Coating electrode wire preparation method based on special coating and heat treatment technology

Abstract

The invention relates to the technical field of electrode wire preparation, and provides a plating electrode wire preparation method based on a special coating and a heat treatment technology. The metal wire base material is pretreated, and impurities and internal stress on the surface of the metal wire base material are removed; preparing a special coating solution, wherein the special coating solution comprises a binder, a functional additive and a solvent; the pretreated metal wire base material is soaked in the special coating solution; the metal wire base material coated with the special coating is dried, and the solvent in the coating is removed; carrying out electroplating treatment on the dried metal wire base material; and carrying out heat treatment on the electroplated metal wire base material. The electrode wire is endowed with high hardness, wear resistance and oxidation resistance through the functional additive in the special coating solution, and in the heat treatment process, the combination between the plating layers and between the coating layers and the metal wire is firmer, meanwhile, the microstructure of the plating layers is improved, and the hardness, wear resistance, corrosion resistance and other properties are improved.

Description

Technical Field

[0001] The invention relates to the technical field of electrode wire preparation, and in particular to a method for preparing a plated electrode wire based on special coating and heat treatment technology. Background Art

[0002] In the field of modern industrial processing, electrode wire is a crucial processing tool, widely used in high-precision processing technologies such as electrospark machining. With the continuous development of industrial technology, the requirements for processing accuracy, processing efficiency and processing quality are increasing, and more stringent requirements are also placed on the performance of electrode wire.

[0003] Traditional electrode wire preparation technology has many limitations. On the one hand, in the selection and processing of electrode wire materials, effective methods for removing stress and impurities in the substrate are often not fully considered, which leads to problems such as lattice defects and deformation caused by internal stress release in the electrode wire during use, affecting the processing accuracy and service life of the electrode wire. In some traditional processes, the parameters such as temperature, atmosphere and time of annealing treatment are not properly controlled, and the residual stress and surface impurities in the metal wire substrate cannot be completely eliminated;

[0004] On the other hand, traditional electrode wires have shortcomings in surface protection and performance improvement. Most traditional preparation processes do not involve the application of special coatings. The electrode wires lack sufficient wear resistance, corrosion resistance and oxidation resistance in complex processing environments, such as high temperature, high pressure, and highly corrosive working conditions. Moreover, during the electroplating process, due to the lack of optimized process parameters and subsequent treatment, the bonding between the coating and the electrode wire is not strong enough, and the coating is prone to peeling. This makes the performance of the electrode wire in high-precision and high-strength processing unsatisfactory, and cannot meet the needs of modern industrial processing for complex shape processing and high-quality surface processing.

[0005] Therefore, a new electrode wire preparation method is urgently needed to overcome the shortcomings of the existing technology and improve the comprehensive performance of the electrode wire to meet the increasing industrial processing requirements. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a method for preparing a coated electrode wire based on a special coating and heat treatment technology, which solves the problem that the performance of the electrode wire in the prior art is not perfect.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for preparing a coated electrode wire based on special coating and heat treatment technology, comprising the following steps:

[0008] S1. Select a metal wire substrate, wherein the diameter of the metal wire substrate is 0.1 mm-0.5 mm;

[0009] S2. Pre-treating the metal wire substrate by annealing the metal wire substrate in a hydrogen atmosphere at a temperature of 300°C-500°C for 1-3 hours at a hydrogen flow rate of 5-10 L / min to remove impurities and internal stress on the surface of the metal wire substrate;

[0010] S3. Preparing a special coating solution, the special coating solution comprising a binder, a functional additive and a solvent, wherein the binder accounts for 10%-30% of the total mass of the solution, the functional additive accounts for 5%-15% of the total mass of the solution, and the solvent accounts for 55%-85% of the total mass of the solution;

[0011] S4. The pretreated metal wire substrate is immersed in the special coating solution for 5-15 minutes, and after immersion, the metal wire substrate is pulled at a speed of 5-10 cm / min to uniformly coat the surface of the metal wire substrate with the special coating;

[0012] S5. Drying the metal wire substrate coated with the special coating at a temperature of 100°C-200°C for 2-4 hours to remove the solvent in the coating;

[0013] S6. The dried metal wire substrate is electroplated, the electroplating solution is a solution containing metal ions, the metal ion concentration is 0.5mol / L-2mol / L, and the electroplating current density is 1-5A / dm 2 , the electroplating time is 10-30 minutes, forming a metal plating layer on the special coating;

[0014] S7. The electroplated metal wire substrate is heat-treated. Under nitrogen protection, the metal wire substrate is heated to 400℃-600℃, kept warm for 1-3 hours, with a nitrogen flow rate of 8-12L / min, and then cooled with the furnace to obtain an electrode wire with a surface having high hardness, high wear resistance, good conductivity and corrosion resistance, and a strong bond between the plating layer and the metal wire substrate.

