A method for preparing a beta type titanium alloy archwire

Abstract

The application discloses a preparation method of a beta type titanium alloy dental arch wire and relates to the technical field of dental arch wires, and comprises the following steps: S1, performing hot drawing treatment on a beta type titanium alloy rod to obtain a coarse wire blank; S2, performing annealing treatment on the coarse wire blank in S1; S3, performing cold deformation drawing on the coarse wire blank after the annealing treatment in S2; repeating S2 and S3 to obtain a medium wire blank; S4, performing polishing on the medium wire blank; S5, performing annealing treatment on the polished medium wire blank; S6, performing multi-pass large-deformation cold deformation drawing on the medium wire blank after the annealing treatment in S5 to obtain a fine wire blank; S7, performing polishing, square wire rolling and arch winding on the fine wire blank obtained in S6, and after shaping, performing cutting and pickling to obtain the beta type titanium alloy dental arch wire.

Description

Technical Field

[0001] This application relates to the field of dental archwire technology, and in particular to a method for preparing a β-type titanium alloy dental archwire. Background Technology

[0002] Titanium and its alloys possess excellent biocompatibility, corrosion resistance, low density, and high specific strength, making them widely used in dental clinics. Currently, nickel-titanium alloys are the most widely used titanium alloys in orthodontic clinics. However, nickel is sensitizing, and some experiments have shown that it is a potential carcinogen; nickel escape from the surface of nickel-titanium alloys is also a concern. Therefore, nickel-free biomedical titanium alloys have been developed to replace nickel-titanium alloys. The development of medical titanium alloys can be divided into three stages: the first stage, represented by pure titanium and Ti6Al4V alloys; the second stage, represented by Ti5Al2.5Fe and Ti6Al7Nb alloys; and now, the third stage—the β-type titanium alloy stage—is characterized by titanium alloys with better biocompatibility and lower elastic modulus.

[0003] Beta-titanium alloy is a titanium alloy containing Mo, Sn, and Zr. The elastic modulus of archwires made from beta-titanium alloy falls between that of nickel-titanium and stainless steel wires. This means that the force generated during orthodontic treatment using beta-titanium alloy archwires is greater than that of nickel-titanium wires but less than that of stainless steel wires. This increases the range of applications for beta-titanium alloy archwires. They can be used for both aligning teeth and for completing the archwire. In orthodontic treatment, beta-titanium alloy archwires are often used as an intermediate choice between stainless steel and nickel-titanium wires. Due to their low elastic modulus and relatively high yield strength, beta-titanium alloy archwires exhibit good elasticity and a large range of elastic deformation. Clinically, this translates to easily adjustable orthodontic forces that remain relatively stable during treatment. Beta-titanium alloy archwires also possess good toughness and formability, allowing them to be bent into various curved and complex shapes. The force generated by beta-titanium alloy archwires is approximately 50% of that of stainless steel of the same size, and it can be released slowly. In addition, β-type titanium alloy archwires have good biocompatibility, do not produce neurotoxicity, and are stable in the complex biological environment of the oral cavity.

[0004] Currently, the performance of domestically produced β-type titanium alloy dental archwires is relatively low, especially their tensile strength, which is less than 900 MPa. Furthermore, they exhibit significant brittleness when bent at 180°, leading to frequent breakage during installation and use. Additionally, the surface finish and roughness of the wires are poor, with some exhibiting noticeable blackening or even drawing marks. This results in low acceptance of domestically produced β-type titanium alloy dental archwires, making them primarily reliant on imports. To address these issues of poor surface quality, low mechanical properties, and high brittleness in domestically produced β-type titanium alloy dental archwires, [further measures are being taken]. Summary of the Invention

[0005] In order to solve at least one of the above-mentioned technical problems and develop a dental archwire with high surface finish, good mechanical properties and low brittleness, this application provides a method for preparing a β-type titanium alloy dental archwire.

[0006] This application provides a method for preparing a β-type titanium alloy dental archwire, comprising the following steps:

[0007] S1. Hot drawing is performed on β-type titanium alloy wire rods with a diameter of 8.00 to 10.00 mm to obtain coarse wire blanks with a diameter of 2.40 to 2.70 mm.

