Silver-coated aluminum wire and its preparation method and application

Abstract

The application discloses a silver-plated aluminum wire and a preparation method and application thereof, and relates to the technical field of metal surface treatment. The silver-plated aluminum wire is composed of an aluminum single wire, a zinc layer, a nickel layer, a copper layer and a silver layer from inside to outside. The diameter of the silver-plated aluminum wire is 0.1mm-0.08mm. In the application, a dense silver layer is formed on the outermost layer, the conductivity and corrosion resistance of the aluminum single wire are improved, and the silver-plated aluminum wire also has an attractive appearance.

Description

Technical Field

[0001] This invention belongs to the field of metal surface treatment technology, specifically a silver-plated aluminum wire, its preparation method, and its application. Background Technology

[0002] With copper prices remaining high, and aluminum being less dense and less than half the price of copper, aluminum alloy conductor cables are widely used in power transmission and distribution systems. Replacing copper cables with aluminum cables not only reduces costs but also offers significant advantages in cable installation, aircraft lightweighting, and energy conservation. Therefore, "saving copper with aluminum" is the general trend in cable development.

[0003] Aluminum wire is widely used in wire and cable, electronic components, and machinery manufacturing. For example, aluminum wire can be used to make electronic components such as resistance wire, inductor wire, and conductors; it can also be used to manufacture mechanical parts and automotive parts; however, the conductivity of a single aluminum wire is relatively low, and its performance is relatively poor. Summary of the Invention

[0004] The purpose of this invention is to provide a silver-plated aluminum wire to solve at least one aspect of the problems and defects mentioned in the background art.

[0005] The present invention also provides a method for preparing the above-mentioned silver-plated aluminum wire.

[0006] The present invention also provides applications of the above-mentioned silver-plated aluminum wire.

[0007] Specifically, the first aspect of the present invention provides a silver-plated aluminum wire, which comprises, from the inside out, an aluminum monofilament, a zinc layer, a nickel layer and a silver layer;

[0008] The diameter of the silver-plated aluminum wire is 0.3mm to 0.08mm.

[0009] According to one technical solution of the silver-plated aluminum wire of the present invention, at least the following beneficial effects exist:

[0010] In this invention, a dense silver layer is formed on the outermost layer, which improves the conductivity and corrosion resistance of the aluminum monofilament; while the nickel layer has a strong bond with the silver layer, which can improve the bond between the silver layer and the inner layer, thereby improving the stability of the silver layer. At the same time, the nickel layer can also improve the corrosion resistance.

[0011] According to some embodiments of the present invention, the aluminum monofilament is composed of the following elements by mass fraction:

[0012] Si: 0.1%–0.2%, Fe: 0.25%–0.55%, Cu: 0.003%–0.022%, Zn: 0.005%–0.010%, Mg: 0.009%–0.01%, Mn: 0.0015%–0.002%, Ce: 0.08%–0.1%, Ga: 0.05%–0.1%, B: 0.02%–0.1%, with the balance being Al and unavoidable impurities.

[0013] Boron in aluminum can reduce the influence of trace element impurities such as V, Mn, Ti, and Cr on conductivity; in addition, the addition of boron can refine the grain size.

[0014] Silicon combines with rare earth elements to form compounds, reducing the harmful effects of free silicon on the aluminum microstructure and improving the electrical conductivity and mechanical properties of aluminum monofilaments.

[0015] According to some embodiments of the present invention, the mass ratio of Fe to Si in the aluminum alloy monofilament is 1.1 to 1.5:1.

[0016] To prevent aluminum wire from cracking and failing to meet mechanical strength standards, the Fe content is made to be greater than the Si content.

[0017] According to some embodiments of the present invention, the mass ratio of Fe to Si in the aluminum alloy monofilament is 1.3 to 1.5:1.

[0018] If the ratio of Fe mass content to Si content in aluminum monofilament is less than 1.3 or the Fe content is less than the Si content, in order to ensure the strength of the aluminum wire while minimizing the reduction in aluminum conductivity, iron control treatment should be performed on the aluminum by adding an appropriate aluminum-iron alloy.

[0019] According to some embodiments of the present invention, the mass fraction of each impurity in the aluminum monofilament is less than 0.05%.

[0020] According to some embodiments of the present invention, the total mass fraction of impurities in the aluminum monofilament is less than 0.50%.

[0021] The second aspect of this invention discloses a method for preparing the above-mentioned silver-plated aluminum wire, comprising the following steps:

[0022] S1. After drawing the aluminum alloy rod into wire, anneal it to obtain the first aluminum alloy wire;

[0023] S2. The first aluminum alloy wire is sequentially plated with zinc, nickel, copper and silver to obtain the second aluminum alloy wire.

[0024] S3. Draw the second aluminum alloy wire;

[0025] The thickness of the silver plating in step S2 is 3μm to 5μm.

[0026] According to some embodiments of the present invention, the thickness of the zinc plating is 3μm to 5μm.

[0027] According to some embodiments of the present invention, the nickel plating solution formulation is as follows:

[0028] Nickel sulfate 200g / L~220g / L, boric acid 20g / L~30g / L, sodium sulfate 70g / L~100g / L, magnesium sulfate 30g / L~50g / L and sodium chloride 10g / L~15g / L.

[0029] According to some embodiments of the present invention, the copper plating requires amalgamation treatment.

[0030] According to some embodiments of the present invention, the annealing temperature in step S1 is 300°C to 360°C.