[0015] Preferably, the metal wire substrate is molybdenum wire, tungsten wire or molybdenum-tungsten alloy wire.

[0016] Preferably, the binder is a silicone resin.

[0017] Preferably, the functional additive is a mixture of nano-ceramic particles and rare earth oxides, and the mass ratio of the nano-ceramic particles to the rare earth oxides is 2:1-3:1.

[0018] Preferably, the nano-ceramic particles are one or more of aluminum oxide and zirconium oxide, and the particle size of the nano-ceramic particles is 50-200 nm.

[0019] Preferably, the rare earth oxide is one or more of yttrium oxide and lanthanum oxide.

[0020] Preferably, the solvent of the special coating solution is ethanol, acetone or a mixed solvent of the two in a mass ratio of 1:1.

[0021] Preferably, the metal ions in the electroplating solution are copper ions, zinc ions or nickel ions.

[0022] The invention provides a method for preparing a plated electrode wire based on special coating and heat treatment technology.

[0023] It has the following beneficial effects:

[0024] 1. The present invention endows the electrode wire with high hardness, wear resistance and oxidation resistance through functional additives in a special coating solution. In addition, during the heat treatment process, the bonding between the coating and the coating, and between the coating and the metal wire becomes stronger. At the same time, the microstructure of the coating is improved, thereby improving the hardness, wear resistance and corrosion resistance, etc., and meeting the requirements of high-precision and high-strength processing.

[0025] 2. In the whole preparation process of the present invention, the oxide impurities on the surface of the metal wire and the internal residual stress can be effectively removed through annealing treatment. The immersion pulling process ensures the coverage integrity and thickness uniformity of the coating on the surface of the metal wire. The drying step provides a stable interface for subsequent electroplating, which not only makes the electrode wire have excellent performance, but also the process has strong repeatability and stable quality, which can effectively improve production efficiency and consistency of product quality. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] Embodiment 1:

[0028] The embodiment of the present invention provides a method for preparing a coated electrode wire based on a special coating and heat treatment technology, comprising the following steps:

[0029] S1. Select a molybdenum wire with a diameter of 0.3 mm as the metal wire substrate;

[0030] S2. Anneal the molybdenum wire in a hydrogen atmosphere at 400°C for 2 hours, with the hydrogen flow rate set at 8L / min. Annealing in a hydrogen atmosphere at 400°C can remove oxide impurities formed on the surface of the molybdenum wire during the processing. At the same time, this temperature range can effectively eliminate the residual stress inside the molybdenum wire and make the lattice structure of the molybdenum wire more stable. The annealing time of 2 hours and the hydrogen flow rate of 8L / min ensure that the matrix properties of the molybdenum wire will not be negatively affected while fully removing impurities and internal stress;

[0031] S3. In the special coating solution, the binder is silicone resin, accounting for 20% of the total mass of the solution; the functional additive is a mixture of aluminum oxide nanoparticles with a particle size of 100nm and yttrium oxide, the mass ratio of the two is 2.5:1, and the functional additive accounts for 10% of the total mass of the solution; the solvent is ethanol, accounting for 70% of the total mass of the solution. The silicone resin binder ensures a good combination of the coating with the molybdenum wire and the inside of the coating, improves the stability of the coating, and the functional additive gives the coating excellent properties such as high hardness, wear resistance and oxidation resistance, so that the electrode wire can withstand harsh working environments during use;

[0032] S4. Immerse the pretreated molybdenum wire in the special coating solution for 10 minutes, then pull the molybdenum wire at a speed of 8 cm / min to evenly coat the surface with the special coating, ensuring the coverage integrity and thickness uniformity of the coating on the molybdenum wire surface. The uniform coating is beneficial to improving the overall performance of the electrode wire, such as conductivity and wear resistance, and also provides a good foundation for subsequent electroplating treatment, ensuring that the electroplating layer can be evenly deposited on the coating surface;

[0033] S5. Dry the molybdenum wire coated with the special coating at 150°C for 3 hours to remove the solvent in the coating, so that the coating changes from liquid to solid and forms a stable structure. The dried coating can better adhere to the surface of the molybdenum wire, providing a stable interface for subsequent electroplating treatment, and is also beneficial to improving the performance of the electrode wire;

[0034] S6. The electroplating solution uses a solution with a copper ion concentration of 1 mol / L and an electroplating current density of 3A / dm 2 The electroplating time is 20 minutes, and a metal coating is formed on the special coating. The copper coating can improve the conductivity of the electrode wire, so that the electrode wire can transfer current more effectively in applications such as electrical discharge machining. The appropriate electroplating parameters ensure the quality of the coating, thereby improving the overall performance and service life of the electrode wire.

