An electrode wire and a preparation method thereof

Abstract

The present invention discloses an electrode wire and a preparation method thereof. The electrode wire includes: a core material; an intermediate layer located outside the core material; and a surface layer located outside the intermediate layer. The core material is a metal or an alloy. The intermediate layer includes a γ-phase copper-zinc alloy layer, and the surface layer discontinuously covers the γ-phase copper-zinc alloy layer. The γ-phase copper-zinc alloy layer has massive β-phase and / or β'-phase copper-zinc alloy at the interface between it and the surface layer. During the preparation process, a γ-phase copper-zinc alloy layer and massive β-phase and / or β'-phase copper-zinc alloy at the interface between it and the surface layer are formed inside the electrode wire through electroplating, stretching, heat treatment and stretching processes, which can simultaneously combine the advantages of β-phase and / or β'-phase copper-zinc alloy and γ-phase copper-zinc alloy. Applying the present invention can greatly improve the wire cutting speed during wire electrical discharge machining.

Description

Technical Field

[0001] The present invention belongs to the field of wire electrical discharge machining, and particularly relates to an electrode wire and a preparation method thereof. Background Art

[0002] The basic working principle of wire cut electrical discharge machining (WEDM for short) is to use a continuously moving thin metal wire (referred to as an electrode wire) as an electrode to perform pulsed spark discharge on a workpiece to erode metal and cut it into shape.

[0003] Cutting speed, cutting accuracy, and the surface finish of the workpiece after machining are evaluation indicators for the quality of the wire cut electrical discharge machining process, and each of the above indicators has a very large relationship with the performance of the electrode wire used. After years of development and iteration, the electrode wire has evolved from the initial copper wire to the subsequent brass wire, then to the zinc-plated copper wire, and now to the commonly used coated wire on the market, with its performance getting better and better. Currently, the commonly used coated wire has a coating layer outside its core material, and this coating layer is generally a β-phase copper-zinc alloy or a γ-phase copper-zinc alloy. Among them, the β-phase copper-zinc alloy has good electrical conductivity, can improve the current transmission efficiency, thereby improving the discharge efficiency and accelerating the wire cutting speed; the γ-phase copper-zinc alloy has a higher zinc content and good gasification effect, which helps to improve the discharge efficiency and thus improve the wire cutting speed. However, correspondingly, the β-phase copper-zinc alloy has a lower zinc content than the γ-phase copper-zinc alloy, so its gasification effect is poor, and the γ-phase copper-zinc alloy has a lower electrical conductivity than the β-phase copper-zinc alloy, so its current transmission efficiency is low, thus restricting the further improvement of the performance of the electrode wire. Summary of the Invention

[0004] The present invention provides an electrode wire and a preparation method thereof, which are used to solve the problem that the performance of the electrode wire in the prior art is limited and affects the wire cut electrical discharge machining speed.

[0005] The present invention adopts the following technical scheme: An electrode wire includes: a core material; an intermediate layer located outside the core material; and a surface layer located outside the intermediate layer; wherein, the core material is a metal or an alloy; the intermediate layer includes a γ-phase copper-zinc alloy layer, and the surface layer discontinuously covers the γ-phase copper-zinc alloy layer; the γ-phase copper-zinc alloy layer has massive β-phase and / or β ’ phase copper-zinc alloy at the interface between it and the surface layer.

[0006] The present invention has the following beneficial effects:

[0007] 1. When the wire cut electrical discharge machining is carried out using this electrode wire, after the surface layer of the electrode wire is consumed by electro-corrosion, the γ-phase copper-zinc alloy layer inside the electrode wire and the massive β-phase and / or β ’The γ-phase copper-zinc alloy will be exposed. The exposed γ-phase copper-zinc alloy layer has the characteristic of high zinc content and good gasification effect, which helps to improve the discharge efficiency; while the exposed massive β-phase and / or β ’ phase copper-zinc alloy has the characteristic of good electrical conductivity, which can improve the current transmission efficiency and thus improve the discharge efficiency. That is, the electrode wire can have both the above two excellent characteristics, so that the discharge efficiency can be further improved and the wire cutting speed can be accelerated compared with the existing electrode wire.

[0008] 2. Since the surface layer intermittently covers the intermediate layer, tips will be formed at the intermittent places of the surface layer, and the tips are more likely to discharge. Therefore, during wire electrical discharge machining, the reaction time for the electrode wire to generate electric sparks can be reduced, thus accelerating the wire electrical discharge machining speed.

[0009] Preferably, the thickness of the massive β-phase and / or β ’ phase copper-zinc alloy on the cross-section of the electrode wire is 0.05 - 10 μm. The massive β-phase and / or β ’ phase copper-zinc alloy with the above size range can ensure its good electrical conductivity and improve the discharge efficiency.

[0010] Preferably, the thickness of the massive β-phase and / or β ’ phase copper-zinc alloy on the cross-section of the electrode wire is 0.5 - 5 μm. Specifically, the thickness of the massive β-phase and / or β ’ phase copper-zinc alloy on the cross-section of the electrode wire is 0.5 - 4 μm, 0.5 - 3 μm, 1 - 5 μm, 1 - 4 μm, 1 - 3 μm.

[0011] Preferably, the intermediate layer further includes a β-phase and / or β ’ phase copper-zinc alloy layer located between the γ-phase copper-zinc alloy layer and the core material.

[0012] Preferably, the intermediate layer has cracks. As mentioned before, tips can be formed at the crack places. During wire electrical discharge machining, the intermittent places are more likely to discharge, which can greatly reduce the reaction time for the electrode wire to generate electric sparks, thus accelerating the wire electrical discharge machining speed. In addition, the cracks can increase the contact area between the intermediate layer and the working fluid. During wire electrical discharge machining, the flushing is faster, the interval between two discharges can be reduced, and the discharge frequency can be increased, thus accelerating the wire cutting speed.

