A processing and preparation method of a novel nickel-titanium alloy nasolacrimal duct stent

Abstract

The application provides a processing and preparation method of a novel nickel-titanium alloy nasolacrimal duct stent, and relates to the technical field of medical devices.It comprises the following steps: S1, obtaining a nickel-titanium alloy bar, and straightening the nickel-titanium alloy bar; S2, mechanically drilling the straight bar; S3, polishing the inner surface and the outer surface of the rough pipe blank; S4, cold rolling deformation of the rough pipe blank by using a hard core rod; S5, hot drawing deformation of the pipe blank by using a hard core rod; S6, room temperature drawing deformation of the pipe blank by using a soft core rod; S7, multi-process coupling heat treatment of the pipe material; S8, centerless grinding and electrochemical polishing of the pipe material; and S9, laser cutting and vacuum heat treatment of the pipe material.The application can provide excellent surface roughness for the pipe material, effectively improve the density of the pipe material, improve the concentricity of the pipe material, effectively improve the inner surface roughness of the pipe material, improve the quality of the pipe material, and significantly improve the super-elasticity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a processing and preparation method of a novel nickel-titanium alloy nasolacrimal duct stent. BACKGROUND

[0002] Adult nasolacrimal duct obstruction and chronic dacryocystitis are common eye diseases, and pediatric congenital nasolacrimal duct obstruction is also a common eye disease in children, which can easily cause clinical symptoms such as epiphora and has a greater impact on the daily life of patients, and combined infection can cause a greater threat to the safety of the eyeball.

[0003] Adult nasolacrimal duct obstruction is mainly treated by lacrimal passage probing and dacryocystorhinostomy. Compared with lacrimal duct incision, lacrimal passage probing has small damage, simple operation and good effect, but the long-term effect is unstable, the recurrence rate is high, and it is especially not suitable for the treatment of chronic dacryocystitis, which limits its application. The effect of dacryocystorhinostomy is better and the success rate is higher, but the operation is more complex, there is much bleeding during the operation, the operation time is long, and there is a scar on the face after the operation. Sometimes, the operation cannot be performed due to surgical contraindications, at the same time, the operation changes the original anatomical channel of the lacrimal passage, and the fibrous formation of the anastomotic stoma after the operation forms a scar or ossification, which is easy to cause anastomotic stoma obstruction and even lacrimal passage obstruction again, and loses the opportunity for reoperation. Pediatric nasolacrimal duct obstruction is mostly caused by incomplete degeneration of the embryonic residual membrane of the nasolacrimal duct opening, and is generally treated by dacryocyst massage and lacrimal passage probing.

[0004] In order to reduce surgical damage and not change the original anatomical channel of the lacrimal passage, a method of using a silicone nasolacrimal duct stent for treatment has also appeared, which places a permanent tear passage between the lacrimal sac and the lower nasal passage. Compared with traditional surgery, the installation of the nasolacrimal duct stent is simple, has minimal trauma, does not change the original anatomical position, has no postoperative scar, and has a wide range of indications.

[0005] The lacrimal passage structure is curved, and it is necessary to not damage the lacrimal passage while having good flexibility and elasticity. The fixing part of the existing nasolacrimal duct stent mostly has a curved structure, and the original material is mainly silicone, but silicone has the main defect of easy dislocation and displacement when the strength is not enough. Therefore, a nasolacrimal duct stent with higher mechanical support than silicone is needed, and pediatric nasolacrimal duct stents have not yet been developed due to limitations on the original material.

[0006] The applicant finds at least the following technical problems in the prior art: in view of the prior art, the above clinical problems can be solved by using a nickel-titanium alloy nasolacrimal duct stent. High-precision thin-walled nickel-titanium alloy pipe has high strength and radial support force, and special shape recovery ability, and is widely used in minimally invasive surgical instruments, especially in interventional endoluminal stents, and is a key material for preparing a nickel-titanium alloy nasolacrimal duct stent. However, the nickel-titanium alloy has a large deformation resistance at room temperature, a fast work hardening rate, and poor plastic deformation capacity, and the pipe is prone to cracking during cold deformation, so the forming problem of the pipe has been a difficulty in the field of plastic processing. SUMMARY

[0007] The purpose of the present application is to provide a new processing and preparation method of a nickel-titanium alloy nasolacrimal duct stent to solve the technical problems existing in the prior art. The preferred technical solutions in the many technical solutions provided by the present application can produce many technical effects, which are described in detail below.

[0008] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0009] A processing and preparation method of a new nickel-titanium alloy nasolacrimal duct stent, comprising the following steps:

[0010] S1, obtaining a nickel-titanium alloy bar, straightening the nickel-titanium alloy bar to form a straight bar;

[0011] S2, mechanically drilling the straight bar to form a rough pipe blank;

[0012] S3, polishing the inner surface and the outer surface of the rough pipe blank;

[0013] S4, using a hard mandrel to cold roll the rough pipe blank to form a pipe blank with a diameter of Φ4.0-8.0mm;

[0014] S5, using a hard mandrel to hot draw the pipe blank to form a pipe blank with a diameter of Φ1.0-4.0mm;

[0015] S6, using a soft mandrel to room temperature draw the pipe blank to form a pipe with a diameter of Φ0.25-2.0mm;

[0016] S7, multi-process coupling heat treatment is performed on the pipe;

[0017] S8, centerless grinding is performed on the pipe, and electrochemical polishing is performed on the pipe;

[0018] S9, laser cutting is performed on the pipe, and vacuum heat treatment is performed on the pipe to obtain a new nickel-titanium alloy nasolacrimal duct stent.

[0019] Preferably, the nickel-titanium alloy bar in step S1 is compounded with the following mass percentage: Ni 54.5-57.0%, C≤0.04%, Co≤0.05%, Cu≤0.01%, Cr≤0.01%, H≤0.005%, Fe≤0.05%, Nb≤0.025%, N≤0.005%, O≤0.04%, and the balance Ti.

[0020] The nickel-titanium alloy bar has a length of 1-4 m, and after being cut according to the length, the straightening equipment is used for straightening, and the straightness after straightening is not greater than 0.5 mm / m.

[0021] Preferably, in step S2, before the straight bar is mechanically drilled, the straight bar after straightening is processed into a fixed length.

[0022] Preferably, in step S3, the inner surface and the outer surface of the rough pipe blank are polished by using a mechanical polishing device, and the roughness of the inner surface after polishing is not greater than 1.6 μm, and the roughness of the outer surface is not greater than 1.0 μm.