[0035] S7. Under nitrogen protection, heat the molybdenum wire to 500℃ and keep it warm for 2 hours with a nitrogen flow rate of 10L / min. Then cool it with the furnace. After heat treatment, the coating on the surface of the electrode wire is more firmly bonded to the coating, and the bonding between the coating and the molybdenum wire is further enhanced. At the same time, heat treatment can improve the microstructure of the coating, improve its hardness, wear resistance and corrosion resistance, so that the prepared electrode wire has excellent properties such as high surface hardness, high wear resistance, good conductivity and corrosion resistance, which can meet the use requirements of the electrode wire in complex processing environments.

[0036] Embodiment 2:

[0037] The embodiment of the present invention provides a method for preparing a coated electrode wire based on a special coating and heat treatment technology, comprising the following steps:

[0038] S1. Select a tungsten wire with a diameter of 0.2 mm as the metal wire substrate;

[0039] S2. Anneal the tungsten wire in a hydrogen atmosphere at 350°C for 1.5 hours, with the hydrogen flow rate controlled at 6L / min;

[0040] S3. In the special coating solution, the binder is silicone resin, accounting for 15% of the total mass; the functional additive is a mixture of zirconium oxide nanoparticles with a particle size of 150 nm and lanthanum oxide, with a mass ratio of 3:1, accounting for 8% of the total mass; the solvent is acetone, accounting for 77% of the total mass;

[0041] S4. The pretreated tungsten wire is immersed in the special coating solution for 8 minutes, and then the tungsten wire is pulled at a speed of 6 cm / min;

[0042] S5. Dry at 120°C for 2.5 hours;

[0043] S6. The plating solution is a solution with a zinc ion concentration of 1.2 mol / L and a plating current density of 2A / dm 2 , electroplating time 15 minutes;

[0044] S7. Under nitrogen protection, heat the tungsten wire to 450°C, keep it warm for 1.5 hours, with a nitrogen flow rate of 9 L / min, and then cool it with the furnace.

[0045] Embodiment three:

[0046] The embodiment of the present invention provides a method for preparing a coated electrode wire based on a special coating and heat treatment technology, comprising the following steps:

[0047] S1. Select a molybdenum-tungsten alloy wire with a diameter of 0.4 mm as the metal wire substrate;

[0048] S2. The molybdenum-tungsten alloy wire was annealed in a hydrogen atmosphere at 450°C for 2.5 hours with a hydrogen flow rate of 9 L / min;

[0049] S3. In the special coating solution, the binder is silicone resin, accounting for 25% of the total mass of the solution; the functional additive is a mixture of 80nm aluminum oxide and zirconium oxide in a 1:1 ratio and yttrium oxide and lanthanum oxide in a 1:1 ratio, accounting for 12% of the total mass of the solution; the solvent is a mixed solvent of ethanol and acetone in a 1:1 ratio, accounting for 63% of the total mass of the solution;

[0050] S4. The pretreated molybdenum-tungsten alloy wire was immersed in a special coating solution for 12 minutes and then pulled at a speed of 7 cm / min;

[0051] S5. Dry at 180°C for 3.5 hours;

[0052] S6. The electroplating solution uses a nickel ion concentration of 1.5 mol / L and an electroplating current density of 4A / dm 2 , the plating time is 25 minutes;

[0053] S7. Under nitrogen protection, heat the molybdenum-tungsten alloy wire to 550°C, keep it warm for 2.5 hours, with a nitrogen flow rate of 11L / min, and then cool it with the furnace.

[0054] Comparative Example:

[0055] The embodiment of the present invention provides a method for preparing an electrode wire based on a traditional process, comprising the following steps:

[0056] S1. Select a molybdenum wire with a diameter of 0.3 mm as the metal wire substrate;

[0057] S2. The molybdenum wire was annealed at 300°C in an air atmosphere for 1 hour;

[0058] S3. No special coating solution is used;

[0059] S4. Directly electroplate the molybdenum wire, the electroplating solution uses a solution with a copper ion concentration of 1 mol / L and an electroplating current density of 3A / dm 2 , the plating time is 20 minutes;

[0060] S5. Do not perform heat treatment on the electroplated molybdenum wire and allow it to cool naturally.

[0061] By testing the hardness, wear resistance, corrosion resistance, conductivity and coating bonding strength of the electrode wires prepared in Example 1, Example 2, Example 3 and the comparative example, the effects of different preparation methods on the performance of the electrode wires were compared. The experimental steps are as follows:

[0062] Hardness test: Cut samples of appropriate length from the electrode wires prepared in Example 1, Example 2, Example 3 and the comparative example, place the samples on the workbench of the Vickers hardness tester, load a certain pressure according to the standard test method, keep it for a specified time and then unload it, record the diagonal length of the indentation, calculate the hardness value by the formula, and take the average value of multiple points tested for each sample;

[0063] Wear resistance test: Install the electrode wire sample on the friction and wear tester, set appropriate friction parameters, start the tester, and make the electrode wire sample rub against the friction pair. After the test, measure the mass loss of the electrode wire sample to evaluate the wear resistance. Repeat the test for each sample multiple times to get the average value.

