An electrode wire and a preparation method thereof

Abstract

The present invention discloses an electrode wire and a preparation method thereof, comprising: a core material, which is a copper alloy; an intermediate layer, which is located outside the core material; and a surface layer, which is located outside the intermediate layer; wherein, the intermediate layer is a copper-zinc alloy; and irregular β-phase and / or β ’ phase copper-zinc alloy exists inside the core material. During the preparation process, β-phase copper-zinc alloy is formed inside the core material of the electrode wire through electroplating, heat treatment and stretching processes. By utilizing the characteristics of β-phase copper-zinc alloy and β ’ phase copper-zinc alloy, the electrical conductivity of the core material can be improved, thereby enhancing the transmission of discharge energy and accelerating the wire cutting speed.

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 into shape.

[0003] Wire electrical discharge machining processes a workpiece through the discharge principle of electric sparks. Before machining, the workpiece is connected to the positive pole of a pulsed power supply, and the electrode wire is connected to the negative pole of a high-frequency pulsed power supply as a tool electrode. The workpiece is cut using spark discharge. The machining accuracy and speed of this process are highly related to the performance of the electrode wire. After decades of iterative development of electrode wire products, from the initial pure copper electrode wire to the currently commonly used coated electrode wire, the performance has been greatly improved. However, after the alloy layer of the existing coated wire is consumed, its cutting speed will decrease significantly. 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 cutting speed of the electrode wire in the prior art decreases significantly after the alloy layer is consumed.

[0005] The present invention adopts the following technical solution: An electrode wire includes: a core material, the core material being a copper alloy; an intermediate layer located outside the core material; and a surface layer located outside the intermediate layer; wherein, the intermediate layer is a copper-zinc alloy; and irregular β-phase and / or β ’ phase copper-zinc alloy exists inside the core material.

[0006] The present invention has the following beneficial effects: Through research by the inventor, it is found that after the alloy layer of the existing coated wire is consumed, the reason for the significant decrease in its cutting speed is that the existing core material generally contains α-phase copper-zinc alloy, which has poor electrical conductivity and poor gasification flushing effect during the discharge process. Therefore, it shows a significant decrease in cutting speed after the alloy layer is consumed. By forming irregular β-phase and / or β ’ phase copper-zinc alloy inside the core material, both β-phase copper-zinc alloy and β ’ phase copper-zinc alloy have good electrical conductivity, which can improve the conductivity of the electrode wire. In this way, the discharge frequency during wire electrical discharge machining using this electrode wire can be greatly increased, and the corresponding machining speed will be greatly improved. In addition, β-phase and / or β ’The ξ-phase copper-zinc alloy has a higher zinc content and produces a better gasification flushing effect during the discharge process than the α-phase copper-zinc alloy. In summary, even as the structure outside the core material is consumed during the processing, the core material itself can still maintain a high cutting speed due to its good electrical conductivity and high zinc content.

[0007] Preferably, part of the irregular β-phase and / or β ’ -phase copper-zinc alloy located near the intermediate layer of the core material is connected to the intermediate layer. During the preparation process, due to the diffusion of zinc elements in the coating layer to the surface of the core material, the β-phase and / or β ’ -phase copper-zinc alloy located near the intermediate layer in the finally prepared electrode wire has a larger size and will be connected to the intermediate alloy layer together, which can further improve the electrical conductivity (current transmission efficiency) and the flushing effect during the discharge process.

[0008] Preferably, on the cross-section of the electrode wire, the area of the irregular β-phase and / or β ’ -phase copper-zinc alloy accounts for 2-80% of the area of the core material. The irregular β-phase and / or β ’ -phase copper-zinc alloy containing the above ratio can give full play to the role of the β-phase and / or β ’ -phase copper-zinc alloy in the core material, ensuring high electrical conductivity of the electrode wire and a continuous and stable high cutting processing speed.

[0009] Preferably, on the cross-section of the electrode wire, the area of the irregular β-phase and / or β ’ -phase copper-zinc alloy accounts for 10-60% of the area of the core material. Specifically, on the cross-section of the electrode wire, the area of the irregular β-phase and / or β'-phase copper-zinc alloy accounts for 10-50%, 15-40%, 15-50%, 15-60%, 20-50%, 20-60% or 30-60% of the area of the core material.

[0010] Preferably, the intermediate layer is a β-phase and / or β ’ -phase copper-zinc alloy layer and / or a γ-phase copper-zinc alloy layer.

[0011] Preferably, the intermediate layer has cracks. Tips can be formed at the cracks. According to the discharge principle, it is easier to discharge at the tips. Therefore, during wire electrical discharge machining, the reaction time for the electrode wire to generate electric sparks can be reduced, thereby increasing the discharge frequency and accelerating the wire electrical discharge machining speed. In addition, during wire electrical discharge machining, the cracks can increase the contact area between the intermediate layer and the working fluid, making the flushing speed faster, thereby shortening the interval between two discharges, further increasing the discharge frequency, and accelerating the wire cutting speed.

[0012] Preferably, the surface layer contains zinc element. The zinc element ensures that the surface layer has excellent gasification and erosion effects, and improves the cutting speed.

[0013] Preferably, the surface layer also contains carbon element. The presence of carbon element improves the conductivity of the electrode wire and increases the cutting speed.

[0014] Preferably, by mass percentage, the carbon element content in the surface layer is ≥ 0.5%, and the zinc element content in the surface layer is ≥ 60%. The above contents ensure that there is sufficient carbon element and zinc element in the surface layer, which is conducive to the full play of the relevant components.

[0015] To solve the above technical problems, the present invention also adopts the following technical solution: A preparation method of an electrode wire, comprising the following steps:

[0016] S100: Provide a brass bus bar, wherein the Cu element content of the brass bus bar is 58.5 - 62%;

[0017] S101: Galvanize the surface of the brass bus bar, thereby forming a galvanized layer on the surface of the bus bar to make a first wire blank;

[0018] S102: Heat-treat the first wire blank, and the copper element in the brass bus bar and the zinc element in the galvanized layer diffuse into each other during the heat treatment process to form an intermediate layer, making a second wire blank. The second wire blank has a core material, an intermediate layer and a surface layer from the inside out;

[0019] S103: Stretch and stress-relieve anneal the second wire blank to make a finished electrode wire. The core material has irregular β-phase and / or β ’ phase copper-zinc alloy inside.

[0020] Applying the above preparation method provided by the present invention, by selecting a specific brass bus bar and through electroplating, heat treatment and stretching processes, irregular β-phase and / or β ’ phase copper-zinc alloy can be generated in the core material inside the electrode wire. Both β-phase copper-zinc alloy and β ’ phase copper-zinc alloy have good electrical conductivity, which can improve the conductivity of the electrode wire. In this way, when using this electrode wire for wire electrical discharge machining, the discharge frequency can be greatly increased, and the corresponding machining speed will be greatly improved. In addition, the zinc content of β-phase and / or β ’ phase copper-zinc alloy is higher, and the gasification flushing effect generated during the discharge process is better than that of α-phase copper-zinc alloy. Therefore, even as the structure outside the core material is consumed during the processing, due to the good conductivity and high zinc content of the core material itself, a relatively high cutting speed can still be maintained.

[0021] Preferably, the heat treatment temperature in the step S102 is 130 - 400 °C, the heat treatment time is 1 - 50 h, and the formed intermediate layer is a β-phase and / or β ’ phase copper-zinc alloy layer and / or γ-phase copper-zinc alloy layer.