[0013] Preferably, the intermediate layer and / or the core material are exposed at the intermittent places of the surface layer. The exposed intermediate layer and core material can improve the electrical conductivity of the surface layer, which is beneficial to improving the transmission of discharge energy and beneficial to increasing the wire cutting speed.

[0014] Preferably, the surface layer contains carbon and zinc elements. The zinc element ensures excellent gasification erosion effect on the surface layer and improves the cutting speed; the presence of carbon element increases the conductivity of the electrode wire and improves the cutting speed.

[0015] Preferably, by mass percentage, the content of carbon element in the surface layer is ≥0.5%, and the content of zinc element is ≥60%. The above component contents ensure that there are sufficient zinc and carbon elements in the surface layer, which is conducive to the full play of the relevant components.

[0016] Preferably, the core material is copper or copper alloy.

[0017] The present invention also adopts the following technical solution: as the preparation method of the aforementioned electrode wire, it includes the following steps:

[0018] S100: Provide a purple copper bus bar or a copper alloy bus bar;

[0019] S200: Galvanize the surface of the bus bar. The electroplating solution includes additives, so as to form a galvanized layer on the surface of the bus bar to make the first wire blank. Among them, the additive is an organic additive containing carbon, hydrogen and oxygen elements;

[0020] S300: Stretch the first wire blank to make the second wire blank;

[0021] S400: Heat-treat the second wire blank. The copper element in the bus bar and the zinc element in the galvanized layer diffuse with each other during the heat treatment process to form a copper-zinc alloy, and the third wire blank is made. The third wire blank includes a core material, an intermediate layer and a surface layer from the inside out. Among them, the intermediate layer includes a γ-phase copper-zinc alloy layer, and the γ-phase copper-zinc alloy layer has massive β-phase and / or β ’ phase copper-zinc alloy at the interface with the surface layer;

[0022] S500: Stretch and stress-relieve anneal the third wire blank to make the finished electrode wire.

[0023] Applying the above preparation method provided by the present invention, through the heat treatment process, the zinc element in the galvanized layer and the copper element in the bus bar first form a γ-phase copper-zinc alloy through diffusion. The additive in the electroplating solution contains carbon, hydrogen and oxygen elements. Through electroplating, the carbon, hydrogen and oxygen elements in the additive enter the coating, and can promote the oxidation reaction of the zinc element in the later stage of the heat treatment process. As a result, in the later stage of the heat treatment process, the zinc content at the interface between the γ-phase copper-zinc alloy layer and the surface layer is rapidly consumed, which will make the part of the γ-phase copper-zinc alloy layer at the above interface prone to transform into β-phase and / or β ’ phase copper-zinc alloy, so as to obtain the massive β-phase and / or β ’ phase copper-zinc alloy described in the present invention.

[0024] Preferably, the concentration of the additive in the electroplating solution is 8-25 g / L.

[0025] Preferably, the additive is one or a mixture of more than one of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose.

[0026] Preferably, the wire diameter specification of the bus bar is 0.5-1.2 mm, and the wire diameter specification of the first wire blank after the stretching treatment in step S300 is 0.3-0.8 mm.

[0027] Preferably, there is also a β-phase and / or β ’ phase copper-zinc alloy layer between the γ-phase copper-zinc alloy layer and the core material in the third wire blank made in step S400.

[0028] Preferably, the temperature of the heat treatment in step S400 is 150-350 °C, and the time of the heat treatment is 1-50 h. Within this heat treatment temperature range and this heat treatment time range, it is possible to ensure the generation of the γ-phase copper-zinc alloy layer and the massive β-phase and / or β ’ phase copper-zinc alloy at the interface between it and the surface layer.

[0029] Preferably, the temperature of the heat treatment in step S400 is 150-200 °C, and the time of the heat treatment is 10-50 h, and the formed intermediate layer is a γ-phase copper-zinc alloy layer.

[0030] Preferably, the temperature of the heat treatment in step S400 is 250-350 °C, and the time of the heat treatment is 1-20 h, and the formed intermediate layer is a γ-phase copper-zinc alloy layer and a β-phase and / or β ’ phase copper-zinc alloy layer.

[0031] Preferably, the heat treatment in step S400 includes two stages S401 and S402, and the heat treatment temperature of stage S402 is higher than that of stage S401. First, a lower heat treatment temperature is adopted. On the one hand, it is beneficial to slow down the mutual diffusion rate of zinc elements in the galvanized layer and copper elements in the bus bar. On the other hand, at this temperature, it is suitable to produce the γ-phase copper-zinc alloy, so it is easy to produce the γ-phase copper-zinc alloy layer on the side close to the galvanized layer. Then, a higher heat treatment temperature is adopted to accelerate the consumption of zinc elements by the carbon, hydrogen, and oxygen elements introduced into the coating by the additive, reduce the zinc content in the γ-phase copper-zinc alloy layer at its interface with the surface layer, and cause part of the γ-phase copper-zinc alloy at this position to transform into the β-phase and / or β ’ phase copper-zinc alloy, which is manifested as massive β-phase and / or β ’ phase copper-zinc alloy in terms of structure. That is, adopting the above two-stage heat treatment method can more easily produce massive β-phase and / or β ’ phase copper-zinc alloy.

[0032] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Description of the Drawings

[0033] Figure 1 is a schematic partial cross-sectional view of an electrode wire produced by using the preparation method provided by the present invention;

[0034] Figure 2 is a schematic partial cross-sectional view of another electrode wire produced by using the preparation method provided by the present invention;

[0035] Figure 3 is a schematic partial cross-sectional view of an electrode wire produced by using the preparation method provided by the comparative example in the present invention.

