Tin-plated aluminum alloy conductor material, and preparation method therefor and use thereof

Abstract

Provided is a tin-plated aluminum alloy wire, which wire comprises 1-40% of Sn in percentage by mass, with the balance being Al and impurities. The provided aluminum alloy conductor material greatly improves the hardness, wear resistance, toughness and corrosion resistance of an existing aluminum alloy material, and effectively optimizes various performance indexes of the aluminum alloy as a conductor material. The tin-plated aluminum alloy has weldability, greatly expands the use field of the aluminum alloy material in terms of replacing a copper conductor, and solves the anti-corrosion problem of the aluminum alloy and the problem of connection with a copper terminal on the premise that the original electrical and mechanical properties of the aluminum alloy conductor are not affected. The tin-plated aluminum alloy conductor material can be used in various fields, such as new energy automobiles, photovoltaic power generation, wind power generation, wires of electrical devices, electrical switches, power distribution cabinets or household appliances.

Description

A tinned aluminum alloy conductor material and its preparation method and application

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on August 1, 2023, with application number 202310968026.4 and invention name “A tin-plated aluminum alloy conductor material, its preparation method and application”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention belongs to the technical field of tin-plated aluminum alloy wire preparation, and relates to a tin-plated aluminum alloy wire and a preparation method and application thereof, and in particular to a tin-plated aluminum alloy conductor material and a preparation method and application thereof. Background Art

[0003] Copper, a commonly used nonferrous metal, is widely used in power electronics, machinery manufacturing, transportation, construction, and the defense industry. In 2020, my country's copper consumption approached 14.5 million tons, accounting for approximately 60% of the global total. Global copper reserves are abundant, with resource development primarily concentrated in developing countries such as Chile, Peru, and Mexico. However, gradual export restrictions could impact global supply and the security of my country's overseas equity assets. my country's copper supply chain is highly fragile, with a severe shortage of raw materials at the mineral end, and external dependence has remained above 70% for many years. Under the "dual carbon" initiative, energy restructuring is driving the development of the power system. The development of clean energy industries, represented by photovoltaics and wind power, and the new energy vehicle industry are creating new incremental demand for copper. my country's copper consumption is expected to continue growing until 2035, with demand remaining high from 2035 to 2050. However, given the weak domestic resource base and limited supply capacity, copper supply will continue to rely primarily on foreign countries. Factors such as the politicization of global resource issues, the globalization of resource nationalism, and the financialization of mineral prices have further exacerbated my country's copper resource security. Strengthening the supply of copper resources is both a practical need and a long-term resource strategic issue. It is related to the development of my country's national economy and society, whether my country's new energy industry chain can build a solid advantage, and whether the country's "dual carbon" goals can be successfully achieved.

[0004] The wire and cable industry is material-intensive and capital-intensive. Wire and cable materials account for approximately 85% to 95% of the total cost of wire and cable. Wire and cable are primarily composed of conductor cores, insulation, and sheaths. The conductor core is primarily made of copper and aluminum, with copper comprising the largest proportion of the raw materials required for wire and cable products. Conductor materials are fundamental to the cable industry. Improving their performance will drive improvements in cable products, meet the needs of diverse scenarios, and add value to cable products.

[0005] Due to the chemically active nature of aluminum and its poor oxidation resistance, it can form an oxide film approximately 0.005 to 0.015 μm thick in the atmosphere. This film is dense and too thin to provide protection. This is particularly true in coastal areas with high salinity and in chemical plants where compounds and acid-base corrosion are more severe. The corrosion resistance of existing aluminum alloys falls far short of meeting industrial requirements. This limits the use of aluminum alloys as a conductor material to replace copper conductors. Furthermore, the highly reactive surface of aluminum easily oxidizes in air, making it difficult to apply multiple metal coatings to the surface, making it unweldable. Connecting aluminum alloy conductors is a major challenge.

[0006] Due to the skyrocketing copper prices, the demand for aluminum alloy materials is increasing, and the technology of aluminum alloy materials is developing into deeper fields. Now, with the country's vigorous development of new energy, the demand for wires and cables in photovoltaic power generation, wind power generation, and new energy vehicles has increased dramatically. Especially in recent years, the explosive growth of new energy power generation and new energy vehicles has reduced costs and increased efficiency, and the demand for materials has increased more and more. However, the existing aluminum alloy conductor material technology can no longer meet the development needs of many fields such as new energy, and the cost of copper is too high, resulting in high cost and thin profit for the development of new energy. Aluminum has good electrical conductivity, light weight and low price, but poor corrosion resistance and lack of weldability greatly limit the promotion of aluminum alloy application technology.

[0007] Therefore, how to find a more appropriate way to solve the above-mentioned problems of aluminum alloy conductor materials and better broaden the depth and breadth of their applications has become one of the focuses of widespread attention of many front-line researchers in the industry.

[0008] Summary of the Invention

[0009] In view of this, the technical problem to be solved by the present invention is to provide a tin-plated aluminum alloy wire and its preparation method and application, in particular, a tin-plated aluminum alloy conductor material. The tin-plated aluminum alloy wire provided by the present invention greatly improves the hardness, wear resistance, toughness, and especially the corrosion resistance of the existing aluminum alloy conductor material. The aluminum alloy conductor material is treated by surface tin plating to make the aluminum alloy weldable and can be welded to the copper terminal. After the aluminum alloy is tin-plated, it can also be used for photovoltaic welding strips, busbars, and power fittings, which greatly expands the application field of aluminum alloy conductor materials. In addition, the process is simple, the controllability is strong, and the on-site feasibility is high, which is suitable for the promotion and application of industrial-scale production.