[0022] To solve the above technical problems, the present invention also adopts the following technical solution: A preparation method of an electrode wire, comprising the following steps:

[0023] S200: Provide a brass bus bar, wherein the Cu element content of the brass bus bar is 58.5 - 62%;

[0024] S201: Galvanize the surface of the brass bus bar, thereby plating a galvanized layer on the surface of the bus bar to make a first wire blank;

[0025] S202: Heat-treat the first wire blank, and the copper element in the brass bus bar and the zinc element in the galvanized layer diffuse into each other during the heat treatment to form a copper-zinc alloy layer, making a second wire blank;

[0026] S203: Stretch the second wire blank to make a third wire blank;

[0027] S204: Heat-treat the third wire blank to make a fourth wire blank, and the fourth wire blank sequentially has a core material, an intermediate layer, and a surface layer from the inside to the outside;

[0028] S205: Stretch and stress-relieve anneal the fourth wire blank to make a finished electrode wire, and the core material inside has irregular β-phase and / or β ’ phase copper-zinc alloy.

[0029] Applying the above preparation method provided by the present invention, by selecting a specific brass bus bar and through electroplating, heat treatment, and stretching processes, irregular β-phase and / or β ’ phase copper-zinc alloy can be generated in the core material inside the electrode wire. Both the β-phase copper-zinc alloy and β ’ phase copper-zinc alloy have good electrical conductivity, which can improve the conductivity of the electrode wire. In this way, the discharge frequency during wire electrical discharge machining using this electrode wire can be greatly increased, and the corresponding machining speed will be greatly improved. In addition, the β-phase and / or β ’ phase copper-zinc alloy has a higher zinc content, and the gasification flushing effect generated during the discharge process is better than that of the α-phase copper-zinc alloy. Therefore, even as the structure outside the core material is consumed during the machining process, the core material itself can still maintain a high cutting speed due to its good electrical conductivity and high zinc content.

[0030] Preferably, the heat treatment temperature in the step S202 is 130 - 250 °C, the heat treatment time is 1 - 50 h, and the formed copper-zinc alloy layer is a γ-phase copper-zinc alloy layer.

[0031] Preferably, the heat treatment temperature in step S204 is 300-500 °C, and the heat treatment time is 1-50 h. The formed intermediate layer is a β-phase and / or β ’ phase copper-zinc alloy layer.

[0032] Preferably, the Cu element content of the brass busbar is 58.5-60%. Using the brass busbar with the above Cu element content can ensure that a large number of irregular β-phases and / or β ’ phase copper-zinc alloys are formed in the core material during the subsequent heat treatment process.

[0033] Preferably, the electroplating solution for galvanizing contains a saccharide organic additive, and the concentration of the additive in the electroplating solution is 8-25 g / L. The saccharide organic additive can slow down the crystallization process of the galvanized layer, making the galvanized layer denser, brittle and harder. In this way, during the subsequent stretching process, the galvanized layer is more likely to break, and the internal intermediate layer and busbar are more likely to be extruded from the galvanized layer, that is, the internal core material and intermediate layer of the finally manufactured electrode wire are more likely to be exposed from the surface layer. The exposed core material and intermediate layer can improve the conductive efficiency of the surface layer during the initial processing and increase the processing speed.

[0034] Preferably, the additive is one or a mixture of maltose, lactose, dextrin and sucrose.

[0035] 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 understood through the practice of the present invention. Brief Description of the Drawings

[0036] Figure 1 is a schematic partial cross-sectional view of an electrode wire produced by using the preparation method provided by the present invention;

[0037] Figure 2 is a cross-sectional electron micrograph of the internal core material of the electrode wire produced in Example 1;

[0038] Figure 3 is a schematic partial cross-sectional view of another electrode wire produced by using the preparation method provided by the present invention;

[0039] Figure 4 is a cross-sectional electron micrograph of the internal core material of the electrode wire produced in Example 7;

[0040] Figure 5 is a schematic partial cross-sectional view of another electrode wire produced by using the preparation method provided by the present invention;

[0041] Figure 6 is a cross-sectional metallograph of the internal core material of the electrode wire produced in Example 13.

[0042] Among them, 1. core material, 10. irregular β-phase copper-zinc alloy, 2. intermediate layer, 20. crack, 21. β-phase copper-zinc alloy layer, 22. γ-phase copper-zinc alloy layer, 3. surface layer. Specific embodiments

[0043] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where 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.

[0044] The embodiments of the present invention will be described below with reference to the drawings.

[0045] 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:

[0046] Through the research of the inventor, it is found that after the alloy layer of the existing coated wire is consumed, the cutting speed will be significantly reduced because the existing core material generally contains α-phase copper-zinc alloy, which has poor electrical conductivity and poor gasification flushing effect during the discharge process. Therefore, it shows a significant decrease in cutting speed after the alloy layer is consumed. The present invention forms irregular β-phase and / or β ’ phase copper-zinc alloy inside the core material. Both β-phase copper-zinc alloy and β ’ phase copper-zinc alloy have good electrical conductivity and can improve the conductivity of the electrode wire. In this way, the discharge frequency during the wire electrical discharge machining using this electrode wire can be greatly increased, and the corresponding machining speed will be greatly increased. In addition, the β-phase and / or β ’ phase copper-zinc alloy has a higher zinc content, and the gasification flushing effect generated during the discharge process is better than that of the α-phase copper-zinc alloy. In summary, even as the structure outside the core material is consumed during the machining process, the core material itself can still maintain a high cutting speed due to its good conductivity and high zinc content.

[0047] Through the experimental research of the inventor, a brass busbar with a Cu content in the range of 58.5 - 62% should be selected during the preparation process, and only through the preparation method provided by the present invention can irregular β-phase and / or β ’ copper-zinc alloy be formed inside the core material of the manufactured electrode wire. The above-mentioned irregular shape in the present invention means that after the electrode wire is transversely cut and the cross-section of the electrode wire is viewed through a scanning electron microscope, the planar shape exhibited by the β-phase and / or β ’ phase copper-zinc alloy inside the core material has no specific shape. Specifically, on the cross-section of the electrode wire, the β-phase and / or β ’ phase copper-zinc alloy can present shapes such as long strips, curved strips, and blocks.

[0048] On the cross-section of the electrode wire, the higher the proportion of the area of the irregular β-phase and / or β-phase copper-zinc alloy in the area of the core material, the higher the conductivity of the electrode wire. The heat treatment process causes alloying inside the core material to generate β-phase and / or β ’ copper-zinc alloy. By controlling the crystal grain size of the generated β-phase and / or β ’ copper-zinc alloy through the heat treatment process, and then controlling the degree of stretching of the β-phase and / or β ’ copper-zinc alloy through the stretching process, that is, the proportion of the area of the irregular β-phase and / or β ’ copper-zinc alloy in the area of the core material can be controlled. It should be noted that during the heat treatment stage in the preparation process, zinc elements in the galvanized layer diffuse with copper elements in the core material to form copper-zinc alloy (i.e., the alloying process). Under different heat treatment process parameters, the intermediate layer can be β-phase or γ-phase or β-phase + γ-phase. Among them, the β-phase can also be β ’ phase. For the convenience of description, in the following embodiments, it is expressed as β-phase. That is, the β-phase in the following text represents one or both of β-phase and β ‘ phase and all have β-phase and / or β ’ copper-zinc alloy. ’ When the surface layer of the electrode wire prepared in this embodiment contains both carbon element and zinc element by mass percentage, the zinc element content in the surface layer ≥ 60%, and the carbon element content ≥ 0.5%. ’

[0049] The present invention provides two preparation methods. The following Examples 1-12 adopt the first preparation method. Among them, the cross-sections of the finished electrode wires made in Examples 1-6 are referred to

