A homogenized titanium alloy rod for medical ultrasonic scalpel and its preparation method and application

Abstract

The present invention discloses a homogenized titanium alloy rod for medical ultrasonic scalpel, and its preparation method and application, belonging to the technical field of titanium alloy materials. The titanium alloy rod includes the following mass percentage components: Al: 5.89-6.30%, V: 3.90-4.25%, Fe: <0.20%, B: <0.02%, O: 0.09-0.12%, N: <0.0040%, H: <0.0010%, inevitable impurities: ≤0.003%, and the balance is Ti. The medical titanium alloy rod of the present invention has a tensile strength of 930-1020MPa, a yield strength of 890-980MPa, an elongation of 20-35%, and a cross-sectional reduction rate of 28-34%. Under the conditions of 55.5KHz and 550Mpa stress amplitude, its fatigue life can reach 10 7 The titanium alloy rod of the present invention has excellent mechanical properties and can be applied to the manufacture of medical ultrasonic scalpels.

Description

Technical Field

[0001] The invention belongs to the technical field of titanium alloy materials, and more specifically relates to a homogenized titanium alloy rod for medical ultrasonic scalpels and a preparation method and application thereof. Background Art

[0002] Ultrasonic scalpel is a newly developed surgical instrument commonly used in surgical operations in recent years. High-intensity focused ultrasound, after being converted into high-frequency ultrasonic oscillation by a converter, vaporizes the tissue and breaks the protein hydrogen bonds, thereby completely disintegrating the tissue that needs to be cut during the operation. Among them, the production of the blade material of the ultrasonic scalpel is one of the key technologies. Ultrasonic scalpel has incomparable characteristics and advantages over traditional manual and electric surgical instruments. On the one hand, it can be set to the corresponding frequency of the tissue, so that the ultrasonic scalpel will only act on the tissue when it contacts the human body, without damaging other tissues, blood vessels and nerves, so as to achieve precise cutting, which greatly improves the safety and reliability of the operation. On the other hand, it can achieve low-temperature cutting without damaging other tissue cells, and can be used in tumor cutting operations in important human organs, so it is more and more widely used in surgical operations.

[0003] The operating frequency of ultrasonic scalpels commonly used in clinical practice is 55.5kHz, and the output amplitude is above 50mm. The high operating frequency and large amplitude can easily cause fatigue, resulting in the breakage of the scalpel head. However, during minimally invasive surgery, once the scalpel breaks, it is difficult to remove the broken fragments in time, posing a serious safety hazard. At present, the most commonly used material for ultrasonic scalpels is TC4 titanium alloy, which is usually prepared by multiple arc melting-forging-rolling-drawing-heat treatment processes, but it can no longer meet the high performance requirements of ultrasonic scalpels. The consistency, stability and uniformity of the titanium alloy composition must be fundamentally improved.

[0004] Therefore, how to develop a homogenized titanium alloy rod for medical ultrasonic scalpel and its preparation method and application is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] In view of this, the present invention provides a homogenized titanium alloy rod for a medical ultrasonic scalpel, and a preparation method and application thereof.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A homogenized titanium alloy rod for medical ultrasonic scalpel comprises the following components by mass percentage: Al: 5.89-6.30%, V: 3.90-4.25%, Fe: <0.20%, B: <0.02%, O: 0.09-0.12%, N: <0.0040%, H: <0.0010%, unavoidable impurities: ≤0.003%, and the balance is Ti.

[0008] Beneficial effects of the present invention: The homogenized titanium alloy rod for medical ultrasonic scalpel of the present invention has a tensile strength of 930-1020MPa, a yield strength of 890-980MPa, an elongation of 20-35%, and a cross-sectional shrinkage of 28-34%. Under the conditions of 55.5KHz and 550Mpa stress amplitude, its fatigue life can reach 10 7 The titanium alloy rod of the present invention has excellent mechanical properties and can be applied to the manufacture of medical ultrasonic scalpels.

