Surface treatment method for bright titanium or titanium alloy wire

Abstract

The invention discloses a surface treatment method for a bright titanium or titanium alloy wire. The surface treatment method comprises the following steps: step 1, performing sand blasting on a to-be-polished wire by using a sand blasting pipe 1; the sand blasting pipe 1 is of a cylindrical structure with the two ends closed, and a through hole is formed in the center of the sand blasting pipe 1 in the axis direction of the sand blasting pipe 1 and used for allowing wires to pass through. 2, the to-be-polished wire subjected to sand blasting treatment in the step 1 sequentially passes through a first mold and a second mold to be subjected to rough scaling and fine scaling; 3, the wire to be polished is subjected to finished product straightening; 4, the surface of the to-be-polished wire is finely decorated through an online abrasive belt polishing machine; and 5, the to-be-polished wire is finely polished through an ultrasonic cleaning machine. The problem that the surface treatment precision of an existing wire with the diameter smaller than 1.0 mm is low is solved.

Description

[Technical field]

[0001] The invention belongs to the technical field of metal material surface treatment, and in particular relates to a method for treating the surface of a bright titanium or titanium alloy wire. [Background technology]

[0002] In the field of materials science and engineering technology, titanium or titanium alloys are widely used in aerospace, medical equipment, chemical equipment, marine engineering and other high-end manufacturing fields due to their excellent corrosion resistance, high strength and low density. However, during the processing of titanium or titanium alloys, especially in the wire preparation stage, a layer of oxide scale (also called black surface or oxide surface) that is difficult to remove often forms on the surface of the titanium or titanium alloys. This oxide scale not only affects the appearance quality of the material, but may also have an adverse effect on the subsequent processing performance and the performance of the final product. Therefore, it is particularly important to develop an efficient, environmentally friendly and suitable titanium or titanium alloy surface treatment method for wire specifications.

[0003] At present, the common bright surface treatment methods for titanium or titanium alloys on the market mainly include pickling and abrasive belt mechanical polishing. Although these methods can improve the surface quality of materials to a certain extent, they all have significant limitations. 1. Pickling method: This method removes oxide scale by chemical corrosion, but there are two major problems. First, the pickling process takes a long time, and due to the penetration of hydrogen, it is easy to increase the hydrogen content inside the wire, which exceeds the standard requirements of the application field and affects the mechanical properties and corrosion resistance of the material. Secondly, the pickling solution will release harmful gases such as fluorides and chlorides during the volatilization process, which poses a potential threat to the health of operators and environmental safety, and does not meet the requirements of modern industrial green production. 2. Abrasive belt mechanical polishing method: This method uses the high-speed rotation of the abrasive belt and the friction between the surface of the wire to remove the oxide scale. Although it can improve the surface finish to a certain extent, its scope of application is limited. It is mainly suitable for wires with a diameter greater than 1.0 mm.

[0004] In recent years, the annual demand for medical titanium alloy ultrafine wire has exceeded 15 million meters, and the market demand for titanium alloy ultrafine wire is huge. At present, the minimum diameter of titanium and titanium alloy wires produced in batches in China is 0.5mm, and for wires with a diameter of 0.5mm to 1mm, problems such as poor product quality uniformity and poor surface condition are often encountered. For wires with a diameter less than 1.0mm, due to the small contact area between the abrasive belt and the wire and uneven pressure distribution, the mechanical polishing effect of the abrasive belt is not ideal, and it is difficult to meet the production needs of high-precision, high-quality and bright wires. [Summary of the invention]

[0005] The purpose of the present invention is to provide a method for surface treatment of bright titanium or titanium alloy wires, so as to solve the problem of low surface treatment precision of wires with diameters less than 1.0 mm.

