High-strength TC4 titanium alloy wire and preparation method thereof

Abstract

The invention discloses a high-strength TC4 titanium alloy wire and a preparation method thereof, and belongs to the technical field of titanium alloy wire materials. The method comprises the following steps: carrying out multi-pass roller die drawing on a TC4 titanium alloy hot-rolled wire blank in a high-temperature two-phase region, and then carrying out annealing treatment to obtain a wire material; then the annealed wire is subjected to multi-pass roller die drawing again, and the temperature is gradually reduced in the drawing process; and finally, the wire obtained after roller die drawing is subjected to multi-pass fixed die drawing in a low-temperature two-phase region, the temperature is not changed in the drawing process, and finally secondary annealing treatment is conducted to obtain the high-strength TC4 titanium alloy wire. The TC4 alloy wire prepared through the roller die and fixed die drawing method is high in strength and uniform and fine in microstructure, and the room-temperature tensile property of the TC4 alloy wire far exceeds the performance requirements of relevant standards such as GB / T 13810-2017 on medical instrument materials.

Description

Technical Field

[0001] The invention belongs to the technical field of titanium alloy wire materials and relates to a high-strength TC4 titanium alloy wire material and a preparation method thereof. Background Art

[0002] As a conventional titanium alloy material, TC4 titanium alloy has excellent mechanical properties and corrosion resistance, and is widely used in aerospace, automobile manufacturing, medical equipment and other fields. In the aerospace field, the use of TC4 titanium alloy bolts can achieve a significant weight reduction effect, and due to its high specific strength, good corrosion resistance and excellent fatigue performance, its use in aircraft is increasing. In the field of medical devices, TC4 is widely used in the biomedical industry due to its good biocompatibility and corrosion resistance, and is often used to make artificial joints, dental implants, bone needles and other medical devices.

[0003] However, with the continuous progress and development of the aerospace industry and the medical industry, the requirements for the performance of titanium alloy materials are also increasing. The existing TC4 medium-strength titanium alloy wire has gradually failed to meet the urgent demand for high-strength and toughness titanium alloy wire for the new generation of aircraft and medical devices such as bone needles with higher performance requirements. Therefore, optimizing and upgrading the conventional preparation process of TC4 titanium alloy wire to achieve its high-strength performance requirements has become an important issue that needs to be solved urgently. Summary of the invention

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

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a method for preparing a high-strength TC4 titanium alloy wire, comprising 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 region, and then annealed to obtain a wire material; The annealed wire is again subjected to multiple roller die drawing, and the temperature is gradually reduced during the drawing process; The wire after roller die drawing is subjected to multiple passes of fixed die drawing in a low temperature two-phase region, and the temperature remains unchanged during the drawing process. Finally, a secondary annealing treatment is performed to obtain a high-strength TC4 titanium alloy wire.

[0006] Furthermore, in the step of subjecting the TC4 titanium alloy hot-rolled wire billet to multi-pass roller die drawing in the high-temperature two-phase region and then annealing to obtain the wire, before the multi-pass roller die drawing, the TC4 titanium alloy hot-rolled wire billet is first subjected to stress relief annealing, and the temperature for the stress relief annealing is 700°C~850°C, and the holding time is 30min~90min.

[0007] Furthermore, in the step of subjecting the TC4 titanium alloy hot-rolled wire billet to multi-pass roller die drawing in the high-temperature two-phase region and then annealing to obtain the wire, 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 drawing temperature of each pass is 700℃~850℃.

[0008] Furthermore, in the step of subjecting the TC4 titanium alloy hot-rolled wire billet to multi-pass roller die drawing in the high-temperature two-phase region and then annealing to obtain the wire, the diameter of the TC4 titanium alloy hot-rolled wire billet is 8 mm to 14 mm, and the drawing speed of the multi-pass roller die drawing is 2.0 m / min to 8.0 m / min.

[0009] Furthermore, in the step of subjecting the TC4 titanium alloy hot-rolled wire billet to multi-pass roller die drawing in the high-temperature two-phase region and then annealing to obtain the wire, the annealing temperature is 700° C. to 850° C. and the holding time is 30 min to 90 min.

