Preparation method of high-strength TC10 titanium alloy wire for fastener

Abstract

The application relates to a preparation method of high-strength TC10 titanium alloy wire for fasteners and relates to the technical field of titanium alloys, and aims to solve at least one of the problems that the existing TC10 titanium alloy wire is affected by heat processing technology, heat treatment technology and the like during preparation, the strength and plasticity are difficult to match, and the wire is prone to the "wire breaking" phenomenon. The method considers the processing characteristics of the TC10 titanium alloy wire, adopts high-temperature deformation heat treatment to perform blank hot drawing and circle processing + roll die cold drawing + low-temperature deformation heat treatment to perform wire sizing processing, and then performs solid solution aging process treatment, so that the TC10 titanium alloy wire with matched strength and plasticity and not prone to wire breaking is prepared.

Description

Technical Field

[0001] This invention relates to the field of titanium alloy technology, and in particular to a method for preparing high-strength TC10 titanium alloy wire for fasteners. Background Technology

[0002] High-strength titanium alloy wire plays a crucial role in aerospace vehicle connections, not only achieving weight reduction and corrosion resistance but also serving as an essential connector for structural components made of titanium alloys and carbon fiber composites. Therefore, it is necessary to meet the high performance requirements of high-strength titanium alloy wire for fasteners in aerospace manufacturing, namely tensile strength ≥1400MPa and elongation ≥10%. During the manufacturing process of TC10 titanium alloy wire, the strength and ductility are difficult to match due to the influence of processing technology and heat treatment processes, and the possibility of wire breakage may occur.

[0003] In the existing technology for TC10 titanium alloy wire preparation, during fixed drawing, sliding friction exists between the fixed die and the wire, leading to surface scratches and increased dimensional tolerances. For small-sized drawing, precise control is impossible, and multiple annealing processes are required to soften the wire and prevent wire breakage. Roller drawing is costly due to the high precision of the equipment; furthermore, precise control of the roll gap and roll pressure is more complex than with a fixed die. Inadequate adjustment can cause uneven wire deformation, resulting in beveling, and the larger the wire, the worse the dimensional consistency. Solution aging significantly affects the microstructure, with varying degrees of transformation between hexagonal α' phase, orthorhombic α' phase, α phase, and β phase depending on the solution aging treatment. This ultimately leads to either increased strength and decreased plasticity, or vice versa. Therefore, the selection of solution aging parameters is crucial in production. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide a method for preparing high-strength TC10 titanium alloy wire for fasteners, in order to solve at least one of the following problems in the preparation of existing TC10 titanium alloy wire: the strength and plasticity are difficult to match due to the influence of hot working process and heat treatment process, and the "wire breakage" phenomenon is easy to occur.

[0005] In a first aspect, the present invention provides a method for preparing high-strength TC10 titanium alloy wire for fasteners, comprising the following steps:

[0006] S1: Select TC10 titanium alloy bars with an oxygen content of 0.185~0.2% as billets; S2: The blank is subjected to heat treatment, rolling treatment and coiling in sequence to obtain wire blank; S3: The wire blank is heated to 30°C to 50°C below the phase change point by high temperature deformation heat treatment process, and then hot drawing and rounding process with fixed mold is carried out. Combined with rapid water cooling, intermediate annealing, cold drawing with roller mold and low temperature deformation heat treatment process, the wire blank is heated to a low temperature. Then, it is cut to length by fixed mold and air cooled to obtain the wire material of fixed length. S4: Peel and trim the wire after it has been cut to length to obtain a bright wire of the target size. Then, perform a solution aging treatment on the wire of the target size to obtain the TC10 titanium alloy wire.

[0007] Furthermore, in S2, the heating treatment temperature is 840~870℃ and the time is 30~90min.

[0008] Furthermore, in S3, the temperature of the high-temperature deformation heat treatment process is 30~50℃ below the phase transformation point, the holding time is 30~90min, and the mold is drawn back to a round shape and then rapidly water-cooled.