[0009] The present invention also provides a method for preparing the homogenized titanium alloy rod for medical ultrasonic scalpel, comprising the following steps:

[0010] (1) pure titanium, pure aluminum and Al-V master alloy are subjected to vacuum suspension induction melting in a water-cooled copper crucible to obtain a master alloy ingot, wherein the mass fraction of V in the Al-V master alloy is 65-85%, and the master alloy ingot comprises the following components by mass percentage: Al: 29-31%, V: 19-21%, O<0.07%, N<0.004%, H<0.0010%, Fe<0.030%, B<0.05%, and the balance is Ti;

[0011] (2) melting the master alloy ingot and sponge titanium in a water-cooled copper crucible in a vacuum consumable arc, and repeatedly melting for 3 times to obtain a titanium alloy rod ingot with a diameter of 380-480 mm;

[0012] (3) forging the titanium alloy bar ingot at high temperature to form a blank, and then fine forging to obtain a titanium alloy forging blank;

[0013] (4) hot rolling the titanium alloy forging blank for multiple passes to obtain a titanium alloy bar;

[0014] (5) The titanium alloy rod is subjected to multiple drawing, solution treatment, aging treatment, and polishing to obtain a homogenized titanium alloy rod for medical ultrasonic scalpel with a diameter of 2-6 mm.

[0015] Beneficial effects of the present invention: The present invention reduces the content of aluminum to about 6% and vanadium to about 4% of the finished ingot by melting the master alloy with about 30% aluminum and about 20% vanadium through vacuum consumable melting of sponge titanium. The advantages of this are: through melting the master alloy, the impurities of the vanadium-aluminum intermediate alloy produced by the aluminothermic method are further reduced and the uniformity is improved, that is, the uniformity and consistency of the alloy composition of the finished titanium alloy ingot can be guaranteed. This is different from other traditional titanium alloy ingots, which are directly produced by the aluminothermic method. The vanadium-aluminum intermediate alloy is directly added to the sponge titanium and melted in a vacuum consumable furnace. This is one of the core technologies of the present invention. The vanadium-aluminum intermediate alloy produced by the aluminothermic method is produced by reducing vanadium oxide with aluminum in an atmospheric environment, so the impurity content of C, N, H, and O is high, and it is unstable and uneven. Therefore, the method of domestic production enterprises to directly add the impurities is an important reason for the instability of the quality of high-quality titanium alloys. The present invention is manufactured by the "two-step method". The vacuum suspension induction furnace can be used for refining and the electromagnetic stirring of the entire metal liquid, which can ensure the complete homogenization of the alloy composition and the removal of impurities.

[0016] The present invention adopts vacuum suspension induction melting technology to prepare a master alloy ingot with uniform composition, and then uses vacuum consumable arc melting technology to obtain an ingot with uniform tissue composition after three repeated meltings. Then the titanium alloy bar ingot is subjected to a high-temperature forging, blanking, hot rolling and drawing process to prepare a homogenized titanium alloy bar for medical ultrasonic scalpel. On the one hand, a titanium alloy ingot with uniform composition is obtained. On the other hand, by regulating the thermoplastic forming and heat treatment processes, the microstructure of the titanium alloy bar is optimized, and a titanium alloy bar with excellent mechanical properties is obtained to meet the service requirements of the ultrasonic scalpel.

[0017] Furthermore, in step (1), the above-mentioned water-cooled copper crucible vacuum suspension induction melting is used, the melting power is 80-500KW, the vacuum degree is 1-6Pa, the melting time is 30-45 minutes, the ingot is vacuum cooled in the furnace to below 100°C, the vacuum is broken and the ingot is taken out of the furnace, and the ingot is turned and peeled to obtain a master alloy ingot.

[0018] The beneficial effect of adopting the above-mentioned further technical scheme is as follows: since the vacuum suspension furnace can be refined under high vacuum, C and other low melting point impurities in the vanadium-aluminum intermediate alloy can be removed. C in the titanium alloy has a great influence on the plasticity and toughness of the material. The vanadium-aluminum intermediate alloy manufactured directly by the aluminothermic method without melting the master alloy in a vacuum suspension furnace is directly melted in a vacuum consumable furnace to manufacture titanium alloy bars. The main component is very likely to produce regional micro-segregation, and the content of impurities such as C cannot be controlled, resulting in poor consistency of mechanical properties.