[0031] According to some embodiments of the present invention, the annealing time in step S1 is 4h to 8h.

[0032] According to some embodiments of the present invention, the method for preparing the aluminum alloy rod includes the following steps:

[0033] Smelting, refining, casting, homogenization and rolling;

[0034] The melting temperature is 700℃~760℃.

[0035] If the smelting temperature is too high, the molten aluminum will absorb a large amount of gas. The gas reacts with the molten aluminum at high temperatures to form inclusions in the molten aluminum, which directly affects the quality of the aluminum rod.

[0036] According to some embodiments of the present invention, the raw materials for smelting are aluminum rare earth, aluminum boron and aluminum-iron master alloy.

[0037] According to some embodiments of the present invention, the refining temperature is 700°C to 750°C.

[0038] The higher the temperature of the molten aluminum, the greater the solubility of hydrogen in the molten aluminum, and the higher the gas content of the molten aluminum. At the same time, if the temperature is too high, the interaction and reaction between the molten aluminum and the furnace lining will be faster, which will reduce the quality of the molten aluminum. Therefore, overheating of the molten aluminum should be prevented.

[0039] According to some embodiments of the present invention, a refining agent is added during the refining process.

[0040] According to some embodiments of the present invention, the refining agent is carried by nitrogen.

[0041] Using nitrogen as a carrier, the refining agent powder is evenly blown into the melt. During the refining process, it is necessary to stir thoroughly to ensure the uniformity of the aluminum liquid composition and to allow the refining agent to fully contact and react with the impurities in the aluminum liquid. Then, the aluminum liquid is allowed to stand for more than 20 minutes to facilitate the separation of impurities from the aluminum liquid.

[0042] Nitrogen is blown into the molten aluminum using a jet refining device. After nitrogen bubbles are generated, hydrogen in the molten aluminum diffuses towards the nitrogen bubbles due to the partial pressure difference. As the bubbles rise in the molten aluminum, they carry the hydrogen out of the molten aluminum to the surface, thus achieving the purpose of degassing.

[0043] According to some embodiments of the present invention, the post-refining filtration is performed.

[0044] The main purpose is to remove some of the aluminum oxide and other impurities from the molten aluminum.

[0045] Mesh filters and block filters are used for filtration.

[0046] According to some embodiments of the present invention, the casting temperature is 690°C to 720°C.

[0047] The lower the casting temperature, the better, as long as normal casting is possible, because the lower the temperature of the molten aluminum, the finer the crystal structure of the ingot.

[0048] According to some embodiments of the present invention, the casting speed is 7.6 m / min to 15 m / min.

[0049] Lower casting speeds tend to produce crystal structures with significant directional orientation; excessively high casting speeds tend to produce overdeveloped dendritic crystals with poor density.

[0050] According to some embodiments of the present invention, the homogenization treatment temperature is 450°C to 500°C.

[0051] According to some embodiments of the present invention, the heat preservation time for the homogenization treatment is 4h to 8h.

[0052] According to some embodiments of the present invention, the rolling temperature is 300°C to 330°C.

[0053] According to some embodiments of the present invention, the wire drawing in step S1 consists of a large wire drawing process and a medium wire drawing process.

[0054] According to some embodiments of the present invention, the diameter after the large wire drawing process is 4.0 mm to 4.5 mm.

[0055] According to some embodiments of the present invention, the tension control of the large wire drawing process is ≤0.25MPa.

[0056] According to some embodiments of the present invention, the diameter after the drawing process is 1.3mm to 1.4mm.

[0057] According to some embodiments of the present invention, the tension control of the drawing process is ≤0.25MPa.

[0058] According to some embodiments of the present invention, the first aluminum alloy wire is subjected to degreasing, water washing, alkaline corrosion, water washing, nitric acid delustering, and then zinc plating.

[0059] According to some embodiments of the present invention, the degreasing is performed using a metal cleaning agent.

[0060] According to some embodiments of the present invention, the degreasing temperature is 40°C to 50°C.

[0061] According to some embodiments of the present invention, the degreasing time is 8 min to 10 min.

[0062] According to some embodiments of the present invention, the alkaline corrosion is carried out using a mixed solution of sodium hydroxide and sodium silicate.

[0063] According to some embodiments of the present invention, the mass concentration of sodium hydroxide in the sodium hydroxide and sodium silicate mixed solution is 480 g / L to 500 g / L.

[0064] According to some embodiments of the present invention, the mass concentration of sodium silicate in the sodium hydroxide and sodium silicate mixed solution is 2 g / L to 3 g / L.

[0065] According to some embodiments of the present invention, the temperature of the alkaline corrosion is 60°C to 70°C.

[0066] According to some embodiments of the present invention, the alkaline corrosion time is 30s to 60s.

[0067] According to some embodiments of the present invention, the mass concentration of nitric acid used for nitric acid removal is 450 g / L to 500 g / L.

[0068] According to some embodiments of the present invention, the temperature for nitric acid removal is 15°C to 25°C.

[0069] According to some embodiments of the present invention, the light removal time of the nitric acid is 10s to 15s.

[0070] According to some embodiments of the present invention, the galvanizing process consists of a first zinc immersion, water washing, zinc stripping with nitric acid, water washing, and a second zinc immersion.