[0009] Furthermore, in S3, the intermediate annealing temperature is 750±30℃, the holding time is 30~90min, and then air cooling is performed.

[0010] Furthermore, in S3, the cold drawing of the roller die is carried out in 3 to 6 passes, with the deformation amount of each pass ≤15% and the cumulative deformation amount <35%.

[0011] Furthermore, in S3, the temperature of the low-temperature deformation heat treatment is 750±30℃, the time is 30~90min, and the mold is fixed and then air-cooled.

[0012] Furthermore, in S4, the solution treatment temperature is 860~940℃, the holding time is 30~120min, the aging treatment temperature is 520~560℃, and the holding time is 3~6h.

[0013] Secondly, the present invention provides a TC10 titanium alloy wire prepared by the above method.

[0014] Furthermore, the microstructure of the filament consists of primary α phase and β phase.

[0015] Furthermore, the TC10 titanium alloy wire has a tensile strength ≥1460MPa, a yield strength ≥1350MPa, an elongation ≥10%, a shear strength ≥830MPa, and a Vickers hardness ≥385MPa.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. The method of this invention considers the processing characteristics of TC10 titanium alloy wire. It employs high-temperature deformation heat treatment for hot drawing and rounding of the billet, followed by cold drawing using a roll die, and then low-temperature deformation heat treatment for wire length determination. Finally, it undergoes solution treatment and aging to produce TC10 titanium alloy wire with a good balance of strength and plasticity, making it less prone to breakage. The TC10 titanium alloy wire prepared by this method has a tensile strength ≥1460MPa, yield strength ≥1350MPa, elongation ≥10%, shear strength ≥830MPa, and Vickers hardness ≥385MPa.

[0017] 2. The purpose of using high-temperature deformation heat treatment to round the wire blank in this invention is twofold: first, to eliminate the chamfers that may occur in the rolled blank and obtain a regular circular cross-section of the target size; second, in the temperature range of 30℃ to 50℃ below the phase transformation point, combined with rapid water cooling, the precipitation amount and morphology of the α phase can be precisely controlled, avoiding performance mismatch caused by an excessive amount of a single phase.

[0018] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0019] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0020] Figure 1 The metallographic microstructure of the TC10 titanium alloy wire prepared in Example 1 of this invention before aging treatment; Figure 2 The metallographic microstructure of TC10 titanium alloy wire prepared in Example 1 of this invention after aging treatment; Figure 3 Metallographic microstructure of TC10 titanium alloy wire prepared in Example 2 of this invention before aging treatment; Figure 4 Metallographic microstructure of TC10 titanium alloy wire prepared in Example 2 of this invention after aging treatment. Detailed Implementation

[0021] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0022] A specific embodiment of the present invention discloses a method for preparing high-strength TC10 titanium alloy wire for fasteners, comprising the following steps: S1: Select TC10 titanium alloy bars with an oxygen content of 0.185~0.2% (e.g., 0.185%, 0.187%, 0.189%, 0.19%, 0.192%, 0.194%, 0.196%, 0.198%, 0.2%) as billets; S2: The blank is subjected to heat treatment, rolling treatment and coiling in sequence to obtain wire blank; S3: The wire blank is heated to 30°C to 50°C below the phase change point by high temperature deformation heat treatment process, and then hot drawing and rounding process with fixed mold is carried out. Combined with rapid water cooling, intermediate annealing, cold drawing with roller mold and low temperature deformation heat treatment process, the wire blank is heated to a low temperature. Then, it is cut to length by fixed mold and air cooled to obtain the wire material of fixed length. S4: Peel and trim the wire after it has been cut to length to obtain a bright wire of the target size. Then, perform a solution aging treatment on the wire of the target size to obtain the TC10 titanium alloy wire.

[0023] Compared with the prior art, the method of the present invention takes into account the processing characteristics of TC10 titanium alloy wire, and adopts high temperature deformation heat treatment for hot drawing and rounding of billet + cold drawing of roller die + low temperature deformation heat treatment for wire length setting, and then through solid solution aging process to prepare TC10 titanium alloy wire with strong plasticity matching and not easy to break.

