Alloy wire cleaning annealing method and annealing device

Abstract

The invention relates to the technical field of alloy annealing, in particular to a clean annealing method and device for alloy wires. The invention provides a clean annealing method for an alloy wire material. The clean annealing method comprises the following steps: carrying out annealing treatment on the alloy wire material by adopting a composite reducing agent; the composite reducing agent comprises a carbon material, potassium fluoborate and vitamin C in a mass ratio of (1-3): (4-6): (2-4). According to the clean annealing method for the alloy wire, oxide on the surface of the alloy wire is effectively removed in the annealing process, and weight loss is avoided; the annealed alloy wire is smooth and clean in surface and free of oxide; and in addition, no harmful substance is discharged in the annealing process, and the reduction effect on alloy wires such as gold, silver and copper is good.

Description

Technical Field

[0001] The invention relates to the technical field of alloy annealing, and in particular to an alloy wire cleaning annealing method and an annealing device. Background Art

[0002] Solder alloys are usually made of gold, silver, and copper as the main elements, with other alloying elements added. The purpose of improving strength and corrosion resistance is achieved by adding elements such as Al, Mg, Ti, Zr, and Re. The added corrosion-resistant elements are generally chemically active and easily form a dense oxide film during processing to protect the internal alloy from oxidation, but the surface oxides will affect the weldability of the solder. At present, solder wires are pickled, mechanically scrubbed, and other methods to remove surface oxides; the pickling process produces a large amount of waste acid, which pollutes the environment; the mechanical scrubbing process will cause excessive loss of solder wires, resulting in waste of resources and metal dust pollution.

[0003] The solder wire processing process usually adopts the procedures of melting, extrusion, annealing and drawing. Since the material processing process produces work hardening and strengthening, the wire needs to be continuously annealed during the processing. At present, the most common annealing method is furnace annealing, which is divided into ordinary atmosphere, reducing atmosphere, protective atmosphere and vacuum atmosphere. Among them, ordinary atmosphere furnace annealing is the most common. Annealing is carried out directly in the atmospheric environment. During the annealing process, the metal is very easy to oxidize and discolor at high temperature, especially silver and copper alloy wires are very easy to produce oxidation discoloration during the annealing process, and alloy wires are also prone to discoloration spots during the annealing process, affecting subsequent use; the surface of the wire is severely oxidized, and the surface oxides are removed through subsequent processes such as pickling and scrubbing, resulting in a large amount of waste acid and material loss. Annealing in a reducing atmosphere furnace is to introduce hydrogen, carbon monoxide, and nitrogen-hydrogen mixed gas during the annealing process of the alloy wire, while protecting the alloy wire from oxidation, reducing the surface oxide of the alloy wire; the anti-oxidation elements such as Al, Ti, Zr, and Mg added to the alloy generally have active electrochemical properties and are difficult to be reduced by commonly used reducing atmospheres such as hydrogen and carbon; annealing in a reducing atmosphere cannot reduce the oxidation of lightweight elements and active elements in the alloy system, and the reducing atmosphere such as hydrogen is active in nature, and there is a certain risk of explosion if the concentration is too high. Annealing in a vacuum atmosphere furnace is to connect the furnace body to a vacuum system to ensure that the metal annealing is not oxidized or discolored in a vacuum environment. Annealing in a protective atmosphere furnace uses inert gases such as nitrogen, argon, and helium, and inert gases are introduced to protect the alloy wire from oxidation at high temperatures. It is difficult to achieve continuous operation in protective atmosphere and vacuum atmosphere annealing, and oxidized alloy wires cannot be reduced.

[0004] In view of this, this invention is proposed. Summary of the invention

[0005] The first object of the present invention is to provide a method for clean annealing of alloy wires, which effectively removes oxides on the surface of the alloy wires without weight loss during the annealing process; the surface of the alloy wires after annealing is smooth and clean without oxides.

[0006] A second object of the present invention is to provide an annealing device capable of achieving clean annealing of alloy wire.