[0050] as shown. The cross-sectional electron micrograph of the internal core material of the electrode wire made by the preparation method of Example 1 is as shown Figure 1 in; the cross-sections of the finished electrode wires made in Examples 7-12 are referred to Figure 2 as shown. The cross-sectional electron micrograph of the internal core material of the electrode wire made by the preparation method of Example 7 is as shown Figure 3 in; the cross-sections of the finished electrode wires made in the following Examples 13-18 adopt the second preparation method. The cross-sections of the finished electrode wires made are referred to Figure 4 as shown. Among them, the metallographic diagram of the cross-section of the internal core material of the electrode wire made by the preparation method of Example 13 is as shown Figure 5 in; the cross-sections of the finished electrode wires made in the following Examples 13-18 adopt the second preparation method. The cross-sections of the finished electrode wires made are referred to Figure 6 as shown. Among them, the metallographic diagram of the cross-section of the internal core material of the electrode wire made by the preparation method of Example 13 is as shown

[0051] ​Example 1: This example provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0052] S100: Provide a brass bus bar with a wire diameter specification of 0.8 mm, wherein the content of Cu element in the brass bus bar is 59.5%;

[0053] S101: Electroplate zinc on the surface of the brass bus bar, so as to form a zinc plating layer with a thickness of 5 μm on the surface of the brass bus bar, and make a first wire blank. Among them, the electroplating solution for electroplating contains a saccharide organic additive. Specifically, the saccharide organic additive is one or a mixture of maltose, lactose, dextrin and sucrose, and the concentration of the saccharide organic additive in the electroplating solution is 8 g / L;

[0054] S102: Perform heat treatment on the first wire blank. The heat treatment temperature is 140 °C and the heat treatment time is 40 h. The copper element in the brass bus bar and the zinc element in the zinc plating layer diffuse into each other during the heat treatment to form an intermediate layer 2, and make a second wire blank. The second wire blank sequentially has a core material 1, an intermediate layer 2 and a surface layer 3 from the inside to the outside. Among them, the intermediate layer 2 is a γ-phase copper-zinc alloy layer 22;

[0055] S103: Stretch and stress relieve the second wire blank to make an electrode wire finished product with a wire diameter specification of 0.25 mm. Irregular β-phase copper-zinc alloy 10 is present inside the core material 1. The cross-sectional schematic diagram of the electrode wire finished product is referred to Figure 1 as shown in, and the electron microscope image of its cross-section is as Figure 2 shown in, and irregular β-phase copper-zinc alloy 10 can be seen.

[0056] Cross-cut the electrode wire provided in this example, and use a scanning electron microscope to observe the cross-section of its internal core material 1. Draw a 20×20 μm square on the scanning electron microscope image at 10,000 times magnification. The minimum unit of the square is 1 μm, and the ratio of the points falling on the irregular β-phase copper-zinc alloy 10 on the square to all points is 35-60%. That is, on the cross-section of the electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 35-60% of the area of the core material 1.

[0057] It can be understood that when cross-cutting the electrode wire at different positions for the above observation, the ratio of the area of the irregular β-phase copper-zinc alloy 10 to the area of the core material 1 is different. Therefore, the above 35-60% refers to multiple ratio values of 35%, 60% and those between 35% and 60% obtained after multiple measurements. The measurement principle for the ratio value of the area of the β-phase copper-zinc alloy 10 to the area of the core material 1 in the subsequent examples is the same as this, and will not be elaborated later.

[0058] Example 2: This example provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0059] S100: Provide a brass busbar with a wire diameter specification of 1.2 mm, wherein the content of Cu element in the brass busbar is 61%;

[0060] S101: Electroplate zinc on the surface of the brass busbar, thereby plating a zinc coating with a thickness of 10 μm on the surface of the brass busbar to make the first wire blank. Among them, the electroplating solution for electroplating contains a saccharide organic additive. Specifically, the saccharide organic additive is one or a mixture of maltose, lactose, dextrin and sucrose, and the concentration of the saccharide organic additive in the electroplating solution is 10 g / L;

[0061] S102: Perform heat treatment on the first wire blank. The heat treatment temperature is 200 °C and the heat treatment time is 10 h. The copper element in the brass busbar and the zinc element in the zinc coating diffuse into each other during the heat treatment process to form an intermediate layer 2, and the second wire blank is made. The second wire blank has a core material 1, an intermediate layer 2 and a surface layer 3 in sequence from inside to outside. Among them, the intermediate layer 2 is a γ-phase copper-zinc alloy layer 22;

[0062] S103: Stretch and stress relieve anneal the second wire blank to make a finished electrode wire with a wire diameter specification of 0.25 mm. The core material 1 has irregular β-phase copper-zinc alloy 10 inside. The cross-sectional schematic diagram of the finished electrode wire refers to Figure 1 as shown in.

[0063] Cross-cut the electrode wire provided in this embodiment and use a scanning electron microscope to observe the cross-section of its internal core material 1. Draw a 20×20 μm grid on the scanning electron microscope image at 10,000 times magnification. The minimum unit of the grid is 1 μm, and the ratio of the points on the grid that fall on the irregular β-phase copper-zinc alloy 10 to all points is 12 - 35%. That is, on the cross-section of this electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 12 - 35% of the area of the core material 1.

[0064] Example 3: This example provides a method for preparing an electrode wire, and this preparation method includes the following steps:

[0065] S100: Provide a brass busbar with a wire diameter specification of 0.8 mm, wherein the content of Cu element in the brass busbar is 58.5%;

[0066] S101: Electroplate zinc on the surface of the brass busbar, thereby plating a zinc coating with a thickness of 8 μm on the surface of the brass busbar to make the first wire blank. Among them, no saccharide organic additive is added to the electroplating solution for electroplating;

[0067] S102: Heat-treat the first wire blank at a heat-treatment temperature of 160 °C for a heat-treatment time of 20 h. The copper element in the brass bus bar and the zinc element in the galvanized layer diffuse into each other during the heat treatment to form an intermediate layer 2, thereby producing a second wire blank. The second wire blank sequentially has a core material 1, an intermediate layer 2, and a surface layer 3 from the inside out. Among them, the intermediate layer 2 is a γ-phase copper-zinc alloy layer 22;

[0068] S103: Stretch and stress-relieve anneal the second wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The core material 1 has irregular β-phase copper-zinc alloy 10 inside. The cross-sectional schematic diagram of the finished electrode wire is referred to Figure 1 as shown in

[0069] Cross-cut the electrode wire provided in this embodiment and observe the cross-section of its internal core material 1 using a scanning electron microscope. Draw a 20×20 μm grid on the scanning electron microscope image at 10,000 times magnification. The minimum unit of the grid is 1 μm. The ratio of the points falling on the irregular β-phase copper-zinc alloy 10 to all the points on the grid is 2-24%. That is, on the cross-section of this electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 2-24% of the area of the core material 1.

[0070] Example 4: This embodiment provides a method for preparing an electrode wire. The preparation method includes the following steps:

[0071] S100: Provide a brass bus bar with a wire diameter specification of 0.5 mm. Among them, the content of the Cu element in the brass bus bar is 62%;

[0072] S101: Electroplate zinc on the surface of the brass bus bar, thereby plating a galvanized layer with a thickness of 5 μm on the surface of the brass bus bar to produce a first wire blank. Among them, the electroplating solution for electroplating contains a saccharide organic additive. Specifically, the saccharide organic additive is one or a mixture of maltose, lactose, dextrin, and sucrose. The concentration of the saccharide organic additive in the electroplating solution is 25 g / L;

[0073] S102: Heat-treat the first wire blank at a heat-treatment temperature of 130 °C for a heat-treatment time of 50 h. The copper element in the brass bus bar and the zinc element in the galvanized layer diffuse into each other during the heat treatment to form an intermediate layer 2, thereby producing a second wire blank. The second wire blank sequentially has a core material 1, an intermediate layer 2, and a surface layer 3 from the inside out. Among them, the intermediate layer 2 is a γ-phase copper-zinc alloy layer 22;

[0074] S103: Stretch and stress-relieve anneal the second wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. The core material 1 has irregular β-phase copper-zinc alloy 10 inside. The cross-sectional schematic diagram of the finished electrode wire is referred to Figure 1 as shown in

[0075] The electrode wire provided in this embodiment is transversely cut, and the cross-section of its internal core material 1 is observed using a scanning electron microscope. A 20×20 μm grid is drawn on the scanning electron microscope image at 10,000 times magnification. The minimum unit of the grid is 1 μm. The ratio of the points falling on the irregular β-phase copper-zinc alloy 10 to all the points on the grid is 18 - 45%. That is, on the cross-section of the electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 18 - 45% of the area of the core material 1.

