Production process of diamond drill bit for artificial blood vessel grinding

Abstract

The application discloses a production process of a diamond drill bit for artificial blood vessel grinding. The process is characterized in that: firstly, raw materials are machined to form a base body; then, the base body and diamond particles are respectively degreased; after the base body is provided with shielding materials, surface activation treatment is performed on the base body, and surface roughening is performed on the diamond particles, thereby completing a pre-plating process; then, the base body is subjected to impact plating and air plating in sequence, thereby forming a nickel bonding layer; then, the diamond particles are mixed into an electroplating solution or directly smeared on the surface of the base body, so that the base body is charged into a tank for electroplating, thereby forming a diamond plating layer; then, the base body is transferred into a chemical plating tank for standing, thereby thickening the nickel layer to reinforce the diamond particles; and then, the electroplating sanding and the chemical plating sand fixing processes are repeated.

Description

Technical Field

[0001] This invention relates to the field of interventional medical device manufacturing technology, specifically to a manufacturing process for diamond drill bits used in artificial blood vessel grinding. Background Technology

[0002] In the fields of medical precision grinding and interventional medical device manufacturing, diamond drill bits have long been widely used in the drilling, trimming, surface grinding and forming of artificial blood vessel substrates such as ePTFE and polyurethane, thanks to the ultra-high hardness, wear resistance, precision micro-cutting and biocompatibility of diamond. The industry has mastered core preparation technologies such as micro-diameter substrate forming, micron-level diamond particle fixation, electroplating / sintering composite process, and medical-grade surface treatment, laying the material, process and structural design foundation for the research and development of intracavitary grinding diamond instruments in the same vascular medical scenario.

[0003] With the development of clinical cardiovascular interventional diagnosis and treatment, the incidence of coronary atherosclerosis with severe calcification is high. Calcified plaques are hard and the vessel walls lack elasticity, making it difficult to open diseased vessels with conventional balloons, stents, and ordinary interventional devices. This easily leads to surgical risks such as dissection, perforation, and stent under-expansion. Existing medical devices cannot meet the clinical need for selective minimally invasive volume reduction of hard calcified tissue. Therefore, the industry relies on the mature miniaturized structural design, diamond abrasive grain arrangement, high-precision grinding mechanism, and medical-grade antiseptic biomodification production technology of diamond drill bits to address this issue. We have developed specialized instruments adapted to intracoronary intervention scenarios. By optimizing the streamlined olive shape, matching the gradient micro-diameter specifications to the inner diameter of the blood vessel, and customizing the diamond grit size and fixation method, combined with high-speed transmission shaft system adaptation technology, we have developed the "diamond drill bit for coronary rotational atherectomy". Utilizing the differentiated cutting principle of hard tissue being grindable and soft tissue being elastically avoidable, we can achieve precise grinding and removal of calcified plaques in blood vessels. This makes up for the technical shortcomings of traditional interventional devices and also continues and upgrades the precision manufacturing and medical adaptation technology system of diamond instruments for artificial blood vessel grinding.

[0004] Since diamond drill bits embed diamond particles into a matrix, and "diamond drill bits for coronary artery rotational atherectomy" need to be inserted into blood vessels, higher requirements are placed on the stability of the diamond particles embedded in the matrix.

[0005] In view of the above, the inventors propose the following technical solution. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a manufacturing process for diamond drill bits used in the grinding of artificial blood vessels.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a manufacturing process for diamond drill bits for artificial blood vessel grinding. The process first processes the raw materials into a substrate by machining, then degreases the substrate and diamond particles separately, adds a shielding material to the substrate and performs surface activation treatment, while simultaneously roughening the surface of the diamond particles to complete the pre-plating process; then, the substrate is subjected to impact plating and air plating in sequence to form a nickel bonding layer, and then the substrate is electroplated by incorporating diamond particles into the electroplating solution or directly applying them to the surface of the substrate to generate a diamond coating layer. After that, the substrate is transferred to a chemical plating tank for static standing to thicken the nickel layer to reinforce the diamond particles. Subsequently, the electroplating and chemical plating sanding processes are repeated to complete the secondary sanding and sanding operations. Finally, the processed substrate is cleaned and dried.