[0007] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0008] In a first aspect, the present invention provides a method for cleaning and annealing an alloy wire, comprising the following steps:

[0009] The alloy wire is annealed by using a composite reducing agent;

[0010] The composite reducing agent comprises: carbon material, potassium fluoroborate and vitamin C in a mass ratio of (1-3): (4-6): (2-4).

[0011] Further, it includes at least one of the following features (1) to (4);

[0012] (1) The carbon material comprises at least one of charcoal, carbon powder and graphite powder;

[0013] (2) The particle size of the graphite powder is less than 30 mesh;

[0014] (3) The particle size of the potassium fluoroborate is less than 30 mesh;

[0015] (4) The particle size of the vitamin C is less than 30 mesh.

[0016] Furthermore, the annealing treatment comprises: passing the alloy wire through an annealing device with the composite reducing agent laid on the bottom.

[0017] Furthermore, the annealing treatment is performed at a temperature of 560-700°C.

[0018] Furthermore, the annealing treatment pressure is ≤0.2 MPa.

[0019] Furthermore, the annealing treatment time is greater than 40s.

[0020] In a second aspect, the present invention also provides an annealing device for implementing the above-mentioned alloy wire cleaning annealing method, comprising: a heating thermostatic box;

[0021] Sealing rubber pads are arranged on both sides of the box body of the heating thermostatic box, and an opening is arranged in the middle of the sealing rubber pad, and the alloy wire enters and exits the heating thermostatic box through the opening;

[0022] A composite reducing agent is arranged at the bottom of the heating thermostatic box.

[0023] Furthermore, the thickness of the composite reducing agent is greater than 3 mm.

[0024] Furthermore, a pressure relief valve is provided on the top of the heating thermostatic box, and the pressure relief valve is connected to the water tank through a pipeline.

[0025] Furthermore, the annealing device also includes a straightening wheel and a tensioning wheel; the heating constant temperature box is arranged between the straightening wheel and the tensioning wheel.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The invention provides a clean annealing method for alloy wires. During the annealing process, the carbon material in the composite reducing agent removes oxygen in the annealing device; potassium fluoroborate is heated to generate boron fluoride gas that can reduce light elements and active elements; vitamin C is gasified during the heating process to reduce oxides on the surface of the alloy wires; thereby, surface oxide removal and reduction are achieved during the annealing process of the alloy wires; the surface of the alloy wires after annealing is bright and free of oxides, showing the metallic color of the alloy wires; and there is no weight loss when the alloy wires are weighed; moreover, no harmful substances are discharged during the annealing process, and the reduction effect on alloy wires such as gold, silver, and copper is good.

[0028] The alloy wire clean annealing method of the present invention solves the problems in the prior art that vacuum annealing and protective atmosphere annealing of alloy wire cannot remove the original oxides on the surface of the alloy wire; annealing in a reducing atmosphere cannot reduce Ti, Si and alkaline oxides; annealing in an atmospheric environment has severe oxidation, subsequent processes are complicated, waste liquid is difficult to handle, and material loss is large. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 It is a schematic structural diagram of the annealing device of the present invention.

[0031] Figure 2 This is a surface morphology of the silver alloy wire after annealing treatment in Example 1 of the present invention.

[0032] Reference numerals:

[0033] 11-compound reducing agent; 12-sealing rubber pad; 13-pressure relief valve; 2-water tank; 3-straightening wheel; 4-tensioning wheel. DETAILED DESCRIPTION

[0034] The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0035] The following is a detailed description of an alloy wire cleaning annealing method and an annealing device of the present invention.

[0036] In some embodiments of the present invention, a method for cleaning and annealing an alloy wire is provided, comprising the following steps:

[0037] The alloy wire is annealed by using a composite reducing agent;

[0038] The composite reducing agent comprises: carbon material, potassium fluoroborate and vitamin C in a mass ratio of (1-3): (4-6): (2-4).