[0071] According to some embodiments of the present invention, the zinc immersion solution for the first zinc immersion consists of the following components at mass concentrations: zinc oxide 5 g / L to 10 g / L, sodium hydroxide 100 g / L to 120 g / L, nickel chloride 5 g / L to 10 g / L, potassium sodium tartrate 40 g / L to 50 g / L, and ferric chloride 1 g / L to 2 g / L.

[0072] After the first aluminum alloy wire was etched in a strong alkaline solution, the oxide film on the surface of the first aluminum alloy wire dissolved first after it was immersed in an alkaline zinc immersion solution.

[0073] Once the first aluminum alloy wire substrate is exposed, a displacement reaction occurs between zinc ions and metallic aluminum. This displacement reaction ceases when the surface of the first aluminum alloy wire is completely covered by an extremely thin layer of zinc. The zinc in the zinc immersion solution exists as the complex ion [Zn(OH)4]. 2- Nickel and iron metal ions exist in the form of complex ions, which combine with ligands (such as potassium sodium tartrate) to form stable complex ions.

[0074] The reaction process of immersing the first aluminum alloy wire in the alkaline zinc immersion solution mainly consists of three stages:

[0075] In the initial stage, during the first few seconds after the first aluminum alloy wire substrate is immersed in the zinc immersion solution, the main reaction is the dissolution of the oxide film.

[0076] In the intermediate stage, fresh active aluminum atoms react with OH groups in the zinc immersion solution. - The reaction proceeds directly, releasing a large amount of hydrogen gas.

[0077] In the later stage of actual zinc immersion, due to the localized OH groups on the surface of the first aluminum alloy wire substrate... - It was consumed in large quantities, which greatly promoted the production of [Zn(OH)4]. 2- The dissociation of complex ions increases the number of free Zn atoms on the surface of the first aluminum alloy wire matrix. 2+ The concentration of Zn 2+ It participates in the electrode reaction, gains electrons, and deposits them on the surface of the first aluminum alloy wire. At this point, the amount of gas released will be significantly reduced. When a relatively dense zinc-impregnated layer is formed on the aluminum substrate, the zinc layer will prevent the dissolution of the internal aluminum, causing the release of hydrogen gas to gradually stop.

[0078] According to some embodiments of the present invention, the time for the single zinc immersion is 40s to 60s.

[0079] According to some embodiments of the present invention, the temperature of the first zinc immersion is 15°C to 25°C.

[0080] According to some embodiments of the present invention, the zinc annealing with nitric acid is an aqueous solution of nitric acid with a mass fraction of 48% to 52%.

[0081] According to some embodiments of the present invention, the temperature for zinc annealing with nitric acid is 15°C to 25°C.

[0082] According to some embodiments of the present invention, the zinc removal time with nitric acid is 10s to 20s.

[0083] According to some embodiments of the present invention, the zinc immersion solution for the secondary zinc immersion is TEAT 90% and 15%.

[0084] According to some embodiments of the present invention, the time for the secondary zinc immersion is 10s to 20s.

[0085] According to some embodiments of the present invention, the temperature of the secondary zinc immersion is 18°C ​​to 25°C.

[0086] According to some embodiments of the present invention, the galvanizing is completed by water washing.

[0087] According to some embodiments of the present invention, the nickel plating solution used for nickel plating consists of solutions with the following mass concentrations:

[0088] Nickel sulfate 200g / L~220g / L, boric acid 20g / L~30g / L, anhydrous sodium sulfate 70g / L~100g / L, magnesium sulfate 30g / L~50g / L, sodium chloride 10g / L~15g / L.

[0089] According to some embodiments of the present invention, the current density for nickel plating is 0.5 A / dm. 2 ~1A / dm 2 .

[0090] According to some embodiments of the present invention, the nickel plating time is 30s to 40s.

[0091] According to some embodiments of the present invention, the nickel plating temperature is 15°C to 25°C.

[0092] According to some embodiments of the present invention, the pH of the nickel plating is 5 to 5.8.

[0093] According to some embodiments of the present invention, the anode of the nickel plating is a nickel plate.

[0094] According to some embodiments of the present invention, the nickel plating is washed with water after completion.

[0095] According to some embodiments of the present invention, the copper plating solution used for copper plating consists of solutions with the following mass concentrations:

[0096] Copper sulfate 200g / L~220g / L, sulfuric acid 70~90g / L, brightener N-1 8mL / L~12mL / L.

[0097] According to some embodiments of the present invention, the current density of the copper plating is 2 A / dm. 2 ~4.5A / dm 2 .

[0098] According to some embodiments of the present invention, the copper plating time is 10s to 15s.

[0099] According to some embodiments of the present invention, the copper plating temperature is 15°C to 25°C.

[0100] According to some embodiments of the present invention, the anode for copper plating is a phosphor bronze plate.

[0101] According to some embodiments of the present invention, the cathode moves at a frequency of 10 times / min to 14 times / min.

[0102] According to some embodiments of the present invention, after the copper plating is completed, hydrochloric acid activation and amalgamation treatment are performed.

[0103] According to some embodiments of the present invention, the hydrochloric acid is used for pre-activation washing with water.

[0104] According to some embodiments of the present invention, in the hydrochloric acid activation, the mass fraction of hydrochloric acid is 30% to 35%, and the volume ratio of hydrochloric acid to water is 1:2 to 3.

[0105] According to some embodiments of the present invention, the hydrochloric acid is used for rinsing after activation.

[0106] According to some embodiments of the present invention, the amalgamation treatment is followed by water washing.

[0107] According to some embodiments of the present invention, mercuric chloride and ammonium chloride are selected in the amalgamation treatment.