[0036] Wherein, 1. core material, 2. intermediate layer, 20. γ-phase copper-zinc alloy layer, 21. massive β-phase copper-zinc alloy, 22. β-phase copper-zinc alloy layer, 3. surface layer, 4. crack. Detailed Embodiments

[0037] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0038] Embodiments of the present invention will be described below with reference to the drawings.

[0039] Before showing the specific embodiments, the structural features of the electrode wire provided by the present invention and the principles of its preparation method are described as follows:

[0040] When preparing the bus bar, brass bus bars are generally used. Specifically, they are generally made of CuZn37 brass or CuZn40 brass. It is also possible to use copper (i.e., pure copper) to prepare the bus bar, or copper alloys other than brass to prepare the bus bar.

[0041] Through the heat treatment process, the zinc element in the galvanized layer and the copper element in the bus bar first form a γ-phase copper-zinc alloy through diffusion. The additive in the electroplating solution contains carbon, hydrogen, and oxygen elements. Through electroplating, the carbon, hydrogen, and oxygen elements in the additive enter the coating, and can promote the oxidation reaction of the zinc element in the later stage of the heat treatment process, so that in the later stage of the heat treatment process, the zinc content at the interface between the γ-phase copper-zinc alloy layer and the surface layer is rapidly consumed, which will make the part of the γ-phase copper-zinc alloy layer at the above interface prone to transform into β-phase and / or β ’ phase copper-zinc alloy, so as to obtain the massive β-phase and / or β ’ phase copper-zinc alloy described above in the present invention.

[0042] Structurally, the massive β-phase and / or β ’ phase copper-zinc alloy is located between the γ-phase copper-zinc alloy layer and the surface layer, and is locally transformed from the γ-phase copper-zinc alloy layer. After the surface layer is corroded and consumed, the massive β-phase and / or β ’ phase copper-zinc alloy and the γ-phase copper-zinc alloy layer can be exposed synchronously and participate in discharge corrosion synchronously. In this way, it can not only have the characteristics of good electrical conductivity of the β-phase and / or β ’ phase copper-zinc alloy, but also have the characteristics of good gasification effect of the γ-phase copper-zinc alloy, thereby significantly improving the discharge efficiency and accelerating the wire cutting speed.

[0043] It should be noted that during the heat treatment stage in the preparation process, the zinc element in the galvanized layer diffuses with the copper element in the core material to form a copper-zinc alloy (i.e., the alloying process). Under different heat treatment process parameters, a β-phase and / or β ’ phase copper-zinc alloy layer will be formed between the γ-phase copper-zinc alloy layer and the core material. For the convenience of description, in the following embodiments, it is all described with the β-phase, that is, the β-phase in the following text means one or both of the β-phase and the β ’ phase have.

[0044] By mass percentage, the carbon element content in the surface layer of the electrode wire prepared in this embodiment is ≥0.5%, and the zinc element content is ≥60%.

[0045] As described in the above principle, in the preparation method provided by the present invention, the process parameters of heat treatment play a very important role. In the following Examples 1-16, the process parameters within the heat treatment parameter range provided by the present invention are adopted. Among them, the cross-sections of the electrode wire products made in Examples 1-8 refer to Figure 1 as shown, and the cross-sections of the electrode wire products made in Examples 9-16 refer to Figure 2 as shown; in the following Comparative Examples 1-3, the process parameters outside the heat treatment parameter range provided by the present invention are adopted, and the cross-sections of the electrode wire products made thereof refer to Figure 3 as shown.

[0046] Example 1: This example provides a preparation method of an electrode wire, and the preparation method includes the following steps:

[0047] S100: Provide a CuZn37 brass bus bar with a wire diameter specification of 1.2 mm;

[0048] S200: Use the electroplating process to galvanize the surface of the above brass bus bar. The electroplating solution includes additives, so as to form a 10-μm galvanized layer on the surface of the bus bar to make the first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as a mixture of one or more of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose, and the additive concentration in the electroplating solution is 10 g / L;

[0049] S300: Stretch the first wire blank to make a second wire blank with a wire diameter specification of 0.8 mm;

[0050] S400: Heat-treat the second wire blank at a heat-treatment temperature of 175 °C for a heat-treatment time of 20 h. The copper element in the bus bar and the zinc element in the galvanized layer diffuse into each other during the heat treatment to form a copper-zinc alloy, and a third wire blank is made. The third wire blank has a core material 1, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 in sequence from the inside out. Among them, the γ-phase copper-zinc alloy layer 20 has massive β-phase copper-zinc alloy 21 at the interface with the surface layer 3;

[0051] S500: Stretch and stress-relief anneal the third wire blank to make an electrode wire product with a wire diameter specification of 0.25 mm. The cross-section of the electrode wire product is referenced Figure 1 as shown in.

[0052] Example 2: This example provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0053] S100: Provide a CuZn40 brass bus bar with a wire diameter specification of 0.5 mm;

[0054] S200: Galvanize the surface of the above brass bus bar by electroplating. The electroplating solution includes additives, so as to form a 5-μm galvanized layer on the surface of the bus bar to make a first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as one or a mixture of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The additive concentration in the electroplating solution is 11 g / L;

[0055] S300: Stretch the first wire blank to make a second wire blank with a wire diameter specification of 0.35 mm;

[0056] S400: Heat-treat the second wire blank at a heat-treatment temperature of 195 °C for a heat-treatment time of 10 h. The copper element in the bus bar and the zinc element in the galvanized layer diffuse into each other during the heat treatment to form a copper-zinc alloy, and a third wire blank is made. The third wire blank has a core material 1, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 in sequence from the inside out. Among them, the γ-phase copper-zinc alloy layer 20 has massive β-phase copper-zinc alloy 21 at the interface with the surface layer 3;

[0057] S500: Stretch and stress-relief anneal the third wire blank to make an electrode wire product with a wire diameter specification of 0.25 mm. The cross-section of the electrode wire product is referenced Figure 1 as shown in.