[0010] The present invention provides a tinned aluminum alloy wire, wherein the tinned aluminum alloy wire comprises, by mass percentage:

[0011] Sn: 1% to 40%;

[0012] The balance is Al and impurities.

[0013] Preferably, the tinned aluminum alloy wire comprises an aluminum alloy wire substrate and a coating composited on the aluminum alloy wire substrate;

[0014] The coating comprises a nickel coating composited on the wire substrate and a tin coating composited on the nickel coating;

[0015] The thickness of the tinned layer is 0.5 to 100 μm;

[0016] The thickness of the nickel plating layer is 100nm to 10μm;

[0017] The lateral dimension of the aluminum alloy wire substrate is 0.1 to 300 mm;

[0018] The aluminum alloy wire matrix includes one or more of 1 series aluminum alloy, 4 series aluminum alloy, 5 series aluminum alloy, 6 series aluminum alloy and 8 series aluminum alloy.

[0019] Preferably, the coating further comprises D with a mass content of 0.01% to 40%;

[0020] The D is one or more of Ni, Zn, Fe, Mg, Cu, Na, K, Ti, V, As, Sb, O, N and Cl;

[0021] The tinned aluminum alloy wire is specifically a tinned aluminum alloy wire conductor;

[0022] The wire conductor includes one or more of a Class 1 circular conductor, a Class 2 circular conductor, a Class 5 circular conductor, a Class 6 circular conductor, a strip conductor, a ribbon conductor, and a tubular conductor.

[0023] Preferably, the coating further comprises E in a mass content of 0.01% to 40%;

[0024] The E is one or more of Cr, Ca, Co, Ga, Cd, Bi, C, Mn, Pb, Ag, Si, S, P, B, H and RE.

[0025] The present invention provides a method for preparing a tinned aluminum alloy wire, comprising the following steps:

[0026] 1) Pre-treating an aluminum alloy wire sample, and then performing conditioning pre-treatment, nickel pre-dipping, and nickel plating to obtain an aluminum alloy wire composite with a nickel plating layer;

[0027] 2) The aluminum alloy wire with the nickel-plated layer obtained in the above step is plated with bright tin and then post-processed to obtain a tinned aluminum alloy wire.

[0028] Preferably, the pre-treatment step comprises one or more of organic solvent degreasing, air drying, alkali etching, water washing and nitric acid polishing and water washing;

[0029] The treatment solution of the conditioned pretreatment comprises:

[0030] Ammonia 320-350ml / L;

[0031] Trisodium citrate 60-70g / L;

[0032] ZnO 50~60g / L;

[0033] The conditioning pretreatment time is 2 to 3 minutes.

[0034] Preferably, the nickel pre-dip treatment solution comprises:

[0035] Nickel acetate 20-30 g / L;

[0036] Trisodium citrate 20-25g / L;

[0037] Ammonia 260-280 ml / L;

[0038] Triethanolamine 50-60ml / L;

[0039] Lactic acid 30-59 ml / L;

[0040] The pH value of the nickel pre-dip treatment solution is 10-11;

[0041] The nickel pre-immersion time is 3 to 6 minutes.

[0042] Preferably, the nickel plating method includes chemical nickel plating;

[0043] The treatment solution of the chemical nickel plating comprises:

[0044] Nickel sulfate 80-90g / L;

[0045] Sodium hypophosphite 70-80g / L;

[0046] Trisodium citrate 18-30g / L;

[0047] Lactic acid 75-85 ml / L;

[0048] Ammonium sulfate 100-120 g / L;

[0049] Dibutyltin dilaurate 30-50ml / L;

[0050] Silicone oil 30-50ml / L;

[0051] The pH value of the chemical nickel plating treatment solution is 4.0 to 5.0;

[0052] The temperature of the chemical nickel plating is 55-65° C.

[0053] The time for the chemical nickel plating is 5 to 10 minutes.

[0054] Preferably, the bright tin plating method includes a bright acid tin plating process;

[0055] The treatment solution of the bright acid tin plating comprises:

[0056] Stannous sulfate 140-160 g / L;

[0057] Sulfuric acid 240-260 g / L;

[0058] Tartaric acid 28-35 g / L;

[0059] Silicone oil 15-25 ml / L;

[0060] Dibutyltin dimaleate 10-20ml / L;

[0061] The current density of the bright acid tin plating is 1 to 4 A / dm 2 ;

[0062] The bright acid tin plating time is 5 to 15 minutes;

[0063] The post-treatment includes one or more steps of water washing, warm water washing, drying and inspection.

[0064] The present invention also provides the use of the tinned aluminum alloy wire described in any one of the above technical solutions or the tinned aluminum alloy wire prepared by the preparation method described in any one of the above technical solutions in the field of wire conductors.