[0108] According to some embodiments of the present invention, the treatment solution for the amalgamation treatment comprises:

[0109] Mercuric chloride 7g / L~8g / L and ammonium chloride 30g / L~40g / L.

[0110] According to some embodiments of the present invention, the pH of the amalgamation treatment is 0.8 to 1.2.

[0111] According to some embodiments of the present invention, the temperature of the amalgamation treatment is 15°C to 25°C.

[0112] According to some embodiments of the present invention, the amalgamation treatment time is 3s to 5s.

[0113] According to some embodiments of the present invention, the silver plating is followed by water washing.

[0114] According to some embodiments of the present invention, the silver plating solution used for silver plating consists of solutions with the following mass concentrations:

[0115] Silver nitrate 25g / L~30g / L, potassium chloride 40g / L~60g / L, potassium nitrate 100g / L~140g / L, potassium thiocyanate 1g / L~25g / L, brightener (AG-1) 1g / L~2g / L.

[0116] According to some embodiments of the present invention, the current density of the silver plating is 0.5 A / dm. 2 ~0.8A / dm 2 .

[0117] According to some embodiments of the present invention, the silver plating time is 35s to 45s.

[0118] According to some embodiments of the present invention, the silver plating temperature is 15°C to 25°C.

[0119] According to some embodiments of the present invention, the anode of the silver plating is a silver plate.

[0120] The third aspect of this invention discloses the application of the above-mentioned silver-plated aluminum wire in the preparation of cables, resistance wires, inductor wires or conductors. Detailed Implementation

[0121] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0122] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0123] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0124] Example 1

[0125] This embodiment is a silver-plated aluminum wire, which consists of an aluminum monofilament, a zinc layer, a nickel layer and a silver layer from the inside out.

[0126] The method for preparing the silver-plated aluminum wire in this embodiment consists of the following steps:

[0127] S1. Preparation of aluminum alloy rod:

[0128] The alloy raw materials were melted (at a temperature of 700℃), refined (at a temperature of 720℃, with refining agent added using nitrogen as a carrier), cast (at a temperature of 720℃, casting speed of 7.6m / min), homogenized (at a temperature of 450℃, with a holding time of 8h), and rolled (at a rolling temperature of 330℃) to obtain an aluminum alloy rod (9.5mm in diameter).

[0129] The aluminum alloy rod is composed of the following elements by mass fraction:

[0130] Si: 0.15%, Fe: 0.35%, Cu: 0.013%, Zn: 0.008%, Mg: 0.01%, Mn: 0.0018%, Ce: 0.09%, Ga: 0.08%, B: 0.08%, balance Al and unavoidable impurities.

[0131] S2. Preparation of aluminum alloy monofilament:

[0132] The aluminum alloy rod is drawn into a single wire with a diameter of 4.2 mm.

[0133] A 4.2mm monofilament was drawn into a 1.35mm diameter monofilament, and then annealed (300℃, annealing time was 4h) to obtain the first aluminum alloy wire.

[0134] S3, Electroplating:

[0135] The first aluminum alloy wire is electroplated to obtain the second aluminum alloy wire (the zinc plating thickness is 4μm and the silver plating thickness is 4μm).

[0136] S4, Brushed:

[0137] The second aluminum alloy wire is drawn into a finer diameter to obtain a 0.15mm aluminum alloy wire;

[0138] A 0.15mm aluminum alloy wire is micro-drawn to produce a 0.08mm silver-plated aluminum wire.

[0139] In this embodiment, the electroplating process consists of the following preparation steps:

[0140] S01, Chemical degreasing:

[0141] The process parameters for chemical degreasing are as follows:

[0142] Metal cleaning agent: potassium hydroxide 10g / L, sodium silicate 25g / L, sodium phosphate 50g / L, temperature 45℃, time 9min;

[0143] Wash with water after degreasing;

[0144] SO2, alkaline corrosion:

[0145] The process parameters for alkaline corrosion are as follows:

[0146] Sodium hydroxide 500g / L, sodium silicate 2.5g / L, temperature 65℃, time 30s;

[0147] After alkaline corrosion is complete, rinse with water.

[0148] S03. Nitric acid light removal:

[0149] The process parameters for nitric acid removal are as follows:

[0150] Nitric acid 500g / L, temperature 20℃, time 10s;

[0151] Wash with water after polishing;

[0152] S04, Single zinc immersion treatment:

[0153] The process parameters for a single zinc immersion treatment are as follows:

[0154] Zinc immersion solution: 7.5 g / L zinc oxide, 120 g / L sodium hydroxide, 7 g / L nickel chloride, 45 g / L sodium potassium tartrate and 1.8 g / L ferric chloride, time 50 s, temperature 20 ℃;

[0155] After a single zinc immersion treatment, the sample is washed with water.

[0156] S05, Zinc annealing with nitric acid:

[0157] The process parameters for zinc stripping with nitric acid are as follows:

[0158] A 50% nitric acid aqueous solution was prepared at 20°C for 15 seconds.