[0076] Example 5: This embodiment provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0077] S100: Provide a brass bus bar with a wire diameter specification of 0.65 mm, wherein the Cu element content in the brass bus bar is 60%;

[0078] S101: Electroplate zinc on the surface of the brass bus bar, so as to form a zinc plating layer with a thickness of 3 μm on the surface of the brass bus bar, and make the first wire blank. Among them, the electroplating solution for electroplating contains a saccharide organic additive. Specifically, the saccharide organic additive is one or a mixture of maltose, lactose, dextrin, and sucrose, and the concentration of the saccharide organic additive in the electroplating solution is 8 g / L;

[0079] S102: Perform heat treatment on the first wire blank. The heat treatment temperature is 150 °C, and the heat treatment time is 18 h. The copper element in the brass bus bar and the zinc element in the zinc plating layer diffuse into each other during the heat treatment process to form an intermediate layer 2, and make the second wire blank. The second wire blank has a core material 1, an intermediate layer 2, and a surface layer 3 from the inside to the outside in sequence. Among them, the intermediate layer 2 is a γ-phase copper-zinc alloy layer 22;

[0080] S103: Stretch and stress relieve the second wire blank to make an electrode wire finished product with a wire diameter specification of 0.25 mm. The core material 1 has an irregular β-phase copper-zinc alloy 10 inside. The cross-sectional schematic diagram of the electrode wire finished product is referred to Figure 1 as shown in.

[0081] The electrode wire provided in this embodiment is transversely cut, and the cross-section of its internal core material 1 is observed using a scanning electron microscope. A 20×20 μm grid is drawn on the scanning electron microscope image at 10,000 times magnification. The minimum unit of the grid is 1 μm. The ratio of the points falling on the irregular β-phase copper-zinc alloy 10 to all the points on the grid is 10 - 25%. That is, on the cross-section of the electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 10 - 25% of the area of the core material 1.

[0082] Example 6: This embodiment provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0083] S100: Provide a brass busbar with a wire diameter specification of 1 mm, wherein the Cu element content in the brass busbar is 62%;

[0084] S101: Electroplate zinc on the surface of the brass busbar, thereby plating a zinc coating with a thickness of 7 μm on the surface of the brass busbar to make a first wire blank. Among them, the electroplating solution for electroplating contains a saccharide organic additive. Specifically, the saccharide organic additive is one or a mixture of maltose, lactose, dextrin, and sucrose, and the concentration of the saccharide organic additive in the electroplating solution is 20 g / L;

[0085] S102: Heat-treat the first wire blank at a heat-treatment temperature of 180 °C for 14 h. The copper element in the brass busbar and the zinc element in the zinc coating diffuse into each other during the heat treatment to form an intermediate layer 2, and a second wire blank is made. The second wire blank has a core material 1, an intermediate layer 2, and a surface layer 3 from the inside to the outside in sequence. Among them, the intermediate layer 2 is a γ-phase copper-zinc alloy layer 22;

[0086] S103: Stretch and stress-relieve anneal the second wire blank to make a finished electrode wire with a wire diameter specification of 0.25 mm. The core material 1 has irregular β-phase copper-zinc alloy 10 inside. The cross-sectional schematic diagram of the finished electrode wire is referred to Figure 1 as shown in.

[0087] Cross-cut the electrode wire provided in this embodiment, and use a scanning electron microscope to observe the cross-section of its internal core material 1. Draw a 20×20 μm grid on the scanning electron microscope image at 10,000 times magnification. The minimum unit of the grid is 1 μm, and the ratio of the points falling on the irregular β-phase copper-zinc alloy 10 on the grid to all points is 10 - 32%. That is, on the cross-section of this electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 10 - 32% of the area of the core material 1.

[0088] Example 7: This embodiment provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0089] S100: Provide a brass busbar with a wire diameter specification of 1 mm, wherein the Cu element content in the brass busbar is 60%;

[0090] S101: Electroplate zinc on the surface of the brass busbar, thereby plating a zinc coating with a thickness of 12 μm on the surface of the brass busbar to make a first wire blank. Among them, the electroplating solution for electroplating contains a saccharide organic additive. Specifically, the saccharide organic additive is one or a mixture of maltose, lactose, dextrin, and sucrose, and the concentration of the saccharide organic additive in the electroplating solution is 10 g / L;

[0091] S102: Heat-treat the first wire blank at a heat-treatment temperature of 320 °C for 16 h. During the heat treatment, the copper element in the brass busbar and the zinc element in the galvanized layer diffuse into each other to form an intermediate layer 2, thus producing a second wire blank. The second wire blank successively has a core material 1, an intermediate layer 2, and a surface layer 3 from the inside out. Among them, the intermediate layer 2 is a β-phase copper-zinc alloy layer 21 and a γ-phase copper-zinc alloy layer 22;

[0092] S103: Stretch and stress-relieve anneal the second wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. Irregular β-phase copper-zinc alloy 10 exists inside the core material 1. A schematic cross-sectional view of the finished electrode wire is shown in Figure 3 as shown. Its cross-sectional electron micrograph is shown in Figure 4 as shown, where irregular β-phase copper-zinc alloy 10 can be seen.

[0093] Cross-cut the electrode wire provided in this embodiment and use a scanning electron microscope to observe the cross-section of its internal core material 1. Draw a 20×20 μm grid on the scanning electron micrograph at 10,000 times magnification. The minimum unit of the grid is 1 μm. The ratio of the points on the grid that fall on the irregular β-phase copper-zinc alloy 10 to all points is 22 - 55%. That is, on the cross-section of this electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 22 - 55% of the area of the core material 1.

[0094] Example 8: This embodiment provides a method for preparing an electrode wire. The preparation method includes the following steps:

[0095] S100: Provide a brass busbar with a wire diameter specification of 1.2 mm. Among them, the content of Cu element in the brass busbar is 59.5%;

[0096] S101: Electroplate zinc on the surface of the brass busbar, thereby plating a galvanized layer with a thickness of 10 μm on the surface of the brass busbar to produce a first wire blank. Among them, the electroplating solution for electroplating contains a saccharide organic additive. Specifically, the saccharide organic additive is one or a mixture of maltose, lactose, dextrin, and sucrose, and the concentration of the saccharide organic additive in the electroplating solution is 22 g / L;

[0097] S102: Heat-treat the first wire blank at a heat-treatment temperature of 250 °C for 50 h. During the heat treatment, the copper element in the brass busbar and the zinc element in the galvanized layer diffuse into each other to form an intermediate layer 2, thus producing a second wire blank. The second wire blank successively has a core material 1, an intermediate layer 2, and a surface layer 3 from the inside out. Among them, the intermediate layer 2 is a β-phase copper-zinc alloy layer 21 and a γ-phase copper-zinc alloy layer 22;

[0098] S103: Stretch and stress-relieving anneal the second wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. Inside the core material 1, there is an irregular β-phase copper-zinc alloy 10. The cross-sectional schematic diagram of the finished electrode wire is referenced in Figure 3 as shown in

[0099] Cross-cut the electrode wire provided in this embodiment and use a scanning electron microscope to observe the cross-section of its internal core material 1. Draw a 20×20 μm grid on the scanning electron microscope image at 10,000 times magnification. The minimum unit of the grid is 1 μm. The ratio of the points falling on the irregular β-phase copper-zinc alloy 10 to all the points on the grid is 20 - 45%. That is, on the cross-section of the electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 20 - 45% of the area of the core material 1.

