution curves of the four atomic chains A, B, C, and D in the phase lattice structure; Figure 5 The Ti-12Mo-3Sn (wt.%) alloy single crystal in Example 2 <111> β Stress-strain curves of oriented nanopillar compression; Figure 6 For the Ti-12Mo (wt.%) alloy sample in Comparative Example 1, the β matrix and ω ath Intensity distribution curves of the four atomic chains A, B, C, and D in the phase lattice structure; Figure 7 For the Ti-12Mo (wt.%) alloy single crystal in Comparative Example 1 <111> β Stress-strain curves of oriented nanopillars under compression. Detailed Implementation

[0027] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0028] Example 1: A method for preparing a titanium alloy with a tunable adiabatic ω-phase lattice structure includes the following steps: S1. For a typical metastable β-type Ti-12Mo (wt.%) alloy, with a fixed Mo content, add 1% by weight of Sn particles with a purity of 99.99% and a particle size of 1-5 mm. At the same time, select Ti particles and Mo particles with a size of 3 mm and purities of 99.99% and 99.95% respectively. Melt the alloy using a vacuum non-consumable arc melting method to obtain a master alloy. Then, remelt the master alloy 16 times and cast it to obtain a button ingot metastable β-type Ti-12Mo-1Sn (wt.%) alloy.

[0029] S2. The metastable β-type Ti-12Mo-1Sn (wt.%) alloy obtained from S1 is sealed in a tube with a vacuum degree of 2.9 × 10⁻⁶. -4 Pa was placed in a box-type resistance furnace and subjected to solution treatment at 950℃ for 2 h, followed by water quenching to room temperature to obtain an equiaxed crystal structure sample composed of a single β phase, which can control the adiabatic ω phase lattice structure of the titanium alloy Ti-12Mo-1Sn (wt.%).

[0030] Example 2: A method for preparing a titanium alloy with a tunable adiabatic ω-phase lattice structure includes the following steps: S1. For a typical metastable β-type Ti-12Mo (wt.%) alloy, with a fixed Mo content, add 3% by weight Sn particles with a purity of 99.99% and a particle size of 1-5 mm. At the same time, select Ti particles and Mo particles with a size of 3 mm and purities of 99.99% and 99.95% respectively. Melt the alloy using a vacuum non-consumable arc melting method to obtain a master alloy. Then, remelt the master alloy 16 times and cast it to obtain a button-shaped metastable β-type Ti-12Mo-3Sn (wt.%) alloy.

[0031] S2. The metastable β-type Ti-12Mo-3Sn (wt.%) alloy obtained from S1 is sealed in a tube with a vacuum degree of 2.9 × 10⁻⁶. -4 Pa was placed in a box-type resistance furnace and subjected to solution treatment at 950℃ for 2 h, followed by water quenching to room temperature to obtain an equiaxed crystal structure sample composed of a single β phase, which can control the adiabatic ω phase lattice structure of the titanium alloy Ti-12Mo-3Sn (wt.%).

[0032] Example 3: A method for preparing a titanium alloy with a tunable adiabatic ω-phase lattice structure includes the following steps: S1. For a typical metastable β-type Ti-12Mo (wt.%) alloy, with a fixed Mo content, add 2% by weight Sn particles with a purity of 99.99% and a particle size of 1-5 mm. At the same time, select Ti particles and Mo particles with a size of 3 mm and purities of 99.99% and 99.95% respectively. Melt the alloy using a vacuum non-consumable arc melting method to obtain a master alloy. Then, remelt the master alloy 16 times and cast it to obtain a button-shaped metastable β-type Ti-12Mo-2Sn (wt.%) alloy.

[0033] S2. The metastable β-type Ti-12Mo-2Sn (wt.%) alloy obtained from S1 is sealed in a tube with a vacuum degree of 2.9 × 10⁻⁶. -4 Pa was placed in a box-type resistance furnace and subjected to solution treatment at 950℃ for 2 h, followed by water quenching to room temperature to obtain an equiaxed crystal structure sample composed of a single β phase, which can control the adiabatic ω phase lattice structure of the titanium alloy Ti-12Mo-2Sn (wt.%).

[0034] Comparative Example 1: A method for preparing a metastable β-type Ti-12Mo alloy includes the following steps: S1. According to the raw material ratio of a typical metastable β-type Ti-12Mo (wt.%) alloy, Ti particles and Mo particles with a size of 3 mm and purities of 99.99% and 99.95% respectively are selected and melted using a vacuum non-consumable arc melting method to obtain a master alloy. Then, the master alloy is remelted 16 times and cast to obtain a button ingot metastable β-type Ti-12Mo (wt.%) alloy.

[0035] S2. The metastable β-type Ti-12Mo (wt.%) alloy obtained from S1 is sealed in a tube with a vacuum degree of 2.9 × 10⁻⁶. -4 Pa was placed in a box-type resistance furnace and solution treated at 950℃ for 2 h, and then quenched in water to room temperature to obtain metastable β-type Ti-12Mo alloy Ti-12Mo (wt.%).

[0036] Experimental example: In the alloys prepared in Examples 1-2 and Comparative Example 1, the β matrix and ω ath Phase lattice structure was characterized (β→ω) ath (Schematic diagram of the phase transition lattice) to obtain the β matrix and ω ath The intensity distribution curves of the four atomic chains A, B, C, and D in the phase lattice structure are obtained, and the lattice collapse amplitude Z is calculated. The lattice collapse amplitude Z is adjacent to the atomic chains B and C (111). β interplanar spacing of crystal planes d

[111] The geometric relationship is 2Z + δ =d

[111] .