[0019] Furthermore, in step (2), the vacuum degree of the water-cooled copper crucible vacuum consumable arc melting is less than 1-3Pa, the melting current is 8000-30000A, and the melting voltage is 20-40V.

[0020] Furthermore, in step (3), the forging temperature of the high temperature forging is 890-1080°C, and the total deformation is greater than 80%; the forging temperature of the fine forging is 890-910°C, and the total deformation is greater than 60%.

[0021] Furthermore, in step (4), the hot rolling temperature is 880-900° C., the deformation per pass is greater than 20%, and the total deformation is greater than 95%.

[0022] Furthermore, in step (5), the drawing temperature is 600-780°C, the deformation per pass is greater than 15%, and the total deformation is greater than 90%.

[0023] Furthermore, in step (5), the solution treatment temperature is 890-950°C, the solution treatment holding time is 30 minutes, air cooling, cooling rate>30°C / s, aging treatment temperature is 550-680°C, aging treatment holding time is 3 hours, and furnace cooling to room temperature.

[0024] The beneficial effect of adopting the above further technical solution is that the heat treatment process plays an important role in ensuring the organizational stability and consistency of mechanical properties of the rod.

[0025] The present invention also provides an application of the homogenized titanium alloy rod for medical ultrasonic scalpel in the preparation of medical ultrasonic scalpel.

[0026] The beneficial effects of the present invention are as follows: due to good fatigue strength and mechanical stability, the service life is 50-80 times, and the price is about 30% of the imported products. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a metallographic structure morphology diagram of the titanium alloy bar ingot in Example 1 of the present invention;

[0028] Figure 2 This is a microstructure morphology diagram of the titanium alloy forging blank in Example 1 of the present invention;

[0029] Figure 3 This is a microstructure morphology diagram of the titanium alloy bar in Example 1 of the present invention;

[0030] Figure 4 This is a microstructure morphology diagram of the homogenized titanium alloy rod for traditional Chinese medical ultrasonic scalpel according to Example 1 of the present invention. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In the embodiment of the present invention, the purity of pure titanium is 99.9%, and the purity of pure aluminum is 99.99%.

[0033] The titanium sponge adopts grade 0 titanium sponge.

[0034] The Al-V master alloy was purchased from Baoti Group, with the mass fraction of V being 65-85% and the remainder being Al.

[0035] The device used for observing the metallographic structure in the embodiment of the present invention is a GX71 inverted system metallographic microscope produced by OLYMPUS.

[0036] The standard adopted for the tensile test in the embodiment of the present invention is the national standard GB / T228-2002 "Method for tensile test of metallic materials at room temperature", and the equipment is the AG-X100kN electronic universal material testing machine produced by Shimadzu Corporation.

[0037] Example 1

[0038] The target is to prepare a homogenized titanium alloy rod for medical ultrasonic scalpel, which includes the following components by mass percentage: Al: 6.10%, V: 4.12%, and the balance is Ti.

[0039] The preparation method comprises the following steps:

[0040] (1) pure titanium, pure aluminum and Al-V master alloy are subjected to vacuum suspension induction melting in a water-cooled copper crucible, with a melting power of 80 kW, a vacuum degree of 1 Pa, and a melting time of 30 minutes. The ingot is vacuum cooled in the furnace to below 100° C. and then taken out of the furnace after breaking the vacuum. The ingot is turned and peeled to obtain a master alloy ingot. The mass fraction of V in the Al-V master alloy is 65-85%. The master alloy ingot comprises the following components by mass percentage: Al: 29-31%, V: 19-21%, O<0.07%, N<0.004%, H<0.0010%, Fe<0.030%, B<0.05%, and the balance is Ti;

[0041] (2) The master alloy ingot and sponge titanium are melted by vacuum consumable arc melting in a water-cooled copper crucible, with a melting vacuum degree of <2 Pa, a melting current of 12000 A, a melting voltage of 35 V, and the melting is repeated 3 times to obtain a titanium alloy rod ingot with a diameter of 420 mm;