[0100] Example 9: This embodiment provides a method for preparing an electrode wire. The preparation method includes the following steps:

[0101] S100: Provide a brass bus bar with a wire diameter specification of 0.85 mm. Among them, the content of Cu element in the brass bus bar is 62%;

[0102] S101: Electroplate zinc on the surface of the brass bus bar, so as to deposit a zinc plating layer with a thickness of 15 μm on the surface of the brass bus bar to produce a first wire blank. Among them, the electroplating solution for electroplating contains a saccharide organic additive. Specifically, the saccharide organic additive is one or a mixture of maltose, lactose, dextrin and sucrose, and the concentration of the saccharide organic additive in the electroplating solution is 25 g / L;

[0103] S102: Heat-treat the first wire blank. The heat-treatment temperature is 400 °C and the heat-treatment time is 1 h. The copper element in the brass bus bar and the zinc element in the zinc plating layer diffuse with each other during the heat-treatment process to form an intermediate layer 2, producing a second wire blank. The second wire blank successively has a core material 1, an intermediate layer 2 and a surface layer 3 from the inside to the outside. Among them, the intermediate layer 2 is a β-phase copper-zinc alloy layer 21 and a γ-phase copper-zinc alloy layer 22;

[0104] S103: Stretch and stress-relieving anneal the second wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. Inside the core material 1, there is an irregular β-phase copper-zinc alloy 10. The cross-sectional schematic diagram of the finished electrode wire is referenced in Figure 3 as shown in

[0105] Cross-section the electrode wire provided in this embodiment, and use a scanning electron microscope to observe the cross-section of its internal core material 1. Draw a 20×20 μm square on the scanning electron microscope image at 10,000 times magnification. The minimum unit of the square is 1 μm. The ratio of the points falling on the irregular β-phase copper-zinc alloy 10 to all the points on the square is 56 - 80%. That is, on the cross-section of this electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 56 - 80% of the area of the core material 1.

[0106] Example 10: This example provides a method for preparing an electrode wire, and this preparation method includes the following steps:

[0107] S100: Provide a brass bus bar with a wire diameter specification of 0.75 mm, wherein the content of Cu element in the brass bus bar is 61.5%;

[0108] S101: Electroplate zinc on the surface of the brass bus bar, so as to form a zinc plating layer with a thickness of 9 μm on the surface of the brass bus bar, and make the first wire blank. Among them, no sugar organic additive is added to the electroplating solution used for electroplating;

[0109] S102: Perform heat treatment on the first wire blank. The heat treatment temperature is 385 °C, and the heat treatment time is 4 h. The copper element in the brass bus bar and the zinc element in the zinc plating layer diffuse with each other during the heat treatment process to form an intermediate layer 2, and make the second wire blank. The second wire blank has a core material 1, an intermediate layer 2 and a surface layer 3 from the inside to the outside in sequence. Among them, the intermediate layer 2 is a β-phase copper-zinc alloy layer 21 and a γ-phase copper-zinc alloy layer 22;

[0110] S103: Stretch and stress relieve the second wire blank to make an electrode wire finished product with a wire diameter specification of 0.25 mm. The core material 1 has irregular β-phase copper-zinc alloy 10 inside. For the cross-sectional schematic diagram of the electrode wire finished product, refer to Figure 3 as shown in.

[0111] Cross-section the electrode wire provided in this embodiment, and use a scanning electron microscope to observe the cross-section of its internal core material 1. Draw a 20×20 μm square on the scanning electron microscope image at 10,000 times magnification. The minimum unit of the square is 1 μm. The ratio of the points falling on the irregular β-phase copper-zinc alloy 10 to all the points on the square is 48 - 69%. That is, on the cross-section of this electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 48 - 69% of the area of the core material 1.

[0112] Example 11: This example provides a method for preparing an electrode wire, and this preparation method includes the following steps:

[0113] S100: Provide a brass bus bar with a wire diameter specification of 1.1 mm, wherein the content of Cu element in the brass bus bar is 60%;

[0114] S101: Electroplate zinc on the surface of the brass busbar to form a zinc coating with a thickness of 11 μm on the surface of the brass busbar, thereby making the first wire blank. Among them, no sugar organic additive is added to the electroplating solution used for electroplating;

[0115] S102: Heat-treat the first wire blank. The heat-treatment temperature is 325 °C and the heat-treatment time is 10 h. The copper element in the brass busbar and the zinc element in the zinc coating diffuse into each other during the heat-treatment process to form an intermediate layer 2, thereby making the second wire blank. The second wire blank has a core material 1, an intermediate layer 2, and a surface layer 3 from the inside out. Among them, the intermediate layer 2 is a β-phase copper-zinc alloy layer 21 and a γ-phase copper-zinc alloy layer 22;

[0116] S103: Stretch and stress-relieve anneal the second wire blank to make a finished electrode wire with a wire diameter specification of 0.25 mm. The core material 1 has irregular β-phase copper-zinc alloy 10 inside. The cross-sectional schematic diagram of the finished electrode wire is referred to Figure 3 as shown in.

[0117] Cross-cut the electrode wire provided in this embodiment and use a scanning electron microscope to observe the cross-section of its internal core material 1. Draw a 20×20 μm grid on the scanning electron microscope image at 10,000 times magnification. The minimum unit of the grid is 1 μm. The ratio of the points falling on the irregular β-phase copper-zinc alloy 10 on the grid to all points is 30 - 65%. That is, on the cross-section of this electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 30 - 65% of the area of the core material 1.

[0118] Example 12: This embodiment provides a method for preparing an electrode wire. The preparation method includes the following steps:

[0119] S100: Provide a brass busbar with a wire diameter specification of 1 mm. Among them, the content of Cu element in the brass busbar is 60%;

[0120] S101: Electroplate zinc on the surface of the brass busbar to form a zinc coating with a thickness of 10 μm on the surface of the brass busbar, thereby making the first wire blank. Among them, the electroplating solution used for electroplating contains sugar organic additives. Specifically, the sugar organic additive is one or a mixture of maltose, lactose, dextrin, and sucrose. The concentration of the sugar organic additive in the electroplating solution is 22 g / L;

[0121] S102: Heat-treat the first wire blank. The heat-treatment temperature is 400 °C and the heat-treatment time is 4 h. The copper element in the brass busbar and the zinc element in the zinc coating diffuse into each other during the heat-treatment process to form an intermediate layer 2, thereby making the second wire blank. The second wire blank has a core material 1, an intermediate layer 2, and a surface layer 3 from the inside out. Among them, the intermediate layer 2 is a β-phase copper-zinc alloy layer 21 and a γ-phase copper-zinc alloy layer 22;

[0122] S103: Stretch and stress-relieving anneal the second wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. Inside the core material 1, there is an irregular β-phase copper-zinc alloy 10. The cross-sectional schematic diagram of the finished electrode wire is referred to Figure 3 as shown in

[0123] Cross-section the electrode wire provided in this embodiment and use a scanning electron microscope to observe the cross-section of its internal core material 1. Draw a 20×20 μm grid on the scanning electron microscope image at 10,000 times magnification. The minimum unit of the grid is 1 μm. The ratio of the points falling on the irregular β-phase copper-zinc alloy 10 on the grid to all the points is 54 - 76%. That is, on the cross-section of this electrode wire, the area ratio of the irregular β-phase copper-zinc alloy 10 to the area of the core material 1 is 54 - 76%.