[0064] Corrosion resistance test: Prepare a specific corrosive medium, immerse the electrode wire sample in the corrosive medium, observe the surface corrosion after immersion for a certain period of time, and calculate the corrosion rate by weighing method;

[0065] Conductivity test: Use a four-probe resistivity tester to connect the electrode wire sample to the test instrument, and measure the resistivity of the electrode wire according to the operating instructions to evaluate the conductivity. Each sample is measured multiple times and the average value is taken;

[0066] Coating bonding strength test: Fix one end of the electrode wire sample on the fixture of the tensile testing machine, and connect the other end to the tensile head of the testing machine through a suitable connection method. Start the tensile testing machine, stretch the electrode wire at a certain stretching speed until the coating is separated from the substrate, record the maximum tensile force, and obtain the coating bonding strength by calculation.

[0067] The experimental results are shown in the following table

[0068]

[0069]

[0070] It can be seen from the above table that the electrode wires prepared in Example 1, Example 2 and Example 3 are superior to the control example in terms of hardness, wear resistance, corrosion resistance, conductivity and coating bonding strength, which indicates that the preparation method based on special coating and heat treatment technology can significantly improve the comprehensive performance of the electrode wire.

[0071] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a coated electrode wire based on special coating and heat treatment technology, characterized in that: The following steps are involved: S1. Select a metal wire substrate, wherein the diameter of the metal wire substrate is 0.1 mm-0.5 mm; S2. Pre-treating the metal wire substrate by annealing the metal wire substrate in a hydrogen atmosphere at a temperature of 300°C-500°C for 1-3 hours at a hydrogen flow rate of 5-10 L / min to remove impurities and internal stress on the surface of the metal wire substrate; S3. Preparing a special coating solution, the special coating solution comprising a binder, a functional additive and a solvent, wherein the binder accounts for 10%-30% of the total mass of the solution, the functional additive accounts for 5%-15% of the total mass of the solution, and the solvent accounts for 55%-85% of the total mass of the solution; S4. The pretreated metal wire substrate is immersed in the special coating solution for 5-15 minutes, and after immersion, the metal wire substrate is pulled at a speed of 5-10 cm / min to uniformly coat the surface of the metal wire substrate with the special coating; S5. Drying the metal wire substrate coated with the special coating at a temperature of 100°C-200°C for 2-4 hours to remove the solvent in the coating; S6. The dried metal wire substrate is electroplated, the electroplating solution is a solution containing metal ions, the metal ion concentration is 0.5mol / L-2mol / L, and the electroplating current density is 1-5A / dm 2 , the electroplating time is 10-30 minutes, forming a metal plating layer on the special coating; S7. The electroplated metal wire substrate is heat-treated. Under nitrogen protection, the metal wire substrate is heated to 400℃-600℃, kept warm for 1-3 hours, with a nitrogen flow rate of 8-12L / min, and then cooled with the furnace to obtain an electrode wire with a surface having high hardness, high wear resistance, good conductivity and corrosion resistance, and a strong bond between the plating layer and the metal wire substrate.

2. The method for preparing a coated electrode wire based on special coating and heat treatment technology according to claim 1, characterized in that: The metal wire substrate is molybdenum wire, tungsten wire or molybdenum-tungsten alloy wire.

3. The method for preparing a coated electrode wire based on special coating and heat treatment technology according to claim 1, characterized in that: The binder is silicone resin.

4. The method for preparing a coated electrode wire based on special coating and heat treatment technology according to claim 1, characterized in that: The functional additive is a mixture of nano ceramic particles and rare earth oxides, and the mass ratio of the nano ceramic particles to the rare earth oxides is 2:1-3:

1.

5. The method for preparing a coated electrode wire based on special coating and heat treatment technology according to claim 4, characterized in that: The nano ceramic particles are one or more of aluminum oxide and zirconium oxide, and the particle size of the nano ceramic particles is 50-200 nm.

6. The method for preparing a coated electrode wire based on special coating and heat treatment technology according to claim 4, characterized in that: The rare earth oxide is one or more of yttrium oxide and lanthanum oxide.

7. The method for preparing a coated electrode wire based on special coating and heat treatment technology according to claim 1, characterized in that: The solvent of the special coating solution is ethanol, acetone or a mixed solvent of the two in a mass ratio of 1:

1.

8. The method for preparing a coated electrode wire based on special coating and heat treatment technology according to claim 1, characterized in that: The metal ions in the electroplating solution are copper ions, zinc ions or nickel ions.

Images