[0023] Preferably, in step S4, the material of the hard core rod is cemented carbide, the hard core rod is inserted into the rough pipe blank to obtain a combination, the combination is cold-rolled by using a cold rolling device, the single pass deformation is less than 13%, the deformation is 25%-50% after intermediate vacuum annealing, and after multiple cycles, a pipe blank with a diameter of 4.0-8.0 mm is formed.

[0024] Preferably, in step S5, the material of the hard core rod is cemented carbide, the hard core rod is inserted into the pipe blank to obtain a combination, the combination is hot-drawn by using a hot drawing device, the single pass deformation is less than 15%, the deformation is 30%-60% after intermediate annealing, and after multiple cycles, a pipe blank with a diameter of 1.0-4.0 mm is formed.

[0025] Preferably, in step S6, the material of the soft core rod is a material with a Vickers hardness less than 100, the soft core rod coated with molybdenum disulfide lubricant is inserted into the pipe blank to obtain a combination, the combination is cold-drawn by using a room temperature drawing device, the single pass deformation is less than 20%, the deformation is 30%-60% after intermediate annealing, and after multiple cycles, a combination with a diameter of 0.25-2.0 mm is formed, and then the combination is drawn to obtain a pipe with a diameter of 0.25-2.0 mm.

[0026] Preferably, in step S7, the pipe is heat treated by using a multi-process coupling mode of electric pulse treatment and aging treatment.

[0027] Preferably, in step S8, when electrochemically polishing the pipe, the polishing solution is composed of 15-25% of perchloric acid and 75-85% of glacial acetic acid by volume fraction, the constant voltage is 5-20V, the electrolytic polishing is carried out at room temperature, the polishing time is 1-30 minutes, and the roughness of the inner surface after polishing is less than 1.0 mu m, and the roughness of the outer surface is less than 0.5 mu m.

[0028] Preferably, in step S9, the pipe is first cut into a corresponding length of the nasolacrimal duct stent, then the pipe is cut by femtosecond laser, and then the pipe is subjected to vacuum heat treatment, the heat treatment temperature is 400-600 DEG C, the heat treatment time is 10-50 min, and then the pipe is cooled by furnace cooling or water cooling.

[0029] The present application has the advantages that: by adopting the mechanical perforation processing mode and the polishing processing mode for the inner surface and the outer surface of the pipe, excellent surface roughness of the pipe is provided, thereby facilitating subsequent processing and use;

[0030] By adopting the cold rolling deformation processing mode, the density of the pipe can be effectively improved, and the concentricity of the pipe is improved;

[0031] By adopting the combination of the hard core rod and the soft core rod for the hot drawing deformation and the room temperature drawing deformation, the inner surface roughness of the pipe can be effectively improved, and the pipe quality is improved;

[0032] By adopting the multi-process coupled heat treatment mode for the finished pipe, the pulse current can interact with defects such as crystal lattice distortion, vacancies, dislocations and grain boundaries, so that the microstructure of the nickel-titanium alloy gradually tends to be uniform and stable, a good stress platform is obtained, a large number of fine and uniformly distributed Ni4Ti3 particles are precipitated by low-temperature aging treatment, and superelasticity is significantly improved.

[0033] The present application can produce various specifications of nickel-titanium alloy pipes and nasolacrimal duct stents, and provide raw materials of nickel-titanium alloy for ophthalmic and ear-nose-throat medical instruments;

[0034] By utilizing the superelasticity and excellent mechanical properties of the nickel-titanium alloy, the present application can meet the requirements of flexibility and supporting force of the nasolacrimal duct stent, and the nickel-titanium alloy also has excellent biocompatibility, which meets the requirements of the nasolacrimal duct stent for the performance of raw materials;

[0035] The present application realizes accurate forming of the stent by precisely cutting the stent structure by femtosecond laser, thereby preparing qualified nasolacrimal duct stents.

[0036] The present application can adjust the product size, so that the produced nasolacrimal duct stents can be applied to adults and children. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only represent some of the embodiments of the present application, and all other drawings obtained by those skilled in the art without creative effort based on these drawings also belong to the protection scope of the present application.

[0038] Figure 1 The flow chart of the present application. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present application more clear, the technical solutions of the present application will be described in detail. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the protection scope of the present application.

[0040] In the description of the present application, it should be understood that the terms "center", "lateral", "length", "width", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "side" and the like indicate the orientation or positional relationship based on the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. Figure 1 The orientation or positional relationship shown is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0041] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0042] With reference to Figure 1 The present application provides a new processing and preparation method of a nickel-titanium alloy nasolacrimal duct stent, comprising the following steps:

[0043] S1, obtaining a nickel-titanium alloy bar, straightening the nickel-titanium alloy bar to form a straight bar;

[0044] Specifically, the nickel-titanium alloy bar is preferably formulated with the following mass percentages: Ni 54.5-57.0%, C≤0.04%, Co≤0.05%, Cu≤0.01%, Cr≤0.01%, H≤0.005%, Fe≤0.05%, Nb≤0.025%, N≤0.005%, O≤0.04%, and the balance Ti;

[0045] The diameter of the nickel-titanium alloy bar is preferably 7-25 mm, and the nickel-titanium alloy bar has a fixed length of 1-4 m. After the nickel-titanium alloy bar is cut to the desired fixed length, the straightening equipment is used for straightening, and the straightness after straightening is not greater than 0.5 mm / m.

[0046] S2, mechanical drilling processing is performed on the straight bar to form a rough pipe blank;

[0047] Specifically, before the mechanical drilling processing is performed on the straight bar, the straight bar after straightening needs to be processed into a fixed length, and the fixed length is a suitable length required;

[0048] Then, the deep drilling process is used to prepare the straight bar into a nickel-titanium alloy pipe blank, and the ratio of the inner diameter to the outer diameter of the nickel-titanium alloy pipe blank is 0.30-0.86.

[0049] S3, polishing is performed on the inner surface and the outer surface of the rough pipe blank;

[0050] Specifically, the mechanical polishing equipment is used to polish the inner surface and the outer surface of the rough pipe blank. In the process of polishing the outer surface, the mechanical polishing equipment includes but is not limited to a centerless grinding machine and a belt sander, and the roughness of the outer surface after polishing is not greater than 1.0 μm;

[0051] In the process of polishing the inner surface, the mechanical polishing equipment includes but is not limited to a grit flow device, an acid pickling or electrolytic polishing device, and the roughness of the inner surface after polishing is not greater than 1.6 μm.