[0006] The present invention adopts the following technical scheme: a method for surface treatment of bright titanium or titanium alloy wire, comprising the following steps:

[0007] Step 1, using a sandblasting tube 1 to sandblast the wire to be polished;

[0008] The sandblasting tube 1 is a cylindrical structure with closed ends. A through hole is provided in the center of the sandblasting tube 1 along its axial direction, and the through hole is used for the wire to pass through;

[0009] Step 2, the wire to be polished after the sandblasting treatment in step 1 is subjected to coarse peeling and fine peeling in sequence through a first mold and a second mold;

[0010] The first mold is a cylinder with a tooth-shaped through hole along the axis, and the inner wall of the tooth-shaped through hole has a plurality of convex columns in a central annular array about the cylinder, and the side surfaces of each convex column close to the center of the cylinder are located on the same ring; the second mold is a cylinder structure with a cylindrical through hole along the axis;

[0011] The side surface of each convex column close to the center of the column is used to contact with the wire material to complete the rough peeling, and the inner wall surface of the cylindrical through hole is used to contact with the wire material to complete the fine peeling;

[0012] Step 3, straightening the finished wire to be polished;

[0013] Step 4: Use an online abrasive belt polisher to finish the surface of the wire to be polished;

[0014] Step 5: Use an ultrasonic cleaner to finely clean the wire to be polished.

[0015] Furthermore, the radius of the ring is the minimum radius of the tooth-shaped through hole, the material discharge of the first die at the maximum radius of the tooth-shaped through hole is 2-5%, and the material discharge at the minimum radius is 5-10%; the material discharge of the second die after peeling is 5-10%.

[0016] Furthermore, the radius of the cylindrical through hole on the second mold is the same as the radius of the annular surface of the convex column on the first mold.

[0017] Furthermore, during the peeling process of step 2, the wire tension is 5 to 200 MPa, and the retracting and releasing line speed is 1 to 100 m / min.

[0018] Furthermore, a plurality of inclined sandblasting branch pipes are connected outwardly from the wall of the sandblasting pipe, and each sandblasting branch pipe is connected to the through hole; each sandblasting branch pipe is arranged in a spiral line along the outer wall of the sandblasting pipe, and the spacing between adjacent sandblasting branch pipes is equal;

[0019] The bottom of the sandblasting tube is connected to a plurality of evenly arranged connecting tubes, each connecting tube being used to connect the through hole with the collecting device;

[0020] Among them, each sandblasting branch pipe is used to introduce abrasives into the through hole, and finally collected to the collection device through each connecting pipe.

[0021] Furthermore, a plurality of sandblasting points are evenly arranged along the axis of the sandblasting tube, and two sandblasting branch pipes are symmetrically arranged at each sandblasting point.

[0022] Furthermore, the angle between each sandblasting branch pipe and the axis of the sandblasting pipe is 5 to 20 degrees.

[0023] Furthermore, during the sandblasting process of step 1, the wire tension is 5 to 200 MPa, the sandblasting pressure is 0.2 to 0.6 MPa, and the retracting and releasing line speed is 1 to 50 m / min.

[0024] Furthermore, in step 3, during the process of straightening the wire material as a finished product, the treatment temperature is 300 to 600° C. and the straightening time is 5 to 300 seconds.

[0025] Furthermore, in the process of finishing the surface of the wire in step 4, the sand belt used by the polishing machine has a particle size of A6-A16 and a polishing speed of 5-10 m / min.

[0026] The beneficial effects of the present invention are as follows: the present invention uses the first mold to perform rough skinning on the wire first. During the process, the toothed through hole inside the first mold has skinning surfaces with two radius sizes, so that some skinning grooves are formed on the surface of the wire, reducing the risk of wire breakage. Fine skinning is then performed through the second mold. Since the radius of the cylindrical through hole of the second mold is the same as the minimum radius of the toothed through hole of the first mold, the fine skinning process is to further remove excess outer skin on the basis of rough skinning, so that the final product reaches the required size and surface quality. Moreover, since the second mold has higher precision, directly using the second mold for skinning will cause greater damage to it, so fine skinning after rough skinning can more effectively protect the second mold and avoid mold damage.

[0027] The present invention designs multiple sandblasting branches on the outside of the sandblasting tube, which are evenly arranged in a 360° surrounding pattern, and the angle between these sandblasting branches and the wire outlet is controlled between 5° and 20°. When the wire enters and passes through the left side of the sandblasting tube, the sandblasting medium is accurately sprayed onto the surface of the wire at an angle of 5° to 20°, avoiding the problem of uneven sandblasting or omissions that may occur in traditional sandblasting methods, aiming to loosen the oxide scale on the surface of the wire to the maximum extent, effectively remove the oxide scale and other impurities, and ensure that the sandblasting medium can evenly and efficiently cover the entire outer surface of the wire, thereby achieving a precise sandblasting effect.