[0008] Furthermore, in the above technical solution, the production process specifically includes the following steps:

[0009] The first step is material selection: copper rods are selected as raw materials and machined into an oval matrix. The diamond particles are diamond sand with a particle size of 600-800.

[0010] The second step is surface treatment: First, place the substrate and diamond particles in an alkaline solution to remove surface grease. Then, cover the non-plated areas of the substrate with shielding material. Next, immerse the substrate in hydrochloric acid solution to remove the surface oxide layer. At the same time, immerse the diamond particles in aqua regia to complete surface roughening.

[0011] The third step is impact plating: the substrate is charged and placed into the impact plating tank to form a nickel bonding layer with a thickness of 1-2 μm on its surface;

[0012] Step 4, dry plating: The substrate is charged and placed into a dry plating tank to form a thickened nickel layer with a thickness of 5μm on the surface;

[0013] Step 5, first electroplating sand coating: The substrate is charged and placed into an electroplating tank mixed with diamond particles. Diamond particles are plated on the surface, so that 15%-25% of the particles are embedded in the nickel layer.

[0014] Step 6, First chemical plating for sand fixation: Immerse the substrate in the chemical plating bath to thicken the nickel layer between the diamond particles, so that the particle embedding depth reaches 50%-70% of its own diameter;

[0015] Step 7, second electroplating and sanding: The substrate is once again charged and placed into an electroplating tank containing mixed diamond particles to add more plating particles to increase the surface particle density. The newly added particles still maintain an embedding ratio of 15%-25%.

[0016] Step 8, Second chemical plating for sand fixation: The substrate is immersed in the chemical plating bath again to further thicken the nickel layer, so that the diamond particles are embedded to a depth exceeding 70% of their own diameter;

[0017] Step 9, post-plating treatment: Clean the substrate with pure water and then dry it with hot air;

[0018] Note: The substrate must be rinsed with pure water each time it is changed to a different solution tank.

[0019] Furthermore, in the above technical solution, the electroplating bath solution comprises 100g / L-300g / L nickel chloride and 100ml / L-200ml / L hydrochloric acid, and the process conditions are: room temperature, 4A / dm². 2 -6A / dm 2 The current density, 3-5 min.

[0020] Furthermore, in the above technical solution, in the fourth step, the electroplating bath solution comprises 200g / L-400g / L nickel sulfamate, 13g / L-17g / L nickel chloride, and 30g / L-50g / L boric acid, with process conditions of 40℃-60℃ and 0.8A / dm³. 2 -1.0A / dm 2 The current density, 20-30 min.

[0021] Furthermore, in the above technical solution, in the fifth step, the electroplating bath solution comprises 200g / L-400g / L nickel sulfamate, 13g / L-17g / L nickel chloride, and 30g / L-50g / L boric acid, with process conditions of 40℃-60℃ and 0.8A / dm³. 2 -1.0A / dm 2 The current density, 30-50 min.

[0022] Furthermore, in the above technical solution, in the sixth step, the chemical plating bath solution comprises 30g / L-40g / L nickel sulfate, 25g / L-35g / L boric acid, and 20g / L-30g / L lactic acid, and the process conditions are: physical immersion at 70℃-85℃ for 35-40 minutes.

[0023] Furthermore, in the above technical solution, after the substrate is coated, the volume ratio of surface diamond is controlled at 40%-50%, and the diamond used is GD2 type.

[0024] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0025] 1. In this invention, diamond particles are fixed to the substrate surface by electroplating and chemical fixation. The density of diamond particles on the substrate surface is increased by secondary electroplating and secondary chemical fixation, so that the diamond particles are stably attached to the substrate surface. This ensures that the diamond particles will not fall into the blood vessels during use, thus ensuring the safety of the drill bit.