[0010] Furthermore, in the step of subjecting the annealed wire to multiple roller die drawing again and gradually reducing the temperature during the drawing process, the total drawing deformation of the multiple roller die drawing is 20%~50%, the deformation of each pass is not less than 8%~15%, the drawing temperature of each pass is 700℃~850℃, and the drawing speed is 2.0m / min~8.0m / min.

[0011] Furthermore, in the step of subjecting the wire after roller die drawing to multiple passes of fixed die drawing in the low-temperature two-phase region, and the temperature remains unchanged during the drawing process, and finally performing a secondary annealing treatment to obtain a high-strength TC4 titanium alloy wire, the total deformation of the multiple passes of 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.

[0012] Furthermore, in the step of subjecting the roller-drawn wire to multiple fixed-die drawing in a low-temperature two-phase region, with the temperature remaining unchanged during the drawing process, and finally subjecting the wire to secondary annealing to obtain a high-strength TC4 titanium alloy wire, the temperature of the secondary annealing is 650°C to 800°C, and the holding time is 30min to 90min.

[0013] Furthermore, the diameter of the high-strength TC4 titanium alloy wire obtained by the secondary annealing treatment is 2 mm to 5 mm.

[0014] In a second aspect, 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.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The invention discloses a high-strength TC4 titanium alloy wire and a preparation method thereof. The TC4 high-strength titanium alloy wire prepared by the roller die + fixed die drawing method has a tensile strength greater than 1180 MPa, a yield strength greater than 1000 MPa, an elongation greater than 5%, and a cross-sectional shrinkage greater than 40% in the room temperature drawn state; after annealing heat treatment, the drawn wire has a room temperature tensile strength greater than 1100 MPa, a yield strength greater than 980 MPa, an elongation greater than 15%, and a cross-sectional shrinkage greater than 40%, which is superior to the TC4 alloy wire prepared by only fixed die drawing. In addition, the TC4 alloy wire prepared by the roller die + fixed die drawing method has good surface quality, uniform and fine microstructure, and room temperature tensile performance far exceeds the performance requirements of relevant standards such as GB / T 13810-2017 for medical device materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 This is a microscopic morphology of the high-strength TC4 titanium alloy wire prepared in Example 1 of the present invention; Figure 2 This is a microscopic morphology of the high-strength TC4 titanium alloy wire prepared in Example 2 of the present invention.

[0018] Figure 3 The present invention is a flow chart of a method for preparing a high-strength TC4 titanium alloy wire. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0020] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0021] In this article, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0022] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0023] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings: See also Figure 3 The embodiment of the present invention discloses a method for preparing a high-strength TC4 titanium alloy wire, comprising the following steps: Step 1, subjecting the TC4 titanium alloy hot-rolled wire blank to multi-pass roller die drawing in a high-temperature two-phase region, and then annealing to obtain a wire material; In this step, the diameter of the hot-rolled wire billet is d8mm~d14mm, and the wire needs to be subjected to stress relief annealing at 700℃~850℃ for 30min~90min before drawing; the total drawing deformation of the multi-pass roller die drawing is 30%~50%, and the drawing temperature of each pass is 700℃~850℃; Annealing treatment is required after drawing. The specific annealing process is the same as the stress relief annealing treatment. The temperature is 700℃~850℃ and the insulation time is 30min~90min.

[0025] Step 2, the annealed wire is again subjected to multiple roller die drawing, and the temperature is gradually reduced during the drawing process; In this step, the total deformation of the multi-pass roller die drawing is 20%~50%, and the drawing temperature of each pass is 700℃~850℃.

[0026] Step 3, the wire after roller die drawing is subjected to multiple fixed die drawing in a low temperature two-phase region, and the temperature remains unchanged during the drawing process, and finally a secondary annealing treatment is performed to obtain a high-strength TC4 titanium alloy wire.

[0027] In this step, the total deformation of the multiple-pass fixed die drawing is 20%~50%, and the fixed die drawing temperature is 600℃~700℃. The secondary annealing process is specifically 650℃~800℃, and the heat preservation is 30~90min. Finally, a high-strength TC4 titanium alloy wire with a diameter of d2mm~d5mm is obtained.

