CNTs modified anti-sticking silver-nickel alloy

Abstract

The invention relates to a CNTs modified anti-sticking silver-nickel alloy, which comprises the following components in percentage by mass: 4.0-5.5% of Ni; 0.03-0.2 part of a rare earth element and an oxide thereof; 0.1 to 0.5 part of CNTs (carbon nanotubes); and the balance being Ag. Compared with a common silver-nickel alloy, the alloy disclosed by the invention is added with the CNTs, the rare earth elements and the oxides of the rare earth elements with specific contents, so that on one hand, the alloy has high mechanical property and the service life is prolonged, and on the other hand, the anti-arc characteristic of the CNTs and a structure different from carbon deposition are utilized; and therefore, tissue adhesion, carbon deposition and the like in contact with the alloy are reduced. Besides, due to the existence of the rare earth and the CNTs, the interface of the silver-nickel alloy is not coherent, and tissue adhesion and carbon deposition are also not coherent, so that the alloy is easier to wipe and clean while the tissue adhesion and the carbon deposition are reduced.

Description

Technical Field

[0001] The invention relates to a modified anti-adhesion conductive alloy, which is particularly suitable for being used as a high-frequency electric knife head material. Background Art

[0002] High-frequency electrosurgical knife is an electrosurgical instrument that replaces mechanical scalpels for tissue cutting. It heats the tissue when it contacts the body through the high-frequency and high-voltage current generated by the effective electrode tip, achieving the separation and coagulation of body tissue, thereby achieving the purpose of cutting and hemostasis. Compared with traditional cold scalpels, high-frequency electrosurgical knife has better hemostasis performance and cutting effect.

[0003] High-frequency electrosurgical unit electrodes are mostly made of stainless steel, which has good electrical and thermal conductivity, but there are the following problems in clinical use: blood and grease are easily accumulated on the surface of the blade. Under the high temperature of the electrosurgical unit, blood and grease are carbonized and easily accumulated on the surface of the blade. Therefore, during the operation, it is necessary to repeatedly scrape the carbon deposits on the blade with a blade, which affects the progress of the operation and wastes operation time. Surgeons often need to wipe the electrosurgical unit once every 2-3 minutes for each operation. CN102090923A discloses a surgical device, the surface of which is treated with CVD or PVD coating to reduce adhesion / adhesion during the operation. However, this special surface treatment step makes the entire production process more complicated and increases the cost. Summary of the invention

[0004] The object of the present invention is to provide a modified anti-stick conductive alloy which is particularly suitable for high-frequency electric knife heads.

[0005] According to one aspect of the present invention, there is provided a modified anti-stick conductive alloy, the mass percentage composition of which is:

[0006] Ni: 4.0-5.5; rare earth elements and their oxides: 0.03-0.2; CNTs: 0.1-0.5; the balance is Ag (and unavoidable impurities).

[0007] According to the alloy of the present invention, the rare earth element may be selected from at least one of Y, Ce, Tn and La; preferably Y, Ce, and / or La; more preferably, the content of each rare earth element is less than 0.1 wt.%.

[0008] According to the alloy of the present invention, the content of CNTs (carbon nanotubes) is preferably 0.2 to 0.4 wt. % and the content of nickel in the alloy is preferably 4.5 to 4.9 wt. %.

[0009] Compared with ordinary silver-nickel alloy, the alloy of the present invention has high mechanical properties and improves service life (improved by more than 3 times) due to the addition of specific content of CNTs and rare earth elements and their oxides. On the other hand, the arc resistance of CNTs and its structure different from carbon deposition are used to reduce tissue adhesion and carbon deposition in contact with the alloy. In addition, due to the presence of rare earth and CNTs, the interface of the silver-nickel alloy is discontinuous, resulting in discontinuous tissue adhesion and carbon deposition, so that the alloy is easier to wipe and clean while reducing tissue adhesion and carbon deposition.

