A high-strength TC4 titanium alloy wire and its preparation method

Abstract

This invention discloses a high-strength TC4 titanium alloy wire and its preparation method, belonging to the technical field of titanium alloy wire materials. The method involves performing multi-pass roll drawing of a hot-rolled TC4 titanium alloy wire blank in a high-temperature two-phase region, followed by annealing to obtain the wire. The annealed wire is then subjected to another multi-pass roll drawing, with the temperature gradually decreasing during the drawing process. Finally, the roll-drawn wire is subjected to multi-pass fixed-die drawing in a low-temperature two-phase region, with the temperature remaining constant throughout the drawing process, followed by a second annealing treatment to obtain the high-strength TC4 titanium alloy wire. The TC4 alloy wire prepared by this invention using the roll drawing + fixed-die method exhibits high strength, a uniform and fine microstructure, and room-temperature tensile properties far exceeding the performance requirements for medical device materials in relevant standards such as GB / T 13810-2017.

Description

Technical Field

[0001] This invention belongs to the technical field of titanium alloy wire materials, and relates to a high-strength TC4 titanium alloy wire and its preparation method. Background Technology

[0002] TC4 titanium alloy, as a conventional titanium alloy material, possesses excellent mechanical properties and corrosion resistance, and is widely used in aerospace, automotive manufacturing, and medical device industries. In the aerospace field, the use of TC4 titanium alloy bolts can achieve significant weight reduction, and due to its high specific strength, good corrosion resistance, and excellent fatigue performance, its usage in aircraft is constantly increasing. In the medical device field, TC4 is widely used in the biomedical industry due to its good biocompatibility and corrosion resistance, and is commonly used in the manufacture of artificial joints, dental implants, bone needles, and other medical devices.

[0003] However, with the continuous progress and development of the aerospace and medical industries, the requirements for the performance of titanium alloy materials are also increasing. Existing TC4 medium-strength titanium alloy wire is gradually becoming insufficient to meet the urgent needs of next-generation aircraft and medical devices such as bone needles for high-strength and high-toughness titanium alloy wire. Therefore, optimizing and upgrading the conventional manufacturing process of TC4 titanium alloy wire to achieve its high-strength performance requirements has become a crucial issue that urgently needs to be addressed. Summary of the Invention

[0004] The purpose of this invention is to provide a high-strength TC4 titanium alloy wire and its preparation method, so as to solve the technical problems of the traditional drawing process of TC4 titanium alloy in the prior art, which is difficult to meet the high strength performance requirements and has low processing efficiency.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing high-strength TC4 titanium alloy wire, comprising the following steps:

[0007] The TC4 titanium alloy hot-rolled wire blank is drawn in multiple passes of roll drawing in the high-temperature two-phase region, and then annealed to obtain the wire.

[0008] The annealed wire is then subjected to multiple rounds of roller drawing, with the temperature gradually decreasing during the drawing process.

[0009] The wire drawn by the roller die is subjected to multiple fixed die drawing in the low-temperature two-phase region, with the temperature remaining constant during the drawing process. Finally, a second annealing treatment is performed to obtain high-strength TC4 titanium alloy wire.

[0010] Furthermore, in the step of drawing the TC4 titanium alloy hot-rolled wire blank through multiple rolls in a high-temperature two-phase region and then annealing it to obtain the wire, before performing the multiple roll drawing, the TC4 titanium alloy hot-rolled wire blank is first subjected to stress-relief annealing. The stress-relief annealing temperature is 700℃~850℃, and the holding time is 30min~90min.

[0011] Furthermore, in the step of drawing TC4 titanium alloy hot-rolled wire blanks in a high-temperature two-phase region using multiple roll dies and then annealing them to obtain wire, the total drawing deformation of the multiple roll dies is 30%~50%, the deformation of each pass is not less than 5%~10%, and the drawing temperature of each pass is 700℃~850℃.

[0012] Furthermore, in the step of drawing TC4 titanium alloy hot-rolled wire blanks in a high-temperature two-phase region using multiple roll dies and then annealing them to obtain wire, the diameter of the TC4 titanium alloy hot-rolled wire blank is 8mm~14mm, and the drawing speed of the multiple roll dies is 2.0m / min~8.0m / min.