[0065] The present invention provides a tin-plated aluminum alloy wire, which comprises, by mass percentage, 1% to 40% Sn; the remainder is Al and impurities. Compared with the prior art, the present invention believes that solving the problem of aluminum alloy surface treatment will greatly improve the substitutability of aluminum for copper, which is one of the feasible directions for solving the aforementioned problems existing in current aluminum alloy wires. Based on this, the present invention provides a tin-plated aluminum alloy wire, which greatly improves the hardness, wear resistance, toughness, and especially corrosion resistance of existing aluminum alloy conductor materials. The alloy cable made of the tin-plated aluminum alloy conductor material provided by the present invention can be directly connected to a copper terminal, eliminating the instability caused by the use of copper-aluminum transition terminals and unnecessary installation problems with supporting facilities. The tinned aluminum alloy cable of the present invention can be directly crimped with a copper terminal, and has passed 1,000 heat cycle tests in accordance with the national standard GB / T9327 "Test methods and requirements for crimping and mechanical connection fittings for power cable conductors with rated voltages of 35 kV (Um=40.5 kV) and below". The installation connection is stable and reliable, and the risk of corrosion caused by exposed conductors at the joints is avoided, thereby increasing the service life of the cable.

[0066] The electrical fittings made of tinned aluminum alloy conductor material provided by the present invention meet various performance indicators in accordance with the national standard GB / T14315 "Crimp-type copper and aluminum terminal blocks and connection tubes for power cable conductors." Furthermore, the terminal blocks or connection tubes made of tinned aluminum alloy material can be directly crimped onto aluminum alloy cables. They have passed 1,000 thermal cycle tests in accordance with the national standard GB / T9327 "Test methods and requirements for crimp-type and mechanical connection fittings for power cable conductors with rated voltages of 35 kV (Um = 40.5 kV) and below," demonstrating stable and reliable installation and connection. This makes connecting aluminum alloy cables more convenient and safe.

[0067] The surface of the aluminum alloy conductor material provided by the present invention is tin-plated, which greatly improves the hardness, wear resistance and toughness of the existing aluminum alloy material, effectively optimizes the various performance indicators of the aluminum alloy as a conductor material, and also makes the aluminum alloy weldable, so that it can be welded to copper terminals. After the aluminum alloy is tin-plated, it can also be used for photovoltaic welding strips, busbars, and power hardware, greatly expanding the application field of the aluminum alloy conductor material. The present invention also provides a corresponding preparation process. According to the present invention, after a complete set of tinning steps, including aluminum alloy wire billet → degreasing with organic solvent → drying → alkaline etching → water washing → nitric acid polishing water washing → conditioning pretreatment → pre-dipping nickel → chemical nickel plating → water washing → bright tin plating → recycling → water washing → warm water washing → drying → inspection → tinning the aluminum alloy wire billet, the prepared tinned aluminum alloy conductor wire core has excellent corrosion resistance, which greatly exceeds the corrosion resistance of non-tinned aluminum alloy. According to GB 10124 "Laboratory Uniform Corrosion Full Immersion Test Method for Metal Materials", atmospheric corrosion tests and electrolyte corrosion tests are carried out. Under the condition of a test period of 720 hours, the corrosion rate is ≤0.03mm / a, and the cable has good stability in salt spray and salt water. This solves the problem that ordinary aluminum alloy cables are not suitable for use in coastal areas with relatively high salinity and severe chemical and acid-base corrosion in chemical plants. The alloy cable prepared with tinned aluminum alloy conductor material fully meets the needs of these relatively harsh environments.

[0068] The tin-plated aluminum alloy process provided by the present invention effectively solves the technical difficulties of tinning the surface of aluminum alloy conductors. By pre-dipping nickel, then chemically plating nickel on this basis, and finally bright acid tin plating, the tin-plating process is successfully achieved on the surface of the aluminum alloy conductor. Without affecting the original electrical and mechanical properties of the aluminum alloy conductor, the corrosion resistance of the aluminum alloy and the problem of connecting with copper terminals are solved. After the aluminum alloy is successfully tinned on the surface, the aluminum is made weldable. The cable conductor, power fittings or photovoltaic welding strip prepared by the tin-plated aluminum alloy material all have weldability. The weldability of the wire meets GB / T 4910 "Tinned Round Copper Wire" and the weldability of the strip meets GB / T31985 "Photovoltaic Tin-Coated Solder Strip". It can be welded and connected with the corresponding power implementation, so that the aluminum alloy is processed into a conductor material, greatly expanding the application field of aluminum alloy materials to replace copper conductors. The application field is more extensive and can be used in various fields such as new energy vehicles, photovoltaic power generation, wind power generation, electrical equipment wires, electrical switches, distribution cabinets or household appliances.

[0069] Experimental results show that the tin-plated aluminum alloy conductor material provided by the present invention has good electrical conductivity, tensile properties, and fatigue resistance, with a conductivity greater than 62% IACS, an elongation at break greater than or equal to 10%, and a tensile strength greater than or equal to 110 MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] FIG1 is a cross-sectional microscopic image of a tinned aluminum alloy conductor wire prepared by the present invention;

[0071] FIG2 is an image of the microstructure of the coating of the tinned aluminum alloy conductor wire prepared by the present invention. DETAILED DESCRIPTION

[0072] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than for limiting the claims of the invention.

[0073] All raw materials of the present invention are not particularly limited in their sources and can be purchased from the market or prepared according to conventional methods well known to those skilled in the art.

[0074] There is no particular limitation on the purity of all raw materials in the present invention. The present invention preferably adopts the conventional purity requirements in the field of tin-plated aluminum alloy wire preparation.