[0052] S4, a hard core rod is used for cold rolling deformation of the rough pipe blank to form a pipe blank with a diameter of Φ4.0-8.0 mm;

[0053] Specifically, the material of the hard core rod is preferably a hard alloy. The hard core rod is inserted into the rough pipe blank to obtain an assembly, and then the cold rolling equipment is used for cold rolling deformation of the assembly. The single-pass deformation amount is less than 13%, and the deformation amount is 25%-50% after intermediate vacuum annealing. After such a cycle is repeated multiple times, a pipe blank with a diameter of Φ4.0-8.0 mm is formed.

[0054] S5, a hard core rod is used for hot drawing deformation of the pipe blank to form a pipe blank with a diameter of Φ1.0-4.0 mm;

[0055] Specifically, the material of the hard core rod is preferably cemented carbide, the hard core rod is first inserted into the pipe blank to obtain an assembly, and then the assembly is subjected to hot drawing deformation by using a hot drawing device, the single-pass deformation amount is less than 15%, and the deformation amount is 30%-60% after intermediate annealing, and the process is repeated for multiple times to form a pipe blank with a diameter of Φ1.0-4.0 mm.

[0056] S6, the pipe blank is subjected to room temperature drawing deformation by using a soft core rod to form a pipe with a diameter of Φ0.25-2.0 mm;

[0057] Specifically, the material of the soft core rod is preferably a material with a Vickers hardness less than 100 such as red copper, the soft core rod coated with molybdenum disulfide lubricant is first inserted into the pipe blank to obtain an assembly, and then the assembly is subjected to cold drawing deformation by using a room temperature drawing device, the single-pass deformation amount is less than 20%, and the deformation amount is 30%-60% after intermediate annealing, and the process is repeated for multiple times to form an assembly with a diameter of Φ0.25-2.0 mm, and then the assembly is subjected to core extraction to obtain a pipe with a diameter of Φ0.25-2.0 mm.

[0058] S7, the pipe is subjected to multi-process coupling heat treatment;

[0059] Specifically, the pipe is subjected to heat treatment by using a multi-process coupling mode of electric pulse treatment and aging treatment.

[0060] S8, the pipe is subjected to centerless grinding and electrochemical polishing;

[0061] Specifically, when the pipe is subjected to electrochemical polishing, the polishing solution is composed of 15-25% of perchloric acid and 75-85% of glacial acetic acid in terms of volume fraction, the constant voltage is 5-20 V, the electrolytic polishing is carried out at room temperature, the polishing time is 1-30 minutes, the roughness of the inner surface after polishing is less than 1.0 μm, and the roughness of the outer surface after polishing is less than 0.5 μm.

[0062] S9, the pipe is subjected to laser cutting and vacuum heat treatment to obtain a new type of nickel-titanium alloy nasolacrimal duct stent;

[0063] Specifically, the pipe is first cut into a corresponding length of the nasolacrimal duct stent, and then subjected to femtosecond laser cutting, in the process of femtosecond laser cutting, the pulse width is 50-600 fs, the pulse energy is 30-160 μJ, the pulse repetition frequency is 80-500 kHz, the cutting speed is 0.2-4.0 mm / s, and the cutting is carried out in a protective atmosphere;

[0064] Then the pipe is subjected to vacuum heat treatment, the heat treatment temperature is 400-600℃, the heat treatment time is 10-50 min, and then the pipe is cooled by furnace cooling or water cooling.

[0065] The application provides excellent surface roughness for the pipe by adopting the mechanical perforation processing mode in step S2, and adopting the polishing processing mode for the inner surface and the outer surface of the pipe in steps S3 and S8, thereby facilitating subsequent processing and use;

[0066] The application can effectively improve the density of the pipe and improve the concentricity of the pipe by adopting the cold rolling deformation processing mode in step S4.

[0067] The application can effectively improve the inner surface roughness of the pipe and improve the pipe quality by adopting the hard core rod and the soft core rod in steps S5 and S6.

[0068] The application adopts the multi-process coupling heat treatment mode for the finished pipe in step S7, pulse current can interact with defects such as lattice distortion, vacancies, dislocations and grain boundaries, so that the microstructure of the nickel-titanium alloy gradually tends to be uniform and stable, a good stress platform appears, a large amount of fine and uniformly distributed Ni4Ti3 particles are precipitated by low-temperature aging treatment, and superelasticity is significantly improved.

[0069] The application provides a processing and preparation method of a novel nickel-titanium alloy nasolacrimal duct stent, and various nickel-titanium alloy pipes and nasolacrimal duct stents of different specifications can be produced by the method, so as to provide raw materials of nickel-titanium alloy for ophthalmic and ear-nose-throat medical instruments.

[0070] The application can meet the requirements of flexibility and supporting force of the nasolacrimal duct stent by utilizing the superelasticity and excellent mechanical properties of the nickel-titanium alloy, and the nickel-titanium alloy also has excellent biocompatibility, thereby meeting the requirements of the nasolacrimal duct stent on the properties of raw materials.

[0071] The application realizes accurate forming of the stent by precisely cutting the stent structure by femtosecond laser, so that the qualified nasolacrimal duct stent is prepared.

[0072] The application can be adjusted according to the size of the product, so that the produced nasolacrimal duct stent can be applied to adults and children.

[0073] The application provides three embodiments and four comparative embodiments.

[0074] The comparative example one is not polished, and the non-mechanical drilling mode is adopted for opening.

[0075] The comparative example two is not cold-rolled.

[0076] The comparative example three adopts the traditional cold-drawing deformation mode.

[0077] Comparative Example 4 is annealing heat treatment in a conventional manner without multi-process coupling heat treatment.

[0078] Example 1

[0079] The embodiment provides a processing and preparation method of a novel nickel-titanium alloy nasolacrimal duct stent, and comprises the following steps:

[0080] In step S1, a nickel-titanium alloy bar is prepared according to the following mass percentage: 56.14% of Ni, 0.0078% of C, <0.005% of Co, <0.005% of Cu, <0.005% of Cr, <0.0016% of H, <0.005% of Fe, <0.002% of Nb, <0.003% of N, 0.029% of O, and the balance of Ti. The diameter of the nickel-titanium alloy bar is 20 mm, and the fixed length is 3 m. After cutting, the bar is straightened by using an electric straightening equipment. The straightness of the bar after straightening is 0.3 mm / m.