[0026] 2. In this invention, before electroplating with sand, a transitional nickel-containing bonding layer is formed on the substrate surface by impact plating to increase the adhesion stability of the nickel plating layer. Meanwhile, the thickness of the nickel layer on the substrate surface is increased by air plating to ensure that the nickel layer for diamond plating has sufficient thickness and to prevent diamond particles from falling off after plating. Attached Figure Description

[0027] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0029] See Figure 1 The diagram illustrates a manufacturing process for diamond drill bits used in artificial blood vessel grinding. The process involves first machining the raw materials into a substrate, then degreasing both the substrate and diamond particles. After adding a shielding material to the substrate, surface activation is performed, while simultaneously roughening the surface of the diamond particles, completing the pre-plating process. Next, the substrate undergoes impact plating and air plating sequentially to form a nickel bonding layer. Then, by incorporating diamond particles into the electroplating solution or directly applying them to the substrate surface, the substrate is charged before electroplating to generate a diamond coating. The substrate is then transferred to a chemical plating bath for settling, thickening the nickel layer to reinforce the diamond particles. This process is repeated with electroplating and chemical plating for sanding, completing a second sanding and sanding operation. Finally, the processed substrate is cleaned and dried. Diamond particles are fixed to the substrate surface using electroplating and chemical fixation. Two rounds of electroplating and chemical fixation are applied to increase the density of diamond particles on the substrate surface, ensuring stable adhesion and preventing them from falling into blood vessels during use, thus guaranteeing drill bit safety. Before electroplating, a transitional nickel-containing bonding layer is formed on the substrate surface through impact plating, increasing the adhesion stability of the nickel plating layer. Air plating further increases the thickness of the nickel layer on the substrate surface, ensuring sufficient thickness for the diamond plating and preventing diamond particles from detaching after plating.

[0030] The above production process includes the following specific steps:

[0031] The first step is material selection: Copper rods are selected as the raw material and machined into an elliptical matrix. The diamond particles used are diamond abrasive with a particle size of 600-800. In this embodiment, copper rods are used as the matrix material because copper and diamond have poor bonding stability. It is necessary to first plate a layer of nickel on the surface of copper to attach the diamond to the copper. However, directly electroplating a nickel layer on the copper surface is not stable enough and there is a risk of peeling off. Therefore, a penetrating nickel layer with copper-nickel bonding is first generated on the copper surface through chemical nickel plating, thereby improving the adhesion stability of the electroplated nickel layer and effectively preventing the nickel layer from peeling off.

[0032] The second step is surface treatment: First, place the substrate and diamond particles in an alkaline solution to remove surface grease. Then, coat the non-plated areas of the substrate with shielding material. Next, immerse the substrate in hydrochloric acid solution to remove the surface oxide layer, while simultaneously immersing the diamond particles in aqua regia to roughen the surface. In this embodiment, the method for degreasing the substrate is to immerse the substrate in an alkaline degreasing agent at 50°C and remove residual grease by ultrasonic vibration for 30 minutes. After degreasing, the substrate is rinsed with pure water to prevent residual agent from remaining on the surface. The method for degreasing the diamond particles is to soak the diamond particles in a 30% concentration caustic soda solution for 12 hours to remove grease from the surface of the diamond particles. After degreasing, the diamond particles are rinsed with pure water to prevent residual agent from remaining on the surface. The method for activating the substrate is to immerse the substrate in a 20% concentration hydrochloric acid solution for 50 seconds to remove the oxide layer on the surface of the substrate. After activation, the substrate is rinsed with pure water to prevent residual agent from remaining on the surface. The method for roughening the diamond is to soak the diamond particles in aqua regia for 12 hours to roughen the diamond surface. After roughening, the diamond particles are rinsed with pure water to prevent residual agent from remaining on the surface.

[0033] The third step is impact plating: the substrate is charged and placed in an impact plating bath to form a nickel bonding layer with a thickness of 1-2 μm on its surface. The plating bath solution consists of 100 g / L-300 g / L nickel chloride and 100 ml / L-200 ml / L hydrochloric acid. The process conditions are: room temperature, 4 A / dm². 2 -6A / dm 2 The current density, 3-5 min.