[0075] All raw materials of the present invention, their brands and abbreviations are conventional brands and abbreviations in the field. Each brand and abbreviation is clear and unambiguous in the field of its relevant use. Those skilled in the art can purchase them from the market or prepare them by conventional methods based on the brand, abbreviation and corresponding use.

[0076] The abbreviations of the processes used in the present invention are all conventional abbreviations in the field. The specific steps and conventional parameters of each abbreviation are clear and definite in its relevant field. Those skilled in the art can implement them in a conventional manner based on the abbreviations.

[0077] The present invention provides a tinned aluminum alloy wire, wherein the tinned aluminum alloy wire comprises, by mass percentage:

[0078] Sn: 1% to 40%;

[0079] The balance is Al and impurities.

[0080] Wherein, the Sn content in the tin-plated aluminum alloy wire may be 5% to 35%, or 10% to 30%, or 15% to 25%.

[0081] In the present invention, the tin-plated aluminum alloy wire preferably includes an aluminum alloy wire substrate and a coating composited on the aluminum alloy wire substrate. Specifically, the coating preferably includes a nickel coating composited on the wire substrate and a tin coating composited on the nickel coating. In the present invention, based on the preparation process, the aluminum alloy wire substrate is first plated with a nickel layer and then plated with a tin layer, resulting in a structure of a tin coating and a nickel coating. However, the electron microscopic microstructure of the finished tin-plated aluminum alloy wire shows no obvious layer boundary structure between the tin coating and the nickel coating. Therefore, it can be considered that the aluminum alloy wire substrate in the present invention has a monolithic coating structure, or a mixed layer structure of tin and nickel between the tin coating and the nickel coating.

[0082] See FIG1 , which is a cross-sectional microscopic image of the tinned aluminum alloy conductor wire prepared by the present invention.

[0083] See FIG2 , which is a microstructure image of the coating of the tinned aluminum alloy conductor wire prepared by the present invention.

[0084] In the present invention, the thickness of the tin-plated layer is preferably 0.5 to 100 μm, more preferably 5 to 80 μm, more preferably 10 to 60 μm, and more preferably 30 to 40 μm.

[0085] In the present invention, the thickness of the nickel plating layer is preferably 100 nm to 10 μm, more preferably 500 nm to 8 μm, and even more preferably 2 μm to 6 μm.

[0086] In the present invention, the transverse dimension of the aluminum alloy wire substrate is preferably 0.1 to 300 mm, more preferably 0.5 to 200 mm, more preferably 1 to 100 mm, and even more preferably 10 to 50 mm. Specifically, the transverse dimension in the present invention refers to the thickness of the aluminum alloy wire substrate, such as the radial dimension of a cylindrical wire, the width of a ribbon conductor, or the width of a strip conductor.

[0087] In the present invention, the tinned aluminum alloy wire is preferably a tinned aluminum alloy wire conductor.

[0088] In the present invention, the wire conductor preferably includes one or more of Class 1 circular conductor, Class 2 circular conductor, Class 5 circular conductor, Class 6 circular conductor, strip conductor, ribbon conductor and tubular conductor, more preferably Class 1 circular conductor, Class 2 circular conductor, Class 5 circular conductor, Class 6 circular conductor, strip conductor, ribbon conductor or tubular conductor.

[0089] In the present invention, in the tinned aluminum alloy wire, the mass content of the tinned layer (or plating layer) is preferably 1% to 40%, more preferably 5% to 30%, and even more preferably 10% to 20%.

[0090] In the present invention, the aluminum alloy wire matrix preferably includes one or more of 1 series aluminum alloy, 4 series aluminum alloy, 5 series aluminum alloy, 6 series aluminum alloy and 8 series aluminum alloy, more preferably 1 series aluminum alloy, 4 series aluminum alloy, 5 series aluminum alloy, 6 series aluminum alloy or 8 series aluminum alloy.

[0091] In the present invention, the coating further comprises D in an amount of preferably 0.01% to 40% by mass, more preferably 0.1% to 20% by mass, and even more preferably 1% to 10% by mass.

[0092] In the present invention, D is preferably one or more of Ni, Zn, Fe, Mg, Cu, Na, K, Ti, V, As, Sb, O, N and Cl, more preferably Ni, Zn, Fe, Mg, Cu, Na, K, Ti, V, As, Sb, O, N or Cl.

[0093] In the present invention, the coating further comprises E in an amount of preferably 0.01% to 40% by mass, more preferably 0.1% to 20% by mass, and even more preferably 1% to 10% by mass.

[0094] In the present invention, the E is preferably one or more of Cr, Ca, Co, Ga, Cd, Bi, C, Mn, Pb, Ag, Si, S, P, B, H, and RE, and more preferably Cr, Ca, Co, Ga, Cd, Bi, C, Mn, Pb, Ag, Si, S, P, B, H, or RE. Specifically, the mass content of RE is preferably 0.01% to 1%, more preferably 0.1% to 0.7% RE, and preferably 0.2% to 0.4% RE. The RE includes one or more of Ce, La, Pr, Nd, Pm, Sm, Eu, Y, and Sc.

[0095] The present invention adopts tin plating to form the tin-plated layer, but due to the inevitable presence of other elements in the raw materials or processes, or due to the reasons of the inspection method, other elements may be present in the result. Therefore, after the tin-plated layer provided by the present invention is inspected, a certain amount of the above-mentioned elements will be present.