[0013] Furthermore, in the step of drawing TC4 titanium alloy hot-rolled wire blanks in a high-temperature two-phase region using multiple roll dies and then annealing them to obtain wire, the annealing temperature is 700℃~850℃ and the holding time is 30min~90min.

[0014] Furthermore, in the step of subjecting the annealed wire to multiple roll drawing passes with the temperature gradually decreasing during the drawing process, the total drawing deformation of the multiple roll drawing passes is 20% to 50%, the deformation of each pass is not less than 8% to 15%, the drawing temperature of each pass is 700℃ to 850℃, and the drawing speed is 2.0m / min to 8.0m / min.

[0015] Furthermore, in the step of performing multiple fixed-die drawing on the wire drawn by the roller die in the low-temperature two-phase region, with the temperature remaining constant during the drawing process, and finally performing secondary annealing to obtain high-strength TC4 titanium alloy wire, the total deformation of the multiple fixed-die drawing is 20%~50%, the fixed-die drawing temperature is 600℃~700℃, the deformation of each pass is not less than 10%~15%, and the drawing speed is 2.0m / min~8.0m / min.

[0016] Furthermore, in the step of performing multiple fixed-die drawing of the wire after roller drawing in a low-temperature two-phase region, with the temperature remaining constant during the drawing process, and finally performing a secondary annealing treatment to obtain high-strength TC4 titanium alloy wire, the temperature of the secondary annealing treatment is 650℃~800℃, and the holding time is 30min~90min.

[0017] Furthermore, a second annealing process is performed to obtain the high-strength TC4 titanium alloy wire with a diameter of 2 mm to 5 mm.

[0018] Secondly, the present invention provides a high-strength TC4 titanium alloy wire, which is prepared by the above-mentioned method for preparing a high-strength TC4 titanium alloy wire.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention discloses a high-strength TC4 titanium alloy wire and its preparation method. The TC4 high-strength titanium alloy wire prepared by the roll die + fixed die drawing method exhibits a tensile strength greater than 1180 MPa, a yield strength greater than 1000 MPa, an elongation after fracture greater than 5%, and a reduction of area greater than 40% in the room temperature drawn state. After annealing heat treatment, the drawn wire exhibits a room temperature tensile strength greater than 1100 MPa, a yield strength greater than 980 MPa, an elongation after fracture greater than 15%, and a reduction of area greater than 40%. Compared with existing TC4 alloy wires prepared by fixed die drawing only, it demonstrates superior strength and toughness. Furthermore, the TC4 alloy wire prepared by the roll die + fixed die drawing method has excellent surface quality, a uniform and fine microstructure, and room temperature tensile properties far exceeding the performance requirements for medical device materials in relevant standards such as GB / T 13810-2017. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 The image shows the microstructure of the high-strength TC4 titanium alloy wire prepared in Example 1 of this invention.

[0023] Figure 2 This is a microscopic morphology image of the high-strength TC4 titanium alloy wire prepared in Example 2 of the present invention.

[0024] Figure 3 This is a flowchart of a method for preparing high-strength TC4 titanium alloy wire according to the present invention. Detailed Implementation

[0025] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0026] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0027] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0028] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0029] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0030] The present invention will now be described in further detail with reference to the accompanying drawings:

[0031] See Figure 3 This invention discloses a method for preparing high-strength TC4 titanium alloy wire, comprising the following steps:

[0032] Step 1: The TC4 titanium alloy hot-rolled wire blank is drawn in a high-temperature two-phase region through multiple rolls and then annealed to obtain the wire.

[0033] In this step, the diameter of the hot-rolled wire blank is d8mm~d14mm. Before drawing, the wire needs to be subjected to stress-relief annealing treatment at 700℃~850℃ for 30min~90min. The total drawing deformation of the multi-pass roll drawing is 30%~50%, and the drawing temperature of each pass is 700℃~850℃.

[0034] After drawing, annealing is required. The specific annealing process is the same as that of stress-relief annealing, with a temperature of 700℃~850℃ and a holding time of 30min~90min.

[0035] Step 2: The annealed wire is drawn through multiple rollers again, with the temperature gradually decreasing during the drawing process.