[0008] S2. Anneal the coarse wire blank in S1;

[0009] S3. Cold deformation drawing of the coarse wire blank after S2 annealing;

[0010] Repeat steps S2 and S3 to obtain medium-diameter wire blanks with a diameter of 1.10–1.30 mm;

[0011] S4. Polish the medium wire blank;

[0012] S5. Anneal the polished medium wire blank;

[0013] S6. The medium wire blank after S5 annealing is cold-deformed and drawn to obtain a fine wire blank with a diameter of 0.62-0.72 mm.

[0014] S7. Polish, roll square wire and wind arch wire of the fine wire blank obtained in S6. After shaping, cut and pickle to obtain β-type titanium alloy dental arch wire.

[0015] By adopting the above technical solution, in the first cold deformation drawing process, the amount of deformation per cold deformation drawing is small, which can ensure the surface quality of the wire while making the coarse wire blank deform uniformly; in the second cold deformation drawing process, the amount of deformation per cold deformation is large, which can obtain fine grains with uniform structure to improve the strength and toughness of titanium alloy, and can reduce the thickness of surface oxide layer, thereby improving the surface quality of wire.

[0016] Optionally, in S1, the process parameters for multi-pass hot drawing are as follows: temperature is 780-820℃, annealing speed is 2-10 m / min, deformation per pass is 10-18%, and graphite emulsion is used as a lubricant.

[0017] By adopting the above technical solution, optionally, in S2, the annealing process parameters are as follows: annealing temperature is 700-750℃, and annealing speed is 2-10 m / min.

[0018] By adopting the above technical solution, stress concentration and dislocation defects caused by drawing are eliminated, thereby reducing subsequent drawing stress and improving surface quality.

[0019] Optionally, in S3, the process parameters for cold deformation drawing are: drawing speed of 10-15 m / min, deformation per pass of 10%-20%, deformation per heat pass of 25%-40%, and water-based lubricant as lubricant.

[0020] Optionally, in S4, the polishing process parameters are: polishing wheel mesh size of 600-1000 and speed of 1-3 meters / minute.

[0021] By adopting the above technical solution, the lubricant on the surface of the wire is removed and the surface smoothness is improved.

[0022] Optionally, in S5, the annealing process parameters are: annealing temperature under protective atmosphere of 700–850℃, annealing speed of 5–10 m / min, and argon atmosphere.

[0023] By adopting the above technical solution, atmospheric protection annealing is performed on the medium wire blank before large deformation cold drawing. On the one hand, the thickness of the oxide layer on the surface of the fine wire blank can be reduced. The thinner oxide layer can reduce the friction between the surface of the fine wire blank and the die, thereby improving its surface quality. On the other hand, the toughness of the alloy can be improved, thereby realizing large deformation drawing.

[0024] Optionally, in S6, the process parameters for cold deformation drawing are: drawing speed of 15-25 m / min, deformation per pass of 15%-25%, total deformation of 57%-78%, and water-based lubricant as lubricant.

[0025] By adopting the above technical solution, the medium filament blank is directly drawn into the fine filament blank without intermediate annealing treatment, thereby improving the surface quality and mechanical properties of the filament and reducing the thickness of the surface oxide layer.

[0026] Optionally, in S7, a wing-shaped polishing wheel is used for polishing at a speed of 2-3 meters per minute, for 1-3 polishing passes.

[0027] By adopting the above technical solution, polishing is carried out using a polishing machine equipped with four wing wheels. The polishing speed is 2-3 meters / minute, and the polishing is done 1-3 times. During polishing, the four surfaces of the fine filament blank pass through the rotating wing wheels, which can ensure the smoothness of different surfaces of the filament. The dimensions of the fine filament blank do not change much before and after polishing by the wing wheels. Using wing wheels can achieve uniform polishing of the entire surface of the fine filament blank and achieve excellent polishing effect.

[0028] Optionally, in S7, the deformation amount of the square wire per pass is 5% to 10%.

[0029] By adopting the above technical solution, the size of the medium wire blank is drawn to φ0.62~0.72mm and then rolled into square wire. The deformation amount in each pass is between 5% and 10%. This can ensure that the rounded corners between two adjacent surfaces of the square wire are smoothly transitioned. If the rounded corners are too large or too small, it will affect the expression of torque of the archwire in the bracket.