[0096] The present invention provides a method for preparing a tinned aluminum alloy wire, comprising the following steps:

[0097] 1) Pre-treating an aluminum alloy wire sample, and then performing conditioning pre-treatment, nickel pre-dipping, and nickel plating to obtain an aluminum alloy wire composite with a nickel plating layer;

[0098] 2) The aluminum alloy wire with the nickel-plated layer obtained in the above step is plated with bright tin and then post-processed to obtain a tinned aluminum alloy wire.

[0099] The invention first pre-treats an aluminum alloy wire sample, then performs conditioning pre-treatment, pre-nickel dipping and nickel plating to obtain an aluminum alloy wire with a composite nickel plating layer.

[0100] In the present invention, the pretreatment step preferably includes one or more of organic solvent degreasing, drying, alkali etching, water washing and nitric acid polishing and water washing, more preferably multiple of organic solvent degreasing, drying, alkali etching, water washing and nitric acid polishing and water washing.

[0101] In the present invention, the treatment solution for the conditioning pretreatment preferably comprises:

[0102] Ammonia 320-350ml / L;

[0103] Trisodium citrate 60-70g / L;

[0104] ZnO 50~60g / L;

[0105] In the present invention, the amount of ammonia water added is preferably 320-350 ml / L, more preferably 325-345 ml / L, and even more preferably 330-340 ml / L.

[0106] In the present invention, the addition amount of trisodium citrate is preferably 60-70 g / L, more preferably 62-68 g / L, and even more preferably 64-66 g / L.

[0107] In the present invention, the added amount of ZnO is preferably 50-60 g / L, more preferably 52-58 g / L, and even more preferably 54-56 g / L.

[0108] In the present invention, the conditioning pretreatment time is preferably 2 to 3 minutes, more preferably 2.2 to 2.8 minutes, and even more preferably 2.4 to 2.6 minutes.

[0109] In the present invention, the nickel pre-dip treatment solution preferably includes:

[0110] Nickel acetate 20-30 g / L;

[0111] Trisodium citrate 20-25g / L;

[0112] Ammonia 260-280 ml / L;

[0113] Triethanolamine 50-60ml / L;

[0114] Lactic acid 30-59 ml / L;

[0115] In the present invention, the amount of nickel acetate added is preferably 20-30 g / L, more preferably 22-28 g / L, and even more preferably 24-26 g / L.

[0116] In the present invention, the addition amount of trisodium citrate is preferably 20-25 g / L, more preferably 21-24 g / L, and even more preferably 22-23 g / L.

[0117] In the present invention, the amount of ammonia water added is preferably 260-280 ml / L, more preferably 264-276 ml / L, and even more preferably 268-272 ml / L.

[0118] In the present invention, the addition amount of triethanolamine is preferably 50-60 ml / L, more preferably 52-58 ml / L, and even more preferably 54-56 ml / L ml / L.

[0119] In the present invention, the amount of lactic acid added is preferably 30-59 ml / L, more preferably 35-54 ml / L, and even more preferably 40-49 ml / L.

[0120] In the present invention, the pH value of the nickel pre-dip treatment solution is preferably 10-11, more preferably 10.2-10.8, and even more preferably 10.4-10.6.

[0121] In the present invention, the nickel pre-dip time is preferably 3 to 6 minutes, more preferably 3.5 to 5.5 minutes, and even more preferably 4 to 5 minutes.

[0122] In the present invention, the nickel plating method preferably includes chemical nickel plating.

[0123] In the present invention, the treatment solution for chemical nickel plating preferably comprises:

[0124] Nickel sulfate 80-90g / L;

[0125] Sodium hypophosphite 70-80g / L;

[0126] Trisodium citrate 18-30g / L;

[0127] Lactic acid 75-85 ml / L;

[0128] Ammonium sulfate 100-120 g / L;

[0129] Dibutyltin dilaurate 30-50ml / L;

[0130] Silicone oil 30-50ml / L.

[0131] In the present invention, the amount of nickel sulfate added is preferably 80-90 g / L, more preferably 82-88 g / L, and even more preferably 84-86 g / L.

[0132] In the present invention, the addition amount of the sodium hypophosphite is preferably 70-80 g / L, more preferably 72-78 g / L, and even more preferably 74-76 g / L.

[0133] In the present invention, the addition amount of trisodium citrate is preferably 18 to 30 g / L, more preferably 20 to 28 g / L, and even more preferably 22 to 26 g / L.

[0134] In the present invention, the amount of lactic acid added is preferably 75-85 ml / L, more preferably 77-83 ml / L, and even more preferably 79-81 g / L.

[0135] In the present invention, the amount of ammonium sulfate added is preferably 100-120 g / L, more preferably 104-116 g / L, and even more preferably 108-112 g / L.

[0136] Specifically, the added amount of the dibutyltin dilaurate is preferably 30-50 ml / L, more preferably 34-46 ml / L, and even more preferably 38-42 ml / L.

[0137] In the present invention, the amount of silicone oil added is preferably 30-50 ml / L, more preferably 34-46 ml / L, and even more preferably 38-42 ml / L.

[0138] In the present invention, the pH value of the treatment solution for chemical nickel plating is preferably 4.0 to 5.0, more preferably 4.2 to 4.8, and even more preferably 4.4 to 4.6.

[0139] In the present invention, the temperature of the chemical nickel plating is preferably 55-65°C, more preferably 57-63°C, and even more preferably 59-61°C.