[0039] The invention uses a mixture of potassium fluoroborate, vitamin C and carbon material as a deoxidizer and a reducing atmosphere generator. During high-temperature annealing, the carbon material is heated to absorb oxygen; the potassium fluoroborate is heated to generate boron fluoride gas that can reduce lightweight elements and active elements; the vitamin C is gasified during the heating process to reduce oxides on the surface of the alloy wire; thereby, surface oxide removal and reduction are achieved during the annealing of the alloy wire, the surface of the annealed alloy wire is bright and free of oxides, the metal color of the alloy wire is revealed, and the alloy wire is weighed without weight loss; in addition, no harmful substances are discharged during the annealing process, and the reduction effect on alloy wires such as gold, silver, and copper is good.

[0040] During the annealing process, carbon materials react with oxygen to produce carbon monoxide and carbon dioxide, which can remove oxygen; the specific chemical reaction is: 2C+O 2 =2CO↑; C+O 2 =CO 2 ↑.

[0041] Potassium fluoroborate is widely used, mainly as a flux and stripping agent for alloys. Its molecular formula is KBF 4, molecular weight is 125.90, and it starts to decompose at 530°C. During the annealing process, potassium fluoroborate is heated and decomposed to obtain decomposition products. The decomposition products (boron fluoride gas) react with oxides on the surface of the alloy wire (for example, Ti oxides, Si oxides) to form boron trioxide and fluorides, which promote slag removal and slag formation; boron trioxide can react with basic oxides to remove them.

[0042] TiO 2 For example, the specific chemical reaction is: KBF 4 →KF+BF 3 ↑;4BF 3 +3TiO 2 →2B 2 O 3 +3TiF 4 ↑. TiF 4 The molecular weight is 123.87, the melting point is 377°C, and it volatilizes at high temperature as the annealing temperature increases, thereby removing the oxide on the surface of the alloy wire.

[0043] The reaction between potassium fluoroborate and silicon oxide is similar to the reaction between potassium fluoroborate and titanium oxide, generating silicon tetrafluoride, which has a melting point of -90°C, thereby effectively removing silicon oxide from the surface of the alloy wire.

[0044] The reaction generated B 2 O 3 , molecular weight 69.62, melting point 450℃, it can dissolve most alkaline oxides (alkaline metal oxides) when melted to form glassy borates and metaborates, and during the smelting process, most of the impurity elements such as calcium, sodium, magnesium, and aluminum oxides can react with boron trioxide to produce corresponding borates and be removed.

[0045] The boron fluoride gas generated by the decomposition of potassium fluoroborate can be dissolved in cold water, and the tail gas can be collected by cold water.

[0046] The molecular formula of vitamin C is C 6 H 8 O 6 The molecular weight is 176.12, with strong reducing properties, melting point of 190-192°C, boiling point of 553°C, and the diene alcohol structure in the molecule easily releases H atoms and has strong reducing properties, which can reduce copper oxide, silver oxide, tin oxide, zinc oxide, etc. on the surface of alloy wire to the corresponding elemental metal. At the same time, vitamin C has a high solubility in water, and the tail gas can be collected by water.

[0047] The alloy wire clean annealing method of the present invention solves the problems in the prior art that vacuum annealing and protective atmosphere annealing of alloy wire cannot remove the original oxides on the surface of the alloy wire; annealing in a reducing atmosphere cannot reduce Ti, Si and alkaline oxides; annealing in a normal atmosphere (under atmospheric environment) causes severe oxidation, and subsequent processes are complicated, waste liquid is difficult to handle, and material loss is large.

[0048] In some embodiments of the present invention, the mass ratio of carbon material, potassium fluoroborate and vitamin C is (1-3):(4-6):(2-4); typically but not limiting, for example, the mass ratio of carbon material, potassium fluoroborate and vitamin C can be 1:4:2, 1:5:2, 2:4:4, 2:5:3, 2:6:6, 3:5:2 and the like.

[0049] The function of the carbon material is to absorb the oxygen in the annealing box. When the oxygen in the box is consumed, it can ensure that there is no metal oxidation discoloration during the annealing process of the alloy wire. Too little carbon material makes it difficult to completely consume oxygen, and the alloy wire oxidizes and discolors; after the oxygen in the box is consumed, no additional carbon material is needed to react with oxygen, and the box always has a positive pressure due to gas volatilization, and it is difficult for external oxygen to enter. The amount of carbon material used is sufficient to ensure that there is no oxygen residue in the box.