[0081] In step S2, the straightened bar is cut according to a fixed length of 600 mm. The bar is drilled by using a deep hole processing equipment. The inner hole diameter of the pipe blank is 14.0 mm.

[0082] In step S3, the outer surface of the pipe blank is polished by using a centerless grinding machine. The inner surface of the pipe blank is polished by using a abrasive grain flow equipment. After polishing, the roughness of the outer surface of the pipe blank is 0.45 μm, and the roughness of the inner surface is 0.75 μm.

[0083] In step S4, a hard alloy is used as a hard core rod. The surface of the hard core rod is uniformly coated with an oily lubricant. The hard core rod is inserted into the pipe blank to obtain a combination. The combination is deformed by using a cold rolling method. The single pass deformation amount is controlled to be 10%. When the total deformation amount reaches 30%, the pipe is subjected to intermediate vacuum annealing. The annealing temperature is 750 ℃, and the time is 5 min. The process is repeated for multiple times. A pipe blank with an outer diameter of 8.0 mm and an inner diameter of 5.1 mm is obtained.

[0084] In step S5, a hard alloy is used as a hard core rod. The surface of the hard core rod is uniformly coated with an oily lubricant. The hard core rod is inserted into the pipe blank to obtain a combination. The combination is deformed by using a hot drawing method. The hot drawing temperature is 780 ℃, and the speed is 5 m / min. The single pass deformation amount is controlled to be 12%. When the total deformation amount reaches 40%, the pipe is subjected to intermediate annealing. The annealing temperature is 750 ℃, and the time is 1 min. The process is repeated for multiple times. A pipe blank with an outer diameter of 2.0 mm and an inner diameter of 1.95 mm is obtained.

[0085] Step S6, adopt red copper as the soft core rod, uniformly coat the surface of the soft core rod with molybdenum disulfide, insert the soft core rod into the pipe blank to obtain a combination, use a room temperature drawing device to continuously cold draw the combination, control the single pass deformation amount to be 15%, when the total deformation amount reaches 45%, carry out intermediate annealing on the combination, the annealing temperature is 650 DEG C, the time is 1 min, cycle multiple times, obtain a combination with an outer diameter of 0.3 mm and an inner diameter of 0.21 mm, then remove the soft core rod to obtain the pipe.

[0086] Step S7, carry out multi-process coupling heat treatment of electric pulse treatment + aging treatment on the pipe, the electric pulse treatment process parameters are duty position P of 0.09, pulse frequency f of 150 Hz, and on time of 600 μs, the aging treatment process parameters are temperature of 250 DEG C and time of 24 h.

[0087] Step S8, carry out centerless grinding on the outer surface of the pipe, then carry out electrochemical polishing on the pipe, the polishing solution is composed of 21% of perchloric acid (HCLO4, content 70.0-70.2%) and 79% of glacial acetic acid (CH3COOH, content not less than 99.5%) by volume fraction, carry out electrolytic polishing at a constant voltage of 10 V and room temperature, the time is 10 minutes, the roughness of the outer surface of the pipe after polishing is 0.21 μm, and the roughness of the inner surface is 0.65 μm.

[0088] Step S9, cut the nickel-titanium alloy pipe into a length of 80 mm, then carry out femtosecond laser cutting, set the pulse width to be 337 fs, the pulse energy to be 80 μJ, the pulse repetition frequency to be 100 kHz, and the cutting speed to be 0.8 mm / s, carry out cutting under helium, carry out heat treatment setting temperature of 480 DEG C for 26 min after cutting is completed, then adopt furnace cooling cooling method, finally obtain the finished nickel-titanium alloy nasolacrimal duct stent.

[0089] Example Two

[0090] The embodiment provides a processing and preparation method of a novel nickel-titanium alloy nasolacrimal duct stent, comprising the following steps:

[0091] Step S1, the nickel-titanium alloy bar is prepared according to the following mass percentage: Ni is 56.14%, C is 0.0078%, Co: <0.005%, Cu: <0.005%, Cr: <0.005%, H: <0.0016%, Fe: <0.005%, Nb: <0.002%, N: <0.003%, O: 0.029%, and the balance is Ti, the diameter of the nickel-titanium alloy bar is 18 mm, the fixed length is 3 m, after cutting, straightening is carried out by using an electric straightening device, and the straightness of the straightened bar is 0.2 mm / m.

[0092] Step S2, the straightened bar is cut according to the fixed length of 500mm, and the bar is drilled by using a deep hole processing equipment, and the inner hole diameter of the pipe blank is 10.0mm.

[0093] Step S3, the outer surface of the pipe blank is polished by using a centerless grinding machine, and the inner surface of the pipe blank is polished by using a abrasive grain flow equipment, and the roughness of the outer surface of the pipe blank is 0.39μm after polishing, and the roughness of the inner surface is 0.81μm.

[0094] Step S4, a hard alloy is used as a hard core rod, and an oily lubricant is uniformly coated on the surface of the hard core rod, the hard core rod is inserted into the pipe blank to obtain an assembly, the assembly is deformed by using a cold rolling method, and the single pass deformation amount is controlled to be 9%, when the total deformation amount reaches 35%, the pipe is subjected to intermediate vacuum annealing, the annealing temperature is 800℃, and the time is 5min, and the pipe blank with an outer diameter of 7.5mm and an inner diameter of 4.5mm is obtained after multiple cycles.

[0095] Step S5, a hard alloy is used as a hard core rod, and an oily lubricant is uniformly coated on the surface of the hard core rod, the hard core rod is inserted into the pipe blank to obtain an assembly, the assembly is deformed by using a hot drawing method, the hot drawing temperature is 780℃, the speed is 8m / min, the single pass deformation amount is controlled to be 11%, when the total deformation amount reaches 40%, the pipe is subjected to intermediate annealing, the annealing temperature is 750℃, and the time is 1min, and the pipe blank with an outer diameter of 2.5mm and an inner diameter of 2.38mm is obtained after multiple cycles.

[0096] Step S6, red copper is used as a soft core rod, and molybdenum disulfide is uniformly coated on the surface of the soft core rod, the soft core rod is inserted into the pipe blank to obtain an assembly, the assembly is continuously cold drawn by using a room temperature drawing equipment, the single pass deformation amount is controlled to be 13%, when the total deformation amount reaches 48%, the assembly is subjected to intermediate annealing, the annealing temperature is 650℃, and the time is 1min, and the assembly with an outer diameter of 0.5mm and an inner diameter of 0.38mm is obtained after multiple cycles, and then the soft core rod is removed to obtain the pipe.