[0140] In the present invention, the time for the chemical nickel plating is preferably 5 to 10 minutes, more preferably 6 to 9 minutes, and even more preferably 7 to 8 minutes.

[0141] Finally, the aluminum alloy wire material with the nickel-plated layer obtained in the above steps is plated with bright tin and then subjected to post-processing to obtain the tinned aluminum alloy wire material.

[0142] In the present invention, the bright tin plating method preferably includes a bright acid tin plating process.

[0143] In the present invention, the bright acid tin plating treatment solution preferably includes:

[0144] Stannous sulfate 140-160 g / L;

[0145] Sulfuric acid 240-260 g / L;

[0146] Tartaric acid 28-35 g / L;

[0147] Silicone oil 15-25 ml / L;

[0148] Dibutyltin dimaleate 10-20ml / L.

[0149] In the present invention, the added amount of stannous sulfate is preferably 140-160 g / L, more preferably 144-156 g / L, and even more preferably 148-152 g / L.

[0150] In the present invention, the amount of sulfuric acid added is preferably 240-260 g / L, more preferably 244-256 g / L, and even more preferably 248-252 g / L.

[0151] In the present invention, the added amount of tartaric acid is preferably 28-35 g / L, more preferably 29-34 g / L, more preferably 30-33 g / L, more preferably 31-32 g / L.

[0152] In the present invention, the amount of silicone oil added is preferably 15 to 25 ml / L, more preferably 17 to 23 ml / L, and even more preferably 19 to 21 ml / L.

[0153] In the present invention, the added amount of the dibutyltin dimaleate is preferably 10-20 ml / L, more preferably 12-18 ml / L, and even more preferably 14-16 ml / L.

[0154] In the present invention, the current density of the bright acid tin plating is preferably 1 to 4 A / dm 2 , more preferably 1.5 to 3.5 A / dm 2 , more preferably 2 to 3 A / dm 2 .

[0155] In the present invention, the bright acid tin plating time is preferably 5 to 15 minutes, more preferably 7 to 13 minutes, and even more preferably 9 to 11 minutes.

[0156] In the present invention, the post-treatment preferably includes one or more steps of water washing, warm water washing, drying and inspection, more preferably multiple steps of water washing, warm water washing, drying and inspection.

[0157] The present invention is to complete and refine the overall technical solution, better ensure the structure and composition of the tinned aluminum alloy wire, and further improve the performance of the tinned aluminum alloy wire. The above-mentioned tinned aluminum alloy wire and its preparation method may specifically include the following contents:

[0158] A tin-plated aluminum alloy, wherein the components and the weight percentages of the components are as follows:

[0159] Sn: 1-40%;

[0160] The balance is Al and impurities.

[0161] For the base aluminum in the aluminum alloy, industrial Al99.70 pure aluminum can be used, so that the aluminum alloy prepared by the present invention has the advantages of sufficient raw material supply, low cost, and convenient procurement; at the same time, the aluminum base can also use refined aluminum or high-purity aluminum as the base alloy. This aluminum base has higher quality than ordinary aluminum-based materials, and the processed products have more advantages in electrical properties and mechanical properties.

[0162] In the specific embodiment of the present invention, aluminum is used as the matrix, and various trace alloying elements are added to improve the performance of the aluminum alloy, thereby improving the mechanical strength, tensile properties, tensile strength, yield properties, heat resistance and creep resistance of the aluminum alloy.

[0163] Specifically, the tin-plated aluminum alloy further contains 0.01 to 40 weight percent of D, wherein D is at least one element selected from the group consisting of Ni, Zn, Fe, Mg, Cu, Na, K, Ti, V, As, Sb, O, N, and Cl.

[0164] Specifically, the tin-plated aluminum alloy further contains 0.01 to 40 weight percent of E, and the E is at least one element selected from Cr, Ca, Co, Ga, Cd, Bi, C, Mn, Pb, Ag, Si, S, P, B, H, and RE.

[0165] Specifically, the tin-plated aluminum alloy further contains 0.01 to 1 weight percent of RE.

[0166] Aluminum alloy materials are obtained through smelting, casting and rolling processes to obtain aluminum alloy rods, bars or strips, and then processed into aluminum alloy wires, bars or tubes.

[0167] In a specific embodiment of the present invention, a layer of tin with a thickness of ≥100 nm is electroplated on the surface of the aluminum alloy material. The thickness of the tin-plated layer on the surface of the aluminum alloy material can be made thicker, but from a cost-effective perspective, the thickness is preferably kept within a reasonable range without affecting performance.

[0168] Specifically, the aluminum alloy material is obtained through smelting, casting, and rolling processes to obtain aluminum alloy rods, bars, or strips, which are then processed into aluminum alloy wires, bars, or tubes, namely, aluminum alloy blanks.

[0169] Specifically, the aluminum alloy sample → degreasing with organic solvent → drying → alkaline etching → water washing → nitric acid polishing water washing → conditioning pretreatment → nickel pre-dip → chemical nickel plating → water washing → bright tin plating → recycling → water washing → warm water washing → drying → inspection → tinning of the aluminum alloy sample.

[0170] Specifically, in order to elaborate on the tinning process in more detail, the present invention further elaborates the conditioning pretreatment process, and the conditioning pretreatment process is as follows:

[0171] Ammonia water 320-350 ml / L; trisodium citrate 60-70 g / L; ZnO 50-60 g / L; room temperature; 2-3 min.