[0050] The main function of potassium fluoroborate is to remove oxides of lightweight elements such as Ti, Al, Zr, and Si that are difficult to reduce, and it has a certain reducing effect on some oxides. Potassium fluoroborate can volatilize BF during the annealing process. 3 Gas, when the amount of potassium fluoroborate is too small, the amount of gas volatilization is small, and the effect of removing lightweight metal oxides on the surface of the alloy wire is weak. When the potassium fluoroborate content is too high, the metal oxides on the surface of the alloy wire will become slag, causing the alloy wire to discolor.

[0051] The main function of vitamin C is to reduce the metal oxides on the surface of the alloy wire to the original color of the metal, avoiding the problem of discoloration of the metal wire surface caused by potassium fluoroborate alone. The low content of vitamin C has a weak effect on the reduction of oxides on the metal surface of the wire. When it is at a certain concentration, it can ensure that the wire is reduced to the original color of the metal alloy, achieving smooth and loss-free annealing.

[0052] In some embodiments of the present invention, the carbon material includes at least one of charcoal, carbon powder and graphite powder; preferably graphite powder.

[0053] In some embodiments of the present invention, the purity of the graphite powder is greater than 99.99%, and the particle size of the graphite powder is less than 30 meshes.

[0054] In some embodiments of the present invention, the purity of potassium fluoroborate is greater than 98%; and the particle size of potassium fluoroborate is less than 30 mesh.

[0055] In some embodiments of the present invention, the purity of vitamin C is greater than 99%; and the particle size of vitamin C is less than 30 mesh.

[0056] Graphite powder, potassium fluoroborate and vitamin C are in powder form, and the powder particles with the above mesh number are used. The smaller the mesh number, the larger the specific surface area, and the faster the gas volatilization or absorption speed.

[0057] In some embodiments of the present invention, the method for preparing the composite reducing agent comprises:

[0058] The carbon material, potassium fluoroborate and vitamin C are uniformly mixed; preferably, a three-dimensional mixer, a V-type mixer or a ball mill can be used for mixing.

[0059] In some embodiments of the present invention, the annealing treatment includes: passing the alloy wire through an annealing device with a composite reducing agent laid at the bottom; that is, laying the composite reducing agent at the bottom of the annealing device, the alloy wire enters the annealing device, and travels above the composite reducing agent at a speed of <20m / min and passes through the annealing device.

[0060] In some embodiments of the present invention, the temperature of the annealing treatment is 560-700°C; typically but not limiting, for example, the temperature of the annealing treatment can be 560°C, 580°C, 600°C, 620°C, 640°C, 660°C, 680°C, 700°C or a range of any two thereof.

[0061] Annealing at 560-700°C can vaporize potassium fluoroborate and vitamin C.

[0062] In some embodiments of the present invention, the pressure of the annealing treatment is ≤0.2 MPa.

[0063] Maintaining a slight positive pressure during the annealing process can prevent air from entering.

[0064] In some embodiments of the present invention, the annealing time is greater than 40 s.

[0065] The present invention does not impose a strict limit on the annealing time, which can be greater than 40 seconds to ensure that the alloy wire reacts completely with the atmosphere.

[0066] During the annealing process, the carbon material in the composite reducing agent removes the oxygen in the annealing device, potassium fluoroborate is heated to release boron fluoride gas, which reacts with Ti and Si on the surface of the alloy wire to generate boron trioxide, which reacts with alkaline oxides, and vitamin C is heated and volatilized to react with oxides on the surface of the alloy wire and reduce to elemental metals. Through the above reaction process, the oxides on the surface of the alloy wire can be effectively removed, the reduction of metal oxides can be promoted, and the surface of the alloy wire can be smooth and clean.

[0067] In some embodiments of the present invention, the alloy wire cleaning annealing method specifically comprises the following steps:

[0068] The composite reducing agent is laid at the bottom of the annealing device, and the annealing device is heated to 560-700°C. The alloy wire is annealed in the annealing device. After entering the annealing device, the alloy wire moves at a certain speed from above the composite reducing agent and passes through the annealing device; the pressure in the annealing device is maintained at ≤0.2MPa, and the excess gas is discharged and collected by cold water.