[0124] Example 13: This embodiment provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0125] S200: Provide a brass bus bar with a wire diameter specification of 1.2 mm, wherein the Cu element content in the brass bus bar is 62%;

[0126] S201: Electroplate zinc on the surface of the brass bus bar, so as to form a zinc-plated layer with a thickness of 10 μm on the surface of the brass bus bar to produce a first wire blank. Among them, the electroplating solution for electroplating contains a saccharide organic additive. Specifically, the saccharide organic additive is one or a mixture of maltose, lactose, dextrin, and sucrose, and the concentration of the saccharide organic additive in the electroplating solution is 25 g / L;

[0127] S202: Perform heat treatment on the first wire blank. The heat treatment temperature is 250 °C, and the heat treatment time is 1 h. The copper element in the brass bus bar and the zinc element in the zinc-plated layer diffuse into each other during the heat treatment process to form a copper-zinc alloy layer, and a second wire blank is produced;

[0128] S203: Stretch the second wire blank to produce a third wire blank with a wire diameter specification of 0.8 mm;

[0129] S204: Perform heat treatment on the third wire blank. The heat treatment temperature is 500 °C, and the heat treatment time is 1 h to produce a fourth wire blank. The fourth wire blank sequentially has a core material 1, an intermediate layer 2, and a surface layer 3 from the inside to the outside, and the intermediate layer 2 is a β-phase copper-zinc alloy layer 21;

[0130] S205: Stretch and stress-relieving anneal the fourth wire blank to produce a finished electrode wire with a wire diameter specification of 0.25 mm. Inside the core material 1, there is an irregular β-phase copper-zinc alloy 10. The cross-sectional schematic diagram of the finished electrode wire is referred to Figure 5 as shown in, and its cross-sectional metallographic diagram is as Figure 6As shown, an irregular β-phase copper-zinc alloy 10 can be seen.

[0131] The electrode wire provided in this embodiment is transversely cut, and the cross-section of its internal core material 1 is observed using a scanning electron microscope. A 50×50 μm grid is drawn on the scanning electron microscope image at 1000 times magnification. The minimum unit of the grid is 5 μm. The ratio of the points falling on the irregular β-phase copper-zinc alloy 10 to all the points on the grid is 40-70%. That is, on the cross-section of the electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 40-70% of the area of the core material 1.

[0132] Example 14: This embodiment provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0133] S200: Provide a brass bus bar with a wire diameter specification of 1 mm, wherein the content of Cu element in the brass bus bar is 60%;

[0134] S201: Electroplate zinc on the surface of the brass bus bar, so as to form a zinc plating layer with a thickness of 14 μm on the surface of the brass bus bar, and make a first wire blank, wherein no sugar organic additive is added to the electroplating solution for electroplating;

[0135] S202: Perform heat treatment on the first wire blank. The heat treatment temperature is 180 °C, and the heat treatment time is 30 h. The copper element in the brass bus bar and the zinc element in the zinc plating layer diffuse with each other during the heat treatment process to form a copper-zinc alloy layer, and make a second wire blank;

[0136] S203: Stretch the second wire blank to make a third wire blank with a wire diameter specification of 0.7 mm;

[0137] S204: Perform heat treatment on the third wire blank. The heat treatment temperature is 300 °C, and the heat treatment time is 50 h, and make a fourth wire blank. The fourth wire blank sequentially has a core material 1, an intermediate layer 2 and a surface layer 3 from the inside to the outside, and the intermediate layer 2 is a β-phase copper-zinc alloy layer 21;

[0138] S205: Stretch and stress relieve the fourth wire blank to make an electrode wire finished product with a wire diameter specification of 0.25 mm. The core material 1 has an irregular β-phase copper-zinc alloy 10 inside. The cross-sectional schematic diagram of the electrode wire finished product refers to Figure 5 as shown in.

[0139] Cross-section the electrode wire provided in this embodiment and observe the cross-section of its internal core material 1 using a scanning electron microscope. Draw a square grid of 50×50 μm on the scanning electron microscope image at 1000 times magnification. The minimum unit of the grid is 5 μm. The ratio of the points falling on the irregular β-phase copper-zinc alloy 10 to all the points on the grid is 33 - 60%. That is, on the cross-section of the electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 33 - 60% of the area of the core material 1.

[0140] Example 15: This example provides a method for preparing an electrode wire, and this preparation method includes the following steps:

[0141] S200: Provide a brass bus bar with a wire diameter specification of 0.8 mm, wherein the content of Cu element in the brass bus bar is 62%;

[0142] S201: Electroplate zinc on the surface of the brass bus bar, thereby plating a zinc coating with a thickness of 9 μm on the surface of the brass bus bar to make a first wire blank. Among them, the electroplating solution for electroplating contains a saccharide organic additive. Specifically, the saccharide organic additive is one or a mixture of maltose, lactose, dextrin, and sucrose, and the concentration of the saccharide organic additive in the electroplating solution is 20 g / L;

[0143] S202: Perform heat treatment on the first wire blank. The heat treatment temperature is 130 °C, and the heat treatment time is 50 h. The copper element in the brass bus bar and the zinc element in the zinc coating diffuse with each other during the heat treatment process to form a copper-zinc alloy layer, and a second wire blank is made;

[0144] S203: Stretch the second wire blank to make a third wire blank with a wire diameter specification of 0.55 mm;

[0145] S204: Perform heat treatment on the third wire blank. The heat treatment temperature is 320 °C, and the heat treatment time is 40 h to make a fourth wire blank. The fourth wire blank has a core material 1, an intermediate layer 2, and a surface layer 3 from the inside to the outside in sequence. The intermediate layer 2 is a β-phase copper-zinc alloy layer 21;

[0146] S205: Stretch and perform stress relief annealing on the fourth wire blank to make an electrode wire finished product with a wire diameter specification of 0.25 mm. The core material 1 has irregular β-phase copper-zinc alloy 10 inside. The cross-sectional schematic diagram of the electrode wire finished product is referred to Figure 5 as shown in.

[0147] Cross-section the electrode wire provided in this embodiment, and use a scanning electron microscope to observe the cross-section of its internal core material 1. Draw a 50×50 μm grid on the scanning electron microscope image at 1000 times magnification. The minimum unit of the grid is 5 μm. The ratio of the points falling on the irregular β-phase copper-zinc alloy 10 to all the points on the grid is 33-66%. That is, on the cross-section of the electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 33-66% of the area of the core material 1.

[0148] Example 16: This example provides a method for preparing an electrode wire, and this preparation method includes the following steps:

[0149] S200: Provide a brass bus bar with a wire diameter specification of 1 mm, wherein the content of Cu element in the brass bus bar is 59.8%;

[0150] S201: Electroplate zinc on the surface of the brass bus bar, so as to form a zinc plating layer with a thickness of 15 μm on the surface of the brass bus bar to make the first wire blank. Among them, the electroplating solution for electroplating contains a saccharide organic additive. Specifically, the saccharide organic additive is one or a mixture of maltose, lactose, dextrin and sucrose, and the concentration of the saccharide organic additive in the electroplating solution is 18 g / L;

[0151] S202: Perform heat treatment on the first wire blank. The heat treatment temperature is 240 °C, and the heat treatment time is 10 h. The copper element in the brass bus bar and the zinc element in the zinc plating layer diffuse into each other during the heat treatment process to form a copper-zinc alloy layer, and the second wire blank is made;

[0152] S203: Stretch the second wire blank to make a third wire blank with a wire diameter specification of 0.65 mm;

[0153] S204: Perform heat treatment on the third wire blank. The heat treatment temperature is 420 °C, and the heat treatment time is 6 h to make the fourth wire blank. The fourth wire blank successively has a core material 1, an intermediate layer 2 and a surface layer 3 from the inside to the outside, and the intermediate layer 2 is a β-phase copper-zinc alloy layer 21;

[0154] S205: Stretch and stress relieve anneal the fourth wire blank to make an electrode wire finished product with a wire diameter specification of 0.25 mm. The core material 1 has irregular β-phase copper-zinc alloy 10 inside. The cross-sectional schematic diagram of the electrode wire finished product is referred to Figure 5 as shown in.