[0097] Step S7, the pipe is subjected to multi-process coupling heat treatment of electric pulse treatment + aging treatment, the electric pulse treatment process parameters are duty position P of 0.12, pulse frequency f of 200Hz, and on time of 600μs, and the aging treatment process parameters are temperature of 280℃ and time of 24h.

[0098] Step S8, centerless grinding is performed on the outer surface of the pipe, and then electrochemical polishing is performed on the pipe, the polishing solution is composed of 15% of perchloric acid (HCLO4, content 70.0-70.2%) and 85% of glacial acetic acid (CH3COOH, content not less than 99.5%) by volume fraction, electrolytic polishing is performed at a constant voltage of 10V and room temperature, the time is 8 minutes, the roughness of the outer surface of the polished pipe is 0.35μm, and the roughness of the inner surface is 0.68μm.

[0099] Step S9, the nickel-titanium alloy pipe is cut to a length of 100mm, and then femtosecond laser cutting is performed, the pulse width is set to 460fs, the pulse energy is 50μJ, the pulse repetition frequency is 333kHz, the cutting speed is 2mm / s, the cutting is performed under helium, the heat treatment setting temperature after cutting is 500℃, the time is 20min, and then the cooling method of furnace cooling is adopted, and finally the finished nickel-titanium alloy nasolacrimal duct stent is obtained.

[0100] Example three

[0101] The embodiment provides a processing and preparation method of a novel nickel-titanium alloy nasolacrimal duct stent, comprising the following steps:

[0102] Step S1, the nickel-titanium alloy bar is prepared according to the following mass percentage: Ni is 55.97%, C is 0.0046%, Co: <0.010%, Cu: <0.005%, Cr: <0.005%, H: <0.001%, Fe: <0.005%, Nb: <0.005%, N: <0.003%, O: 0.032%, and the balance is Ti, the diameter of the nickel-titanium alloy bar is 24mm, the fixed length is 2m, after cutting, the straightening equipment is used for straightening, and the straightness of the straightened bar is 0.35mm / m.

[0103] Step S2, the straightened bar is cut according to a fixed length of 500mm, the deep hole machining equipment is used for drilling the bar, and the inner hole diameter of the pipe blank is 19.0mm.

[0104] Step S3, the outer surface of the pipe blank is polished by using a centerless grinding machine, and the inner surface of the pipe blank is polished by using a abrasive grain flow equipment, the roughness of the outer surface of the polished pipe blank is 0.24μm, and the roughness of the inner surface is 0.68μm.

[0105] Step S4, a hard alloy is used as the hard core rod, and the surface of the hard core rod is uniformly coated with an oily lubricant, the hard core rod is inserted into the pipe blank to obtain an assembly, the assembly is deformed by cold rolling, the single pass deformation is controlled to be 10%, when the total deformation reaches 30%, the pipe is subjected to intermediate vacuum annealing, the annealing temperature is 800 DEG C, the time is 6 min, and the process is repeated multiple times, to obtain a pipe blank with an outer diameter of 10.0 mm and an inner diameter of 6.4 mm.

[0106] Step S5, a hard alloy is used as the hard core rod, and the surface of the hard core rod is uniformly coated with an oily lubricant, the hard core rod is inserted into the pipe blank to obtain an assembly, the assembly is deformed by hot drawing, the hot drawing temperature is 800 DEG C, the speed is 5 m / min, the single pass deformation is controlled to be 10%, when the total deformation reaches 40%, the pipe is subjected to intermediate annealing, the annealing temperature is 750 DEG C, the time is 1 min, and the process is repeated multiple times, to obtain a pipe blank with an outer diameter of 4.0 mm and an inner diameter of 3.68 mm.

[0107] Step S6, red copper is used as the soft core rod, the surface of the soft core rod is uniformly coated with molybdenum disulfide, the soft core rod is inserted into the pipe blank to obtain an assembly, the assembly is continuously cold drawn using a room temperature drawing device, the single pass deformation is controlled to be 15%, when the total deformation reaches 45%, the assembly is subjected to intermediate annealing, the annealing temperature is 620 DEG C, the time is 1 min, and the process is repeated multiple times, to obtain an assembly with an outer diameter of 2.0 mm and an inner diameter of 1.71 mm, then the soft core rod is removed to obtain the pipe.

[0108] Step S7, the pipe is subjected to multi-process coupling heat treatment of electric pulse treatment + aging treatment, the electric pulse treatment process parameters are duty position P of 0.18, pulse frequency f of 300 Hz, and on time of 600 μs, the aging treatment process parameters are temperature of 310 DEG C and time of 36 h.

[0109] Step S8, the outer surface of the pipe is subjected to centerless grinding, and then the pipe is subjected to electrochemical polishing, the polishing solution is composed of 21% by volume of perchloric acid (HCLO4, content 70.0-70.2%) and 79% of glacial acetic acid (CH3COOH, content not less than 99.5%), electrolytic polishing is carried out at a constant voltage of 10 V and room temperature, the time is 6 min, the roughness of the outer surface of the polished pipe is 0.29 μm, and the roughness of the inner surface is 0.74 μm.

[0110] Step S9, cut the nickel-titanium alloy pipe into a length of 120 mm, then perform femtosecond laser cutting on it, set the pulse width to 100 fs, the pulse energy to 80 μJ, the pulse repetition frequency to 100 kHz, the cutting speed to 0.8 mm / s, perform cutting under helium, and perform heat treatment at a temperature of 540℃ for 25 min after cutting, then adopt the furnace cooling cooling method, and finally obtain the finished nickel-titanium alloy nasolacrimal duct stent.

[0111] Comparative Example One

[0112] The comparative example provides a processing preparation method, including the following steps:

[0113] Step S1, the nickel-titanium alloy bar is prepared according to the following mass percentage: Ni is 55.97%, C is 0.0046%, Co: <0.010%, Cu: <0.005%, Cr: <0.005%, H: <0.001%, Fe: <0.005%, Nb: <0.005%, N: <0.003%, O: 0.032%, and the balance is Ti. The diameter of the nickel-titanium alloy bar is 24 mm, and the fixed length is 2 m. After cutting, the straightening equipment is used for straightening, and the straightness of the straightened bar is 0.35 mm / m.

[0114] Step S2, the straightened bar is cut according to a fixed length of 500 mm. Different from the above example, the bar is drilled by using the electric spark combined with the wire cutting equipment, and the inner hole diameter of the pipe blank is 19.0 mm.