[0058] Example 3: This example provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0059] S100: Provide a CuZn40 brass busbar with a wire diameter specification of 1 mm;

[0060] S200: Zinc plate the surface of the above brass busbar using an electroplating process. The electroplating solution includes additives, thereby plating and forming a 12-μm zinc coating on the busbar surface to produce a first wire blank. Among them, the additives are organic compounds containing carbon, hydrogen, and oxygen elements, such as one or a mixture of multiple of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The additive concentration in the electroplating solution is 16 g / L;

[0061] S300: Stretch the first wire blank to produce a second wire blank with a wire diameter specification of 0.65 mm;

[0062] S400: Heat-treat the second wire blank. The heat-treatment temperature is 190 °C, and the heat-treatment time is 25 h. The copper element in the busbar and the zinc element in the zinc coating diffuse into each other during the heat treatment to form a copper-zinc alloy, producing a third wire blank. The third wire blank has a core material 1, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 from the inside out. Among them, the γ-phase copper-zinc alloy layer 20 has a massive β-phase copper-zinc alloy 21 at the interface with the surface layer 3;

[0063] S500: Stretch and stress-relieve anneal the third wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is referenced Figure 1 as shown in.

[0064] Example 4: This example provides a method for preparing an electrode wire, and this preparation method includes the following steps:

[0065] S100: Provide a CuZn40 brass busbar with a wire diameter specification of 0.6 mm;

[0066] S200: Zinc plate the surface of the above brass busbar using an electroplating process. The electroplating solution includes additives, thereby plating and forming a 7-μm zinc coating on the busbar surface to produce a first wire blank. Among them, the additives are organic compounds containing carbon, hydrogen, and oxygen elements, such as one or a mixture of multiple of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The additive concentration in the electroplating solution is 20 g / L;

[0067] S300: Stretch the first wire blank to produce a second wire blank with a wire diameter specification of 0.4 mm;

[0068] S400: Heat-treat the second wire blank at a heat-treatment temperature of 150 °C for 50 h. The copper element in the bus bar and the zinc element in the galvanized layer diffuse into each other during the heat treatment to form a copper-zinc alloy, thereby producing a third wire blank. The third wire blank sequentially has a core material 1, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 from the inside to the outside. Among them, the γ-phase copper-zinc alloy layer 20 has massive β-phase copper-zinc alloy 21 at the interface between it and the surface layer 3;

[0069] S500: Stretch and stress-relieve anneal the third wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is shown in Figure 1 as shown.

[0070] Example 5: This example provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0071] S100: Provide a CuZn40 brass bus bar with a wire diameter specification of 1.1 mm;

[0072] S200: Galvanize the surface of the above-mentioned brass bus bar using an electroplating process. The electroplating solution includes additives, thereby forming a 5-μm galvanized layer on the surface of the bus bar to produce a first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as one or a mixture of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The additive concentration in the electroplating solution is 22 g / L;

[0073] S300: Stretch the first wire blank to produce a second wire blank with a wire diameter specification of 0.8 mm;

[0074] S400: Heat-treat the second wire blank at a heat-treatment temperature of 200 °C for 10 h. The copper element in the bus bar and the zinc element in the galvanized layer diffuse into each other during the heat treatment to form a copper-zinc alloy, thereby producing a third wire blank. The third wire blank sequentially has a core material 1, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 from the inside to the outside. Among them, the γ-phase copper-zinc alloy layer 20 has massive β-phase copper-zinc alloy 21 at the interface between it and the surface layer 3;

[0075] S500: Stretch and stress-relieve anneal the third wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is shown in Figure 1 as shown.

[0076] Example 6: This example provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0077] S100: Provide a CuZn37 brass bus bar with a wire diameter specification of 0.9 mm;

[0078] S200: Galvanize the surface of the above-mentioned brass busbar using an electroplating process. The electroplating solution includes additives, thereby forming a 3-μm galvanized layer on the surface of the busbar to produce a first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as one or a mixture of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The concentration of the additive in the electroplating solution is 25 g / L;

[0079] S300: Stretch the first wire blank to produce a second wire blank with a wire diameter specification of 0.55 mm;

[0080] S400: Perform heat treatment on the second wire blank. The heat treatment temperature is 180 °C, and the heat treatment time is 26 h. The copper element in the busbar and the zinc element in the galvanized layer diffuse into each other during the heat treatment process to form a copper-zinc alloy, producing a third wire blank. The third wire blank sequentially has a core material 1, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 from the inside out. Among them, the γ-phase copper-zinc alloy layer 20 has a massive β-phase copper-zinc alloy 21 at the interface with the surface layer 3;

[0081] S500: Stretch and stress-relief anneal the third wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is referenced Figure 1 as shown in.

[0082] Example 7: This example provides a method for preparing an electrode wire. The preparation method includes the following steps:

[0083] S100: Provide a CuZn37 brass busbar with a wire diameter specification of 1 mm;

[0084] S200: Galvanize the surface of the above-mentioned brass busbar using an electroplating process. The electroplating solution includes additives, thereby forming an 8-μm galvanized layer on the surface of the busbar to produce a first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as one or a mixture of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The concentration of the additive in the electroplating solution is 10 g / L;

[0085] S300: Stretch the first wire blank to produce a second wire blank with a wire diameter specification of 0.7 mm;

[0086] S400: Perform heat treatment on the second wire blank in two stages. The heat treatment temperature in the first stage is 150 °C, and the heat treatment time is 20 h. The heat treatment temperature in the second stage is 185 °C, and the heat treatment time is 10 h. The copper element in the busbar and the zinc element in the galvanized layer diffuse into each other during the heat treatment process to form a copper-zinc alloy, producing a third wire blank. The third wire blank sequentially has a core material 1, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 from the inside out. Among them, the γ-phase copper-zinc alloy layer 20 has a massive β-phase copper-zinc alloy 21 at the interface with the surface layer 3;