[0028] In a feasible embodiment of the present invention, the deformation amount of each pass in step 1 is not less than 5%~10%; the deformation amount of each pass in step 2 is not less than 8%~15%; the deformation amount of each pass in step 3 is not less than 10%~15%; and the multi-pass roller die + fixed die drawing speed in step 1, step 2 and step 3 is 2.0m / min~8.0m / min.

[0029] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0030] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0031] Embodiment 1: This embodiment adopts the preparation method of high-strength TC4 titanium alloy wire roller die + fixed die, takes the hot-rolled strip with a specification of Ф11mm as the blank, and prepares the high-strength TC4 titanium alloy wire with a diameter of 5mm.

[0032] Step 1, heat-relieve annealing of a hot-rolled billet with a diameter of 11 mm at 750°C for 60 minutes, and then draw it with a roller die at a heating temperature of 850°C; reduce the billet with a diameter of 11 mm to 8.3 mm through 4 drawing passes, with a deformation of not less than 7% in each pass, a drawing speed of 3.0 m / min, and a total deformation of 43%; then, heat-relieve annealing of the wire at 750°C for 60 minutes; Step 2, the 8.3 mm diameter wire material heat-treated in step 1 is reduced to 6.3 mm diameter by roller die drawing, the drawing temperature is reduced from 700° C. to 650° C. die by die, the drawing speed is 3.0 m / min, the deformation amount of each pass is not less than 10%, and the total deformation amount is 42%; Step 3, the wire with a diameter of 6.3 mm after roller drawing in step 2 is drawn to 5.0 mm through a fixed die, the drawing temperature is 650°C, the drawing speed is 2m / min, the deformation amount of each pass is not less than 13%, the total deformation amount is 37%, and finally an annealing heat treatment is performed at 650°C and kept for 1 hour to obtain a high-strength TC4 titanium alloy wire.

[0033] The properties of the Ф5.0 mm high-strength titanium alloy wire prepared through the above steps are shown in Table 1: Table 1

[0034] It can be seen from Table 1 that the annealed performance of the two-phase high-strength TC4 titanium alloy wire prepared by this method is consistent, the deviation of the tensile strength and yield strength data is no more than 10MPa, the difference of elongation and cross-sectional shrinkage is no more than 0.5%, and the test data is much higher than the requirements of GB / T 13810-2017 for the performance of TC4 wire, which truly achieves good toughness while maintaining high strength, and the comprehensive performance of the wire is better.

[0035] In addition, according to Figure 1 As shown, the high-strength TC4 titanium alloy wire prepared by the method has uniform annealed structure, fully refined grains, and the difference in grain size ratings at different locations is ≤ 1. According to the high-strength TC4 titanium alloy wire prepared by the above implementation case, it can be seen that the method can be used to prepare a two-phase Ф5.0mm titanium alloy wire with superior performance and good consistent structure.

[0036] Embodiment 2: This embodiment adopts the preparation method of high-strength TC4 titanium alloy wire roller die + fixed die, takes the hot-rolled strip with a specification of Ф9.0mm as the blank, and prepares the Ф4.0mm high-strength TC4 titanium alloy wire.

[0037] Step 1, the hot-rolled billet with a diameter of 9.0 mm is kept at 800° C. for 50 minutes for stress relief annealing, and then roller die drawing is performed at a heating temperature of 800° C. at a drawing speed of 3.5 m / min; the billet with a diameter of 9.0 mm is reduced to 7.2 mm by roller die drawing, and the deformation amount of each pass is not less than 6%, and the total deformation amount is 36%; then the wire is annealed at 800° C. for 50 minutes; Step 2, roller-drawing the wire with a diameter of 7.2 mm after heat treatment in step 1 to a diameter of 5.4 mm, cooling the drawing temperature from 800° C. to 740° C. die by die, drawing speed 4 m / min, deformation of each pass not less than 9%, and total deformation of 43%; Step 3, the wire with a diameter of 5.4 mm after roller die drawing in step 2 is subjected to fixed die drawing at a heating temperature of 700°C and a drawing speed of 3m / min, with a deformation amount of not less than 12% in each pass and a total deformation amount of 45%, that is, the wire with a diameter of 5.7 mm is drawn to a diameter of 4.0 mm through a fixed die. Finally, an annealing heat treatment is performed at 680°C and kept for 60 minutes to obtain a high-strength TC4 titanium alloy wire.