[0159] Zinc removal with nitric acid followed by rinsing with water;

[0160] S06, Secondary zinc immersion:

[0161] Process parameters for double zinc immersion:

[0162] Zinc immersion solution: 7.5 g / L zinc oxide, 120 g / L sodium hydroxide, 7 g / L nickel chloride, 45 g / L potassium sodium tartrate and 1.8 g / L ferric chloride, temperature 20℃, time 15 s;

[0163] After the second zinc immersion, rinse with water;

[0164] S07, Dark Nickel Plating:

[0165] The process parameters for dark nickel plating are as follows:

[0166] Nickel sulfate 210 g / L, boric acid 25 g / L, sodium sulfate 90 g / L, magnesium sulfate 40 g / L, sodium chloride 15 g / L, current density 1 A / dm³ 2 The time was 30 seconds, the temperature was 20°C, the pH value was 5.7, and the anode was a nickel plate (containing 99.99% nickel).

[0167] Wash with water after dark nickel plating;

[0168] S08, Copper plating:

[0169] The copper plating process parameters are as follows:

[0170] Copper plating solution: copper sulfate 210g / L, sulfuric acid 70g / L, brightener N-1 10mL / L;

[0171] Current density 2.5 A / dm 2 Temperature 20℃, time 10s, cathode movement 14 times / min, anode: phosphor bronze plate;

[0172] Wash with water after copper plating;

[0173] S09, Hydrochloric acid activation:

[0174] The activation parameters for hydrochloric acid are as follows:

[0175] Hydrochloric acid (35% by mass) and water = 1:2, time 40s, temperature 20℃;

[0176] After activation with hydrochloric acid, wash with water;

[0177] S10, amalgamation treatment:

[0178] The amalgamation treatment parameters are as follows:

[0179] Mercuric chloride 7.5 g / L, ammonium chloride 40 g / L, pH 1, temperature 20℃, time 4 s;

[0180] Amalgamation treatment followed by water washing;

[0181] S11, Silver Plated:

[0182] Silver nitrate 28 g / L, potassium chloride 50 g / L, potassium nitrate 120 g / L, potassium thiocyanate 20 g / L, brightener AG-1 2 g / L, current 0.8 A / dm 2 Temperature 20℃, time 40s, cathode plate (silver content 99.99%).

[0183] After silver plating, wash with water, wash with hot water (60℃), and blow dry.

[0184] Example 2

[0185] This embodiment uses a silver-plated aluminum wire, which differs from Embodiment 1 in that:

[0186] In this embodiment, the aluminum alloy rod is composed of the following elements by mass fraction:

[0187] Si: 0.18%, Fe: 0.48%, Cu: 0.018%, Zn: 0.005%, Mg: 0.009%, Mn: 0.0015%, Ce: 0.08%, Ga: 0.05%, B: 0.05%, balance Al and unavoidable impurities.

[0188] Other parameters in this embodiment are the same as in Embodiment 1.

[0189] Example 3

[0190] This embodiment uses a silver-plated aluminum wire, which differs from Embodiment 1 in that:

[0191] In this embodiment, the aluminum alloy rod is composed of the following elements by mass fraction:

[0192] Si: 0.13%, Fe: 0.5%, Cu: 0.015%, Zn: 0.007%, Mg: 0.01%, Mn: 0.0017%, Ce: 0.09%, Ga: 0.06%, B: 0.01%, balance Al and unavoidable impurities.

[0193] Other parameters in this embodiment are the same as in Embodiment 1.

[0194] Example 4

[0195] This embodiment uses a silver-plated aluminum wire, which differs from Embodiment 1 in that:

[0196] In this embodiment, the aluminum alloy rod is composed of the following elements by mass fraction:

[0197] Si: 0.12%, Fe: 0.45%, Cu: 0.011%, Zn: 0.007%, Mg: 0.01%, Mn: 0.002%, Ce: 0.09%, Ga: 0.1%, B: 0.05%, balance being Al and unavoidable impurities.

[0198] Other parameters in this embodiment are the same as in Embodiment 1.

[0199] Example 5

[0200] This embodiment uses a silver-plated aluminum wire, which differs from Embodiment 1 in that:

[0201] In this embodiment, the aluminum alloy rod is composed of the following elements by mass fraction:

[0202] Si: 0.14%, Fe: 0.47%, Cu: 0.01%, Zn: 0.005%, Mg: 0.01%, Mn: 0.0015%, Ce: 0.08%, Ga: 0.05%, B: 0.02%, balance being Al and unavoidable impurities.

[0203] Other parameters in this embodiment are the same as in Embodiment 1.

[0204] Comparative Example 1

[0205] This comparative example is a silver-plated aluminum wire, which consists of an aluminum monofilament, a nickel layer, and a silver layer from the inside out.

[0206] The preparation method of the silver-plated aluminum wire in this comparative example consists of the following steps:

[0207] S1. Preparation of aluminum alloy rod:

[0208] The alloy raw materials were melted (at a temperature of 700℃), refined (at a temperature of 720℃, with refining agent added using nitrogen as a carrier), cast (at a temperature of 720℃, casting speed of 7.6m / min), homogenized (at a temperature of 450℃, with a holding time of 8h), and rolled (at a rolling temperature of 330℃) to obtain an aluminum alloy rod (9.5mm in diameter).

[0209] The aluminum alloy rod is composed of the following elements by mass fraction:

[0210] Si: 0.15%, Fe: 0.35%, Cu: 0.013%, Zn: 0.008%, Mg: 0.01%, Mn: 0.0018%, Ce: 0.09%, Ga: 0.08%, B: 0.08%, balance Al and unavoidable impurities.

[0211] S2. Preparation of aluminum alloy monofilament:

[0212] The aluminum alloy rod is drawn into a single wire with a diameter of 4.2 mm.