[0024] It should be noted that this invention selects TC10 titanium alloy bars with high oxygen content (0.185~0.2%) as the billet to improve both the tensile strength and shear strength of the wire. This is because, on one hand, the radius of an oxygen atom is smaller than that of a titanium atom. As an interstitial atom, its integration into the titanium matrix causes lattice distortion, forming a localized stress field. This stress field hinders the slip and movement of dislocations. During shear resistance, the obstruction of dislocation slip also increases the shear resistance of the shear surface, thereby improving shear strength. On the other hand, the oxide particles formed by oxygen and titanium (or other alloying elements) enhance performance by "pinning" dislocation movement. Titanium alloys contain easily oxidized elements, and oxygen preferentially combines with these elements to form fine, uniformly distributed oxide particles. These particles are typically nanometer to micrometer in size and have good interfacial bonding with the titanium matrix. When a dislocation moves to the oxide particles, the particles act like "pins," locking the dislocation and preventing it from slipping further. This improves the material's resistance to tensile fracture and strengthens its stress-bearing capacity during shearing, preventing premature failure of the shear surface.

[0025] Specifically, in S1, the specifications of the bar are φ50~90mm, for example, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, and 90mm.

[0026] Specifically, in S2, the temperature of the heat treatment is 840~870℃, for example, 840℃, 845℃, 850℃, 855℃, 860℃, 865℃, 870℃, and the time is 30~90min, for example, 30min, 40min, 50min, 60min, 70min, 80min, 90min.

[0027] Specifically, in S2, the rolling process is performed to produce a coil with a diameter of φ7.0±0.2mm.

[0028] Specifically, in S3, the temperature of the high-temperature deformation heat treatment process is 30~50℃ below the phase transformation point, for example, 30℃, 32℃, 34℃, 36℃, 38℃, 40℃, 42℃, 44℃, 46℃, 48℃, and 50℃, and the holding time is 30~90min, for example, 30min, 40min, 50min, 60min, 70min, 80min, and 90min.

[0029] It should be noted that the purpose of using high-temperature deformation heat treatment to round the wire blank in this invention is twofold: first, to eliminate the chamfers that may occur in the rolled blank and obtain a regular circular cross-section of the target size; second, in the temperature range of 30℃ to 50℃ (e.g., 30℃, 35℃, 40℃, 45℃, 50℃) below the phase transformation point, combined with rapid water cooling, the precipitation amount and morphology of the α phase can be precisely controlled, avoiding performance mismatch caused by an excessive amount of a single phase.

[0030] Specifically, in S3, the intermediate annealing temperature is 750±30℃, for example, 720℃, 725℃, 730℃, 735℃, 740℃, 750℃, 755℃, 760℃, 765℃, 770℃, 775℃, 780℃, and the holding time is 30~90min, for example, 30min, 35min, 40min, 45min, 50min, 55min, 60min, 65min, 70min, 75min, 80min, 85min, 90min, followed by air cooling.

[0031] It should be noted that the above annealing conditions are used to reduce internal stress and work hardening, thus preventing wire breakage.

[0032] Specifically, in S3, the cold drawing of the roller die is carried out in 3 to 6 passes, with the deformation amount of each pass ≤15% and the cumulative deformation amount <35%.

[0033] Specifically, in S3, the temperature of the low-temperature thermal deformation heat treatment is 750±30℃, for example, 720℃, 725℃, 730℃, 735℃, 740℃, 750℃, 755℃, 760℃, 765℃, 770℃, 775℃, 780℃, and the time is 30~90min, for example, 30min, 35min, 40min, 45min, 50min, 55min, 60min, 65min, 70min, 75min, 80min, 85min, 90min.

[0034] The low-temperature deformation heat treatment is intended to precisely control the dimensional accuracy and shape regularity of the filament material by eliminating cold working defects and regulating its microstructure.