[0042] (3) subjecting the titanium alloy bar ingot to high temperature forging, the forging temperature being 1000° C., and the total deformation being 85%; and then fine forging, the forging temperature being 900° C., and the total deformation being 70%, to obtain a titanium alloy forging billet;

[0043] (4) performing multiple hot rolling on the titanium alloy forging billet, the hot rolling temperature is 890° C., the pass deformation is 23%, and the total deformation is 96%, to obtain a titanium alloy bar;

[0044] (5) The titanium alloy rod is subjected to multi-pass drawing, the drawing temperature is 640°C, the pass deformation is 18%, the total deformation is 96%, the solution treatment, the aging treatment, the solution treatment temperature is 890°C, the solution treatment holding time is 30 minutes, the air cooling, the cooling rate is >30°C / s, the aging treatment temperature is 550°C, the aging treatment holding time is 3 hours, the furnace is cooled to room temperature, and the polishing is performed to obtain a homogenized titanium alloy rod with a diameter of 5 mm for medical ultrasonic scalpel.

[0045] The actual composition of the homogenized titanium alloy rod for medical ultrasonic scalpel, calculated by mass percentage, includes the following components: Al: 6.05%, V: 4.10%, Fe: 0.10%, B: 0.015%, O: 0.105%, N: 0.0023%, H: 0.00040%, unavoidable impurities: 0.0023%, and the balance is Ti.

[0046] The tensile strength of the homogenized titanium alloy rod for medical ultrasonic scalpel is 1000MPa, the yield strength is 930MPa, the elongation is 28%, and the cross-sectional shrinkage is 30%. Under the conditions of 55.5KHz and 550Mpa stress amplitude, its fatigue life can reach 3.5×10 7 .

[0047] Example 2

[0048] The target prepared homogenized titanium alloy rod for medical ultrasonic scalpel includes the following components by mass percentage: Al: 6.35%, V: 4.28%, and the balance is Ti.

[0049] The preparation method comprises the following steps:

[0050] (1) Pure titanium, pure aluminum and Al-V master alloy are melted by vacuum suspension induction melting in a water-cooled copper crucible, with a melting power of 500 kW, a vacuum degree of 6 Pa, and a melting time of 45 minutes. The ingot is vacuum cooled in the furnace to below 100° C. and then taken out of the furnace after breaking the vacuum. The ingot is turned and peeled to obtain a master alloy ingot. The mass fraction of V in the Al-V master alloy is 65-85%. The master alloy ingot includes the following components by mass percentage: Al: 29-31%, V: 19-21%, O<0.07%, N<0.004%, H<0.0010%, Fe<0.030%, B<0.05%, and the balance is Ti;

[0051] (2) The master alloy ingot and sponge titanium are melted by vacuum consumable arc melting in a water-cooled copper crucible, with a melting vacuum degree of <1 Pa, a melting current of 30000 A, a melting voltage of 40 V, and the melting is repeated 3 times to obtain a titanium alloy rod ingot with a diameter of 480 mm;

[0052] (3) high temperature forging the titanium alloy bar ingot to open the blank, the forging temperature is 1080° C., and the total deformation is 95%; then fine forging is performed, the forging temperature is 910° C., and the total deformation is 85%, to obtain a titanium alloy forging blank;

[0053] (4) performing multiple hot rolling on the titanium alloy forging billet, the hot rolling temperature is 900° C., the pass deformation is 27%, and the total deformation is 97%, to obtain a titanium alloy bar;

[0054] (5) The titanium alloy rod is subjected to multi-pass drawing, the drawing temperature is 750°C, the pass deformation is 20%, the total deformation is 95%, solution treatment, aging treatment, the solution treatment temperature is 950°C, the solution treatment holding time is 30 minutes, air cooling, the cooling rate is >30°C / s, the aging treatment temperature is 680°C, the aging treatment holding time is 3 hours, and the rod is cooled to room temperature in the furnace and polished to obtain a homogenized titanium alloy rod with a diameter of 3 mm for medical ultrasonic scalpel.