[0213] A 4.2mm monofilament was drawn into a 1.35mm diameter monofilament, and then annealed (300℃, annealing time was 4h) to obtain the first aluminum alloy wire.

[0214] S3, Electroplating:

[0215] The first aluminum alloy wire is electroplated to obtain the second aluminum alloy wire (the zinc plating thickness is 4μm and the silver plating thickness is 4μm).

[0216] S4, Brushed:

[0217] The second aluminum alloy wire is drawn into a finer diameter to obtain a 0.15mm aluminum alloy wire;

[0218] A 0.15mm aluminum alloy wire is micro-drawn to produce a 0.08mm silver-plated aluminum wire.

[0219] In this embodiment, the electroplating process consists of the following preparation steps:

[0220] S01, Chemical degreasing:

[0221] The process parameters for chemical degreasing are as follows:

[0222] Metal cleaning agent: potassium hydroxide 10g / L, sodium silicate 25g / L, sodium phosphate 50g / L, temperature 45℃, time 9min;

[0223] Wash with water after degreasing;

[0224] SO2, alkaline corrosion:

[0225] The process parameters for alkaline corrosion are as follows:

[0226] Sodium hydroxide 500g / L, sodium silicate 2.5g / L, temperature 65℃, time 30s;

[0227] After alkaline corrosion is complete, rinse with water.

[0228] S03. Nitric acid light removal:

[0229] The process parameters for nitric acid removal are as follows:

[0230] Nitric acid 500g / L, temperature 20℃, time 10s;

[0231] Wash with water after polishing;

[0232] S04, Dark Nickel Plating:

[0233] The process parameters for dark nickel plating are as follows:

[0234] Nickel sulfate 210 g / L, boric acid 25 g / L, sodium sulfate 90 g / L, magnesium sulfate 40 g / L, sodium chloride 15 g / L, current density 1 A / dm³ 2 The time was 30 seconds, the temperature was 20°C, the pH value was 5.7, and the anode was a nickel plate (containing 99.99% nickel).

[0235] Wash with water after dark nickel plating;

[0236] S05, Copper plating:

[0237] The copper plating process parameters are as follows:

[0238] Copper plating solution: copper sulfate 210g / L, sulfuric acid 70g / L, brightener N-1 10mL / L;

[0239] Current density 2.5 A / dm 2 Temperature 20℃, time 10s, cathode movement 14 times / min, anode: phosphor bronze plate;

[0240] Wash with water after copper plating;

[0241] S06, activated with hydrochloric acid:

[0242] The activation parameters for hydrochloric acid are as follows:

[0243] Hydrochloric acid (35% by mass) and water = 1:2, time 40s, temperature 20℃;

[0244] After activation with hydrochloric acid, wash with water;

[0245] S07, Amalgamation treatment:

[0246] The amalgamation treatment parameters are as follows:

[0247] Mercuric chloride 7.5 g / L, ammonium chloride 40 g / L, pH 1, temperature 20℃, time 4 s;

[0248] Amalgamation treatment followed by water washing;

[0249] S08, Silver plating:

[0250] Silver nitrate 28 g / L, potassium chloride 50 g / L, potassium nitrate 120 g / L, potassium thiocyanate 20 g / L, brightener AG-1 2 g / L, current 0.8 A / dm 2 Temperature 20℃, time 40s, cathode plate (silver content 99.99%).

[0251] After silver plating, wash with water, wash with hot water (60℃), and blow dry.

[0252] Comparative Example 2

[0253] This comparative example is a silver-plated aluminum wire, which consists of an aluminum monofilament, a zinc layer, and a silver layer from the inside out.

[0254] The preparation method of the silver-plated aluminum wire in this comparative example consists of the following steps:

[0255] S1. Preparation of aluminum alloy rod:

[0256] The alloy raw materials were melted (at a temperature of 700℃), refined (at a temperature of 720℃, with refining agent added using nitrogen as a carrier), cast (at a temperature of 720℃, casting speed of 7.6m / min), homogenized (at a temperature of 450℃, with a holding time of 8h), and rolled (at a rolling temperature of 330℃) to obtain an aluminum alloy rod (9.5mm in diameter).

[0257] The aluminum alloy rod is composed of the following elements by mass fraction:

[0258] Si: 0.15%, Fe: 0.35%, Cu: 0.013%, Zn: 0.008%, Mg: 0.01%, Mn: 0.0018%, Ce: 0.09%, Ga: 0.08%, B: 0.08%, balance Al and unavoidable impurities.

[0259] S2. Preparation of aluminum alloy monofilament:

[0260] The aluminum alloy rod is drawn into a single wire with a diameter of 4.2 mm.

[0261] A 4.2mm monofilament was drawn into a 1.35mm diameter monofilament, and then annealed (300℃, annealing time was 4h) to obtain the first aluminum alloy wire.

[0262] S3, Electroplating:

[0263] The first aluminum alloy wire is electroplated to obtain the second aluminum alloy wire (the zinc plating thickness is 4μm and the silver plating thickness is 4μm).

[0264] S4, Brushed:

[0265] The second aluminum alloy wire is drawn into a finer diameter to obtain a 0.15mm aluminum alloy wire;

[0266] A 0.15mm aluminum alloy wire is micro-drawn to produce a 0.08mm silver-plated aluminum wire.