[0035] Specifically, in S4, the solution treatment temperature is 860~940℃, for example, 860℃, 870℃, 880℃, 890℃, 900℃, 910℃, 920℃, 930℃, 940℃, and the holding time is 30~120min, for example, 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min, 120min, using water cooling. The aging treatment temperature is 520~560℃, for example, 520℃, 525℃, 530℃, 535℃, 540℃, 550℃, 555℃, 560℃, and the holding time is 3~6h, for example, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, using air cooling.

[0036] The TC10 titanium alloy wire prepared by this invention has a specification of Φ4-6×Lmm.

[0037] Another specific embodiment of the present invention discloses a high-strength TC10 titanium alloy wire for fasteners prepared by the above method. The microstructure of the wire consists of primary α phase and β phase, with the primary α phase accounting for more than 70% by volume.

[0038] The technical solution of the present invention will be further explained below with reference to specific embodiments. The TC10 titanium alloy bar billets selected in the present invention are all materials in the prior art, and their mass fractions meet the following requirements: Al: 5.0-6.0%, V: 5.0-6.0%, Sn: 1.5-2.5%, Cu: 0.35-1.0%, Fe: 0.35-1.0%, 0.185~0.2%.

[0039] Example 1 This embodiment describes a method for preparing high-strength TC10 titanium alloy wire for fasteners, comprising the following steps: S1: Select TC10 titanium alloy bars with a hot-worked specification of φ53mm and an oxygen content of 0.195% as the billet; S2: The blank is subjected to heat treatment, rolling treatment and coiling in sequence to obtain wire blank; The heat treatment temperature is 850±10℃ and the time is 60min. After exiting the furnace, it is rolled with a large deformation and hot rolled to φ7±0.2mm coil. S3: The high-temperature deformation heat treatment process is adopted in sequence. The process mainly involves heating the wire to 30℃~50℃ below the phase change point, then hot drawing and rounding through a fixed mold, followed by rapid water cooling, intermediate annealing, cold drawing through a roller, and low-temperature deformation heat treatment. The wire is then cut to length through a fixed mold to obtain the wire material. The high-temperature deformation heat treatment process involves a temperature of 900℃ (TC10 phase transformation point is 935℃), a holding time of 60 minutes, and the billet is rapidly drawn from φ7.0mm→φ6.6mm→φ6.2mm to φ6.0mm (hot drawing start temperature is 900℃). After this, it is rapidly water-cooled, followed by intermediate annealing at a temperature of 750±10℃ for 50 minutes, and then air-cooled. The roller die cold drawing process involves three cold drawing passes on the φ6.0mm intermediate wire blank, with the specific parameters as follows: A single cold drawing of φ5.6mm resulted in a deformation of 12.8%. The φ5.3mm diameter was cold-drawn in two passes, with a deformation of 10.4% in this pass. The φ5.0mm diameter was cold-drawn in three passes, with a deformation of 11% per pass and a cumulative deformation of 30%. The low-temperature deformation heat treatment was performed at a temperature of 750±10℃ for 50 minutes, followed by cutting to length using a fixed mold, with the wire size being φ4.8±0.1mm. S4: Peel the wire after it has been cut to length φ4.6+0 / -0.02mm, and then polish it to φ4.55+0 / -0.02mm to obtain a bright wire of the target size. Then, perform a solution aging treatment on the wire of the target size to obtain the TC10 titanium alloy wire. The solution treatment temperature is 880℃, the holding time is 90min, and water cooling is used. The aging temperature is 540℃, the holding time is 4h, and air cooling is used.