[0030] Optionally, in S7, the finalization adopts a two-stage aging treatment method, including the following steps: first, heat in a muffle furnace at 330-420℃ for 10-30 minutes, then air-cool to room temperature, and then heat in a muffle furnace at 500-550℃ for 10-30 minutes, then air-cool to room temperature.

[0031] By adopting the above technical solution, the alloy is first held in a muffle furnace at 330–420℃ for 10–30 minutes and then air-cooled. The purpose is to precipitate a large amount of ω phase in the β-type titanium alloy. The ω phase is a brittle phase that can refine the α phase in the alloy, thereby strengthening the β-type titanium alloy. Then, the alloy is held in a muffle furnace at 500–550℃ for 10–30 minutes and then air-cooled. The purpose is to dissolve the large amount of brittle ω phase precipitated in the alloy back into the matrix and precipitate smaller α phases, thereby reducing brittleness and improving toughness. The effect of this process is that, in addition, the recrystallization temperature of β titanium alloy is 650℃, and choosing a temperature range of 500~550℃ ensures that the brittle w phase in the alloy is completely dissolved back into the matrix and a large number of small α phases precipitate, thereby obtaining β-type titanium alloy wire with excellent mechanical properties. On the other hand, it also makes the oxide layer on the surface of the titanium alloy dental archwire thinner after shaping, which is convenient for subsequent processing. The two-stage aging treatment can ensure the tensile strength of the wire while also ensuring good elongation, thereby meeting the strength and toughness requirements of dental archwire.

[0032] Optionally, in S7, the pickling uses a special pickling solution for titanium alloys, and the pickling time is 10 to 30 seconds.

[0033] By adopting the above technical solution, the thin oxide layer on the surface of the dental archwire after shaping is removed.

[0034] In summary, the present invention has at least one of the following beneficial technical effects:

[0035] 1. This application first hot-draws β-type titanium alloy wire rod to φ2.40~2.70mm, and then draws it to the expected value of φ0.62~0.72mm in two cold-drawing processes. The first cold deformation drawing process is a small deformation drawing, which includes annealing treatment to ensure uniform deformation of the round wire blank and guarantee the surface quality of the wire. The second cold deformation drawing process is a large deformation drawing. Before drawing, polishing and atmosphere-protected annealing treatment are required. Then, the size is directly drawn to the expected value through multiple passes to improve the mechanical properties of the wire and reduce the thickness of the surface oxide layer. Finally, it is rolled to the square wire size and shaped to obtain β-titanium alloy dental archwire with excellent comprehensive performance. 2. Before the large deformation cold drawing of the medium wire blank in this application, atmosphere-protected annealing treatment is required. On the one hand, it can reduce the thickness of the oxide layer on the surface of the wire. The thinner oxide layer can reduce the friction between the wire surface and the die, thereby improving its surface quality. On the other hand, it can improve the toughness of the alloy, thereby achieving large deformation drawing. Attached Figure Description

[0036] Figure 1 Here is a metallographic image of the β-type titanium alloy dental archwire prepared in Example 1;

[0037] Figure 2 Here is a surface morphology image of the β-type titanium alloy dental archwire prepared in Example 1;

[0038] Figure 3 This is a diagram illustrating the bending performance of the β-type titanium alloy dental archwire prepared in Example 1;

[0039] Figure 4 This is a graph showing the tensile properties of the β-type titanium alloy dental archwire prepared in Example 1;

[0040] Figure 5 The image shows the surface morphology of the β-type titanium alloy dental archwire used in Comparative Example 1.

[0041] Figure 6 This is a surface morphology diagram of the β-type titanium alloy dental archwire used in Comparative Example 2. Detailed Implementation

[0042] The present application will be further described in detail below with reference to the embodiments.

[0043] This application presents a method for preparing a β-type titanium alloy dental archwire, comprising the following steps:

[0044] S1. Hot drawing is performed on β-type titanium alloy wire rods with a diameter of 8.00 to 10.00 mm to obtain coarse wire blanks with a diameter of 2.40 to 2.70 mm.

[0045] S2. Anneal the coarse wire blank in S1;

[0046] S3. Cold deformation drawing of the coarse wire blank after S2 annealing;

[0047] Repeat steps S2 and S3 to obtain medium-diameter wire blanks with a diameter of 1.10–1.30 mm;

[0048] S4. Polish the medium wire blank;

[0049] S5. Anneal the polished medium wire blank;

[0050] S6. The medium wire blank after S5 annealing is cold-deformed and drawn to obtain a fine wire blank with a diameter of 0.62-0.72 mm.