Brief Description of the Drawings

[0028] Figure 1 It is a structural schematic diagram of the sandblasting tube of the present invention;

[0029] Figure 2 for Figure 1 Side view of

[0030] Figure 3 It is a structural schematic diagram of the first mold of the present invention;

[0031] Figure 4 is a schematic structural diagram of a second mold of the present invention;

[0032] Figure 5 This is a stereomicroscope image of the wire material after being treated in Example 1 of the present invention at a magnification of 140 times;

[0033] Figure 6 This is a stereomicroscope image of the wire material after being treated in Example 2 of the present invention at a magnification of 140 times;

[0034] Figure 7 This is a stereomicroscope image of the wire material after being treated in Example 3 of the present invention at a magnification of 140 times;

[0035] Figure 8 This is a stereomicroscope image of the wire material after treatment in Comparative Example 1 at a magnification of 140 times;

[0036] Fig. 9 This is a stereomicroscope image of the wire material after treatment in Comparative Example 2 at a magnification of 140 times.

[0037] Among them, 1. sandblasting pipe, 2. sandblasting branch pipe, 3. connecting pipe, 4. collecting device. [Specific implementation method]

[0038] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] A method for surface treatment of bright titanium or titanium alloy wire, particularly suitable for wire with a diameter of 0.1 to 1.0 mm, comprises the following steps:

[0040] Step 1: Use a sandblasting tube 1 to sandblast the wire to be polished; the wire is titanium or titanium alloy.

[0041] The sandblasting tube 1 is a cylindrical structure with closed ends. A through hole is provided in the center of the sandblasting tube 1 along its axial direction, and the through hole is used for the wire to pass through;

[0042] Step 2, the wire to be polished after the sandblasting treatment in step 1 is subjected to coarse peeling and fine peeling in sequence through a first mold and a second mold;

[0043] The first mold is a cylinder with a tooth-shaped through hole along the axis. The inner wall of the tooth-shaped through hole has a plurality of convex columns in a central annular array about the cylinder. The side of each convex column close to the center of the cylinder is located on the same ring with a radius of R2. The size of the mold hole is matched according to the specifications of the blank. The side of each convex column close to the center of the cylinder is used to contact with the wire to complete the rough peeling. This design helps to quickly remove a large amount of outer skin in the early stage of peeling and achieve the effect of rough peeling.

[0044] The second mold is a columnar structure with a cylindrical through hole along the axis. The inner wall surface of the cylindrical through hole is used to contact the wire to complete fine peeling, so that the amount of wire removal can be more accurately controlled during the fine peeling process, achieving a smoother and finer peeling effect.

[0045] Step 3, straightening the wire to be polished in an inert gas furnace;

[0046] Step 4: Use an online abrasive belt polisher to finish the surface of the wire to be polished;

[0047] Step 5: Use an ultrasonic cleaner to clean the wire to be polished. The cleaning temperature is 40-60°C.

[0048] Since the diameter of the wire may be uneven, for extremely fine wires with a diameter of less than 1.0 mm, if the wires are directly peeled in one go, there is a risk that the extremely fine wires will break at the smaller diameter. The present invention uses a first mold to roughly peel the wire first. During this process, the toothed through hole inside the first mold has a peeling surface with two radius sizes, which will form some peeling grooves on the surface of the wire, reducing the risk of wire breakage. The second mold is then used for fine peeling. Since the radius of the cylindrical through hole of the second mold is the same as the minimum radius of the toothed through hole of the first mold, the fine peeling process is to further remove excess outer skin on the basis of rough peeling, so that the final product reaches the required size and surface quality. Moreover, since the second mold has higher precision, directly using the second mold for peeling will cause greater damage to it, so fine peeling after rough peeling can more effectively protect the second mold and avoid mold damage.