[0087] S500: Stretch and stress-relieving anneal the third wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is referenced Figure 1 as shown in

[0088] Example 8: This example provides a method for preparing an electrode wire, which includes the following steps:

[0089] S100: Provide a CuZn40 brass bus bar with a wire diameter specification of 1 mm;

[0090] S200: Zinc plate the surface of the above brass bus bar using an electroplating process. The electroplating solution includes additives, thereby plating a 5-μm zinc coating on the surface of the bus bar to produce a first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as a mixture of one or more of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The additive concentration in the electroplating solution is 8 g / L;

[0091] S300: Stretch the first wire blank to produce a second wire blank with a wire diameter specification of 0.7 mm;

[0092] S400: Perform heat treatment on the second wire blank in two stages. The heat treatment temperature in the first stage is 160 °C, and the heat treatment time is 30 h. The heat treatment temperature in the second stage is 200 °C, and the heat treatment time is 5 h. The copper element in the bus bar and the zinc element in the zinc coating diffuse into each other during the heat treatment process to form a copper-zinc alloy, producing a third wire blank. The third wire blank sequentially has a core material 1, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 from the inside out. Among them, the γ-phase copper-zinc alloy layer 20 has a massive β-phase copper-zinc alloy 21 at the interface with the surface layer 3;

[0093] S500: Stretch and stress-relieving anneal the third wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is referenced Figure 1 as shown in

[0094] Example 9: This example provides a method for preparing an electrode wire, which includes the following steps:

[0095] S100: Provide a CuZn37 brass bus bar with a wire diameter specification of 1.2 mm;

[0096] S200: Zinc plate the surface of the above brass bus bar using an electroplating process. The electroplating solution includes additives, thereby plating a 5-μm zinc coating on the surface of the bus bar to produce a first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as a mixture of one or more of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The additive concentration in the electroplating solution is 15 g / L;

[0097] S300: Stretch the first wire blank to produce a second wire blank with a wire diameter specification of 0.8 mm;

[0098] S400: Heat-treat the second wire blank at a heat-treatment temperature of 250 °C for a heat-treatment time of 20 h. The copper element in the bus bar and the zinc element in the galvanized layer diffuse into each other during the heat treatment to form a copper-zinc alloy, producing a third wire blank. The third wire blank sequentially has a core material 1, a β-phase copper-zinc alloy layer 22, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 from the inside out. Among them, the γ-phase copper-zinc alloy layer 20 has massive β-phase copper-zinc alloy 21 at the interface with the surface layer 3;

[0099] S500: Stretch and stress-relieve anneal the third wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is shown in the reference Figure 2 as shown.

[0100] Example 10: This example provides a method for preparing an electrode wire, which includes the following steps:

[0101] S100: Provide a CuZn40 brass bus bar with a wire diameter specification of 1 mm;

[0102] S200: Galvanize the surface of the above-mentioned brass bus bar using an electroplating process. The electroplating solution includes additives, thereby plating a 6-μm galvanized layer on the surface of the bus bar to produce a first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as one or a mixture of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The additive concentration in the electroplating solution is 12 g / L;

[0103] S300: Stretch the first wire blank to produce a second wire blank with a wire diameter specification of 0.65 mm;

[0104] S400: Heat-treat the second wire blank at a heat-treatment temperature of 280 °C for a heat-treatment time of 2 h. The copper element in the bus bar and the zinc element in the galvanized layer diffuse into each other during the heat treatment to form a copper-zinc alloy, producing a third wire blank. The third wire blank sequentially has a core material 1, a β-phase copper-zinc alloy layer 22, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 from the inside out. Among them, the γ-phase copper-zinc alloy layer 20 has massive β-phase copper-zinc alloy 21 at the interface with the surface layer 3;

[0105] S500: Stretch and stress-relieve anneal the third wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is shown in the reference Figure 2 as shown.

[0106] Example 11: This example provides a method for preparing an electrode wire, which includes the following steps:

[0107] S100: Provide a CuZn40 brass busbar with a wire diameter specification of 0.5 mm;

[0108] S200: Use an electroplating process to galvanize the surface of the above-mentioned brass busbar. The electroplating solution includes additives, thereby forming a 5-μm galvanized layer on the surface of the busbar to make the first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as a mixture of one or more of fructooligosaccharides, sorbitol, dextrin, sucrose, and maltose. The additive concentration in the electroplating solution is 15 g / L;

[0109] S300: Stretch the first wire blank to make a second wire blank with a wire diameter specification of 0.35 mm;

[0110] S400: Heat-treat the second wire blank. The heat treatment temperature is 300 °C, and the heat treatment time is 3 h. The copper element in the busbar and the zinc element in the galvanized layer diffuse into each other during the heat treatment process to form a copper-zinc alloy, making the third wire blank. The third wire blank has a core material 1, a β-phase copper-zinc alloy layer 22, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 from the inside out. Among them, the γ-phase copper-zinc alloy layer 20 has a massive β-phase copper-zinc alloy 21 at the interface with the surface layer 3;

[0111] S500: Stretch and stress-relieve anneal the third wire blank to make a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is referred to Figure 2 as shown in

[0112] Example 12: This example provides a method for preparing an electrode wire. The preparation method includes the following steps:

[0113] S100: Provide a CuZn40 brass busbar with a wire diameter specification of 0.9 mm;

[0114] S200: Use an electroplating process to galvanize the surface of the above-mentioned brass busbar. The electroplating solution includes additives, thereby forming a 10-μm galvanized layer on the surface of the busbar to make the first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as a mixture of one or more of fructooligosaccharides, sorbitol, dextrin, sucrose, and maltose. The additive concentration in the electroplating solution is 21 g / L;

[0115] S300: Stretch the first wire blank to make a second wire blank with a wire diameter specification of 0.6 mm;

[0116] S400: Heat-treat the second wire blank at a heat-treatment temperature of 320 °C for 5 h. During the heat treatment, the copper element in the bus bar and the zinc element in the galvanized layer diffuse into each other to form a copper-zinc alloy, producing a third wire blank. The third wire blank successively has a core material 1, a β-phase copper-zinc alloy layer 22, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 from the inside out. Among them, the γ-phase copper-zinc alloy layer 20 has massive β-phase copper-zinc alloy 21 at the interface with the surface layer 3;

[0117] S500: Stretch and stress-relieve anneal the third wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is shown in Figure 2 as shown.