[0051] S7. Polish, roll square wire and wind arch wire of the fine wire blank obtained in S6. After shaping, cut and pickle to obtain β-type titanium alloy dental arch wire.

[0052] This application first hot-draws β-type titanium alloy wire rod to φ2.40~2.70mm, and then draws it to the expected value of φ0.62~0.72mm in two cold-drawing processes. The cold deformation drawing process in S3 is a small deformation drawing, which includes annealing treatment to make the coarse wire blank deform uniformly and ensure the surface quality of the wire. The cold deformation drawing process in S6 is a large deformation drawing. Before drawing, polishing and atmosphere-protected annealing treatment are required. Then, the size is directly drawn to the expected value through multiple passes to improve the mechanical properties of the wire and reduce the thickness of the surface oxide layer. Finally, it is rolled to square wire size and shaped to obtain β-titanium alloy dental archwire with excellent comprehensive performance.

[0053] In S7 of this application, the finalization adopts a two-stage aging treatment method, which includes the following steps: first, holding the material in a muffle furnace at 330-420℃ for 10-30 minutes, then air-cooling it to room temperature; then holding the material in a muffle furnace at 500-550℃ for 10-30 minutes, then air-cooling it to room temperature.

[0054] First, the wire is held in a muffle furnace at 330–420℃ for 10–30 minutes and then air-cooled. This process precipitates a large amount of wt phase in the β-type titanium alloy. The wt phase is a brittle phase that can refine the α phase in the alloy, thereby strengthening the β-type titanium alloy. Then, it is held in a muffle furnace at 500–550℃ for 10–30 minutes and then air-cooled. This process dissolves the large amount of brittle wt phase back into the matrix and precipitates smaller α phases, thereby reducing brittleness and improving toughness. In addition, the recrystallization temperature of β-titanium alloy is 650℃. Choosing a temperature range of 500–550℃ ensures that the brittle wt phase is completely dissolved back into the matrix and that a large amount of smaller α phase precipitates, resulting in β-type titanium alloy wire with excellent mechanical properties. It also results in a thinner oxide layer on the surface of the titanium alloy archwire after shaping, which facilitates subsequent processing.

[0055] Titanium alloy pickling solution: 450 pickling solution was used and purchased from Guangzhou Yishun Chemical Co., Ltd.

[0056] Water-based lubricant: prepared by mixing soapy water and graphite emulsion in a weight ratio of 5:2;

[0057] β-Titanium Alloy Ingot: Model: TMA Alloy, Composition: Ti-11.5Mo-6Zr-4.5Sn; Manufacturer: GRINM Medical Devices (Beijing) Co., Ltd.

[0058] Preparation Example

[0059] β-titanium alloy ingots with a size of φ110.00mm were prepared by vacuum arc melting. In order to make the alloy composition more uniform, the melting was repeated 4 times. The composition of the prepared β-titanium alloy met the requirements of medical application alloys (GB / T 4698 and ASTM E1941 / 1409).

[0060] To further reduce the segregation of nickel-titanium alloy composition, the β-titanium alloy ingot prepared in S1 was solution treated at 800℃ for 30 minutes, and then water-cooled.

[0061] The β-titanium alloy ingot after solution treatment in S2 was forged to finally obtain a β-titanium alloy bar with a size of φ65.00mm.

[0062] The surface oxide scale of the β titanium alloy bar in S3 was removed by machining and turning to obtain a bar blank with a size of φ60.00mm;

[0063] The above-mentioned billets are hot-rolled to obtain wire rods with dimensions of φ8.00-10.00mm. Specific Implementation

[0065] Example 1

[0066] Take the wire rod with a size of φ8.00mm obtained in the preparation example, and perform hot drawing according to the process in Table 1 to obtain a coarse wire blank with a size of φ2.60mm:

[0067] Table 1 Hot drawing process

[0068]

[0069] The above-mentioned coarse wire blanks were cold-formed and drawn according to the procedures in Table 2 to obtain medium wire blanks with a size of φ1.20mm:

[0070] Table 2 First Cold Deformation Drawing Process

[0071]

[0072]

[0073] The above-mentioned medium wire blank was polished using an 800-mesh polishing wheel at a polishing speed of 2 m / min; the medium wire blank was subjected to atmosphere-protected annealing at a temperature of 800℃ and a speed of 5 m / min, with argon as the protective atmosphere; the medium wire blank was then cold-deformed and drawn according to the procedures in Table 3 below to obtain a fine wire blank with a size of φ0.68mm.