[0037] The alloys prepared in Examples 1-2 and Comparative Example 1 were subjected to nanoindentation using a Hysitron Ti-950 nanoindenter equipped with a 10 μm diamond flat indenter. <111> β Single-crystal nanopillars at 1×10 -3 s -1 Micropillar compression was performed at a strain rate to obtain yield strength and elastic modulus values.

[0038] Experimental results are as follows Figures 2-7 As shown in Table 1.

[0039] Table 1 ω of each alloy ath Statistical results of phase δ and Z values

[0040] The results show that by incorporating Sn into the Ti-12Mo (wt.%) alloy, ω can be significantly improved. ath The phase δ value decreases and the Z value decreases. Simultaneously, when the mass fraction of Sn increases from 1% in Example 1 to 3% in Example 2, ω... ath With further increases in the δ value, the lattice collapse amplitude Z value significantly decreased. The Ti-12Mo (wt.%) alloy prepared in Comparative Example 1 had a lattice collapse amplitude Z value of 0.1397, and its lattice structure was closest to that of an ideal hexagonal ω-type alloy. ath Furthermore, according to the micropillar compression test results, the yield strength of the Ti-12Mo (wt.%) alloy is lower than that of the Ti-12Mo-1Sn (wt.%) and Ti-12Mo-3Sn (wt.%) alloys, while its elastic modulus is the highest among the three alloys. This result indicates that incorporating Sn into the Ti-12Mo (wt.%) alloy can significantly improve the yield strength and reduce the elastic modulus. The results show that this invention, through adjustable ω... ath The compositional design of Ti-12Mo-xSn (wt.%) alloys with phase lattice structures can reduce ω ath The Z-value of the phase lattice collapse amplitude is crucial for achieving an excellent combination of high strength and low modulus in the alloy, which is of great significance for the design of high-strength and high-toughness titanium alloys.

[0041] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A titanium alloy with an adjustable adiabatic ω-phase lattice structure, characterized in that, The titanium alloy is a Ti-12Mo-xSn alloy, where 0 < x ≤ 3.

2. The titanium alloy with an adjustable adiabatic ω-phase lattice structure according to claim 1, characterized in that, The titanium alloy is a Ti-12Mo-xSn alloy, where x = 1~3.

3. The method for preparing the titanium alloy with an adjustable adiabatic ω-phase lattice structure as described in claim 1 or 2, characterized in that, Includes the following steps: S1. Weigh each alloy component according to the alloy ratio of Ti-12Mo-xSn, 0<x≤3, and then melt it to obtain the cast alloy. S2. The as-cast alloy obtained in S1 is subjected to solution quenching treatment to obtain a titanium alloy with an adjustable adiabatic ω-phase lattice structure.

4. The method for preparing a titanium alloy with an adjustable adiabatic ω-phase lattice structure according to claim 3, characterized in that, The smelting process in S1 includes the following steps: first, smelting each component to obtain a master alloy, then remelting the master alloy 10 to 20 times, and finally casting to obtain a cast alloy.

5. The method for preparing a titanium alloy with an adjustable adiabatic ω-phase lattice structure according to claim 3, characterized in that, The heat treatment temperature for solution quenching in S2 is 900~1000℃, and the time is 1~3 h.

6. The method for preparing a titanium alloy with an adjustable adiabatic ω-phase lattice structure according to claim 5, characterized in that, The heat treatment is performed under a vacuum degree of 2 x 10 -4 4 x 10 -4 Pa.

7. The method for preparing a titanium alloy with an adjustable adiabatic ω-phase lattice structure according to claim 3, characterized in that, In S2, the solution quenching is performed by water quenching to room temperature.

8. A titanium alloy with an adjustable adiabatic ω-phase lattice structure as described in claim 1 or 2, wherein the ω phase... ath A quantitative control method for the phase collapse amplitude Z value, characterized in that, The mass fraction of Sn in the titanium alloy with adjustable adiabatic ω phase point lattice structure is adjusted to realize quantitative regulation of ω ath Quantitative regulation of the phase collapse amplitude Z value.

9. The ω phase of the titanium alloy with an adjustable adiabatic ω phase lattice structure according to claim 8. ath A quantitative control method for the phase collapse amplitude Z value, characterized in that, Includes the following steps: First, the titanium alloys with adjustable adiabatic ω phase point lattice structure of different component proportions are prepared, and then the ω ath The phase collapse amplitude Z value is measured, and finally the ω ath The one-to-one mapping relationship between the phase collapse amplitude Z value and the Sn mass fraction in the titanium alloy with adjustable adiabatic ω phase point lattice structure is established, and the ω ath The quantitative regulation of the phase collapse amplitude Z value is realized.

10. The titanium alloy with an adjustable adiabatic ω-phase lattice structure according to claim 9, ω ath A quantitative control method for the phase collapse amplitude Z value, characterized in that, The ω ath The phase collapse amplitude Z value is calculated using the following formula: 2Z+δ= d [111] ; In the formula, Z is ω ath Phase collapse amplitude; δ represents titanium alloy ω ath The intensity deviation of atomic rows in a phase lattice structure; d [111] For titanium alloy adjacent (111) β Interplanar spacing of crystal planes.

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