[0118] Example 13: This example provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0119] S100: Provide a CuZn40 brass bus bar with a wire diameter specification of 0.9 mm;

[0120] S200: Zinc plate the surface of the above-mentioned brass bus bar using an electroplating process. The electroplating solution includes additives, thereby plating a 12-μm galvanized layer on the surface of the bus bar to produce a first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as one or a mixture of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The additive concentration in the electroplating solution is 8 g / L;

[0121] S300: Stretch the first wire blank to produce a second wire blank with a wire diameter specification of 0.5 mm;

[0122] S400: Heat-treat the second wire blank at a heat-treatment temperature of 350 °C for 1 h. During the heat treatment, the copper element in the bus bar and the zinc element in the galvanized layer diffuse into each other to form a copper-zinc alloy, producing a third wire blank. The third wire blank successively has a core material 1, a β-phase copper-zinc alloy layer 22, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 from the inside out. Among them, the γ-phase copper-zinc alloy layer 20 has massive β-phase copper-zinc alloy 21 at the interface with the surface layer 3;

[0123] S500: Stretch and stress-relieve anneal the third wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is shown in Figure 2 as shown.

[0124] Example 14: This example provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0125] S100: Provide a CuZn37 brass bus bar with a wire diameter specification of 1 mm;

[0126] S200: Galvanize the surface of the above-mentioned brass busbar using an electroplating process. The galvanizing solution includes additives, thereby plating a 10-μm galvanized layer on the surface of the busbar to produce a first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as one or a mixture of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The concentration of the additive in the electroplating solution is 13 g / L;

[0127] S300: Stretch the first wire blank to produce a second wire blank with a wire diameter specification of 0.8 mm;

[0128] S400: Heat-treat the second wire blank. The heat-treatment temperature is 260 °C, and the heat-treatment time is 20 h. The copper element in the busbar and the zinc element in the galvanized layer diffuse into each other during the heat treatment to form a copper-zinc alloy, producing a third wire blank. The third wire blank sequentially has a core material 1, a β-phase copper-zinc alloy layer 22, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 from the inside to the outside. Among them, the γ-phase copper-zinc alloy layer 20 has massive β-phase copper-zinc alloy 21 at the interface with the surface layer 3;

[0129] S500: Stretch and stress-relieve anneal the third wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is shown in Figure 2 as shown.

[0130] Example 15: This example provides a method for preparing an electrode wire. The preparation method includes the following steps:

[0131] S100: Provide a CuZn40 brass busbar with a wire diameter specification of 0.8 mm;

[0132] S200: Galvanize the surface of the above-mentioned brass busbar using an electroplating process. The electroplating solution includes additives, thereby plating an 8-μm galvanized layer on the surface of the busbar to produce a first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as one or a mixture of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The concentration of the additive in the electroplating solution is 25 g / L;

[0133] S300: Stretch the first wire blank to produce a second wire blank with a wire diameter specification of 0.5 mm;

[0134] S400: Perform heat treatment on the second wire blank in two stages. The heat treatment temperature in the first stage is 250 °C and the heat treatment time is 10 h. The heat treatment temperature in the second stage is 270 °C and the heat treatment time is 3 h. The copper element in the bus bar and the zinc element in the galvanized layer diffuse into each other during the heat treatment process to form a copper-zinc alloy, and the third wire blank is made. The third wire blank successively has a core material 1, a β-phase copper-zinc alloy layer 22, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 from the inside to the outside. Among them, the γ-phase copper-zinc alloy layer 20 has massive β-phase copper-zinc alloy 21 at the interface with the surface layer 3;

[0135] S500: Perform stretching and stress-relieving annealing on the third wire blank to make an electrode wire product with a wire diameter specification of 0.25 mm. The cross-section of the electrode wire product is referred to Figure 2 as shown in.

[0136] Example 16: This example provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0137] S100: Provide a CuZn40 brass bus bar with a wire diameter specification of 1 mm;

[0138] S200: Use electroplating technology to galvanize the surface of the above brass bus bar. The electroplating solution includes additives, so as to form a 15-μm galvanized layer on the surface of the bus bar to make the first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as one or a mixture of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The additive concentration in the electroplating solution is 9 g / L;

[0139] S300: Stretch the first wire blank to make a second wire blank with a wire diameter specification of 0.7 mm;

[0140] S400: Perform heat treatment on the second wire blank in two stages. The heat treatment temperature in the first stage is 270 °C and the heat treatment time is 10 h. The heat treatment temperature in the second stage is 350 °C and the heat treatment time is 1 h. The copper element in the bus bar and the zinc element in the galvanized layer diffuse into each other during the heat treatment process to form a copper-zinc alloy, and the third wire blank is made. The third wire blank successively has a core material 1, a β-phase copper-zinc alloy layer 22, a γ-phase copper-zinc alloy layer 20, and a surface layer 3 from the inside to the outside. Among them, the γ-phase copper-zinc alloy layer 20 has massive β-phase copper-zinc alloy 21 at the interface with the surface layer 3;

[0141] S500: Perform stretching and stress-relieving annealing on the third wire blank to make an electrode wire product with a wire diameter specification of 0.25 mm. The cross-section of the electrode wire product is referred to Figure 2 as shown in.