[0040] The metallographic microstructures of the TC10 titanium alloy wire prepared in Example 1 before and after aging treatment are shown below. Figure 1 and 2As shown, TD (transverse) mainly consists of equiaxed / near-equiaxed α phases, uniformly distributed with grain sizes of approximately 10-30 μm. Numerous fine secondary α phase particles appear in the matrix, refining the original α phase grains and resulting in a more "dense" overall microstructure. RD (rolling direction) mainly consists of elongated α phases along the rolling direction, appearing fibrous. Secondary α phases precipitate oriented along the deformation direction on the elongated α phase matrix, but the microstructure becomes "coarser" due to the precipitated phases. Furthermore, after aging at 540℃, a large number of secondary α phases (fine needle-like or granular) precipitate from the supersaturated β phase. These secondary α phases are diffusely distributed in the matrix, significantly improving the alloy's properties through "precipitation strengthening."

[0041] Example 2 This embodiment describes a method for preparing high-strength TC10 titanium alloy wire for fasteners, comprising the following steps: S1: Select TC10 titanium alloy bars with a hot-worked specification of φ53mm and an oxygen content of 0.195% as the billet; S2: The blank is subjected to heat treatment, rolling treatment and coiling in sequence to obtain wire blank; The heat treatment temperature is 860±10℃ and the time is 60min. After exiting the furnace, it is rolled with a large deformation and hot rolled to a coil of φ7.0±0.2mm. S3: The wire blank is heated to 30°C to 50°C below the phase change point by high temperature deformation heat treatment process, and then hot drawing and rounding process with fixed mold is carried out. Combined with rapid water cooling, intermediate annealing, cold drawing with roller mold and low temperature deformation heat treatment process, the wire blank is heated to a low temperature. Then, it is cut to length by fixed mold and air cooled to obtain the wire material of fixed length. The high-temperature deformation heat treatment process involves a temperature of 900℃ (TC10 phase transformation point is 935℃), a holding time of 60 minutes, and the billet is rapidly drawn into the hot drawing unit's fixed die from φ7.0mm→φ6.6mm→φ6.2mm to round it to φ6.0mm (hot drawing start temperature is 900℃). Then, the outer layer is peeled off to φ5.8±0.1mm, followed by intermediate annealing at a temperature of 770±10℃ for 50 minutes, and then air cooling. The roller die cold drawing process involves three passes of cold drawing on the φ5.8±0.1mm intermediate wire blank. The specific parameters are as follows: A single cold drawing process produces a diameter of 5.6mm, with a deformation rate of 6.78%. The φ5.2mm diameter was cold-drawn in two passes, with a deformation of 13.78% in this pass. The φ4.8mm material was cold-drawn in three passes, with a deformation of 14.8% in each pass and a cumulative deformation of 33.4%. The low-temperature deformation heat treatment was performed at a temperature of 770±10℃ for 50 minutes, followed by cutting to length using a fixed mold, with the wire size being φ4.6±0.1mm. S4: Peel the wire after it has been cut to length φ4.4±0.05mm, and then polish it to φ4.4+0 / -0.02mm to obtain a bright wire of the target size. Then, perform a solution aging treatment on the wire of the target size to obtain the TC10 titanium alloy wire. The solution treatment temperature is 900℃, the holding time is 90min, and water cooling is used. The aging temperature is 540℃, the holding time is 4h, and air cooling is used.

[0042] The metallographic microstructures of the TC10 titanium alloy wire prepared in Example 2 before and after aging treatment are shown below. Figure 3 and 4 As shown in the figure, the metallographic structure after heat treatment is an α+β two-phase structure. Due to its smaller diameter and greater deformation, the φ4.4mm wire exhibits more significant deformation orientation in the RD direction (more obvious α phase elongation) and finer grains in the TD direction. After aging, a large amount of secondary α phase precipitates to achieve strengthening. Furthermore, due to the more complete deformation, the φ4.4mm wire exhibits finer and more uniform secondary α phase precipitation, resulting in a superior strengthening effect.

[0043] Example 3 The preparation method of the high-strength TC10 titanium alloy wire for fasteners in this embodiment is similar to that in Embodiment 1, except that the oxygen content in S1 is 0.185%. In S3, the temperature of the high-temperature deformation heat treatment process is 50°C below the phase transformation point, the holding time is 30 min, the annealing temperature is 750±20°C, and the holding time is 90 min. In S4, the solution temperature is 940℃, the holding time is 120min, the aging temperature is 560℃, and the holding time is 6h.