[0034] In this embodiment, the electroplating bath solution for impact plating comprises 200 g / L nickel chloride and 150 ml / L hydrochloric acid. The process conditions are: at room temperature, 5 A / dm³ is introduced into the substrate. 2 The current density was applied for 5 minutes to deposit a 1.5 μm nickel bonding layer on the surface of the substrate. After the impact plating was completed, the substrate was rinsed with pure water to prevent residual agents from remaining on the surface.

[0035] Because copper readily oxidizes in air to form copper oxide, and the surface of a substrate using copper rods as raw material is easily covered by this copper oxide, reducing the adhesion between the substrate and the nickel layer, the impact plating solution is a highly acidic nickel plating solution. When the copper substrate is placed in the impact nickel solution, the hydrogen ions in the solution preferentially dissolve the copper oxide on the copper substrate surface, and then a nickel layer is deposited on the copper substrate surface, ensuring the adhesion between the copper substrate and the nickel layer. Therefore, adding an impact plating process before diamond plating can better ensure the adhesion between the nickel and the substrate, ensuring a stable and non-detached nickel plating layer.

[0036] Step 4, Empty Plating: The substrate is placed in an empty plating bath while charged, forming a thickened nickel layer of 5 μm on the surface. The plating bath solution consists of 200 g / L-400 g / L nickel sulfamate, 13 g / L-17 g / L nickel chloride, and 30 g / L-50 g / L boric acid. The process conditions are: 40℃-60℃, 0.8 A / dm³. 2 -1.0A / dm 2 The current density, 20-30 min.

[0037] In this embodiment, the plating bath solution for empty plating comprises 300 g / L nickel sulfamate, 15 g / L nickel chloride, and 40 g / L boric acid. The process conditions are as follows: 0.9 A / dm³ is introduced into the substrate. 2 After applying a current density of 50°C, the substrate is immersed in an electroplating solution at 50°C for 25 minutes to deposit a 5μm nickel layer on the surface of the substrate. After the plating is completed, the substrate is rinsed with pure water to prevent residual chemicals from remaining on the surface.

[0038] Step 5, First Electroplating with Abrasive: The substrate is placed in an electroplating bath containing diamond particles while still charged. Diamond particles are then plated onto the surface, embedding 15%-25% of the particles into the nickel layer. The electroplating bath solution consists of 200g / L-400g / L nickel sulfamate, 13g / L-17g / L nickel chloride, and 30g / L-50g / L boric acid. The process conditions are: 40℃-60℃, 0.8A / dm³. 2 -1.0A / dm 2 The current density, 30-50 min.

[0039] In this embodiment, the electroplating bath solution comprises 300 g / L nickel sulfamate, 15 g / L nickel chloride, 40 g / L boric acid, and 12 g / L diamond particles. The process conditions are as follows: 0.9 A / dm³ is introduced into the substrate. 2 After applying a current density of 100 kJ / kg, immerse the substrate in a 50°C electroplating solution for 40 minutes. This allows 20% of the diamond particles to be encapsulated and embedded in the nickel layer of the substrate by nickel. After completing the first diamond plating, rinse the substrate with pure water to prevent residual chemicals from remaining on the surface.

[0040] Since nickel sulfamate plating solution is a plating solution with nickel sulfamate as the core component, the plating layer has a silvery-white metallic luster, fine crystals, low internal stress, and good ductility. Moreover, nickel sulfamate allows for higher current densities, making it suitable for high-speed electroplating or electroforming. It is generally used in high-precision electronic electroplating, semiconductor electroplating, and other scenarios that require low stress and high ductility. Therefore, nickel sulfamate plating solution is used as the base nickel-containing main salt in air plating and electroplating sandblasting.