[0049] In some embodiments, Figure 3 As shown, the radius of the ring is the minimum radius R2 of the tooth-shaped through hole, and the maximum radius of the tooth-shaped through hole is R1. The first mold has a material discharge amount of 2-5% at the maximum radius of the tooth-shaped through hole and a material discharge amount of 5-10% at the minimum radius; Figure 4 As shown, the radius of the cylindrical through hole of the second mold is R2, and the material discharge after peeling is 5-10%.

[0050] The corresponding relationship between the feeding amount and the radius is as follows:

[0051] The material discharge amount at the maximum radius of the first die = (wire cross-sectional area - area corresponding to radius R1) / wire cross-sectional area.

[0052] The amount of material discharged at the minimum radius of the first die = the amount of material discharged at the second die = (wire cross-sectional area - area corresponding to radius R2) / wire cross-sectional area.

[0053] In some embodiments, the radius R2 of the cylindrical through hole on the second mold is the same as the radius R2 of the convex cylindrical annular surface on the first mold.

[0054] Among them, the peeling system is divided into three parts: wire pay-off machine, wire peeling machine and wire take-up machine. All three devices are commercially available. The wire pay-off machine needs to be able to adjust the wire tension, the wire take-up machine can control the wire take-up speed, and the wire peeling machine can be used to place the wire peeling mold in the equipment and ensure that the wire can be completely in a straight line at the wire entry and exit. The specific peeling steps are: remove the sandblasted wire, install it on the wire pay-off machine of the peeling system, lead it out from the wire pay-off machine, and fix the wire end on the wire take-up machine of the peeling system through the wire peeling system mold.

[0055] In some embodiments, during the peeling process of step 2, the wire tension is 5 to 200 MPa, and the retracting and releasing line speed is 1 to 100 m / min.

[0056] In some embodiments, Figure 1 and Figure 2 As shown, a plurality of inclined sandblasting branch pipes 2 are connected outwardly on the wall of the sandblasting tube 1, and each sandblasting branch pipe 2 is connected to the through hole; each sandblasting branch pipe 2 is arranged in a spiral line along the outer wall of the sandblasting tube 1, and the spacing between adjacent sandblasting branch pipes 2 is equal. The bottom of the sandblasting tube 1 is connected to a plurality of evenly arranged connecting pipes 3, and each connecting pipe 3 is used to connect the through hole with the collecting device 4. Among them, each sandblasting branch pipe 2 is used to introduce abrasives into the through hole, and finally collected to the collecting device 4 through each connecting pipe 3.

[0057] In some embodiments, a plurality of sandblasting points are evenly arranged along the axis of the sandblasting tube 1 , and two sandblasting branch pipes 2 are symmetrically arranged at each sandblasting point.

[0058] In some embodiments, the angle between each sandblasting branch pipe 2 and the axis of the sandblasting tube 1 is 5 to 20 degrees. The angle between these sandblasting branch pipes and the wire outlet is controlled between 5 and 20 degrees. When the wire enters and passes through the left side of the sandblasting tube, the sandblasting medium is precisely sprayed onto the surface of the wire at an angle of 5 to 20 degrees, avoiding the problems of uneven sandblasting or omissions that may occur in traditional sandblasting methods, aiming to loosen the oxide scale on the surface of the wire to the maximum extent, effectively remove the oxide scale and other impurities, and ensure that the sandblasting medium can evenly and efficiently cover the entire outer surface of the wire, thereby achieving a precise sandblasting effect.

[0059] The present invention designs a sandblasting system that can adjust the position and angle of the sandblasting nozzle according to the diameter of wires of different specifications, ensuring that the sandblasting medium can evenly and effectively cover the surface of the wires, thereby achieving precise sandblasting. It realizes efficient and continuous online sandblasting of various types of wires, and can achieve ideal sandblasting effects for both ultra-fine wires and thicker wires. This process can not only effectively make the oxide scale on the surface of the wire fall off or become loose, but also increase the roughness of the wire surface to a certain extent, creating favorable conditions for subsequent peeling treatment, and significantly improving the quality and efficiency of the peeling treatment.