[0267] In this embodiment, the electroplating process consists of the following preparation steps:

[0268] S01, Chemical degreasing:

[0269] The process parameters for chemical degreasing are as follows:

[0270] Metal cleaning agent: potassium hydroxide 10g / L, sodium silicate 25g / L, sodium phosphate 50g / L, temperature 45℃, time 9min;

[0271] Wash with water after degreasing;

[0272] SO2, alkaline corrosion:

[0273] The process parameters for alkaline corrosion are as follows:

[0274] Sodium hydroxide 500g / L, sodium silicate 2.5g / L, temperature 65℃, time 30s;

[0275] After alkaline corrosion is complete, rinse with water.

[0276] S03. Nitric acid light removal:

[0277] The process parameters for nitric acid removal are as follows:

[0278] Nitric acid 500g / L, temperature 20℃, time 10s;

[0279] Wash with water after polishing;

[0280] S04, Single zinc immersion treatment:

[0281] The process parameters for a single zinc immersion treatment are as follows:

[0282] Zinc immersion solution: 7.5 g / L zinc oxide, 120 g / L sodium hydroxide, 7 g / L nickel chloride, 45 g / L sodium potassium tartrate and 1.8 g / L ferric chloride, time 50 s, temperature 20 ℃;

[0283] After a single zinc immersion treatment, the sample is washed with water.

[0284] S05, Zinc annealing with nitric acid:

[0285] The process parameters for zinc stripping with nitric acid are as follows:

[0286] A 50% nitric acid aqueous solution was prepared at 20°C for 15 seconds.

[0287] Zinc removal with nitric acid followed by rinsing with water;

[0288] S06, Secondary zinc immersion:

[0289] Process parameters for double zinc immersion:

[0290] Zinc immersion solution: 7.5 g / L zinc oxide, 120 g / L sodium hydroxide, 7 g / L nickel chloride, 45 g / L potassium sodium tartrate and 1.8 g / L ferric chloride, temperature 20℃, time 15 s;

[0291] After the second zinc immersion, rinse with water;

[0292] S07, Copper Plating:

[0293] The copper plating process parameters are as follows:

[0294] Copper sulfate 210 g / L, sulfuric acid 70 g / L, brightener N-1 10 mL / L;

[0295] Current density 2.5 A / dm 2 Temperature 20℃, time 10s, cathode movement 14 times / min, anode: phosphor bronze plate;

[0296] Wash with water after copper plating;

[0297] S08, activated with hydrochloric acid:

[0298] The activation parameters for hydrochloric acid are as follows:

[0299] Hydrochloric acid (35% by mass) and water = 1:2, time 40s, temperature 20℃;

[0300] After activation with hydrochloric acid, wash with water;

[0301] S09, Amalgamation treatment:

[0302] The amalgamation treatment parameters are as follows:

[0303] Mercuric chloride 7.5 g / L, ammonium chloride 40 g / L, pH 1, temperature 20℃, time 4 s;

[0304] Amalgamation treatment followed by water washing;

[0305] S10, Silver Plated:

[0306] Silver nitrate 28 g / L, potassium chloride 50 g / L, potassium nitrate 120 g / L, potassium thiocyanate 20 g / L, brightener AG-1 2 g / L, current 0.8 A / dm 2 Temperature 20℃, time 40s, cathode plate (silver content 99.99%).

[0307] After silver plating, wash with water, wash with hot water (60℃), and blow dry.

[0308] Comparative Example 3

[0309] This comparative example is a silver-plated aluminum wire, which consists of an aluminum monofilament and a silver layer from the inside out.

[0310] The method for preparing the silver-plated aluminum wire in this embodiment consists of the following steps:

[0311] S1. Preparation of aluminum alloy rod:

[0312] The alloy raw materials were melted (at a temperature of 700℃), refined (at a temperature of 720℃, with refining agent added using nitrogen as a carrier), cast (at a temperature of 720℃, casting speed of 7.6m / min), homogenized (at a temperature of 450℃, with a holding time of 8h), and rolled (at a rolling temperature of 330℃) to obtain an aluminum alloy rod (9.5mm in diameter).

[0313] The aluminum alloy rod is composed of the following elements by mass fraction:

[0314] Si: 0.15%, Fe: 0.35%, Cu: 0.013%, Zn: 0.008%, Mg: 0.01%, Mn: 0.0018%, Ce: 0.09%, Ga: 0.08%, B: 0.08%, balance Al and unavoidable impurities.

[0315] S2. Preparation of aluminum alloy monofilament:

[0316] The aluminum alloy rod is drawn into a single wire with a diameter of 4.2 mm.

[0317] A 4.2mm monofilament was drawn into a 1.35mm diameter monofilament, and then annealed (300℃, annealing time was 4h) to obtain the first aluminum alloy wire.

[0318] S3, Electroplating:

[0319] The first aluminum alloy wire is electroplated to obtain the second aluminum alloy wire (the zinc plating thickness is 4μm and the silver plating thickness is 4μm).

[0320] S4, Brushed:

[0321] The second aluminum alloy wire is drawn into a finer diameter to obtain a 0.15mm aluminum alloy wire;

[0322] A 0.15mm aluminum alloy wire is micro-drawn to produce a 0.08mm silver-plated aluminum wire.

[0323] In this embodiment, the electroplating process consists of the following preparation steps:

[0324] S01, Chemical degreasing:

[0325] The process parameters for chemical degreasing are as follows:

[0326] Metal cleaning agent: potassium hydroxide 10g / L, sodium silicate 25g / L, sodium phosphate 50g / L, temperature 45℃, time 9min;

[0327] Wash with water after degreasing;

[0328] SO2, alkaline corrosion:

[0329] The process parameters for alkaline corrosion are as follows:

[0330] Sodium hydroxide 500g / L, sodium silicate 2.5g / L, temperature 65℃, time 30s;

[0331] After alkaline corrosion is complete, rinse with water.