[0055] The actual composition of the homogenized titanium alloy rod for medical ultrasonic scalpel, calculated by mass percentage, includes the following components: Al: 6.30%, V: 4.24%, Fe: 0.16%, B: 0.017, O: 0.112%, N: 0.0032%, H: 0.00060%, unavoidable impurities: 0.0025%, and the balance is Ti.

[0056] The tensile strength of homogenized titanium alloy rods for medical ultrasonic scalpels is 1020MPa, the yield strength is 980MPa, the elongation is 21%, and the cross-sectional shrinkage is 29%. Under the conditions of 55.5KHz and 550Mpa stress amplitude, its fatigue life can reach 6×10 7 .

[0057] Example 3

[0058] The target prepared homogenized titanium alloy rod for medical ultrasonic scalpel includes the following components by mass percentage: Al: 6.05%, V: 4.11%, and the balance is Ti.

[0059] The preparation method comprises the following steps:

[0060] (1) pure titanium, pure aluminum and Al-V master alloy are melted by vacuum suspension induction melting in a water-cooled copper crucible, with a melting power of 300 kW, a vacuum degree of 4 Pa, and a melting time of 35 minutes. The ingot is vacuum cooled in the furnace to below 100° C. and then taken out of the furnace after breaking the vacuum. The ingot is turned and peeled to obtain a master alloy ingot. The mass fraction of V in the Al-V master alloy is 65-85%. The master alloy ingot includes the following components by mass percentage: Al: 29-31%, V: 19-21%, O<0.07%, N<0.004%, H<0.0010%, Fe<0.030%, B<0.05%, and the balance is Ti;

[0061] (2) The master alloy ingot and sponge titanium are melted by vacuum consumable arc melting in a water-cooled copper crucible, with a melting vacuum degree of less than 3 Pa, a melting current of 8000 A, and a melting voltage of 20 V, and the melting is repeated 3 times to obtain a titanium alloy rod ingot with a diameter of 380 mm;

[0062] (3) high temperature forging the titanium alloy bar ingot to open the blank, the forging temperature is 890° C., and the total deformation is 85%; then fine forging is performed, the forging temperature is 890° C., and the total deformation is 75%, to obtain a titanium alloy forging blank;

[0063] (4) performing multiple hot rolling on the titanium alloy forging billet, the hot rolling temperature is 880° C., the pass deformation is 24%, and the total deformation is 96%, to obtain a titanium alloy bar;

[0064] (5) The titanium alloy rod is subjected to multi-pass drawing, the drawing temperature is 600°C, the pass deformation is 18%, the total deformation is 96%, solution treatment, aging treatment, the solution treatment temperature is 900°C, the solution treatment holding time is 30 minutes, air cooling, the cooling rate is >30°C / s, the aging treatment temperature is 600°C, the aging treatment holding time is 3 hours, and the rod is cooled to room temperature in the furnace and polished to obtain a homogenized titanium alloy rod with a diameter of 2 mm for medical ultrasonic scalpel.

[0065] The actual composition of the homogenized titanium alloy rod for medical ultrasonic scalpel, calculated by mass percentage, includes the following components: Al: 5.98%, V: 4.01%, Fe: 0.10%, B: 0.011%, O: 0.102%, N: 0.0022%, H: 0.00030%, unavoidable impurities: 0.0020%, and the balance is Ti.

[0066] The tensile strength of homogenized titanium alloy rods for medical ultrasonic scalpels is 930MPa, the yield strength is 890MPa, the elongation is 32%, and the cross-sectional shrinkage is 34%. Under the conditions of 55.5KHz and 550Mpa stress amplitude, its fatigue life can reach 5×10 7 .

[0067] Methods for comparing the uniformity and consistency of materials are:

[0068] Three bars of each example were randomly sampled to test the composition and mechanical properties. The error of the main component of the present invention was controlled within 1 / 10,000, which is much higher than the national standard GB / T 3620.2-2023 titanium and titanium alloy processing products chemical composition allowable deviation, indicating that the uniformity of the composition is good. The composition determines the organization, and the organization determines the performance. Therefore, for medical high-end titanium alloys, the uniformity of the composition is the decisive factor that ultimately affects the quality of titanium alloy bars. The "two-step method" smelting used in the present invention affects the quality of bars for ultrasonic knives. Due to the good uniformity of the composition, fine grains, good strength and hardness, the transmission efficiency and accuracy of ultrasonic waves of the ultrasonic knife will be greatly improved, and the anti-fatigue performance will be improved, so the service life and application effect of the ultrasonic knife can be improved.