[0172] After the aluminum parts are conditioned and pretreated, their surfaces are in an activated state and can be directly immersed in the pre-dip nickel solution without washing.

[0173] Since the existing technology cannot solve the problem of tinning on the surface of aluminum wire, in order to enhance the bonding strength between the tinned layer and the aluminum substrate, the present invention chooses to pre-plate a layer of nickel on the surface of the aluminum alloy and then tin-plate on the basis of nickel, which is very easy to achieve.

[0174] According to the present invention, the present invention further details the pre-dip nickel process, which is as follows:

[0175] Nickel acetate 20-30 g / L; trisodium citrate 20-25 g / L; aqueous ammonia 260-280 ml / L; triethanolamine 50-60 ml / L; lactic acid 30-59 ml / L; pH 10-11; room temperature; time 3-6 min.

[0176] Because the pre-dip nickel layer is very thin, it is easy to break down when directly plating acid bright tin on it, resulting in poor bonding between the tin plating layer and the aluminum substrate. Therefore, a thicker intermediate layer is required. After testing, the chemical nickel plating process is adopted. After the aluminum parts are pre-dip nickel, the chemical nickel plating process is directly carried out without water washing.

[0177] According to the present invention, the present invention further details the chemical nickel plating process, and the described chemical nickel plating process is as follows:

[0178] Nickel sulfate 80-90 g / L; sodium hypophosphite 70-80 g / L; trisodium citrate 18-30 g / L; lactic acid 75-85 ml / L; ammonium sulfate 100-120 g / L; dibutyltin dilaurate 30-50 ml / L; silicone oil 30-50 ml / L; pH 4.0-5.0; temperature (60±5)°C; time 5-10 min.

[0179] The chemical nickel plating time is generally controlled at 5 to 10 minutes. If the time is too short, the chemical nickel plating layer will be thinner and easily penetrated in the bright acidic tin plating solution, thus affecting the bonding strength of the coating.

[0180] According to the present invention, the present invention further details the bright acid tin plating process, and the bright acid tin plating process is as follows:

[0181] Stannous sulfate 140-160 g / L; sulfuric acid 240-260 g / L; tartaric acid 28-35 g / L; silicone oil 15-25 ml / L; dibutyltin dimaleate 10-20 ml / L; current density 1-4 A / dm 2 ; Cathode moves; Anode is pure tin plate; Time is 5 to 15 minutes.

[0182] During the operation, the workpiece must be charged and placed in the tank, the cathode must be moved, and the workpiece must be cleaned after plating. The tinning time depends on the required thickness.

[0183] Specifically, the tin-plated aluminum alloy material prepared by the above process can be made into Class 1, Class 2, Class 5, or Class 6 circular conductors, or strip conductors, or ribbon conductors, or tubular conductors. The tin-plated aluminum alloy material prepared by the above process can be further processed into Class 1, Class 2, Class 5, or Class 6 circular conductors, which can be used as conductor cores for wires and cables. It can also be processed into strip conductors, ribbon conductors, tubular conductors, or special-shaped conductors for use in photovoltaic welding ribbons, busbars, or electrical hardware.

[0184] The present invention provides the use of the tinned aluminum alloy wire described in any one of the above technical solutions or the tinned aluminum alloy wire prepared by the preparation method described in any one of the above technical solutions in the field of wire conductors.

[0185] The above content of the present invention provides a tin-plated aluminum alloy conductor material and its preparation method and application. The tin-plated aluminum alloy wire provided by the present invention and the alloy cable prepared from the tin-plated aluminum alloy conductor material can be directly connected to the copper terminal, eliminating the instability caused by the use of copper-aluminum transition terminal connections and unnecessary installation problems with supporting facilities. The tin-plated aluminum alloy cable of the present invention can be directly crimped with the copper terminal, and according to the national standard GB / T9327 "Test methods and requirements for crimping and mechanical connection hardware for power cable conductors with rated voltage 35kV (Um=40.5kV) and below", it has passed 1000 heat cycle tests, and the installation connection is stable and reliable. It also avoids the risk of corrosion caused by the exposed conductor at the joint, thereby improving the service life of the cable.

[0186] The electrical fittings made of tinned aluminum alloy conductor material provided by the present invention meet various performance indicators in accordance with the national standard GB / T14315 "Crimp-type copper and aluminum terminal blocks and connection tubes for power cable conductors." Furthermore, the terminal blocks or connection tubes made of tinned aluminum alloy material can be directly crimped onto aluminum alloy cables. They have passed 1,000 thermal cycle tests in accordance with the national standard GB / T9327 "Test methods and requirements for crimp-type and mechanical connection fittings for power cable conductors with rated voltages of 35 kV (Um = 40.5 kV) and below," demonstrating stable and reliable installation and connection. This makes connecting aluminum alloy cables more convenient and safe.