[0155] The electrode wire provided in this embodiment is transversely cut, and the cross-section of its internal core material 1 is observed using a scanning electron microscope. A 50×50 μm grid is drawn on the scanning electron microscope image at 1000 times magnification, with the smallest unit of the grid being 5 μm. The ratio of the points falling on the irregular β-phase copper-zinc alloy 10 to all the points on the grid is 58-80%. That is, on the cross-section of the electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 58-80% of the area of the core material 1.

[0156] Example 17: This embodiment provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0157] S200: Provide a brass bus bar with a wire diameter specification of 1.1 mm, wherein the Cu element content in the brass bus bar is 60.6%;

[0158] S201: Electroplate zinc on the surface of the brass bus bar, so as to form a zinc plating layer with a thickness of 12 μm on the surface of the brass bus bar to make a first wire blank, wherein no sugar-based organic additive is added to the electroplating solution for electroplating;

[0159] S202: Perform heat treatment on the first wire blank, the heat treatment temperature is 210 °C, and the heat treatment time is 28 h. The copper element in the brass bus bar and the zinc element in the zinc plating layer diffuse with each other during the heat treatment process to form a copper-zinc alloy layer, making a second wire blank;

[0160] S203: Stretch the second wire blank to make a third wire blank with a wire diameter specification of 0.8 mm;

[0161] S204: Perform heat treatment on the third wire blank, the heat treatment temperature is 460 °C, and the heat treatment time is 11 h, making a fourth wire blank. The fourth wire blank has a core material 1, an intermediate layer 2, and a surface layer 3 from the inside out in sequence, and the intermediate layer 2 is a β-phase copper-zinc alloy layer 21;

[0162] S205: Stretch and stress relieve anneal the fourth wire blank to make a finished electrode wire with a wire diameter specification of 0.25 mm, and the core material 1 has irregular β-phase copper-zinc alloy 10 inside. The cross-sectional schematic diagram of the finished electrode wire is referred to Figure 5 as shown in.

[0163] The electrode wire provided in this embodiment is transversely cut, and the cross-section of its internal core material 1 is observed using a scanning electron microscope. A 50×50 μm grid is drawn on the scanning electron microscope image at 1000 times magnification, with the smallest unit of the grid being 5 μm. The ratio of the points falling on the irregular β-phase copper-zinc alloy 10 to all the points on the grid is 52-78%. That is, on the cross-section of the electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 52-78% of the area of the core material 1.

[0164] Example 18: This example provides a method for preparing an electrode wire, and the preparation method includes the following steps:

[0165] S200: Provide a brass bus bar with a wire diameter specification of 1 mm, wherein the content of Cu element in the brass bus bar is 60%;

[0166] S201: Electroplate zinc on the surface of the brass bus bar, so as to form a zinc plating layer with a thickness of 14 μm on the surface of the brass bus bar to make a first wire blank. Among them, the electroplating solution for electroplating contains a saccharide organic additive. Specifically, the saccharide organic additive is one or a mixture of maltose, lactose, dextrin and sucrose, and the concentration of the saccharide organic additive in the electroplating solution is 18 g / L;

[0167] S202: Perform heat treatment on the first wire blank. The heat treatment temperature is 150 °C and the heat treatment time is 30 h. The copper element in the brass bus bar and the zinc element in the zinc plating layer diffuse into each other during the heat treatment process to form a copper-zinc alloy layer, so as to make a second wire blank;

[0168] S203: Stretch the second wire blank to make a third wire blank with a wire diameter specification of 0.55 mm;

[0169] S204: Perform heat treatment on the third wire blank. The heat treatment temperature is 300 °C and the heat treatment time is 50 h to make a fourth wire blank. The fourth wire blank sequentially has a core material 1, an intermediate layer 2 and a surface layer 3 from the inside to the outside, and the intermediate layer 2 is a β-phase copper-zinc alloy layer 21;

[0170] S205: Stretch and stress-relieving anneal the fourth wire blank to make an electrode wire finished product with a wire diameter specification of 0.25 mm. The core material 1 has irregular β-phase copper-zinc alloy 10 inside. The cross-sectional schematic diagram of the electrode wire finished product is referred to Figure 5 as shown in.

[0171] Cross-cut the electrode wire provided in this example, and use a scanning electron microscope to observe the cross-section of its internal core material 1. Draw a 50×50 μm grid on the scanning electron microscope image at 1000 times magnification. The minimum unit of the grid is 5 μm, and the ratio of the points falling on the irregular β-phase copper-zinc alloy 10 on the grid to all points is 25-48%. That is, on the cross-section of the electrode wire, the area of the irregular β-phase copper-zinc alloy 10 accounts for 25-48% of the area of the core material 1.

[0172] The electrode wire prepared by the above embodiments has an irregular β-phase copper-zinc alloy 10 in the inner core material 1. The β-phase copper-zinc alloy has good electrical conductivity, which can improve the conductivity of the electrode wire. Thus, when using this electrode wire for wire electrical discharge machining, the discharge frequency can be greatly increased, and the corresponding machining speed will be significantly improved. In addition, the zinc content in the β-phase copper-zinc alloy is higher, and the gasification flushing effect generated during the discharge process is better than that of the α-phase copper-zinc alloy. In summary, even as the structure outside the core material is consumed during the machining process, due to the good conductivity and high zinc content of the core material itself, a relatively high cutting speed can still be maintained.

[0173] The electrode wire prepared by the above embodiments, the intermediate layer 2 also has cracks 20, and tips can be formed at the cracks 20. According to the discharge principle, it is easier to discharge at the tips. Therefore, during wire electrical discharge machining, the reaction time for the electrode wire to generate electrical discharges can be reduced, thereby increasing the discharge frequency and accelerating the speed of wire electrical discharge machining. In addition, during wire electrical discharge machining, the cracks can increase the contact area between the intermediate layer and the working fluid, making the flushing speed faster, thereby shortening the interval between two discharges and further increasing the discharge frequency and accelerating the wire cutting speed.

[0174] Comparative Example 1: This embodiment is used as a comparative example, and the specifications of the brass bus bar in the preparation method provided in the above embodiments are changed. Specifically:

[0175] S100: Provide a brass bus bar with a wire diameter specification of 0.65 mm, wherein the Cu element content in the brass bus bar is 65%;

[0176] S101: Electroplate zinc on the surface of the brass bus bar, thereby plating a zinc coating with a thickness of 3 μm on the surface of the brass bus bar to make a first wire blank. Among them, the electroplating solution for electroplating contains saccharide organic compounds. Specifically, the saccharide organic compound is one or a mixture of maltose, lactose, dextrin, and sucrose, and the concentration of the saccharide organic compound in the electroplating solution is 8 g / L;

[0177] S102: Perform heat treatment on the first wire blank. The heat treatment temperature is 150 °C, and the heat treatment time is 18 h. The copper element in the brass bus bar and the zinc element in the zinc coating diffuse with each other during the heat treatment process to form an intermediate layer 2, and a second wire blank is made. The second wire blank sequentially has a core material 1, an intermediate layer 2, and a surface layer 3 from the inside to the outside, wherein the intermediate layer 2 is a γ-phase copper-zinc alloy layer 22;

[0178] S103: Perform stretching and stress relief annealing on the second wire blank to make an electrode wire finished product with a wire diameter specification of 0.25 mm.