[0074] Table 3 Second Cold Deformation Drawing Process

[0075]

[0076] The above-mentioned fine wire blank is polished twice using a flying wing wheel at a polishing speed of 2 meters / minute; then, square wire is rolled according to the procedures in Table 4 below to obtain a square wire blank with a specification of 0.46*0.64mm.

[0077] Table 4. Rolling process of square wire

[0078] Wire size / mm Deformation per pass Lubricating fluid First 0.60*0.68 12.40％ Water-based lubricant Second 0.55*0.68 8.33％ Water-based lubricant The third 0.50*0.67 10.43％ Water-based lubricant Fourth 0.48*0.66 5.43％ Water-based lubricant Fifth 0.46*0.64 7.07％ Water-based lubricant

[0079] The above square wire blank is wound into a bow; after winding, the mold is subjected to two-stage aging and shaping. First, it is kept in a muffle furnace at 350℃ for 20 minutes. After the holding time is completed, it is taken out and air-cooled to room temperature. Then, it is placed in a muffle furnace at 550℃ for 30 minutes. After the holding time is completed, it is taken out and air-cooled to room temperature.

[0080] The shaped archwire blank is cut using a laser cutting machine to obtain the archwire blank;

[0081] Immersing the archwire blank in a special pickling solution for titanium alloys for 15 seconds will produce a β-titanium alloy archwire with a bright surface.

[0082] Test the performance of the above-mentioned β-type titanium alloy dental archwire:

[0083] The metallographic structure of β-type titanium alloy dental archwires was observed, and the results are as follows: Figure 1 As shown, the alloy grain size is small, and a large number of small, long needle-like α phases precipitate on the β matrix.

[0084] The surface of the β-type titanium alloy dental archwire was observed, and the results are as follows: Figure 2 As shown, the surface of the archwire has a high smoothness and low roughness, with Ra: 0.1103.

[0085] The bending properties of β-type titanium alloy dental archwires were tested, and the results are as follows: Figure 3 As shown, the archwire did not break after being clamped by orthodontic forceps, nor did it break after being bent 180°. Furthermore, the archwire did not break when bent in the opposite direction at a certain angle after being bent 180°.

[0086] The tensile properties of β-type titanium alloy dental archwires were tested, and the results are as follows: Figure 4 As shown, the alloy exhibits excellent mechanical properties, with a tensile strength of 1113 MPa and an elongation at break of 3.2%.

[0087] Example 2

[0088] Take the wire rod with a size of φ9.00mm obtained in the preparation example, and perform hot drawing according to the process in Table 1 to obtain a coarse wire blank with a size of φ2.70mm:

[0089] Table 1 Hot drawing process

[0090]

[0091]

[0092] The above-mentioned coarse wire blanks were cold-formed and drawn according to the procedures in Table 2 to obtain medium wire blanks with a size of φ1.10mm:

[0093] Table 2 First Cold Deformation Drawing Process

[0094]

[0095]

[0096] The above-mentioned medium wire blank was polished using a 600-mesh polishing wheel at a polishing speed of 3 m / min; the medium wire blank was subjected to atmosphere-protected annealing at a temperature of 700℃ and a speed of 8 m / min, with argon as the protective atmosphere; the medium wire blank was then cold-deformed and drawn according to the procedures in Table 3 below to obtain a fine wire blank with a size of φ0.72mm.

[0097] Table 3 Second Cold Deformation Drawing Process

[0098]

[0099] The above-mentioned fine wire blank is polished once using a flying wing wheel at a polishing speed of 3 meters / minute; then, square wire is rolled according to the procedures in Table 4 below to obtain a square wire blank with a specification of 0.53*0.64mm.