[0060] In some embodiments, during the sandblasting process of step 1, the wire tension is 5 to 200 MPa, the sandblasting pressure is 0.2 to 0.6 MPa, and the retracting and releasing line speed is 1 to 50 m / min.

[0061] In some embodiments, in step 3, the treatment temperature is 300-600°C and the straightening time is 5-300s during the finished product straightening process of the wire. The gas used is an inert gas. Since the wire is deformed to a certain extent during the peeling process, the wire has internal stress. The purpose of the finished product straightening is to remove the internal stress generated by the wire during the peeling process and straighten the wire. Inert gas is used during the straightening process to prevent secondary oxidation and discoloration of the wire surface.

[0062] In some embodiments, in step 4, during the finishing of the wire surface, the sand belt used by the polishing machine has a grain size of A6-A16, and the polishing speed is 5-10 m / min. Since the wire has been stripped by the sandblasting machine in the early stage to meet the requirements of the surface brightness of the wire, but there may be a small amount of stripping lines on the wire after stripping, a finer sand belt is used to finish the wire surface to remove the stripping lines on the wire surface, further smooth the wire surface, and eliminate the stripping lines, thereby achieving a higher surface quality.

[0063] Example

[0064] The present invention provides three embodiments, which respectively perform surface treatment on wires with wire diameters of 1.0 mm, 0.1 mm and 0.5 mm. The parameters involved in each step are shown in the following table:

[0065] Table 1 Process parameters involved in each step of the three embodiments

[0066]

[0067] Table 2 Wire material performance data of three embodiments

[0068] Example 1 Example 2 Example 3 Surface roughness Ra / nm 36.1 30.9 48.3 Dimensional tolerance / mm ±0.005 ±0.004 ±0.004

[0069] The performance data of the wires after treatment in the three embodiments are shown in Table 2. Figure 5 to Figure 7From the comparison, it can be seen that the surfaces of the wires of the three embodiments are all bright, and the surface roughness Ra of the wires can reach below 50nm, and the wire size tolerance can be controlled within ±0.005mm, meeting the technical index requirements of bright ultrafine wires.

[0070] Comparative Example 1: Figure 8 The finished wire material obtained by surface treatment of the wire material of the same specification as Example 3 using the traditional pickling process has deep pickling corrosion pits on its surface. Due to the presence of these pits, the wire material roughness is greater than 200nm, and the dimensional tolerance is ±0.02mm, which does not meet the dimensional tolerance requirement of ±0.01mm for conventional wire materials. The H content requirement of conventional titanium alloy is 0.015wt.%, and the H content requirement of medical wire titanium alloy is 0.008wt.%. However, due to the effect of the pickling solution, the H content of the wire material treated in Comparative Example 1 seriously exceeds the standard to 0.025wt.%.

[0071] Comparative Example 2: Fig. 9 The finished wire is obtained by surface treatment of the wire of the same specification as in Example 3 using a conventional abrasive belt polishing process. Its surface is brighter than that of the pickling process, but its dimensional tolerance is ±0.02mm, and the wire roughness is greater than 100nm, which is difficult to meet the technical index requirements.

[0072] From the above comparison, it can be seen that the method of the present invention can solve the problems of low precision of bright surface treatment of wires with a diameter less than 1.0 mm and difficulty in controlling size and chemical composition.

[0073] The surface treatment method of a bright titanium or titanium alloy wire of the present invention cleverly combines the two technologies of sandblasting and peeling, aiming to remove the oxide scale on the surface of the wire efficiently and environmentally friendly, and realize the preparation of bright wire. The organic combination of sandblasting and peeling overcomes the limitations of traditional methods, and provides a new solution for the surface treatment of titanium or titanium alloy wire that is efficient, environmentally friendly, and widely applicable, which is of great significance for promoting technological progress and product upgrades in related industries.

[0074] The surface treatment method of bright titanium or titanium alloy wire of the present invention realizes efficient and continuous online sandblasting treatment of various wires, and can obtain an ideal sandblasting effect for both ultra-fine wires and relatively thick wires. This process can not only effectively make the oxide scale on the surface of the wire fall off or become loose, but also increase the roughness of the wire surface to a certain extent, creating favorable conditions for subsequent stripping treatment, and significantly improving the quality and efficiency of the stripping treatment.