[0115] Step S3, the outer surface of the pipe blank is polished by using the centerless grinding machine, and the inner surface of the pipe blank is polished by using the abrasive flow equipment. After polishing, the roughness of the outer surface of the pipe blank is 0.24 μm, and the roughness of the inner surface is 0.68 μm.

[0116] Step S4, use a hard alloy as a hard core rod, and uniformly coat the surface of the hard core rod with an oily lubricant, insert the hard core rod into the pipe blank to obtain a combination, deform the combination by using cold rolling, and control the single pass deformation amount to be 10%. When the total deformation amount reaches 30%, perform intermediate vacuum annealing on the pipe, the annealing temperature is 800℃, and the time is 6 min. Repeat the process multiple times to obtain a pipe blank with an outer diameter of 10.0 mm and an inner diameter of 6.4 mm.

[0117] Step S5, a hard alloy is used as the hard core rod, and the surface of the hard core rod is uniformly coated with an oily lubricant, the hard core rod is inserted into the pipe blank to obtain an assembly, the assembly is deformed by hot drawing, the hot drawing temperature is 800℃, the speed is 5m / min, the single pass deformation amount is controlled to be 10%, when the total deformation amount reaches 40%, the pipe is subjected to intermediate annealing, the annealing temperature is 750℃, the time is 1min, and the cycle is repeated multiple times, to obtain a pipe blank with an outer diameter of 4.0mm and an inner diameter of 3.68mm.

[0118] Step S6, red copper is used as the soft core rod, the surface of the soft core rod is uniformly coated with molybdenum disulfide, the soft core rod is inserted into the pipe blank to obtain an assembly, the assembly is continuously cold drawn by using a room temperature drawing device, the single pass deformation amount is controlled to be 15%, when the total deformation amount reaches 45%, the assembly is subjected to intermediate annealing, the annealing temperature is 620℃, the time is 1min, and the cycle is repeated multiple times, to obtain an assembly with an outer diameter of 2.0mm and an inner diameter of 1.71mm, and then the soft core rod is removed to obtain the pipe.

[0119] Step S7, the pipe is subjected to multi-process coupling heat treatment of electric pulse treatment + aging treatment, the electric pulse treatment process parameters are duty position P of 0.18, pulse frequency f of 300Hz, and on-time of 600μs, and the aging treatment process parameters are temperature of 310℃ and time of 36h.

[0120] Step S8, the outer surface of the pipe is subjected to centerless grinding, and then the pipe is subjected to electrochemical polishing, the polishing solution is composed of 21% of perchloric acid (HCLO4, content of 70.0-70.2%) and 79% of glacial acetic acid (CH3COOH, content of not less than 99.5%) by volume fraction, electrolytic polishing is carried out at a constant voltage of 10V and room temperature, the time is 6 minutes, and the roughness of the outer surface of the pipe after polishing is 0.58μm, and the roughness of the inner surface is 2.41μm.

[0121] Step S9, the nickel-titanium alloy pipe is cut to a length of 120mm, and then subjected to femtosecond laser cutting, the pulse width is set to 100fs, the pulse energy is 80μJ, the pulse repetition frequency is 100kHz, the cutting speed is 0.8mm / s, the cutting is carried out under helium, the heat treatment setting temperature after cutting is 540℃, the time is 25min, then the cooling mode is furnace cooling, and finally the finished nickel-titanium alloy nasolacrimal duct stent is obtained.

[0122] Comparative Example Two

[0123] The present comparative example provides a processing and preparation method, comprising the following steps:

[0124] Step S1, the nickel-titanium alloy bar is prepared according to the following mass percentage: Ni is 55.97%, C is 0.0046%, Co: <0.010%, Cu: <0.005%, Cr: <0.005%, H: <0.001%, Fe: <0.005%, Nb: <0.005%, N: <0.003%, O: 0.032%, and the balance is Ti. The diameter of the nickel-titanium alloy bar is 24 mm, and the fixed length is 2 m. After cutting, the bar is straightened by using an electric straightening device. The straightness of the bar after straightening is 0.35 mm / m.

[0125] Step S2, the straightened bar is cut according to a fixed length of 500 mm. The bar is drilled by using a deep hole processing device. The inner hole diameter of the tube blank is 19.0 mm.

[0126] Step S3, the outer surface of the tube blank is polished by using a centerless grinding machine. The inner surface of the tube blank is polished by using a abrasive grain flow device. The roughness of the outer surface of the tube blank after polishing is 0.24 μm, and the roughness of the inner surface is 0.68 μm.

[0127] Step S4, a hard alloy is used as a hard core rod. The surface of the hard core rod is uniformly coated with an oily lubricant. The hard core rod is inserted into the tube blank to obtain an assembly. The assembly is deformed by using a hot drawing method. The hot drawing temperature is 800°C. The speed is 3 m / min. The single pass deformation amount is controlled to be 10%. When the total deformation amount reaches 30%, the tube is subjected to intermediate annealing. The annealing temperature is 750°C. The time is 2 min. The cycle is repeated multiple times. The tube blank with an outer diameter of 4.0 mm and an inner diameter of 3.68 mm is obtained.

[0128] Step S5, red copper is used as a soft core rod. The surface of the soft core rod is uniformly coated with molybdenum disulfide. The soft core rod is inserted into the tube blank to obtain an assembly. The assembly is continuously cold drawn by using a room temperature drawing device. The single pass deformation amount is controlled to be 15%. When the total deformation amount reaches 45%, the assembly is subjected to intermediate annealing. The annealing temperature is 620°C. The time is 1 min. The cycle is repeated multiple times. The assembly with an outer diameter of 2.0 mm and an inner diameter of 1.71 mm is obtained. Then, the soft core rod is removed to obtain the tube.

[0129] Step S6, the tube is subjected to multi-process coupling heat treatment of electric pulse treatment + aging treatment. The electric pulse treatment process parameters are duty position P of 0.18, pulse frequency f of 300 Hz, and on-time of 600 μs. The aging treatment process parameters are temperature of 310°C and time of 36 h.

[0130] Step S7, centerless grinding is performed on the outer surface of the pipe, and then electrochemical polishing is performed on the pipe, the polishing solution is composed of 21% of perchloric acid (HCLO4, content 70.0-70.2%) and 79% of glacial acetic acid (CH3COOH, content not less than 99.5%) by volume fraction, electrolytic polishing is performed at a constant voltage of 10V and room temperature, the time is 6 minutes, the roughness of the outer surface of the polished pipe is 0.31μm, and the roughness of the inner surface is 0.75μm.