[0044] Comparative Example 1 The preparation method of the high-strength TC10 titanium alloy wire for fasteners in this comparative example is similar to that in Example 1, except that the oxygen content in S1 is 0.15%.

[0045] Comparative Example 2 The preparation method of high-strength TC10 titanium alloy wire for fasteners in this comparative example is similar to that in Example 1, except that in S3, the high-temperature deformation heat treatment process is omitted and the wire is directly drawn using a fixed die.

[0046] Comparative Example 3 The preparation method of the high-strength TC10 titanium alloy wire for fasteners in this comparative example is similar to that in Example 1, except that the rapid water cooling step in the high-temperature deformation heat treatment process is removed in S3.

[0047] Comparative Example 4 The preparation method of the high-strength TC10 titanium alloy wire for fasteners in this comparative example is similar to that in Example 1, except that the low-temperature deformation heat treatment step is omitted in S3.

[0048] Comparative Example 5 The preparation method of the high-strength TC10 titanium alloy wire for fasteners in this comparative example is similar to that in Example 1, except that in S3, the temperature of the high-temperature deformation heat treatment process is 10°C below the phase transformation point.

[0049] Comparative Example 6 The preparation method of the high-strength TC10 titanium alloy wire for fasteners in this comparative example is similar to that in Example 1, except that the intermediate annealing temperature in S3 is 700±10℃.

[0050] Comparative Example 7 The preparation method of the high-strength TC10 titanium alloy wire for fasteners in this comparative example is similar to that in Example 1, except that in S3, the temperature of the low-temperature deformation heat treatment is 900±10℃.

[0051] Experimental Example 1 The room temperature mechanical properties of the TC10 titanium alloy wires finally prepared in the examples and comparative examples were tested respectively, and the results are shown in Table 1.

[0052] Table 1

[0053] Compared with Example 1, Comparative Example 1 showed that an oxygen content of 0.195% was more beneficial to improving the tensile strength and elongation of TC10 titanium alloy wire than 0.15%. Furthermore, as the oxygen content decreased, the shear strength and Vickers hardness of the material also decreased slightly. Compared to Example 1, the rounding process in the high-temperature deformation heat treatment is a key step in improving the mechanical properties of the TC10 titanium alloy wire blank in Comparative Example 2. This step effectively improves the material's performance, ensuring a good balance between strength and plasticity, and enhancing its overall mechanical properties. In Comparative Example 2, omitting the high-temperature deformation heat treatment and directly drawing the wire with a fixed die directly affects the target performance of TC10, resulting in a decrease in tensile strength of approximately 80 MPa, a slight decrease in yield strength of approximately 33 MPa, a 4% decrease in elongation, a 48 MPa decrease in shear strength, and a slight decrease in Vickers hardness.

[0054] Compared with Example 1, Comparative Example 3 removed the rapid water cooling step in the high-temperature deformation heat treatment process. As a result, Comparative Example 3 showed a comprehensive decline in hard properties such as strength and hardness, accompanied by a sharp decline in plasticity and toughness. The strength-plasticity matching was severely deteriorated, and the overall mechanical properties were extremely poor, failing to reach the excellent performance level of Example 1.

[0055] Compared with Example 1, Comparative Example 4, by omitting the low-temperature deformation heat treatment step, exhibits significantly deteriorated performance in key practical indicators such as strength, hardness, and shear properties, with only a slight increase in elongation. Its overall mechanical properties are far lower than those of Example 1, failing to meet the application requirements of TC10 titanium alloy wire blanks. Compared with Example 1, the temperature of the high-temperature deformation heat treatment process in Comparative Example 5 is 10°C below the phase transformation point, which fully verifies that the high-temperature deformation heat treatment temperature used in Example 1 is the optimal parameter for TC10 titanium alloy wire. Temperatures close to the phase transformation point will have irreversible negative effects on the material's microstructure and properties.