[0100] Table 4. Rolling process of square wire

[0101] Wire size / mm Deformation per pass / % Lubricating fluid First 0.66*0.69 11.91％ Water-based lubricant Second 0.61*0.68 8.92％ Water-based lubricant The third 0.57*0.67 7.93％ Water-based lubricant Fourth 0.55*0.66 4.95％ Water-based lubricant Fifth 0.53*0.64 6.56％ Water-based lubricant

[0102] The above square wire blank is wound into a bow; after winding, the mold is subjected to two-stage aging and shaping. First, it is kept in a muffle furnace at 330℃ for 30 minutes. After the holding time is completed, it is taken out and air-cooled to room temperature. Then, it is placed in a muffle furnace at 500℃ for 20 minutes. After the holding time is completed, it is taken out and air-cooled to room temperature.

[0103] The shaped archwire blank is cut using a laser cutting machine to obtain the archwire blank;

[0104] Immersing the archwire blank in a special pickling solution for titanium alloys for 10 seconds will produce a β-titanium alloy archwire with a bright surface.

[0105] Test the performance of the above-mentioned β-type titanium alloy dental archwire:

[0106] Observation of the metallographic structure of β-type titanium alloy dental archwires revealed that the alloy grain size was small, and a large number of small, long needle-like α phases precipitated on the β matrix.

[0107] The surface of the dental archwire has a high degree of smoothness and a low degree of roughness (Ra: 0.0953).

[0108] The bending performance of β-type titanium alloy dental archwires was tested. The archwires did not break after being clamped by orthodontic forceps, nor did they exhibit brittle fracture after being bent 180°. Furthermore, the archwires bent 180° were not broken when bent in the opposite direction at a certain angle.

[0109] The tensile properties of β-type titanium alloy dental archwires were tested, and the tensile strength reached 1038 MPa, with a fracture elongation of 3.1%.

[0110] Example 3

[0111] Take the wire rod with a size of φ10.00mm obtained in the preparation example, and perform hot drawing according to the process in Table 1 to obtain a coarse wire blank with a size of φ2.40mm:

[0112] Table 1 Hot drawing process

[0113]

[0114]

[0115] The above-mentioned coarse wire blanks were cold-formed and drawn according to the procedures in Table 2 to obtain medium wire blanks with a size of φ1.30mm:

[0116] Table 2 First Cold Deformation Drawing Process

[0117]

[0118]

[0119] The above-mentioned filament blank was polished using a 1000-grit polishing wheel at a polishing speed of 1 m / min; the filament blank was subjected to atmosphere-protected annealing at a temperature of 850℃ and a speed of 10 m / min, with argon as the protective atmosphere; the medium filament blank was then cold-deformed and drawn according to the procedures in Table 3 below to obtain a filament blank with a size of φ0.62mm.

[0120] Table 3 Second Cold Deformation Drawing Process

[0121]

[0122] The above-mentioned round wire blank is polished three times using a flying wing wheel at a polishing speed of 2 meters / minute; then, square wire is rolled according to the procedures in Table 4 below to obtain a square wire blank with a specification of 0.41*0.56mm.

[0123] Table 4. Rolling process of square wire

[0124]

[0125]

[0126] The above square wire blank is wound into a bow; after winding, the mold is subjected to two-stage aging and shaping. First, it is kept in a muffle furnace at 420℃ for 10 minutes. After the holding time is completed, it is taken out and air-cooled to room temperature. Then, it is placed in a muffle furnace at 520℃ for 10 minutes. After the holding time is completed, it is taken out and air-cooled to room temperature.

[0127] The shaped archwire blank is cut using a laser cutting machine to obtain the archwire blank;

[0128] Immersing the archwire blank in a special pickling solution for titanium alloys for 30 seconds will produce a β-titanium alloy archwire with a bright surface.

[0129] Test the performance of the above-mentioned β-type titanium alloy dental archwire:

[0130] Observation of the metallographic structure of β-type titanium alloy dental archwires revealed that the alloy grain size was small, and a large number of small, long needle-like α phases precipitated on the β matrix.

[0131] The surface of the archwire has a high degree of smoothness and a low roughness (Ra: 0.1208).

[0132] The bending performance of β-type titanium alloy dental archwires was tested. The archwires did not break after being clamped by orthodontic forceps, nor did they exhibit brittle fracture after being bent 180°. Furthermore, the archwires bent 180° were not broken when bent in the opposite direction at a certain angle.