[0332] S03. Nitric acid light removal:

[0333] The process parameters for nitric acid removal are as follows:

[0334] Nitric acid 500g / L, temperature 20℃, time 10s;

[0335] Wash with water after polishing;

[0336] S04, Silver plating:

[0337] Silver nitrate 28 g / L, potassium chloride 50 g / L, potassium nitrate 120 g / L, potassium thiocyanate 20 g / L, brightener AG-1 2 g / L, current 0.8 A / dm 2 Temperature 20℃, time 40s, cathode plate (silver content 99.99%).

[0338] After silver plating, wash with water, wash with hot water (60℃), and blow dry.

[0339] Comparative Example 4

[0340] This comparative example uses a silver-plated aluminum wire, which differs from Example 1 in that:

[0341] The aluminum alloy rod is composed of the following elements by mass fraction:

[0342] Si: 0.15%, Fe: 0.35%, Cu: 0.013%, Zn: 0.008%, Mg: 0.01%, Mn: 0.0018%, Ga: 0.08%, balance being Al and unavoidable impurities.

[0343] Other parameters in this comparative example are the same as in Example 1.

[0344] Comparative Example 5

[0345] This comparative example uses a silver-plated aluminum wire, which differs from Example 1 in that:

[0346] The aluminum alloy rod is composed of the following elements by mass fraction:

[0347] Si: 0.15%, Fe: 0.15%, Cu: 0.013%, Zn: 0.008%, Mg: 0.01%, Mn: 0.0018%, Ga: 0.08%, balance Al and unavoidable impurities.

[0348] Other parameters in this comparative example are the same as in Example 1.

[0349] The performance test results of the final products obtained in Examples 1-5 and Comparative Examples 1-5 of this invention are shown in Table 1.

[0350] Table 1. Performance test results of the final products obtained in Examples 1-5 and Comparative Examples 1-5 of the present invention.

[0351] - Conductivity (IACS%) <![CDATA[Tensile strength R m (MPa)]]> Example 1 65.73 255 Example 2 64.18 248 Example 3 63.87 243 Example 4 62.65 237 Example 5 62.34 234 Comparative Example 1 61.23 226 Comparative Example 2 60.79 221 Comparative Example 3 59.36 217 Comparative Example 4 60.95 223 Comparative Example 5 58.02 212

[0352] In summary, this invention improves the conductivity and corrosion resistance of aluminum monofilaments by forming a dense silver layer on the outermost layer, while also providing an aesthetically pleasing appearance.

[0353] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A silver-plated aluminum wire, characterized in that, From the inside out, it consists of an aluminum monofilament, a zinc layer, a nickel layer, a copper layer, and a silver layer; The diameter of the silver-plated aluminum wire is 0.1mm~0.08mm; The aluminum monofilament is composed of the following elements by mass fraction composition: Si: 0.1%~0.2%, Fe: 0.25%~0.55%, Cu: 0.003%~0.022%, Zn: 0.005%~0.010%, Mg: 0.009%~0.01%, Mn: 0.0015%~0.002%, Ce: 0.08%~0.1%, Ga: 0.05%~0.1%, B: 0.02%~0.1%, with the balance being Al and unavoidable impurities.

2. A method for preparing silver-plated aluminum wire as described in claim 1, characterized in that, Includes the following steps: S1. After drawing the aluminum alloy rod into wire, anneal it to obtain the first aluminum alloy wire; S2. The first aluminum alloy wire is sequentially plated with zinc, nickel, copper and silver to obtain the second aluminum alloy wire. S3. Draw the second aluminum alloy wire; The thickness of the silver plating in step S2 is 3μm~5μm; The zinc plating thickness in step S2 is 3μm~5μm; The current density for nickel plating is 0.5 A / dm. 2 ~1A / dm 2 ; The nickel plating time is 30s to 40s; The nickel plating temperature is 15℃~25℃; The pH of the nickel plating is 5 to 5.8; The current density for copper plating is 2 A / dm. 2 ~4.5A / dm 2 ; The copper plating time is 10s to 15s.

3. The preparation method according to claim 2, characterized in that, The nickel plating solution formulation is as follows: Nickel sulfate 200g / L~220g / L, boric acid 20g / L~30g / L, sodium sulfate 70g / L~100g / L, magnesium sulfate 30g / L~50g / L and sodium chloride 10g / L~15g / L.

4. The preparation method according to claim 2, characterized in that, The copper plating process requires amalgamation treatment.

5. The preparation method according to claim 2, characterized in that, The annealing temperature in step S1 is 300℃~360℃.

6. The preparation method according to claim 2, characterized in that, The method for preparing the aluminum alloy rod includes the following steps: Smelting, refining, casting, homogenization and rolling; The melting temperature is 700℃~760℃.

7. The preparation method according to claim 6, characterized in that, The homogenization process is carried out at a temperature of 450℃~500℃.

8. The application of the silver-plated aluminum wire as described in claim 1 in the preparation of conductors.

9. The application according to claim 8, characterized in that, The conductor includes resistance wire or inductance wire.

10. The application of the silver-plated aluminum wire as described in claim 1 in the manufacture of cables.