[0036] In this step, the total deformation of the multi-pass roll drawing is 20%~50%, and the drawing temperature of each pass is 700℃~850℃.

[0037] Step 3: The wire drawn by the roller die is subjected to multiple fixed die drawing in the low temperature two-phase region, and the temperature remains constant during the drawing process. Finally, a second annealing treatment is performed to obtain high-strength TC4 titanium alloy wire.

[0038] In this step, the total deformation of the multi-pass fixed-die drawing is 20%~50%, and the fixed-die drawing temperature is 600℃~700℃. The secondary annealing process is specifically 650℃~800℃, held for 30~90 minutes. The final product is a high-strength TC4 titanium alloy wire with a diameter of d2mm~d5mm.

[0039] In one feasible embodiment of the present invention, the deformation amount of each pass in step 1 is not less than 5% to 10%; the deformation amount of each pass in step 2 is not less than 8% to 15%; the deformation amount of each pass in step 3 is not less than 10% to 15%; and the drawing speed of the multi-pass roller die + fixed die in steps 1, 2 and 3 is 2.0m / min to 8.0m / min.

[0040] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0041] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0042] Example 1:

[0043] This implementation case adopts the preparation method of high-strength TC4 titanium alloy wire using a roller die + fixed die, and uses a Ф11mm hot-rolled strip as the blank to prepare Ф5mm high-strength TC4 titanium alloy wire.

[0044] Step 1: The hot-rolled billet with a diameter of Ф11mm is stress-relieved and annealed at 750℃ for 60min, and then drawn by a roll die at a heating temperature of 850℃; the diameter of the billet with a diameter of Ф11mm is reduced to Ф8.3mm through 4 passes of drawing, with a deformation of not less than 7% in each pass, a drawing speed of 3.0m / min, and a total deformation of 43%; then the wire is annealed at 750℃ for 60min.

[0045] Step 2: The Ф8.3mm wire after heat treatment in Step 1 is reduced to Ф6.3mm by roller drawing. The drawing temperature is reduced from 700℃ to 650℃ in each die. The drawing speed is 3.0m / min. The deformation amount of each pass is not less than 10%, and the total deformation amount is 42%.

[0046] Step 3: The wire with a diameter of Ф6.3mm drawn by the roller die in Step 2 is drawn to Ф5.0mm by a fixed die. The drawing temperature is 650℃, the drawing speed is 2m / min, the deformation amount of each pass is not less than 13%, and the total deformation amount is 37%. Finally, the wire is subjected to annealing heat treatment at 650℃ for 1 hour to obtain high-strength TC4 titanium alloy wire.

[0047] The properties of the Φ5.0mm high-strength titanium alloy wire prepared through the above steps are shown in Table 1 below:

[0048] Table 1

[0049]

[0050] As shown in Table 1, the two-phase high-strength TC4 titanium alloy wire prepared by this method exhibits good consistency in annealed properties. The deviations in tensile strength and yield strength are both no greater than 10 MPa, and the differences in elongation and reduction of area are no greater than 0.5%. Moreover, the test data are far higher than the requirements of GB / T 13810-2017 for the performance of TC4 wire, truly achieving good toughness while maintaining high strength, resulting in excellent comprehensive performance of the wire.

[0051] In addition, according to Figure 1 As shown, the high-strength TC4 titanium alloy wire prepared by this method exhibits a uniform annealed microstructure with sufficiently refined grains, and the difference in grain size rating between different parts is ≤1. Based on the high-strength TC4 titanium alloy wire prepared in the above implementation case, it can be seen that this method can prepare two-phase Ф5.0mm titanium alloy wire with superior performance and good microstructure.

[0052] Example 2:

[0053] This implementation case adopts the preparation method of high-strength TC4 titanium alloy wire using a roller die + fixed die, and uses a hot-rolled strip with a specification of Ф9.0mm as the blank to prepare Ф4.0mm high-strength TC4 titanium alloy wire.

[0054] Step 1: Stress-relief annealing of hot-rolled billet with a diameter of Ф9.0mm is carried out at 800℃ for 50min. Then, the billet is drawn by a roller at a heating temperature of 800℃ and a drawing speed of 3.5m / min. The diameter of the billet is reduced from Ф9.0mm to Ф7.2mm by roller drawing. The deformation amount in each pass is not less than 6%, and the total deformation amount is 36%. After that, the wire is annealed at 800℃ for 50min.