[0010] According to another aspect of the present invention, there is also provided a method for preparing alloy filaments for a high-frequency electric knife head, comprising:

[0011] A rare earth Ag powder with an average particle size of 20 to 74 μm is formed by a water mist method, wherein the rare earth element and its oxide are 0.03 to 0.2 wt.%, and the balance is Ag;

[0012] Adding rare earth Ag powder to nickel nitrate aqueous solution, adding ammonia water to adjust the pH of the reaction system to 8.8-9.8, and then reacting at a pressure of 5.5-7 MPa and 70-85° C. for 2-3 hours to generate a precipitate;

[0013] The obtained precipitate is separated, washed, filtered, dried, ground, and then calcined at 700-750° C. for 2.5-3.5 hours to obtain Ag / Ni composite rare earth powder, wherein the Ni content is 4.0-5.5 wt.%;

[0014] Vapor-depositing CNTs on Ag / Ni composite rare earth powder to obtain CNTs / Ag-Ni composite rare earth powder, wherein the CNTs content is 0.1-0.5wt.%;

[0015] Pressing the CNTs / Ag-Ni composite rare earth powder into a rod alloy;

[0016] Vacuum sintered bar alloy, where the sintering vacuum is less than 1*10 -2 , the sintering temperature is controlled at 950℃~1150℃, and the sintering holding time is 2h~4h; and

[0017] The alloy wires of corresponding sizes are produced by hot extrusion and drawing the vacuum sintered rod alloy.

[0018] According to the preparation method of the present invention, the vapor deposition may include: heating the Ag / Ni composite rare earth powder to 630-720°C under argon protection, and then introducing 700-1300 ml / min of H 2 , 40~90ml / min C 2 H 4 , keep warm for 20 to 70 minutes.

[0019] According to the preparation method of the present invention, the pressing molding is preferably divided into two steps of cold pressing and cold isostatic pressing. The cold pressing pressure is preferably 300-350 MPa. The cold isostatic pressing pressure is preferably 400-450 MPa, and the holding time can be 70-100 s.

[0020] According to the preparation method of the present invention, the hot extrusion preferably adopts forward extrusion, and the extrusion ratio is controlled to be less than 12.

[0021] According to the preparation method of the present invention, during the argon protection and heating process, the trace oxygen element in the argon gas can partially oxidize the rare earth elements into rare earth oxides through internal oxidation. Due to the presence of CNTs and rare earth and its oxides, the dispersion strengthening effect is obtained, and the strength and mechanical properties of the alloy are significantly increased without significantly reducing the electrical and thermal conductivity of the alloy material.

[0022] According to the preparation method of the present invention, Ni is uniformly distributed on the surface of Ag particles by chemical deposition. On the one hand, the uniform distribution of Ni in the alloy composite material is achieved, and the performance of the silver-nickel composite material is improved; on the other hand, the uniformly distributed Ni, as a catalyst, can promote the synthesis of CNTs, and make the in-situ synthesized CNTs uniformly distributed, which can better play the role of electron transmission and energy transmission. In addition, the present invention can regulate the synthesis amount of CNTs by precise control of CVD process parameters, which not only ensures the uniform distribution of CNTs, but also realizes the quantitative addition of CNTs. In addition, due to the super hydrophobic properties of CNTs, the surface hydrophobicity of the alloy composite material can be greatly increased, thereby reducing the adhesion to biological tissues, oils and fats, etc.

[0023] The alloy preparation method of the present invention has simple process, environmental protection and safety, short production cycle, low energy consumption, low cost and simple operation, and is more suitable for industrial production.

[0024] According to another aspect of the present invention, there is also provided a high-frequency electric knife, which is at least partially made of the above alloy.

[0025] According to the high-frequency electric knife of the present invention, the discharge part of the electrode tip is concentrated, which can significantly reduce the diameter of the working tip, make the cutting rapid, and make the wound small, so as to achieve fine cutting; in addition, the thermal damage area is small, which can effectively reduce the damage to healthy tissue; in addition, there is less smoke during the operation and the field of vision is clearer. In addition, due to the presence of CNTs and rare earth and its oxides, the thermal electron emission ability of the high-frequency electric knife can be improved, the working temperature can be reduced, and the adhesion of tissue to the working tip can be reduced; at the same time, the polishing property of the working tip of the high-frequency electric knife can also be improved. The highly polished needle tip can effectively reduce the adhesion of tissue scorch during the cutting process, and the adhered scorch is also easier to wipe off with clean gauze, making the operation smoother and faster. DETAILED DESCRIPTION

[0026] The present invention will be further described below by taking the preparation of alloy filaments for electrocoagulation forceps as an example.

[0027] Example 1

[0028] Preparation of rare earth Ag powder: A rare earth Ag powder with an average particle size of 20 to 74 μm is formed by a water mist method, wherein Y is 0.05 wt.% and the balance is Ag.