[0142] Applying the above-mentioned preparation method provided by the present invention, through the heat treatment process, zinc elements in the galvanized layer and copper elements in the busbar form a γ-phase copper-zinc alloy by diffusion. The additive in the electroplating solution contains carbon, hydrogen, and oxygen elements. Through electroplating, the carbon, hydrogen, and oxygen elements in the additive enter the coating, and can promote the oxidation reaction of zinc elements in the later stage of the heat treatment process. As a result, in the later stage of the heat treatment process, the zinc content at the interface between the formed γ-phase copper-zinc alloy layer 20 and the surface layer 3 is rapidly consumed, which makes the part of the γ-phase copper-zinc alloy layer 20 at the above interface prone to transform into the β-phase copper-zinc alloy, thereby obtaining the aforementioned massive β-phase copper-zinc alloy 21 in the present invention.

[0143] When performing wire electrical discharge machining with this electrode wire, when the surface layer 3 of the electrode wire is electrically eroded and consumed, the γ-phase copper-zinc alloy layer 20 inside the electrode wire and the massive β-phase copper-zinc alloy 21 thereon will be exposed. The exposed γ-phase copper-zinc alloy layer 20 has the characteristic of high zinc content and good gasification effect, which helps to improve the discharge efficiency; while the exposed massive β-phase copper-zinc alloy 21 has the characteristic of good electrical conductivity, which can improve the current transmission efficiency and further improve the discharge efficiency. That is to say, this electrode wire can possess the above two excellent characteristics, so that compared with the existing electrode wire, it can further improve the discharge efficiency and accelerate the wire cutting speed.

[0144] In addition, due to direct drawing after the plating process, the core material 1 and the intermediate layer 2 of this electrode wire can be extruded by the surface layer 3. The exposed intermediate layer 2 or core material 1 can improve the electrical conductivity of the surface layer 3, which is beneficial to improving the transmission of discharge energy and further accelerating the cutting speed. Moreover, the intermediate layer 2 in this electrode wire has cracks 4, and the discharge will preferentially occur at the edge of the cracks 4. Compared with the situation where there are no cracks 4 in the intermediate layer 2, applying the electrode wire with cracks 4 in the intermediate layer 2 can improve the reaction time for the electrode wire to generate electric sparks, thereby accelerating the speed of wire electrical discharge machining.

[0145] Comparative Example 1: This example is used as a comparative example, and the heat treatment process parameters in the preparation method provided in the above example are changed. Specifically:

[0146] S100: Provide a CuZn37 brass busbar with a wire diameter specification of 1 mm;

[0147] S200: Use the electroplating process to galvanize the surface of the above brass busbar. The electroplating solution includes an additive, so as to form a 10-μm galvanized layer on the surface of the busbar and make the first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as one or a mixture of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The additive concentration in the electroplating solution is 13 g / L;

[0148] S300: Stretch the first wire blank to make a second wire blank with a wire diameter specification of 0.8 mm;

[0149] S400: Heat-treat the second wire blank at a heat-treatment temperature of 130 °C for 50 h. The copper element in the bus bar and the zinc element in the galvanized layer diffuse into each other during the heat treatment to form a copper-zinc alloy, thus producing the third wire blank;

[0150] S500: Stretch and stress-relieve anneal the third wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is shown in the reference Figure 3 as shown.

[0151] Comparative Example 2: This example is used as a comparative example, and the heat-treatment process parameters in the preparation method provided in the above example are changed. Specifically:

[0152] S100: Provide a CuZn40 brass bus bar with a wire diameter specification of 0.8 mm;

[0153] S200: Galvanize the surface of the above brass bus bar using an electroplating process. The galvanizing solution includes additives, thereby plating an 8-μm thick galvanized layer on the surface of the bus bar to produce the first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as one or a mixture of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The concentration of the additive in the electroplating solution is 25 g / L;

[0154] S300: Stretch the first wire blank to produce a second wire blank with a wire diameter specification of 0.5 mm;

[0155] S400: Heat-treat the second wire blank at a heat-treatment temperature of 450 °C for 20 h. The copper element in the bus bar and the zinc element in the galvanized layer diffuse into each other during the heat treatment to form a copper-zinc alloy, thus producing the third wire blank;

[0156] S500: Stretch and stress-relieve anneal the third wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is shown in the reference Figure 3 as shown.

[0157] Comparative Example 3: This example is used as a comparative example, and the heat-treatment process parameters in the preparation method provided in the above example are changed. Specifically:

[0158] S100: Provide a CuZn40 brass bus bar with a wire diameter specification of 0.9 mm;

[0159] S200: Zinc is electroplated on the surface of the above-mentioned brass busbar using an electroplating process. The electroplating solution includes additives, thereby forming a 12-μm zinc coating on the surface of the busbar to produce a first wire blank. Among them, the additive is an organic compound containing carbon, hydrogen, and oxygen elements, such as one or a mixture of fructooligosaccharide, sorbitol, dextrin, sucrose, and maltose. The concentration of the additive in the electroplating solution is 8 g / L;

[0160] S300: The first wire blank is drawn to produce a second wire blank with a wire diameter specification of 0.5 mm;

[0161] S400: The second wire blank is heat-treated at a heat treatment temperature of 140 °C for 3 h. The copper element in the busbar and the zinc element in the zinc coating diffuse into each other during the heat treatment process to form a copper-zinc alloy, thereby producing a third wire blank;

[0162] S500: The third wire blank is drawn and stress-relieved annealed to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The cross-section of the finished electrode wire is shown in the reference Figure 3 as shown.

[0163] As shown in the above comparative example, when the heat treatment process parameters are inappropriate, it is impossible to prepare the electrode wire obtained in the example.