[0055] Step 2: The Ф7.2mm wire after heat treatment in Step 1 is drawn to Ф5.4mm using a roller die. The drawing temperature is gradually reduced from 800℃ to 740℃, the drawing speed is 4m / min, the deformation per pass is not less than 9%, and the total deformation is 43%.

[0056] Step 3: The wire with a diameter of Ф5.4mm drawn by the roller die in Step 2 is drawn by a fixed die at a heating temperature of 700℃ and a drawing speed of 3m / min. The deformation amount in each pass is not less than 12%, and the total deformation amount is 45%, that is, the wire with a diameter of Ф5.7mm is drawn to a diameter of Ф4.0mm by the fixed die. Finally, it is annealed at 680℃ for 60 minutes to obtain high-strength TC4 titanium alloy wire.

[0057] The properties of the Φ4.0mm high-strength titanium alloy wire prepared through the above steps are shown in Table 2:

[0058] Table 2

[0059]

[0060] The high-strength titanium alloy wire prepared in this embodiment exhibits high strength and good toughness in the annealed state. Furthermore, its mechanical properties show good consistency. Microstructural observation of the Φ4.0mm high-strength titanium alloy wire revealed a uniform structure, refined grains, and grain size differences ≤1 in different locations. Figure 2 As shown.

[0061] Example 3:

[0062] This implementation case adopts the preparation method of high-strength TC4 titanium alloy wire using a roller die + fixed die, and uses a hot-rolled strip with a specification of Ф13.0mm as the blank to prepare Ф5.2mm high-strength TC4 titanium alloy wire.

[0063] Step 1: Stress-relief annealing is performed on a hot-rolled billet with a diameter of Ф13.0mm at 850℃ for 80 minutes. Then, the billet is drawn using a roll die at a heating temperature of 800℃ and a drawing speed of 7m / min. The diameter of the billet is reduced from Ф13.0mm to Ф9.5mm through the roll die drawing. The deformation amount in each pass is not less than 9%, and the total deformation amount is 46%. After that, the wire is annealed at 850℃ for 80 minutes.

[0064] Step 2: The Ф9.5mm wire after heat treatment in Step 1 is drawn to Ф6.9mm using a roller die. The drawing temperature is gradually reduced from 850℃ to 750℃, the drawing speed is 7m / min, the deformation per pass is not less than 13%, and the total deformation is 47%.

[0065] Step 3: The wire with a diameter of Ф6.9mm drawn by the roller die in Step 2 is drawn by a fixed die at a heating temperature of 600℃ and a drawing speed of 7m / min. The deformation amount in each pass is not less than 10%, and the total deformation amount is 43%, that is, the wire with a diameter of Ф6.9mm is drawn to a diameter of Ф5.2mm by the fixed die. Finally, it is annealed at 750℃ for 50 minutes to obtain high-strength TC4 titanium alloy wire.

[0066] Example 4:

[0067] This implementation case adopts the preparation method of high-strength TC4 titanium alloy wire using a roller die + fixed die, and uses a hot-rolled strip with a specification of Ф10.0mm as the blank to prepare Ф4.5mm high-strength TC4 titanium alloy wire.

[0068] Step 1: The hot-rolled billet with a diameter of Ф10.0mm is stress-relieved annealed at 700℃ for 40min, and then drawn by a roller at a heating temperature of 750℃ and a drawing speed of 6m / min; the diameter of the billet with a diameter of Ф10.0mm is reduced to Ф7.8mm by roller drawing, with a deformation of not less than 8% per pass and a total deformation of 39%; then the wire is annealed at 700℃ for 40min.

[0069] Step 2: The Φ7.8mm wire after heat treatment in Step 1 is drawn to Φ6.2mm using a roller die. The drawing temperature is gradually reduced from 750℃ to 680℃, the drawing speed is 5m / min, the deformation per pass is not less than 12%, and the total deformation is 37%.