[0029] Preparation of Ag / Ni composite rare earth powder: In an autoclave, 17.5 g of Ni(NO 3 ) 2 6H 2 O was dissolved in 100 ml of deionized water and stirred until the solution was completely clear, then 95.1 g of the above-mentioned rare earth-containing Ag powder was added, and ammonia water was slowly added to control the pH to 9. After reacting at a pressure of 6 MPa and 75°C for 2.5 hours, the precipitate was obtained by centrifugation. The obtained precipitate was washed with deionized water, filtered, dried, and ground, and finally calcined at 720°C for 3 hours to obtain Ag / Ni composite rare earth powder.

[0030] Preparation of CNTs / Ag-Ni composite rare earth powder: The Ag / Ni composite rare earth powder was placed in a chemical vapor deposition system: the temperature was raised to 650°C under argon protection, and then 800 ml / min of H 2 , 50ml / min C 2 H 4 , and keep warm for 30 minutes to obtain CNTs / Ag-Ni composite rare earth powder.

[0031] Molding rod alloy: The CNTs / Ag-Ni composite rare earth powder is loaded into a molding die for cold pressing and then further molded into a rod alloy (about 100 mm in diameter) by cold isostatic pressing; the cold pressing molding pressure is 300 MPa; the pressure medium of the cold isostatic pressing is oil, the molding pressure is 400 MPa, and the holding time is 80 s.

[0032] Sintered bar alloy: The bar alloy is sintered in a vacuum sintering furnace; the vacuum degree is 9.52*10 -3 The sintering temperature is controlled at 1000℃ and the sintering holding time is 3h.

[0033] Alloy filaments are obtained by extrusion and stretching: Alloy filaments of corresponding size (about 3 mm) are obtained by hot extrusion (forward extrusion, extrusion ratio controlled at 9) and drawing of the sintered rod alloy.

[0034] Example 2

[0035] Preparation of rare earth Ag powder: The rare earth Ag powder with an average particle size of 20 to 74 μm is formed by a water mist method, wherein Ce: 0.04 wt. %; La: 0.08 wt. %; and the balance is Ag.

[0036] Preparation of Ag / Ni composite rare earth powder: In an autoclave, 18.2 g of Ni(NO 3 ) 2 6H 2 O was dissolved in 100 ml of deionized water and stirred until the solution was completely clear, then 95.1 g of the above-mentioned rare earth-containing Ag powder was added, and ammonia water was slowly added to control the pH to 9.1. After reacting at a pressure of 6.5 MPa and 75°C for 2.5 hours, the precipitate was obtained by centrifugation. The obtained precipitate was washed with deionized water, filtered, dried, and ground, and finally calcined at 720°C for 3 hours to obtain Ag / Ni composite rare earth powder.

[0037] Preparation of CNTs / Ag-Ni composite rare earth powder: The Ag / Ni composite rare earth powder was placed in a chemical vapor deposition system: the temperature was raised to 680°C under argon protection, and then 1000 ml / min of H 2 , 70ml / min C 2 H 4 , and keep warm for 30 minutes to obtain CNTs / Ag-Ni composite rare earth powder.

[0038] Molding rod alloy: The CNTs / Ag-Ni composite rare earth powder is loaded into a molding die for cold pressing and then further molded into a rod alloy by cold isostatic pressing; wherein the cold pressing molding pressure is 350 MPa; the pressure medium of the cold isostatic pressing is oil, the molding pressure is 450 MPa, and the holding time is 80 s.

[0039] Sintered bar alloy: The bar alloy is sintered in a vacuum sintering furnace; the vacuum degree is 9.31*10 -3 The sintering temperature is controlled at 1050℃ and the sintering holding time is 3h.

[0040] Alloy filaments are obtained by extrusion and stretching: Alloy filaments of corresponding sizes are obtained by hot extrusion (forward extrusion, extrusion ratio controlled at 9) and drawing of the sintered rod alloy.

[0041] Example 3

[0042] Preparation of rare earth Ag powder: Use water mist method to form rare earth Ag powder with an average particle size of 20 to 74 μm, of which Y: 0.03 wt. %; Ce: 0.08 wt. %; La: 0.05 wt. %; and the balance is Ag.