[0164] Comparative Example 1: A brass electrode wire with a wire diameter specification of 0.25 mm obtained by procurement;

[0165] Comparative Example 2: An electrode wire with a wire diameter specification of 0.25 mm coated with a zinc coating obtained by procurement;

[0166] Comparative Example 3: A gamma electrode wire with a wire diameter specification of 0.25 mm coated with an alloy layer obtained by procurement.

[0167] The following table is a comparison table of the structural characteristics of the electrode wires made in Examples 1 to 16, the electrode wires made in Comparative Examples 1 to 3, and the electrode wires obtained by procurement in Comparative Examples 1 to 3:

[0168]

[0169]

[0170] The electrode wires made in Examples 1 to 16, the electrode wires made in Comparative Examples 1 to 3, and the electrode wires obtained by procurement in Comparative Examples 1 to 3 are used for wire electrical discharge machining tests. The test conditions are shown in the following table:

[0171] The test conditions are shown in the following table:

[0172] Machine tool Agie E350 Workpiece thickness 50 mm Workpiece shape 6 * 6 mm Workpiece material 8407 Electrode wire specification 0.25 mm Number of machining passes Rough cutting

[0173] The test results are shown in the following table:

[0174]

[0175]

[0176] In the present invention, unless otherwise clearly defined or limited in the embodiments, the terms "installed", "connected", "joined" and "fixed" etc. appearing in the embodiments shall be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or integrated. Understandably, it can also be a mechanical connection, an electrical connection, etc.; of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the communication inside two components, or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific implementation situations.

[0177] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An electrode wire, comprising: A core material; An intermediate layer, which is located outside the core material; And A surface layer, which is located outside the intermediate layer; Wherein, the core material is a metal or an alloy; It is characterized in that the intermediate layer includes a γ-phase copper-zinc alloy layer, and the surface layer discontinuously covers the γ-phase copper-zinc alloy layer; The γ-phase copper-zinc alloy layer has massive β-phase and / or β ’ -phase copper-zinc alloy at its interface with the surface layer; the thickness of the massive β-phase and / or β ’ -phase copper-zinc alloy on the cross-section of the electrode wire is 0.05 - 10 μm.

2. The electrode wire according to claim 1, wherein: The thickness of the massive β-phase and / or β ’ phase copper-zinc alloy on the cross-section of the electrode wire is 0.5 - 5 μm.

3. The electrode wire according to claim 1, characterized in that, The intermediate layer further includes a β-phase and / or β-phase copper-zinc alloy layer located between the γ-phase copper-zinc alloy layer and the core material. ’ copper-zinc alloy layer.

4. The electrode wire according to claim 1, characterized in that, The intermediate layer has cracks.

5. The electrode wire according to claim 1, characterized in that, The intermediate layer and / or the core material are exposed at the discontinuities of the surface layer.

6. The electrode wire according to claim 1, wherein The surface layer contains carbon element and zinc element.

7. The electrode wire according to claim 6, characterized in that, By mass percentage, the carbon element content in the surface layer is ≥0.5%, and the zinc element content is ≥60%.

8. The electrode wire according to claim 1, wherein, The core material is copper or a copper alloy.

9. The method for preparing an electrode wire according to any one of claims 1 to 8, characterized in that, Including the following steps: S100: Provide a pure copper bus bar or a copper alloy bus bar; S200: Galvanize the surface of the bus bar. The electroplating solution includes an additive, so as to form a galvanized layer on the surface of the bus bar to make a first wire blank. Among them, the additive is an organic additive containing carbon, hydrogen and oxygen elements; S300: Stretch the first wire blank to make a second wire blank; S400: Heat-treat the second wire blank, where copper elements in the bus bar and zinc elements in the galvanized layer diffuse into each other during the heat treatment process to form a copper-zinc alloy, and manufacture a third wire blank. The third wire blank includes a core material, an intermediate layer, and a surface layer from the inside out. Among them, the intermediate layer includes a γ-phase copper-zinc alloy layer, and the γ-phase copper-zinc alloy layer has massive β-phase and / or β ’ phase copper-zinc alloy at the interface between it and the surface layer; S500: Stretch and stress-relieving anneal the third wire blank to make the finished electrode wire.

10. The method for preparing the electrode wire according to claim 9, wherein, The concentration of the additive in the electroplating solution is 8-25 g / L.

11. The method for preparing the electrode wire according to claim 9, characterized in that, The additive is one or a mixture of more than one of fructooligosaccharide, sorbitol, dextrin, sucrose and maltose.

12. The manufacturing method of the electrode wire according to claim 9, characterized in that, The wire diameter specification of the bus bar is 0.5-1.2 mm, and the wire diameter specification of the first wire blank after being stretched in step S300 is 0.3-0.8 mm.

13. The method for preparing the electrode wire according to claim 9, characterized in that, There is also a β-phase and / or β-phase copper-zinc alloy layer between the γ-phase copper-zinc alloy layer and the core material in the third wire blank produced in step S400. ’ phase copper-zinc alloy layer.

14. The method for preparing the electrode wire according to claim 9, wherein The temperature of the heat treatment in step S400 is 150-350 °C, and the time of the heat treatment is 1-50 h.

15. The method for preparing the electrode wire according to claim 14, wherein The temperature of the heat treatment in step S400 is 150-200 °C, and the time of the heat treatment is 10-50 h, and the formed intermediate layer is a γ-phase copper-zinc alloy layer.

16. The method for preparing an electrode wire according to claim 14, characterized in that, The temperature of the heat treatment in step S400 is 250 - 350 °C, the time of the heat treatment is 1 - 20 h, and the formed intermediate layer is a γ-phase copper-zinc alloy layer and a β-phase and / or β ’ phase copper-zinc alloy layer.

17. The method for preparing the electrode wire according to claim 9, wherein The heat treatment in step S400 includes two stages S401 and S402, and the heat treatment temperature of stage S402 is higher than that of stage S401.

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