[0056] Compared with Example 1, the intermediate annealing temperature of Comparative Example 6 was 700±10℃. Due to the improper selection of intermediate annealing temperature parameters, Comparative Example 6 disrupted the microstructure optimization rhythm of TC10 titanium alloy, resulting in poor grain structure control and insufficient internal stress release. Ultimately, this led to a comprehensive deterioration in strength, plasticity, shear properties and hardness, and the overall mechanical properties were far lower than those of Example 1.

[0057] Compared to Example 1, Comparative Example 7 used a low-temperature deformation heat treatment at 900±10℃. The core function of low-temperature deformation heat treatment is to eliminate internal residual stress and optimize phase structure and distribution through deformation and thermal effects at low temperatures. However, the high temperature of 900±10℃ completely deviates from the original intention of low-temperature deformation heat treatment. At high temperatures, it directly affects abnormal phase structure transformation and brittle phase precipitation, ultimately leading to severe deterioration of the microstructure of the TC10 titanium alloy and comprehensive degradation of its mechanical properties.

[0058] The TC10 titanium alloy wire prepared by the method of this invention has a tensile strength ≥1460MPa, a yield strength ≥1350MPa, an elongation ≥10%, a shear strength ≥830MPa, and a Vickers hardness ≥385MPa.

[0059] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing high-strength TC10 titanium alloy wire for fasteners, characterized in that, Includes the following steps: S1: Select TC10 titanium alloy bars with an oxygen content of 0.185~0.2% as billets; S2: The blank is subjected to heat treatment, rolling treatment and coiling in sequence to obtain wire blank; S3: The wire blank is heated to 30°C to 50°C below the phase change point using a high-temperature deformation heat treatment process, followed by hot drawing and rounding with a fixed mold, combined with rapid water cooling, intermediate annealing, cold drawing with a roller, and low-temperature deformation heat treatment process to heat the wire blank at low temperature. Then, it is cut to length using a fixed mold and air-cooled to obtain the wire material in length. S4: Peel and trim the wire after it has been cut to length to obtain a bright wire of the target size. Then, perform a solution aging treatment on the wire of the target size to obtain the TC10 titanium alloy wire.

2. The method for preparing high-strength TC10 titanium alloy wire for fasteners according to claim 1, characterized in that, In S2, the heating treatment temperature is 840~870℃ and the time is 30~90min.

3. The method for preparing high-strength TC10 titanium alloy wire for fasteners according to claim 1, characterized in that, In S3, the holding time for the high-temperature deformation heat treatment process is 30~90min.

4. The method for preparing high-strength TC10 titanium alloy wire for fasteners according to claim 1, characterized in that, In S3, the intermediate annealing temperature is 750±30℃, the holding time is 30~90min, and then air cooling is performed.

5. The method for preparing high-strength TC10 titanium alloy wire for fasteners according to claim 1, characterized in that, In S3, the cold drawing of the roller die is carried out in 3 to 6 passes, with the deformation amount of each pass ≤15% and the cumulative deformation amount <35%.

6. The method for preparing high-strength TC10 titanium alloy wire for fasteners according to claim 1, characterized in that, In S3, the temperature of the low-temperature deformation heat treatment is 750±30℃, and the time is 30~90min.

7. The method for preparing high-strength TC10 titanium alloy wire for fasteners according to claim 1, characterized in that, In S4, the solution treatment temperature is 860~940℃ and the holding time is 30~120min, the aging treatment temperature is 520~560℃ and the holding time is 3~6h.

8. A TC10 titanium alloy wire prepared by the method according to any one of claims 1-7.

9. The TC10 titanium alloy wire according to claim 8, characterized in that, The microstructure of the filament consists of primary α phase and β phase.

10. The TC10 titanium alloy wire according to claim 8, characterized in that, The TC10 titanium alloy wire has a tensile strength ≥1460MPa, a yield strength ≥1350MPa, an elongation ≥10%, a shear strength ≥830MPa, and a Vickers hardness ≥385MPa.

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