[0041] Step 6, First chemical plating for sand fixation: The substrate is immersed in the chemical plating bath to thicken the nickel layer between the diamond particles, so that the particle embedding depth reaches 50%-70% of its own diameter. The chemical plating bath solution consists of 30g / L-40g / L nickel sulfate, 25g / L-35g / L boric acid, and 20g / L-30g / L lactic acid. The process conditions are: physical immersion at 70℃-85℃ for 35-40 minutes.

[0042] In this embodiment, the chemical plating bath solution comprises 35 g / L nickel sulfate, 30 g / L boric acid, and 25 g / L lactic acid. The process conditions are to immerse the substrate in the chemical plating solvent at 80°C for 35 minutes to add a layer of nickel to the surface of the substrate, so that 60% of the diamond particles are encapsulated and embedded in the substrate by nickel. After the first sand fixation is completed, the substrate is cleaned with pure water to prevent residual agents on the surface.

[0043] Electroless nickel plating is a metal surface treatment solution that chemically deposits a nickel-phosphorus alloy coating onto the surface of a workpiece. Electroless nickel plating does not require electricity; the reaction occurs through the self-catalysis of the solution itself. The coating is uniform (regardless of shape or current level), with low internal stress, high hardness, and good corrosion and wear resistance. However, electroless nickel plating has a relatively slow plating rate, and the coating is a nickel-phosphorus alloy rather than pure nickel. Precise control of the thickness gradient is not possible. It is widely used in complex parts and for nickel plating of non-conductive components (after activation).

[0044] Step 7, Second electroplating and sandblasting: The substrate is once again charged and placed into an electroplating tank containing mixed diamond particles to replenish the plating particles and increase the surface particle density. The newly added particles still maintain an embedding ratio of 15%-25%.

[0045] In this embodiment, the process conditions for the second electroplating are the same as those for the first electroplating. The second electroplating allows diamond particles to be plated between the diamond particles on the substrate surface again. Due to the same process conditions, 20% of the diamond particles in the second electroplating are still wrapped and fixed on the substrate by the nickel layer. After the second electroplating, the diamond volume ratio on the substrate surface can reach 50%.

[0046] Step 8, Second Chemical Plating for Sand Fixation: The substrate is immersed in the chemical plating bath again to further thicken the nickel layer, ensuring that the diamond particles are embedded to a depth exceeding 70% of their diameter. It is important to emphasize that chemical nickel plating does not require electricity; the nickel layer is deposited on the substrate surface through the solution's own self-catalytic reaction. Compared to nickel sulfate plating solutions, chemical nickel plating does not differentiate between high and low current levels, resulting in a more uniform coating. Furthermore, the nickel layer from chemical nickel plating has lower internal stress, higher hardness, and better corrosion and wear resistance compared to nickel sulfate plating.

[0047] In this embodiment, the process conditions for the second chemical sand fixation are the same as those for the first chemical sand fixation. After the second chemical sand fixation, the diamond particles are embedded in the nickel layer on the substrate surface to a depth of 70% of their own diameter, which greatly improves the stability of the diamond particles embedded in the substrate and ensures that the diamond particles will not fall out into the blood vessels during use, thus meeting the requirements for medical use.

[0048] Step 9, post-plating treatment: Clean the substrate with pure water and then dry it with hot air;

[0049] Note: The substrate must be rinsed with pure water after each change of solution tank. GD2 type diamond is used, and the volume percentage of diamond on the surface is controlled at 40%-50% after the substrate is coated.

[0050] Of course, the above description is only a specific embodiment of the present invention and is not intended to limit the scope of the present invention. All equivalent changes or modifications made to the structure, features and principles described in the claims of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A manufacturing process for diamond drill bits used in grinding artificial blood vessels, characterized in that: First, the raw materials are machined into a substrate. Then, the substrate and diamond particles are degreased separately. After adding shielding material to the substrate, surface activation treatment is performed, and the surface of the diamond particles is roughened to complete the pre-plating process. Next, the substrate is subjected to impact plating and air plating in sequence to form a nickel bonding layer. Then, by adding diamond particles to the electroplating solution or directly applying them to the surface of the substrate, the substrate is charged and immersed in the electroplating tank to generate a diamond coating. After that, the substrate is transferred to a chemical plating tank and left to stand to thicken the nickel layer to reinforce the diamond particles. Then, the electroplating and chemical plating sanding processes are repeated to complete the secondary sanding and sanding operations. Finally, the processed substrate is cleaned and dried.