[0069] In some embodiments of the present invention, the alloy wire includes at least one of a silver alloy solder, a copper alloy solder, and a gold alloy solder.

[0070] See also Figure 1 , in some embodiments of the present invention, there is also provided an annealing device for implementing the above alloy wire cleaning annealing method, comprising: a heating thermostatic box;

[0071] Sealing pads 12 are provided on both sides of the box body of the heating thermostatic box, and an opening is provided in the middle of the sealing pad 12, and the alloy wire enters and exits the heating thermostatic box through the opening;

[0072] A composite reducing agent 11 is arranged at the bottom of the heating thermostatic box.

[0073] In some embodiments of the invention, the heating incubator comprises a resistive heating incubator.

[0074] In some embodiments of the present invention, the thickness of the composite reducing agent 11 is greater than 3 mm.

[0075] In some embodiments of the present invention, a pressure relief valve 13 is provided on the top of the heating thermostatic box, and the pressure relief valve 13 is connected to the water tank 2 through a pipeline.

[0076] In some embodiments of the present invention, the annealing device further comprises a straightening wheel 3 and a tensioning wheel 4 ; and the heating constant temperature box is arranged between the straightening wheel 3 and the tensioning wheel 4 .

[0077] The annealing device of the present invention is used to clean and anneal the alloy wire, which specifically includes the following steps:

[0078] The alloy wire enters the heating thermostat from the opening in the middle of the sealing pad 12 on one side of the heating thermostat, moves over the composite reducing agent 11 at a certain speed in the heating thermostat, and passes through the opening in the middle of the sealing pad 12 on the other side of the heating thermostat. When the pressure inside the heating thermostat exceeds 0.2MPa, the pressure relief valve 13 is opened, and the gas inside the box enters the water tank 2 through the pipeline.

[0079] Example 1

[0080] The annealing device provided in this embodiment comprises: four pairs of straightening wheels 3, a heating thermostatic box and two tensioning wheels 4 arranged in sequence;

[0081] A composite reducing agent 11 with a thickness of more than 3 mm is arranged at the bottom of the heating thermostatic box;

[0082] Sealing rubber pads 12 are provided on both sides of the box body of the heating thermostatic box, and an opening is provided in the middle of the sealing rubber pads 12;

[0083] A pressure relief valve 13 is provided on the top of the heating thermostatic box, and the pressure relief valve 13 is connected to the water tank 2 through a pipeline.

[0084] The silver alloy wire cleaning annealing method provided in this embodiment is implemented by using the above-mentioned annealing device, and comprises the following steps:

[0085] A silver alloy wire with a diameter of 1.0 mm enters the heating thermostat from the opening in the middle of the sealing pad 12 on one side of the heating thermostat for annealing. The heating thermostat is heated to 650°C. The silver alloy wire travels above the composite reducing agent at a speed of 8 m / min in the heating thermostat and passes through the opening in the middle of the sealing pad 12 on the other side of the heating thermostat (the required time is > 40 s). When the pressure in the heating thermostat exceeds 0.2 MPa, the pressure relief valve 13 is opened, and the gas in the box enters the water tank 2 through the pipeline.

[0086] The silver alloy wire material includes the following components by weight percentage:

[0087] Cu 26%~27%, Ti 1%~1.5%, and the balance is Ag.

[0088] The composite reducing agent, measured by mass percentage, comprises the following components:

[0089] Graphite powder 20%, potassium fluoroborate 50% and vitamin C 30%.

[0090] During the annealing process, at 650°C, graphite powder reacts with oxygen, potassium fluoroborate decomposes to generate volatile boron fluoride, boron fluoride reacts with titanium oxide on the surface of the silver alloy wire to generate volatile titanium tetrafluoride, and vitamin C volatilizes to reduce silver and copper oxides on the surface of the silver alloy wire.

[0091] The surface morphology of the silver alloy wire after annealing is as follows: Figure 2 As shown; the surface of the silver alloy wire after annealing is smooth and has no oxidation discoloration.