[0038] The properties of the Ф4.0mm high-strength titanium alloy wire prepared by the above steps are shown in Table 2: Table 2

[0039] The high-strength titanium alloy wire prepared in this embodiment has high annealing strength and good toughness. At the same time, the mechanical properties are consistent. The microstructure of the Ø4.0 mm high-strength titanium alloy wire is observed, and the structure is uniform, the grains are refined, and the difference in grain size ratings at different locations is ≤1. Figure 2 shown.

[0040] Embodiment 3: This embodiment adopts the preparation method of high-strength TC4 titanium alloy wire roller die + fixed die, takes the hot-rolled bar with a specification of Ф13.0mm as the blank, and prepares the high-strength TC4 titanium alloy wire with a diameter of 5.2mm.

[0041] Step 1, the hot-rolled billet with a diameter of 13.0 mm is kept at 850° C. for 80 min for stress relief annealing, and then roller die drawing is performed at a heating temperature of 800° C. at a drawing speed of 7 m / min; the billet with a diameter of 13.0 mm is reduced to 9.5 mm by roller die drawing, and the deformation amount of each pass is not less than 9%, and the total deformation amount is 46%; then the wire is annealed at 850° C. for 80 min; Step 2, the 9.5 mm diameter wire heat-treated in step 1 is roller-drawn to 6.9 mm diameter, the drawing temperature is lowered from 850° C. to 750° C. die by die, the drawing speed is 7 m / min, the deformation of each pass is not less than 13%, and the total deformation is 47%; Step 3, the wire with a diameter of 6.9 mm after roller die drawing in step 2 is subjected to fixed die drawing at a heating temperature of 600°C and a drawing speed of 7m / min, with a deformation amount of not less than 10% in each pass and a total deformation amount of 43%, that is, the wire with a diameter of 6.9 mm is drawn to a diameter of 5.2 mm through a fixed die. Finally, an annealing heat treatment at 750°C and heat preservation for 50 minutes is performed to obtain a high-strength TC4 titanium alloy wire.

[0042] Embodiment 4: This embodiment adopts the preparation method of high-strength TC4 titanium alloy wire roller die + fixed die, takes the hot-rolled bar with a specification of Ф10.0mm as the blank, and prepares the high-strength TC4 titanium alloy wire with a diameter of 4.5mm.

[0043] Step 1, the hot-rolled billet with a diameter of 10.0 mm is kept at 700°C for 40 minutes for stress relief annealing, and then roller die drawing is performed at a heating temperature of 750°C at a drawing speed of 6m / min; the billet with a diameter of 10.0 mm is reduced to 7.8 mm by roller die drawing, and the deformation amount of each pass is not less than 8%, and the total deformation amount is 39%; then the wire is annealed at 700°C and kept for 40 minutes; Step 2, roller-drawing the wire with a diameter of 7.8 mm after the heat treatment in step 1 to a diameter of 6.2 mm, cooling the drawing temperature from 750° C. to 680° C. die by die, drawing speed 5 m / min, deformation of each pass not less than 12%, and total deformation of 37%; Step 3, the wire with a diameter of 6.2 mm after roller die drawing in step 2 is subjected to fixed die drawing at a heating temperature of 650°C and a drawing speed of 6 m / min, with a deformation amount of not less than 11% in each pass and a total deformation amount of 47%, that is, the wire with a diameter of 6.2 mm is drawn to a diameter of 4.5 mm through a fixed die. Finally, an annealing heat treatment is performed at 700°C and kept for 80 minutes to obtain a high-strength TC4 titanium alloy wire.