[0069] The mechanical properties illustrate the consistency of the titanium alloy rods. Three rod samples are randomly selected from each embodiment, and the mechanical properties of the three rods in each embodiment are exactly the same.

[0070] The disclosed embodiments are described to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a homogenized titanium alloy rod for medical ultrasonic scalpel, characterized in that: The following steps are involved: (1) pure titanium, pure aluminum and Al-V master alloy are subjected to vacuum suspension induction melting in a water-cooled copper crucible to obtain a master alloy ingot, wherein the mass fraction of V in the Al-V master alloy is 65-85%, and the master alloy ingot comprises the following components by mass percentage: Al: 29-31%, V: 19-21%, O<0.07%, N<0.004%, H<0.0010%, Fe<0.030%, B<0.05%, and the balance is Ti; (2) melting the master alloy ingot and sponge titanium in a water-cooled copper crucible in a vacuum consumable arc, and repeatedly melting for 3 times to obtain a titanium alloy rod ingot with a diameter of 380-480 mm; (3) forging the titanium alloy bar ingot at high temperature to form a blank, and then fine forging to obtain a titanium alloy forging blank; (4) hot rolling the titanium alloy forging blank for multiple passes to obtain a titanium alloy bar; (5) subjecting the titanium alloy rod to multiple drawing, solution treatment, aging treatment, and polishing to obtain a homogenized titanium alloy rod for medical ultrasonic scalpel with a diameter of 2-6 mm; In step (1), the vacuum suspension induction melting is carried out in a water-cooled copper crucible, the melting power is 80-500KW, the vacuum degree is 1-6Pa, the melting time is 30-45 minutes, the ingot is vacuum-cooled in the furnace to below 100°C, the vacuum is broken and the ingot is taken out of the furnace, and the ingot is turned and peeled to obtain a master alloy ingot; In step (5), the solution treatment temperature is 890-950°C, the solution treatment holding time is 30 minutes, air cooling, cooling rate>30°C / s, aging treatment temperature is 550-680°C, aging treatment holding time is 3 hours, and furnace cooling to room temperature; The homogenized titanium alloy rod for medical ultrasonic scalpel includes the following components by mass percentage: Al: 5.89-6.30%, V: 3.90-4.25%, Fe: <0.20%, B: <0.02%, O: 0.09-0.12%, N: <0.0040%, H: <0.0010%, unavoidable impurities: ≤0.003%, and the balance is Ti.

2. The method for preparing a homogenized titanium alloy rod for medical ultrasonic scalpel according to claim 1, characterized in that: In step (2), the vacuum degree of the water-cooled copper crucible vacuum consumable arc melting is less than 1-3Pa, the melting current is 8000-30000A, and the melting voltage is 20-40V.

3. The method for preparing a homogenized titanium alloy rod for medical ultrasonic scalpel according to claim 1, characterized in that: In step (3), the forging temperature of the high temperature forging is 890-1080°C, and the total deformation is greater than 80%; the forging temperature of the precision forging is 890-910°C, and the total deformation is greater than 60%.

4. The method for preparing a homogenized titanium alloy rod for medical ultrasonic scalpel according to claim 1, characterized in that: In step (4), the hot rolling temperature is 880-900° C., the deformation per pass is greater than 20%, and the total deformation is greater than 95%.

5. The method for preparing a homogenized titanium alloy rod for medical ultrasonic scalpel according to claim 1, characterized in that: In step (5), the drawing temperature is 600-780°C, the deformation per pass is greater than 15%, and the total deformation is greater than 90%.

6. Use of the homogenized titanium alloy rod for medical ultrasonic scalpel according to claim 1 in the preparation of medical ultrasonic scalpel.

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