[0092] Example 2

[0093] The silver alloy wire cleaning annealing method provided in this embodiment is implemented using the annealing device of embodiment 1, and comprises the following steps:

[0094] A silver alloy wire with a diameter of 2.0 mm enters the heating thermostat from the opening in the middle of the sealing pad 12 on one side of the heating thermostat for annealing. The heating thermostat is heated to 600°C. The silver alloy wire travels above the composite reducing agent at a speed of 5 m / min in the heating thermostat and passes through the opening in the middle of the sealing pad 12 on the other side of the heating thermostat (the required time is > 40 s). When the pressure in the heating thermostat exceeds 0.2 MPa, the pressure relief valve 13 is opened, and the gas in the box enters the water tank 2 through the pipeline.

[0095] The silver alloy wire material includes the following components by weight percentage:

[0096] Cu 43%~45%, Zn 34%~38%, Si 0.05%~0.25%, and the balance is Ag.

[0097] The composite reducing agent comprises the following components in terms of mass percentage:

[0098] Graphite powder 10%, potassium fluoroborate 50% and vitamin C 40%.

[0099] During the annealing process, at 600°C, graphite powder reacts with oxygen, potassium fluoroborate decomposes to generate volatile boron fluoride, boron fluoride reacts with silicon oxide on the surface of the silver alloy wire to generate volatile silicon tetrafluoride, and vitamin C volatilizes to reduce silver and copper oxides on the surface of the silver alloy wire.

[0100] The surface of the silver alloy wire after annealing is smooth and has no oxidation discoloration.

[0101] Example 3

[0102] The copper alloy wire cleaning annealing method provided in this embodiment is implemented using the annealing device of Embodiment 1, and comprises the following steps:

[0103] A copper alloy wire with a diameter of 2.0 mm enters the heating thermostat from the opening in the middle of the sealing pad 12 on one side of the heating thermostat for annealing. The heating thermostat is heated to 700°C. The copper alloy wire travels above the composite reducing agent at a speed of 4 m / min in the heating thermostat and passes through the opening in the middle of the sealing pad 12 on the other side of the heating thermostat (the required time is > 40 s). When the pressure in the heating thermostat exceeds 0.2 MPa, the pressure relief valve 13 is opened, and the gas in the box enters the water tank 2 through the pipeline.

[0104] The copper alloy wire material includes the following components by mass percentage:

[0105] Ti 2%~3%, Si 1%~2%, and the balance is Cu.

[0106] The composite reducing agent comprises the following components in terms of mass percentage:

[0107] Graphite powder 30%, potassium fluoroborate 50% and vitamin C 20%.

[0108] During the annealing process, at 700°C, graphite powder reacts with oxygen, potassium fluoroborate decomposes to generate volatile boron fluoride, boron fluoride reacts with silicon oxide and silicon oxide on the surface of the copper alloy wire to generate volatile silicon tetrafluoride and silicon tetrafluoride, and vitamin C volatilizes to reduce copper oxide on the surface of the copper alloy wire;

[0109] The surface of the copper alloy wire after annealing is smooth and has no oxidation discoloration.

[0110] Example 4

[0111] The copper alloy wire cleaning annealing method provided in this embodiment is implemented using the annealing device of Embodiment 1, and comprises the following steps:

[0112] A copper alloy wire with a diameter of 1.0 mm enters the heating thermostat from the opening in the middle of the sealing pad 12 on one side of the heating thermostat for annealing. The heating thermostat is heated to 600°C. The copper alloy wire travels above the composite reducing agent at a speed of 12 m / min in the heating thermostat and passes through the opening in the middle of the sealing pad 12 on the other side of the heating thermostat (the required time is > 40 s). When the pressure in the heating thermostat exceeds 0.2 MPa, the pressure relief valve 13 is opened, and the gas in the box enters the water tank 2 through the pipeline.

[0113] The copper alloy wire material includes the following components by mass percentage:

[0114] Zn 29%~33%, Al 0.8%~2%, Si 0.7%~1.5%, and the balance is Cu.