[0044] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing high-strength TC4 titanium alloy wire, characterized in that: The following steps are involved: The TC4 titanium alloy hot-rolled wire blank is subjected to multi-pass roller die drawing in a high-temperature two-phase region, and then annealed to obtain a wire material; The annealed wire is again subjected to multiple roller die drawing, and the temperature is gradually reduced during the drawing process; The wire after roller die drawing is subjected to multiple passes of fixed die drawing in a low temperature two-phase region, and the temperature remains unchanged during the drawing process. Finally, a secondary annealing treatment is performed to obtain a high-strength TC4 titanium alloy wire.

2. The method for preparing a high-strength TC4 titanium alloy wire according to claim 1, characterized in that: In the step of subjecting the TC4 titanium alloy hot-rolled wire billet to multi-pass roller die drawing in the high-temperature two-phase region and then annealing to obtain the wire, before the multi-pass roller die drawing, the TC4 titanium alloy hot-rolled wire billet is first subjected to stress relief annealing treatment, the temperature for the stress relief annealing treatment is 700°C~850°C, and the holding time is 30min~90min.

3. The method for preparing a high-strength TC4 titanium alloy wire according to claim 1, characterized in that: In the step of subjecting the TC4 titanium alloy hot-rolled wire billet to multi-pass roller die drawing in the high-temperature two-phase region and then annealing to obtain the wire, the total drawing deformation of the multi-pass roller die drawing is 30% to 50%, the deformation of each pass is not less than 5% to 10%, and the drawing temperature of each pass is 700°C to 850°C.

4. The method for preparing a high-strength TC4 titanium alloy wire according to claim 1, characterized in that: In the step of subjecting the TC4 titanium alloy hot-rolled wire billet to multi-pass roller die drawing in the high-temperature two-phase region and then annealing to obtain the wire, the diameter of the TC4 titanium alloy hot-rolled wire billet is 8 mm to 14 mm, and the drawing speed of the multi-pass roller die drawing is 2.0 m / min to 8.0 m / min.

5. The method for preparing a high-strength TC4 titanium alloy wire according to claim 1, characterized in that: In the step of subjecting the TC4 titanium alloy hot-rolled wire billet to multi-pass roller die drawing in a high-temperature two-phase region and then annealing to obtain the wire material, the annealing temperature is 700° C. to 850° C. and the holding time is 30 min to 90 min.

6. The method for preparing a high-strength TC4 titanium alloy wire according to claim 1, characterized in that: In the step of subjecting the annealed wire to multiple roller die drawing again and gradually reducing the temperature during the drawing process, the total drawing deformation of the multiple roller die drawing is 20% to 50%, the deformation of each pass is not less than 8% to 15%, the drawing temperature of each pass is 700° C. to 850° C., and the drawing speed is 2.0 m / min to 8.0 m / min.

7. The method for preparing a high-strength TC4 titanium alloy wire according to claim 1, characterized in that: In the step of subjecting the roller-drawn wire to multiple-pass fixed-die drawing in a low-temperature two-phase region, with the temperature remaining unchanged during the drawing process, and finally performing a secondary annealing treatment to obtain a high-strength TC4 titanium alloy wire, the total deformation of the multiple-pass fixed-die drawing is 20% to 50%, the fixed-die drawing temperature is 600° C. to 700° C., the deformation of each pass is not less than 10% to 15%, and the drawing speed is 2.0 m / min to 8.0 m / min.

8. The method for preparing a high-strength TC4 titanium alloy wire according to claim 1, characterized in that: In the step of subjecting the roller-drawn wire to multiple-pass fixed-die drawing in a low-temperature two-phase region, with the temperature remaining unchanged during the drawing process, and finally subjecting the wire to secondary annealing to obtain a high-strength TC4 titanium alloy wire, the temperature of the secondary annealing is 650°C to 800°C, and the holding time is 30min to 90min.

9. The method for preparing a high-strength TC4 titanium alloy wire according to claim 1, characterized in that: Finally, secondary annealing is performed to obtain the high-strength TC4 titanium alloy wire with a diameter of 2 mm to 5 mm.

10. A high-strength TC4 titanium alloy wire, characterized in that: The high-strength TC4 titanium alloy wire is prepared by the preparation method of any one of claims 1 to 9.

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