[0070] Step 3: The wire with a diameter of Ф6.2mm drawn by the roller die in Step 2 is drawn by a fixed die at a heating temperature of 650℃ and a drawing speed of 6m / min. The deformation in each pass is not less than 11%, and the total deformation is 47%, that is, the wire with a diameter of Ф6.2mm is drawn to a diameter of Ф4.5mm by the fixed die. Finally, it is annealed at 700℃ for 80 minutes to obtain high-strength TC4 titanium alloy wire.

[0071] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing high-strength TC4 titanium alloy wire, characterized in that, The method comprises the following steps: the TC4 titanium alloy hot-rolled wire blank is subjected to multi-pass roller die drawing in a high-temperature two-phase zone, and then annealing treatment is performed to obtain a wire material; the annealing treatment temperature is 700-850 DEG C, and the holding time is 30-90 min; the total drawing deformation of the multi-pass roller die drawing is 30-50%, the deformation of each pass is not less than 5-10%, and the pass drawing temperature is 700-850 DEG C; the annealed wire material is subjected to multi-pass roller die drawing again, and the temperature gradually decreases during the drawing process; the roller die drawn wire material is subjected to multi-pass fixed die drawing in a low-temperature two-phase zone, and the temperature is constant during the drawing process, and finally secondary annealing treatment is performed to obtain a high-strength TC4 titanium alloy wire material.

2. The method of claim 1, wherein the high-strength TC4 titanium alloy wire is prepared by the steps of: In the step of performing multi-pass roller die drawing on the TC4 titanium alloy hot-rolled wire blank in a high-temperature two-phase zone, and then performing annealing treatment to obtain a wire material, the TC4 titanium alloy hot-rolled wire blank is subjected to stress relief annealing treatment before the multi-pass roller die drawing, the stress relief annealing treatment temperature is 700-850 DEG C, and the holding time is 30-90 min. ​ 3. The method of claim 1, wherein the high-strength TC4 titanium alloy wire is prepared by the steps of: In the step of performing multi-pass roller die drawing on the TC4 titanium alloy hot-rolled wire blank in a high-temperature two-phase zone, and then performing annealing treatment to obtain a wire material, the diameter of the TC4 titanium alloy hot-rolled wire blank is 8-14 mm, and the drawing speed of the multi-pass roller die drawing is 2.0-8.0 m / min. ​ 4. The method of claim 1, wherein the high-strength TC4 titanium alloy wire is prepared by the steps of: In the step of performing multi-pass roller die drawing again on the annealed wire material, and the temperature gradually decreases during the drawing process, the total drawing deformation of the multi-pass roller die drawing is 20-50%, the deformation of each pass is not less than 8-15%, the pass drawing temperature is 700-850 DEG C, and the drawing speed is 2.0-8.0 m / min. ​ 5. The method of claim 1, wherein the high-strength TC4 titanium alloy wire is prepared by the steps of: preparing a TC4 titanium alloy wire; and performing a heat treatment on the TC4 titanium alloy wire. In the step of performing multi-pass fixed die drawing on the roller die drawn wire material in a low-temperature two-phase zone, and the temperature is constant during the drawing process, and finally performing secondary annealing treatment to obtain a high-strength TC4 titanium alloy wire material, the total deformation of the multi-pass fixed die drawing is 20-50%, the fixed die drawing temperature is 600-700 DEG C, the deformation of each pass is not less than 10-15%, and the drawing speed is 2.0-8.0 m / min.

6. The method of claim 1, wherein the high-strength TC4 titanium alloy wire is prepared by the steps of: In the step of performing multi-pass fixed die drawing on the roller die drawn wire material in a low-temperature two-phase zone, and the temperature is constant during the drawing process, and finally performing secondary annealing treatment to obtain a high-strength TC4 titanium alloy wire material, the secondary annealing treatment temperature is 650-800 DEG C, and the holding time is 30-90 min. ​ 7. The method of claim 1, wherein the high-strength TC4 titanium alloy wire is prepared by the steps of: preparing a TC4 titanium alloy wire; and performing a heat treatment on the TC4 titanium alloy wire. The diameter of the high-strength TC4 titanium alloy wire material obtained by finally performing secondary annealing treatment is 2-5 mm.

8. A high-strength TC4 titanium alloy wire, characterized in that, The high-strength TC4 titanium alloy wire material is prepared by the method of any one of claims 1-7.

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