Claims

1. A method for treating the surface of a bright titanium or titanium alloy wire, characterized in that: It consists of the following steps: Step 1, using a sandblasting tube 1 to sandblast the wire to be polished; The sandblasting tube 1 is a cylindrical structure with closed ends. A through hole is provided in the center of the sandblasting tube 1 along its axial direction, and the through hole is used for the wire to pass through; Step 2, the wire to be polished after the sandblasting treatment in step 1 is subjected to coarse peeling and fine peeling in sequence through a first mold and a second mold; The first mold is a column with a tooth-shaped through hole along the axis, and the inner wall of the tooth-shaped through hole has a plurality of convex columns in a central annular array about the column, and the side surfaces of each convex column close to the center of the column are located on the same ring; the second mold is a column structure with a cylindrical through hole along the axis; The side surface of each of the convex columns close to the center of the column is used to contact with the wire material to complete rough peeling, and the inner wall surface of the cylindrical through hole is used to contact with the wire material to complete fine peeling; Step 3, straightening the finished wire to be polished; Step 4: Use an online abrasive belt polisher to finish the surface of the wire to be polished; Step 5: Use an ultrasonic cleaner to finely clean the wire to be polished.

2. A method for surface treatment of bright titanium or titanium alloy wire according to claim 1, characterized in that: The radius of the ring is the minimum radius of the tooth-shaped through hole. The material discharge of the first die at the maximum radius of the tooth-shaped through hole is 2-5%, and the material discharge at the minimum radius is 5-10%; the material discharge of the second die after peeling is 5-10%.

3. A method for surface treatment of bright titanium or titanium alloy wire according to claim 2, characterized in that: The radius of the cylindrical through hole on the second mold is the same as the radius of the annular surface of the convex column on the first mold.

4. A method for surface treatment of bright titanium or titanium alloy wire according to claim 2 or 3, characterized in that: During the peeling process of step 2, the wire tension is 5 to 200 MPa, and the retracting and releasing speed is 1 to 100 m / min.

5. A method for surface treatment of bright titanium or titanium alloy wire according to claim 1, characterized in that: A plurality of inclined sandblasting branch pipes (2) are connected outwardly from the tube wall of the sandblasting tube (1), and each of the sandblasting branch pipes (2) is connected to the through hole; each of the sandblasting branch pipes (2) is arranged in a spiral line along the outer wall of the sandblasting tube (1), and the spacing between adjacent sandblasting branch pipes (2) is equal; The bottom of the sandblasting tube (1) is connected to a plurality of evenly arranged connecting tubes (3), each of the connecting tubes (3) being used to connect the through hole with a collecting device (4); Wherein, each of the sandblasting branch pipes (2) is used to introduce abrasives into the through hole, and finally collected into the collection device (4) through each of the connecting pipes (3).

6. A method for surface treatment of bright titanium or titanium alloy wire according to claim 5, characterized in that: A plurality of sandblasting points are evenly arranged along the axis of the sandblasting tube (1), and two sandblasting branch pipes (2) are symmetrically arranged at each of the sandblasting points.

7. The method according to claim 5, characterized in that: The angle between each of the sandblasting branch pipes (2) and the axis of the sandblasting pipe (1) is 5 to 20 degrees.

8. The method for surface treatment of bright titanium or titanium alloy wire according to claim 1, characterized in that: During the sandblasting process of step 1, the wire tension is 5 to 200 MPa, the sandblasting pressure is 0.2 to 0.6 MPa, and the retracting and releasing line speed is 1 to 50 m / min.

9. A method for surface treatment of bright titanium or titanium alloy wire according to claim 1, characterized in that: In the process of straightening the wire material as a finished product in step 3, the treatment temperature is 300 to 600° C. and the straightening time is 5 to 300 seconds.

10. A method for surface treatment of bright titanium or titanium alloy wire according to claim 1, characterized in that In, In the process of finishing the surface of the wire in step 4, the sanding belt used by the polishing machine has a grain size of A6-A16. The polishing speed is 5-10m / min.

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