[0115] The composite reducing agent comprises the following components in terms of mass percentage:

[0116] Graphite powder 20%, potassium fluoroborate 40% and vitamin C 40%.

[0117] During the annealing process, at 600°C, graphite powder reacts with oxygen, potassium fluoroborate decomposes to generate volatile boron fluoride, boron fluoride reacts with silicon oxide on the surface of the copper alloy wire to generate volatile silicon tetrafluoride and boron trioxide, boron trioxide reacts with aluminum oxide on the surface of the copper alloy wire to form borate, and vitamin C volatilizes to reduce copper oxide on the surface of the copper alloy wire.

[0118] The surface of the copper alloy wire after annealing is smooth and has no oxidation discoloration.

[0119] Example 5

[0120] The gold alloy wire cleaning annealing method provided in this embodiment is implemented using the annealing device of embodiment 1, and comprises the following steps:

[0121] A gold alloy wire with a diameter of 15 μm enters the heating thermostat from the opening in the middle of the sealing pad 12 on one side of the heating thermostat for annealing. The heating thermostat is heated to 680° C. The gold alloy wire travels above the composite reducing agent at a speed of 20 m / min in the heating thermostat and passes through the opening in the middle of the sealing pad 12 on the other side of the heating thermostat (the required time is > 40 s). When the pressure in the heating thermostat exceeds 0.2 MPa, the pressure relief valve 13 is opened, and the gas in the box enters the water tank 2 through the pipeline.

[0122] The gold alloy wire material includes the following components by weight percentage:

[0123] Ca 0.01%, Ti 0.01%, Si 0.01%, Mg 0.01%, Cu 0.01%, and the balance is Au.

[0124] The composite reducing agent comprises the following components in terms of mass percentage:

[0125] Graphite powder 20%, potassium fluoroborate 60% and vitamin C 20%.

[0126] During the annealing process, at 680°C, graphite powder reacts with oxygen, potassium fluoroborate decomposes to generate volatile boron fluoride, boron fluoride reacts with titanium oxide and silicon oxide on the surface of the gold alloy wire to generate volatile titanium tetrafluoride, silicon tetrafluoride, and boron trioxide, boron trioxide reacts with calcium oxide and magnesium oxide on the surface of the gold alloy wire to form corresponding borates, and vitamin C volatilizes to reduce copper oxide on the surface of the gold alloy wire;

[0127] The surface of the gold alloy wire after annealing is smooth and has no oxidation discoloration.

[0128] Comparative Example 1

[0129] The alloy wire cleaning annealing method provided in this comparative example is to use ammonia decomposition gas to anneal the alloy wire in Example 1, where the ammonia decomposition gas is a mixture of nitrogen and hydrogen. The annealing conditions refer to those in Example 1.

[0130] The silver alloy wire contains Ti element, which is an active element and easily reacts with most metals and ceramics, as well as nitrogen, hydrogen and oxygen. When the silver alloy wire in Example 1 is reduced by ammonia decomposition gas, Ti in the silver alloy wire reacts with both nitrogen and hydrogen, causing the silver alloy wire to turn black and blue, affecting the subsequent use of the wire.

[0131] Comparative Example 2

[0132] The alloy wire cleaning annealing method provided in this comparative example is to anneal the silver alloy wire in Example 1 in a vacuum atmosphere, and the annealing conditions refer to Example 1.

[0133] Since titanium easily absorbs oxygen, it needs to be annealed under high vacuum conditions, which places high demands on the annealing equipment. The titanium oxide on the surface of the silver alloy wire is stable and will not decompose at the annealing temperature. There is still spotty oxidation on the surface of the vacuum annealed alloy wire.

[0134] Comparative Example 3

[0135] The alloy wire cleaning method provided in this comparative example is to pickle the silver alloy wire in Example 1.

[0136] In Example 1, the surface oxide of the silver alloy wire needs to be pickled and removed using concentrated sulfuric acid, alkali solution or hydrofluoric acid. After pickling, a large amount of waste acid and alkali solution needs to be treated, which brings more cumbersome processes to the processing and subsequent environmental protection treatment, and is not conducive to large-scale production.