[0043] Preparation of Ag / Ni composite rare earth powder: In an autoclave, 19 g of Ni(NO3 ) 2 6H 2 O was dissolved in 100 ml of deionized water and stirred until the solution was completely clear, then 94.7 g of the above-mentioned rare earth-containing Ag powder was added, and ammonia water was slowly added to control the pH to 9.5. After reacting at a pressure of 6.5 MPa and 79°C for 2.5 hours, the precipitate was obtained by centrifugation. The obtained precipitate was washed with deionized water, filtered, dried, and ground, and finally calcined at 720°C for 3 hours to obtain Ag / Ni composite rare earth powder.

[0044] Preparation of CNTs / Ag-Ni composite rare earth powder: The Ag / Ni composite rare earth powder was placed in a chemical vapor deposition system: the temperature was raised to 700°C under argon protection, and then 1200 ml / min of H 2 , 80ml / min C 2 H 4 , and keep warm for 60 minutes to obtain CNTs / Ag-Ni composite rare earth powder.

[0045] Molding rod alloy: The CNTs / Ag-Ni composite rare earth powder is loaded into a molding die for cold pressing and then further molded into a rod alloy by cold isostatic pressing; wherein the cold pressing molding pressure is 350 MPa; the pressure medium of the cold isostatic pressing is oil, the molding pressure is 450 MPa, and the holding time is 90 s.

[0046] Sintered bar alloy: The bar alloy is sintered in a vacuum sintering furnace; the vacuum degree is 9.47*10 -3 The sintering temperature is controlled at 1100℃ and the sintering holding time is 3h.

[0047] Alloy filaments are obtained by extrusion and stretching: Alloy filaments of corresponding sizes are obtained by hot extrusion (forward extrusion, extrusion ratio controlled at 8) and drawing the sintered rod alloy.

[0048] Table 1 shows the relevant physical properties of the alloy filaments prepared in Examples 1-3.

[0049] Table 1

[0050]

[0051] Table 2 shows the anti-adhesion performance indexes of the alloy filaments of Examples 1 to 3. The alloy filaments were processed into a high-frequency electric knife structure, connected to the power supply of the high-frequency electric knife to prepare a test version of the high-frequency electric knife, and the prepared high-frequency electric knife was used to test the pig's front leg for 20 minutes.

[0052] Table 2

[0053] Anti-adhesion performance Ordinary AgNi alloy A small amount of adhesion Example 1 No adhesion Example 2 No adhesion Example 3 No adhesion

Claims

1. A modified anti-stick conductive alloy, the mass percentage composition of which is: Ni: 4.0-5.5; rare earth elements and their oxides: 0.03-0.2; CNTs: 0.1-0.5; the balance is Ag.

2. The alloy according to claim 1, wherein the rare earth element is selected from at least one of Y, Ce, Tn and La.

3. A method for preparing alloy filaments for high-frequency electric knife heads, comprising: A rare earth Ag powder with an average particle size of 20 to 74 μm is formed by a water mist method, wherein the rare earth element and its oxide are 0.03 to 0.2 wt.%, and the balance is Ag; Adding rare earth Ag powder to nickel nitrate aqueous solution, adding ammonia water to adjust the pH of the reaction system to 8.8-9.8, and then reacting at a pressure of 5.5-7 MPa and 70-85° C. for 2-3 hours to generate a precipitate; The obtained precipitate is separated, washed, filtered, dried, ground, and then calcined at 700-750° C. for 2.5-3.5 hours to obtain Ag / Ni composite rare earth powder, wherein the Ni content is 4.0-5.5 wt.%; Vapor-depositing CNTs on Ag / Ni composite rare earth powder to obtain CNTs / Ag-Ni composite rare earth powder, wherein the CNTs content is 0.1-0.5wt.%; Pressing the CNTs / Ag-Ni composite rare earth powder into a rod alloy; Vacuum sintered bar alloy, where the sintering vacuum is less than 1*10 -2 , the sintering temperature is controlled at 950℃~1150℃, and the sintering holding time is 2h~4h; and The alloy wires of corresponding sizes are produced by hot extrusion and drawing the vacuum sintered rod alloy.

4. The preparation method according to claim 3, wherein the vapor deposition comprises: The Ag / Ni composite rare earth powder is heated to 630-720°C under argon protection, and then 700-1300 ml / min of H2 and 40-90 ml / min of C2H4 are introduced, and the temperature is kept for 20-70 minutes.

5. The preparation method according to claim 3, wherein the pressing molding is divided into two steps of cold pressing molding and cold isostatic pressing molding.

6. A high-frequency electric knife, at least partly made of the alloy according to claim 1 or 2.

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