[0131] Step S8, the nickel-titanium alloy pipe is cut to a length of 120mm, and then femtosecond laser cutting is performed, the pulse width is set to 100fs, the pulse energy is 80μJ, the pulse repetition frequency is 100kHz, the cutting speed is 0.8mm / s, the cutting is performed under helium, the heat treatment setting temperature after cutting is 540℃, the time is 25min, and then the cooling method of furnace cooling is adopted, and finally the finished product of the nickel-titanium alloy nasolacrimal duct stent is obtained.

[0132] Comparative Example Three

[0133] The present comparative example provides a processing preparation method, comprising the following steps:

[0134] Step S1, the nickel-titanium alloy bar is prepared according to the following mass percentage: Ni is 55.97%, C is 0.0046%, Co: <0.010%, Cu: <0.005%, Cr: <0.005%, H: <0.001%, Fe: <0.005%, Nb: <0.005%, N: <0.003%, O: 0.032%, and the balance is Ti, the diameter of the nickel-titanium alloy bar is 24mm, the fixed length is 2m, after cutting, the straightening equipment is used for straightening, and the straightness of the straightened bar is 0.35mm / m.

[0135] Step S2, the straightened bar is cut according to the fixed length of 500mm, the deep hole machining equipment is used for drilling the bar, and the inner hole diameter of the pipe blank is 19.0mm.

[0136] Step S3, the outer surface of the pipe blank is polished by using a centerless grinding machine, and the inner surface of the pipe blank is polished by using a abrasive grain flow equipment, the roughness of the outer surface of the pipe blank after polishing is 0.24μm, and the roughness of the inner surface is 0.68μm.

[0137] Step S4, the hard alloy is used as the hard core rod, and the surface of the hard core rod is uniformly coated with the oily lubricant, the hard core rod is inserted into the pipe blank to obtain a combination, the combination is deformed by cold rolling, the single pass deformation amount is controlled to be 10%, when the total deformation amount reaches 30%, the pipe is subjected to intermediate vacuum annealing, the annealing temperature is 800 DEG C, the time is 6 min, and the operation is repeated for multiple times, and the pipe blank with an outer diameter of 10.0 mm and an inner diameter of 6.4 mm is obtained.

[0138] Step S5, different from the above embodiment, the aluminum alloy is used as the hard core rod, and the surface of the hard core rod is uniformly coated with the molybdenum disulfide, the hard core rod is inserted into the pipe blank to obtain a combination, the combination is reduced in diameter by hot drawing, the single pass deformation amount is controlled to be 12%, when the total deformation amount reaches 45%, the pipe is subjected to intermediate annealing, the annealing temperature is 720 DEG C, the time is 1 min, and the operation is repeated for multiple times, and the pipe blank with an outer diameter of 2.0 mm and an inner diameter of 1.71 mm is obtained.

[0139] Step S6, the pipe is subjected to the multi-process coupling heat treatment of the electric pulse treatment + aging treatment, the electric pulse treatment process parameters are that the duty position P is 0.18, the pulse frequency f is 300 Hz, and the on time is 600 μs, and the aging treatment process parameters are that the temperature is 310 DEG C, and the time is 36 h.

[0140] Step S7, the outer surface of the pipe is subjected to the centerless grinding, and then the pipe is subjected to the electrochemical polishing, the polishing liquid is composed of 21% of the perchloric acid (HCLO4, content 70.0-70.2%) and 79% of the glacial acetic acid (CH3COOH, content not less than 99.5%) in volume fraction, the electrolytic polishing is carried out at a constant voltage of 10 V and room temperature, the time is 6 min, the roughness of the outer surface of the pipe after polishing is 0.48 μm, and the roughness of the inner surface is 1.81 μm.

[0141] Step S8, the nickel-titanium alloy pipe is cut into a length of 120 mm, and then subjected to the femtosecond laser cutting, the pulse width is set to be 100 fs, the pulse energy is 80 μJ, the pulse repetition frequency is 100 kHz, the cutting speed is 0.8 mm / s, the cutting is carried out under helium, the heat treatment setting temperature after cutting is 540 DEG C, the time is 25 min, then the cooling mode of furnace cooling is adopted, and finally the finished nickel-titanium alloy nasolacrimal duct stent is obtained.

[0142] Comparative Example Four

[0143] The comparative example provides a processing preparation method, which comprises the following steps:

[0144] Step S1, the nickel-titanium alloy rod is prepared according to the following mass percentage: Ni is 55.97%, C is 0.0046%, Co: <0.010%, Cu: <0.005%, Cr: <0.005%, H: <0.001%, Fe: <0.005%, Nb: <0.005%, N: <0.003%, O: 0.032%, and the balance is Ti. The diameter of the nickel-titanium alloy rod is 24 mm, and the fixed length is 2 m. After cutting, the rod is straightened by using an electric straightening device. The straightness of the rod after straightening is 0.35 mm / m.

[0145] Step S2, the straightened rod is cut according to a fixed length of 500 mm. Different from the above embodiment, the rod is drilled by using an electric spark combined with a wire cutting device in this comparative example. The inner hole diameter of the pipe blank is 19.0 mm.

[0146] Step S3, the outer surface of the pipe blank is polished by using a centerless grinding machine, and the inner surface of the pipe blank is polished by using a abrasive grain flow device. The roughness of the outer surface of the pipe blank after polishing is 0.24 μm, and the roughness of the inner surface is 0.68 μm.

[0147] Step S4, a hard alloy is used as a hard mandrel, and an oily lubricant is uniformly coated on the surface of the hard mandrel. The hard mandrel is inserted into the pipe blank to obtain an assembly. The assembly is deformed by using a cold rolling method. The single pass deformation amount is controlled to be 10%. When the total deformation amount reaches 30%, the pipe is subjected to intermediate vacuum annealing. The annealing temperature is 800°C, and the time is 6 min. The process is repeated multiple times to obtain a pipe blank with an outer diameter of 10.0 mm and an inner diameter of 6.4 mm.