[0137] Comparative Example 4

[0138] The alloy wire cleaning method provided in this comparative example is to mechanically wipe the silver alloy wire in Example 1.

[0139] The silver alloy wire in Example 1 is mechanically wiped to remove the oxide film, and the wiping loss is greater than 0.5%, resulting in great waste.

[0140] Comparative Example 5

[0141] The silver alloy wire cleaning annealing method provided in this comparative example refers to Example 1, except that the composite reducing agent, measured by mass percentage, includes the following components: 20% graphite powder, 30% potassium fluoroborate and 50% vitamin C.

[0142] There are still grayish white spots on the silver alloy wire after annealing. Analysis shows that the potassium fluoroborate content is too low and the titanium oxide is not completely reduced, resulting in color spots on the wire surface.

[0143] Comparative Example 6

[0144] The silver alloy wire cleaning annealing method provided in this comparative example refers to Example 1, except that the composite reducing agent, calculated by mass percentage, includes the following components: 20% graphite powder, 70% potassium fluoroborate and 10% vitamin C.

[0145] The surface of the silver alloy wire after annealing is in poor condition and has local discoloration. The potassium fluoroborate is too high, and the volatilized boron trioxide forms a composite oxide with the oxide on the surface of the wire. The composite oxide has poor adhesion to the surface of the wire, and the surface is in a peeled state, resulting in a rough surface of the wire. The composite oxide on the surface of the wire is not completely peeled off from the wire, resulting in local discoloration of the wire.

[0146] Comparative Example 7

[0147] The silver alloy wire cleaning annealing method provided in this comparative example refers to Example 1, except that the composite reducing agent, measured by mass percentage, includes the following components: 5% graphite powder, 50% potassium fluoroborate and 45% vitamin C.

[0148] After annealing, the silver alloy wire has oxidation discoloration and unstable surface state. The carbon content is too low, resulting in unconsumed oxygen in the furnace. During the heating process, the wire is still slowly oxidized, resulting in instability of the wire and discoloration.

[0149] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for cleaning and annealing alloy wire, characterized in that: The steps include: The alloy wire is annealed by using a composite reducing agent; The composite reducing agent comprises: carbon material, potassium fluoroborate and vitamin C in a mass ratio of (1-3): (4-6): (2-4).

2. The alloy wire cleaning annealing method according to claim 1, characterized in that: The method comprises at least one of the following features (1) to (4); (1) The carbon material comprises at least one of charcoal, carbon powder and graphite powder; (2) The particle size of the graphite powder is less than 30 mesh; (3) The particle size of the potassium fluoroborate is less than 30 mesh; (4) The particle size of the vitamin C is less than 30 mesh.

3. The alloy wire cleaning annealing method according to claim 1, characterized in that: The annealing treatment comprises: passing the alloy wire through an annealing device with the composite reducing agent laid on the bottom.

4. The alloy wire cleaning annealing method according to claim 1, characterized in that: The temperature of the annealing treatment is 560-700°C.

5. The alloy wire cleaning annealing method according to claim 1, characterized in that: The pressure of the annealing treatment is ≤0.2MPa.

6. The alloy wire cleaning annealing method according to claim 1, characterized in that: The annealing treatment time is greater than 40 s.

7. An annealing device for implementing the alloy wire clean annealing method according to any one of claims 1 to 6, characterized in that: include: Heating thermostat; Sealing rubber pads are arranged on both sides of the box body of the heating thermostatic box, and an opening is arranged in the middle of the sealing rubber pad, and the alloy wire enters and exits the heating thermostatic box through the opening; A composite reducing agent is arranged at the bottom of the heating thermostatic box.

8. The annealing device according to claim 7, characterized in that: The thickness of the composite reducing agent is greater than 3 mm.

9. The annealing device according to claim 7, characterized in that: A pressure relief valve is arranged on the top of the box body of the heating thermostatic box, and the pressure relief valve is connected to the water tank through a pipeline.

10. The annealing device according to claim 7, characterized in that: The annealing device also includes a straightening wheel and a tensioning wheel; the heating constant temperature box is arranged between the straightening wheel and the tensioning wheel.

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