[0133] The tensile properties of β-type titanium alloy dental archwires were tested, and the tensile strength reached 1123 MPa, with a fracture elongation of 3.15%.

[0134] Comparative Example 1

[0135] β-type titanium alloy dental archwires, purchased from Shanghai Emondi Materials Technology Co., Ltd., with specifications of 1825 (0.46*0.64mm); their surface morphology and mechanical properties were tested.

[0136] like Figure 5 As shown, this is the surface morphology of the Emundi β titanium alloy dental archwire, which is noticeably blackened.

[0137] Its mechanical properties were tested, and the tensile strength was 903.2 MPa, and the elongation at break was 3.8%.

[0138] Comparative Example 2

[0139] β-type titanium alloy dental archwires, purchased from Jiangsu Shengmate New Material Technology Co., Ltd., with specifications of 2125 (0.53*0.64mm); their surface morphology and mechanical properties were tested.

[0140] like Figure 6 The image shows the surface morphology of Shengmate β-titanium alloy dental archwire, with obvious wire drawing marks on the surface.

[0141] Its mechanical properties were tested, and the tensile strength was 862.3 MPa, and the elongation at break was 3.3%.

[0142] By comparing the embodiments of the present invention, its performance and surface morphology are both lower.

[0143] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for preparing a β-type titanium alloy dental archwire, characterized in that, Includes the following steps: S1. Hot drawing is performed on β-type titanium alloy wire rods with a diameter of 8.00~10.00mm to obtain coarse wire blanks with a diameter of 2.40~2.70mm; S2. Anneal the coarse wire blank in S1; S3. Cold deformation drawing of the coarse wire blank after S2 annealing; Repeat steps S2 and S3 to obtain medium-diameter wire blanks with a diameter of 1.10~1.30mm; S4. Polish the medium wire blank; S5. Anneal the polished medium wire blank; S6. The medium wire blank after S5 annealing is cold-deformed and drawn to obtain a fine wire blank with a diameter of 0.62~0.72mm; S7. Polish, roll square wire and wind arch wire of the fine wire blank obtained in S6. After shaping, cut and pickle to obtain β-type titanium alloy dental arch wire. In S2, the annealing process parameters are as follows: annealing temperature is 700-750℃, and annealing speed is 2-10 m / min.

2. The method for preparing β-type titanium alloy dental archwire according to claim 1, characterized in that, In S1, the process parameters for multi-pass hot drawing are as follows: temperature is 780-820℃, annealing speed is 2-10 m / min, deformation per pass is 10-18%, and graphite emulsion is used as a lubricant.

3. The method for preparing β-type titanium alloy dental archwire according to claim 1, characterized in that, In S3, the process parameters for cold deformation drawing are: drawing speed of 10~15 m / min, deformation per pass of 10%~20%, deformation per heat pass of 25%~40%, and water-based lubricant is used as the lubricant.

4. The method for preparing β-type titanium alloy dental archwire according to claim 1, characterized in that, In S4, the polishing process parameters are: polishing wheel mesh size of 600~1000 mesh, and speed of 1~3 meters / minute.

5. The method for preparing β-type titanium alloy dental archwire according to claim 1, characterized in that, In S5, the annealing process parameters are: annealing temperature under protective atmosphere is 700~850℃, annealing speed is 5~10 m / min, and the protective atmosphere is argon.

6. The method for preparing β-type titanium alloy dental archwire according to claim 1, characterized in that, In S6, the process parameters for cold deformation drawing are: drawing speed of 15~25 m / min, deformation per pass of 15%~25%, total deformation of 57%~78%, and water-based lubricant is used as lubricant.

7. The method for preparing β-type titanium alloy dental archwire according to claim 1, characterized in that, In S7, a wing-shaped polishing wheel is used for polishing at a speed of 2-3 meters per minute, and the polishing is performed 1-3 times.

8. The method for preparing β-type titanium alloy dental archwire according to claim 1, characterized in that, In S7, the deformation of the square wire per pass is 5% to 10%.

9. The method for preparing β-type titanium alloy dental archwire according to claim 1, characterized in that, In S7, the finalization process adopts a two-stage aging treatment method, which includes the following steps: first, heat in a muffle furnace at 330~420℃ for 10~30 minutes, then air cool to room temperature, and then heat in a muffle furnace at 500~550℃ for 10~30 minutes, then air cool to room temperature.

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