[0148] Step S5, a hard alloy is used as a hard mandrel, and an oily lubricant is uniformly coated on the surface of the hard mandrel. The hard mandrel is inserted into the pipe blank to obtain an assembly. The assembly is deformed by using a hot drawing method. The hot drawing temperature is 800°C, and the speed is 5 m / min. The single pass deformation amount is controlled to be 10%. When the total deformation amount reaches 40%, the pipe is subjected to intermediate annealing. The annealing temperature is 750°C, and the time is 1 min. The process is repeated multiple times to obtain a pipe blank with an outer diameter of 4.0 mm and an inner diameter of 3.68 mm.

[0149] Step S6, red copper is used as a soft mandrel, and molybdenum disulfide is uniformly coated on the surface of the soft mandrel. The soft mandrel is inserted into the pipe blank to obtain an assembly. The assembly is continuously cold drawn by using a room temperature drawing device. The single pass deformation amount is controlled to be 15%. When the total deformation amount reaches 45%, the assembly is subjected to intermediate annealing. The annealing temperature is 620°C, and the time is 1 min. The process is repeated multiple times to obtain an assembly with an outer diameter of 2.0 mm and an inner diameter of 1.71 mm. Then, the soft mandrel is removed to obtain a pipe.

[0150] Step S7, unlike the above-mentioned embodiments, in this comparative example, the pipe material is subjected to heat treatment, and the process parameters are a temperature of 500 DEG C and a time of 50 min.

[0151] Step S8, the outer surface of the pipe material is subjected to centerless grinding, and then the pipe material is subjected to electrochemical polishing, the polishing solution is composed of 21% by volume of perchloric acid (HCLO4, content 70.0-70.2%) and 79% of glacial acetic acid (CH3COOH, content not less than 99.5%), electrolytic polishing is carried out at a constant voltage of 10 V and room temperature, and the time is 6 min, the roughness of the outer surface of the polished pipe material is 0.30 μm, and the roughness of the inner surface is 0.82 μm.

[0152] Step S9, the nickel-titanium alloy pipe material is cut to a length of 120 mm, and then subjected to femtosecond laser cutting, the pulse width is set to 100 fs, the pulse energy is 80 μJ, the pulse repetition frequency is 100 kHz, the cutting speed is 0.8 mm / s, the cutting is carried out under helium, the heat treatment setting temperature after cutting is 540 DEG C, the time is 25 min, and then the cooling method is furnace cooling, and finally the finished nickel-titanium alloy nasolacrimal duct stent is obtained.

[0153] The following Table 1 is the performance test results of the nickel-titanium alloy pipe material obtained by the three embodiments and the four comparative examples of the present application.

[0154]

[0155] From the above comparative performance test results, it can be seen that the nickel-titanium alloy nasolacrimal duct stent produced by the processing and preparation method of the novel nickel-titanium alloy nasolacrimal duct stent of the present application has more excellent tensile strength, upper platform strength and lower platform strength, higher uniform strain and lower residual strain, lower outer surface roughness and inner surface roughness, which proves that the nickel-titanium alloy nasolacrimal duct stent produced by the present application has good flexibility and supporting force, and meets the requirements of the nasolacrimal duct stent for the performance of the raw material.

[0156] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A novel method for fabricating a nickel-titanium alloy nasolacrimal duct stent, characterized in that, Includes the following steps: S1. Obtain nickel-titanium alloy bars and straighten them to form straight bars; S2. The straight bar is mechanically drilled to form a rough tube blank; S3. Polish the inner and outer surfaces of the rough tube blank; S4. Insert a hard mandrel into the rough tube blank to obtain an assembly. Perform cold rolling deformation on the assembly. The deformation amount in a single pass is less than 13%. After the deformation amount is 25%-50%, perform intermediate vacuum annealing. After multiple cycles, a tube blank with a diameter of Φ4.0-8.0mm is formed. S5. Insert the hard mandrel into the tube blank to obtain an assembly. Perform hot drawing deformation on the assembly. The deformation amount in a single pass is less than 15%. After the deformation amount is 30%-60%, perform intermediate annealing. After multiple cycles, a tube blank with a diameter of Φ1.0-4.0mm is formed. S6. Insert a soft mandrel coated with molybdenum disulfide lubricant into the tube blank to obtain an assembly. Perform cold drawing deformation on the assembly, with a single-pass deformation amount of less than 20%. After the deformation amount is 30%-60%, perform intermediate annealing. After multiple cycles, an assembly with a diameter of Φ0.25-2.0mm is formed. Then, perform core pulling on the assembly to obtain a tube with a diameter of Φ0.25-2.0mm. S7. The pipe is heat-treated using a multi-process coupling method of electric pulse treatment and aging treatment, wherein the pulse frequency of the electric pulse treatment is 150Hz-300Hz. S8. Perform centerless grinding on the pipe and electrochemical polishing on the pipe; S9. The tube is laser-cut and then subjected to vacuum heat treatment at a temperature of 400℃-600℃ for 10-50 minutes. After cooling, a novel nickel-titanium alloy nasolacrimal duct stent is obtained.

2. The method for processing and preparing the novel nickel-titanium alloy nasolacrimal duct stent according to claim 1, characterized in that, The nickel-titanium alloy bar stock in step S1 is prepared according to the following mass percentages: Ni 54.5-57.0%, C≤0.04%, Co≤0.05%, Cu≤0.01%, Cr≤0.01%, H≤0.005%, Fe≤0.05%, Nb≤0.025%, N≤0.005%, O≤0.04%, with the balance being Ti; The nickel-titanium alloy bar has a fixed length of 1-4m. After being cut to the fixed length, it is straightened using a straightening device. The straightness after straightening is no more than 0.5mm / m.

3. The method for processing and preparing the novel nickel-titanium alloy nasolacrimal duct stent according to claim 1, characterized in that, In step S2, before mechanically drilling the straight bar, the straight bar after straightening is further processed into a fixed length.

4. The method for processing and preparing the novel nickel-titanium alloy nasolacrimal duct stent according to claim 1, characterized in that, In step S3, the inner and outer surfaces of the rough tube blank are polished using a mechanical polishing device. The roughness of the inner surface after polishing is no greater than 1.6 μm, and the roughness of the outer surface is no greater than 1.0 μm.

5. The method for processing and preparing the novel nickel-titanium alloy nasolacrimal duct stent according to claim 1, characterized in that, In step S8, when electrochemically polishing the pipe, the polishing solution is composed of 15-25% perchloric acid and 75-85% glacial acetic acid by volume, the constant voltage is 5-20V, the electrolytic polishing is carried out at room temperature, the polishing time is 1-30 minutes, and the roughness of the inner surface after polishing is less than 1.0μm and the roughness of the outer surface is less than 0.5μm.

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