[0179] Comparative Example 2: This example is used as a comparative example, and the specifications of the brass busbars in the preparation method provided in the above example are changed. Specifically:

[0180] S100: Provide a brass busbar with a wire diameter specification of 1 mm, wherein the Cu element content in the brass busbar is 64%;

[0181] S101: Electroplate zinc on the surface of the brass busbar, thereby forming a zinc plating layer with a thickness of 12 μm on the surface of the brass busbar to make the first wire blank. Among them, the electroplating solution for electroplating contains saccharide organic compounds. Specifically, the saccharide organic compound is one or a mixture of maltose, lactose, dextrin, and sucrose, and the concentration of the saccharide organic compound in the electroplating solution is 10 g / L;

[0182] S102: Perform heat treatment on the first wire blank. The heat treatment temperature is 320 °C, and the heat treatment time is 16 h. The copper element in the brass busbar and the zinc element in the zinc plating layer diffuse into each other during the heat treatment process to form an intermediate layer 2, and the second wire blank is made;

[0183] S103: Perform stretching and stress relief annealing on the second wire blank to make an electrode wire finished product with a wire diameter specification of 0.25 mm.

[0184] Comparative Example 3: This example is used as a comparative example, and the parameters of the heat treatment in the preparation method provided in the above example are changed. Specifically:

[0185] S100: Provide a brass busbar with a wire diameter specification of 0.8 mm, wherein the Cu element content in the brass busbar is 59.5%;

[0186] S101: Electroplate zinc on the surface of the brass busbar, thereby forming a zinc plating layer with a thickness of 5 μm on the surface of the brass busbar to make the first wire blank. Among them, the electroplating solution for electroplating contains saccharide organic compounds. Specifically, the saccharide organic compound is one or a mixture of maltose, lactose, dextrin, and sucrose, and the concentration of the saccharide organic compound in the electroplating solution is 8 g / L;

[0187] S102: Perform heat treatment on the first wire blank. The heat treatment temperature is 110 °C, and the heat treatment time is 30 h. The copper element in the brass busbar and the zinc element in the zinc plating layer diffuse into each other during the heat treatment process to form a copper-zinc alloy layer, and the second wire blank is made;

[0188] S103: Perform stretching and stress relief annealing on the second wire blank to make an electrode wire finished product with a wire diameter specification of 0.25 mm.

[0189] Comparative Example 1: Purchase a brass electrode wire with a wire diameter specification of 0.25 mm on the market;

[0190] Comparative Example 2: An electrode wire with a galvanized layer and a wire diameter specification of 0.25 mm purchased from the market;

[0191] Comparative Example 3: A gamma electrode wire with a wire diameter specification of 0.25 mm purchased from the market;

[0192] The following table is a comparison table of the structural characteristics of the electrode wires made in Examples 1 to 18, the electrode wires made in Comparative Examples 1 to 3, and the electrode wires purchased in Comparative Examples 1 to 3:

[0193]

[0194]

[0195] The electrode wires made in Examples 1 to 18, the electrode wires made in Comparative Examples 1 to 3, and the electrode wires purchased in Comparative Examples 1 to 3 were used for wire electrical discharge machining tests, and the test conditions are shown in the following table:

[0196]

[0197] The test results are shown in the following table:

[0198]

[0199]

[0200] Through test comparison, it can be known that the electrode wire prepared by the preparation method provided by the present invention, due to the presence of irregular β-phase copper-zinc alloy in its internal core material, can improve the conductivity and gasification flushing effect of the electrode wire, and thus significantly improve the cutting speed of wire electrical discharge machining.

[0201] In the present invention, unless otherwise clearly specified or limited in the embodiments, the terms "installation", "connection", "connection" and "fixation" etc. appearing in the embodiments should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or integrated, and can be understood as 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 the specific implementation situations.

[0202] 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, which is a copper alloy; an intermediate layer, which is located outside the core material; and a surface layer, which is located outside the intermediate layer; wherein, the intermediate layer is a copper-zinc alloy; It is characterized in that the core material has irregular β-phase and / or β ’ phase copper-zinc alloy inside; part of the irregular β-phase and / or β ’ phase copper-zinc alloy located near the intermediate layer of the core material is connected to the intermediate layer.

2. The electrode wire according to claim 1, characterized in that, On the cross-section of the electrode wire, the proportion of the area of the irregular β-phase and / or β-phase copper-zinc alloy in the area of the core material is 2-80%. ’ The proportion of the area of the irregular β-phase and / or β-phase copper-zinc alloy in the area of the core material is 2-80%.

3. The electrode wire according to claim 2, characterized in that, On the cross-section of the electrode wire, the proportion of the area of the irregular β-phase and / or β-phase copper-zinc alloy in the area of the core material is 10-60%. ’ The proportion of the area of the irregular β-phase and / or β-phase copper-zinc alloy in the area of the core material is 10-60%.

4. The electrode wire according to claim 1, wherein, The intermediate layer is a β-phase and / or β ’ phase copper-zinc alloy layer and / or γ-phase copper-zinc alloy layer.

5. The electrode wire according to any one of claims 1 to 4, characterized in that, the intermediate layer has cracks.

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

7. The wire electrode according to claim 6, wherein, The surface layer also contains carbon element.

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

9. A method for preparing an electrode wire, characterized in that, Comprising the following steps: S100: Provide a brass busbar, wherein the Cu element content of the brass busbar is 58.5 - 62%; S101: Galvanize the surface of the brass busbar, thereby forming a galvanized layer on the surface of the busbar to make a first wire blank; S102: Heat-treat the first wire blank, and the copper element in the brass busbar and the zinc element in the galvanized layer diffuse into each other during the heat treatment process to form an intermediate layer, making a second wire blank. The second wire blank has a core material, an intermediate layer, and a surface layer in sequence from inside to outside; S103: Stretch and stress-relieving anneal the second wire blank to produce a finished electrode wire, with irregular β-phase and / or β-phase copper-zinc alloy inside the core material. ’ phase copper-zinc alloy.

10. The preparation method of the electrode wire according to claim 9, characterized in that, The heat treatment temperature in the step S102 is 130 - 400 °C, and the heat treatment time is 1 - 50 h. The formed intermediate layer is a β-phase and / or a β ’ -phase copper-zinc alloy layer and / or a γ-phase copper-zinc alloy layer.

11. A method for preparing an electrode wire, characterized in that, Comprising the following steps: S200: Provide a brass busbar, wherein the Cu element content of the brass busbar is 58.5 - 62%; S201: Galvanize the surface of the brass busbar, thereby forming a galvanized layer on the surface of the busbar to make a first wire blank; S202: Heat-treat the first wire blank, and the copper element in the brass busbar and the zinc element in the galvanized layer diffuse into each other during the heat treatment process to form a copper-zinc alloy layer, making a second wire blank; S203: Stretch the second wire blank to make a third wire blank; S204: Heat-treat the third wire blank to make a fourth wire blank. The fourth wire blank has a core material, an intermediate layer, and a surface layer in sequence from inside to outside; S205: Stretch and stress-relieving anneal the fourth wire rod to produce a finished electrode wire, and the core material has irregular β-phase and / or β ’ phase copper-zinc alloy inside.

12. The method for preparing the electrode wire according to claim 11, wherein, The heat treatment temperature in step S202 is 130 - 250 °C, and the heat treatment time is 1 - 50 h. The formed copper-zinc alloy layer is a γ-phase copper-zinc alloy layer.

13. The method for preparing the electrode wire according to claim 11, characterized in that, The heat treatment temperature in the step S204 is 300-500 °C, and the heat treatment time is 1-50 h. The formed intermediate layer is a β-phase and / or β ’ phase copper-zinc alloy layer.

14. The method for preparing an electrode wire according to any one of claims 9-13, characterized in that, The Cu element content of the brass busbar is 58.5 - 60%.

15. The method for preparing an electrode wire according to any one of claims 9-13, characterized in that, The electroplating solution for galvanizing contains a saccharide organic additive, and the concentration of the additive in the electroplating solution is 8 - 25 g / L.

16. The method for preparing the electrode wire according to claim 15, wherein, The additive is one or a mixture of maltose, lactose, dextrin, and sucrose.

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