2. The manufacturing process of a diamond drill bit for grinding artificial blood vessels according to claim 1, characterized in that: The production process includes the following specific steps: The first step is material selection: copper rods are selected as raw materials and machined into an oval matrix. The diamond particles are diamond sand with a particle size of 600-800. The second step is surface treatment: First, place the substrate and diamond particles in an alkaline solution to remove surface grease. Then, cover the non-plated areas of the substrate with shielding material. Next, immerse the substrate in hydrochloric acid solution to remove the surface oxide layer. At the same time, immerse the diamond particles in aqua regia to complete surface roughening. The third step is impact plating: the substrate is charged and placed into the impact plating tank to form a nickel bonding layer with a thickness of 1-2 μm on its surface; Step 4, dry plating: The substrate is charged and placed into a dry plating tank to form a thickened nickel layer with a thickness of 5μm on the surface; Step 5, first electroplating sand coating: The substrate is charged and placed into an electroplating tank mixed with diamond particles. Diamond particles are plated on the surface, so that 15%-25% of the particles are embedded in the nickel layer. Step 6, First chemical plating for sand fixation: Immerse the substrate in the chemical plating bath to thicken the nickel layer between the diamond particles, so that the particle embedding depth reaches 50%-70% of its own diameter; Step 7, second electroplating and sanding: The substrate is once again charged and placed into an electroplating tank containing mixed diamond particles to add more plating particles to increase the surface particle density. The newly added particles still maintain an embedding ratio of 15%-25%. Step 8, Second chemical plating for sand fixation: The substrate is immersed in the chemical plating bath again to further thicken the nickel layer, so that the diamond particles are embedded to a depth exceeding 70% of their own diameter; Step 9, post-plating treatment: Clean the substrate with pure water and then dry it with hot air; Note: The substrate must be rinsed with pure water each time it is changed to a different solution tank.

3. The manufacturing process for a diamond drill bit for grinding artificial blood vessels according to claim 2, characterized in that: In the third step, the electroplating bath solution comprises 100g / L-300g / L nickel chloride and 100ml / L-200ml / L hydrochloric acid, and the process conditions are: room temperature, 4A / dm². 2 -6A / dm 2 The current density, 3-5 min.

4. The manufacturing process of a diamond drill bit for grinding artificial blood vessels according to claim 2, characterized in that: In the fourth step, the electroplating bath solution comprises 200g / L-400g / L nickel sulfamate, 13g / L-17g / L nickel chloride, and 30g / L-50g / L boric acid, with process conditions of 40℃-60℃ and 0.8A / dm³. 2 -1.0A / dm 2 The current density, 20-30 min.

5. The manufacturing process of a diamond drill bit for grinding artificial blood vessels according to claim 2, characterized in that: In the fifth step, the electroplating bath solution comprises 200g / L-400g / L nickel sulfamate, 13g / L-17g / L nickel chloride, and 30g / L-50g / L boric acid, with process conditions of 40℃-60℃ and 0.8A / dm³. 2 -1.0A / dm 2 The current density, 30-50 min.

6. The manufacturing process of a diamond drill bit for grinding artificial blood vessels according to claim 2, characterized in that: In the sixth step, the chemical plating bath solution contains 30g / L-40g / L nickel sulfate, 25g / L-35g / L boric acid, and 20g / L-30g / L lactic acid. The process conditions are: physical immersion at 70℃-85℃ for 35-40 minutes.

7. A manufacturing process for diamond drill bits for grinding artificial blood vessels according to any one of claims 1-6, characterized in that: After the substrate is coated, the volume ratio of diamond on the surface is controlled at 40%-50%, and the diamond used is GD2 type.

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