[0187] The surface of the aluminum alloy conductor material provided by the present invention is tinned, which greatly improves the hardness, wear resistance and toughness of the existing aluminum alloy material and effectively optimizes various performance indicators of the aluminum alloy as a conductor material. The present invention also provides a corresponding preparation process. According to the present invention, after a complete set of tinning steps, including aluminum alloy wire billet → degreasing with organic solvent → drying → alkaline etching → water washing → nitric acid polishing water washing → conditioning pretreatment → pre-dipping nickel → chemical nickel plating → water washing → bright tin plating → recycling → water washing → warm water washing → drying → inspection → tinning the aluminum alloy wire billet, the prepared tinned aluminum alloy conductor wire core has excellent corrosion resistance, which greatly exceeds the corrosion resistance of non-tinned aluminum alloy. According to GB 10124 "Laboratory Uniform Corrosion Full Immersion Test Method for Metal Materials", atmospheric corrosion tests and electrolyte corrosion tests are carried out. Under the condition of a test period of 720 hours, the corrosion rate is ≤0.03mm / a, and the cable has good stability in salt spray and salt water. This solves the problem that ordinary aluminum alloy cables are not suitable for use in coastal areas with relatively high salinity and severe chemical and acid-base corrosion in chemical plants. The alloy cable prepared with tinned aluminum alloy conductor material fully meets the needs of these relatively harsh environments.

[0188] The tin-plated aluminum alloy process provided by the present invention solves the technical difficulties of tin-plating on the surface of aluminum alloy conductors. Through the pre-nickel dipping process, chemical nickel plating is performed on this basis, and finally bright acid tin plating is performed to successfully realize the tin-plating process on the surface of aluminum alloy conductors. Under the premise of not affecting the original electrical and mechanical properties of the aluminum alloy conductors, the corrosion resistance of aluminum alloy and the problem of connection with copper terminals are solved. After the aluminum alloy is successfully tinned on the surface, the aluminum has weldability. Cable conductors, power fittings or photovoltaic welding strips prepared from tin-plated aluminum alloy materials all have weldability. The weldability of wires complies with GB / T 4910 "Tinned Round Copper Wire" and the weldability of strips complies with GB / T31985 "Photovoltaic Tin-Coated Solder Strips". They can be welded with corresponding power implementations to achieve welding connections, making aluminum alloys processed into conductor materials with a wider range of applications.

[0189] Experimental results show that the tin-plated aluminum alloy conductor material provided by the present invention has good electrical conductivity, tensile properties, and fatigue resistance, with a conductivity greater than 62% IACS, an elongation at break greater than or equal to 10%, and a tensile strength greater than or equal to 110 MPa.

[0190] To further illustrate the present invention, a tin-plated aluminum alloy wire provided by the present invention, a preparation method thereof, and an application thereof are described in detail below in conjunction with embodiments. However, it should be understood that these embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating processes are provided only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the present invention. The scope of protection of the present invention is not limited to the following embodiments.

[0191] Example 1

[0192] (1) Putting aluminum alloy ingot raw materials into a furnace, manufacturing aluminum alloy rods through smelting, casting, and rolling processes, and then making the aluminum alloy rods into aluminum alloy wires;

[0193] (2) Electroplating a layer of tin with a thickness of 100 nm on the surface of the aluminum alloy wire obtained in step (1). The tin plating process flow of the aluminum alloy wire surface is as follows:

[0194] Aluminum alloy wire billet → degreasing with organic solvent → air drying → alkaline etching → water washing → nitric acid brightening and water washing → conditioning pretreatment → nickel pre-dip → electroless nickel plating → water washing → bright tin plating → recycling → water washing → warm water washing → drying → inspection → tinning of aluminum alloy wire billet. Other components are added in the form of chlorides. The composition of the tinned aluminum alloy is listed in Table 1.

[0195] See Table 1, which is a composition table (wt %) of the tin-plated aluminum alloy prepared in accordance with an embodiment of the present invention.

[0196] (3) The pretreatment process in step (2) is as follows:

[0197] Ammonia 320ml / L; trisodium citrate 60g / L; ZnO 50g / L; room temperature; time 2min;

[0198] (4) The nickel pre-dip process in step (2) is as follows:

[0199] Nickel acetate 20g / L; trisodium citrate 20g / L; ammonia 260ml / L; triethanolamine 50ml / L; lactic acid 30ml / L; pH 10; room temperature; time 3min;

[0200] (5) Chemical nickel plating process in step (2) is as follows:

[0201] Nickel sulfate 80g / L; sodium hypophosphite 70g / L; trisodium citrate 18g / L; lactic acid 75ml / L; ammonium sulfate 100g / L; dibutyltin dilaurate 30ml / L; silicone oil 30ml / L; pH 4.0; temperature (60±5)℃; time 5min;

[0202] (6) The bright acid tin plating process in step (2) is as follows:

[0203] Stannous sulfate 140g / L; sulfuric acid 240g / L; tartaric acid 28g / L; silicone oil 15ml / L; dibutyltin dimaleate 10ml / L; current density 1A / dm 2 ; Cathode moves; Anode is pure tin plate; Time is 5 minutes.

[0204] The properties of the aluminum alloy prepared according to the above method and the aluminum alloy after the tinning process were tested, and the results are shown in Table 2. Table 2 is a performance test data table of the tinned aluminum alloy conductor material prepared in accordance with the embodiment of the present invention.

[0205] Example 2

[0206] (1) Putting aluminum alloy ingot raw materials into a furnace, manufacturing aluminum alloy rods through smelting, casting, and rolling processes, and then making the aluminum alloy rods into aluminum alloy wires;

[0207] (2) Electroplating a layer of tin with a thickness of 1 μm on the surface of the aluminum alloy wire obtained in step (1). The tin plating process flow of the aluminum alloy wire surface is as follows:

[0208] Aluminum alloy wire billet → degreasing with organic solvent → air drying → alkaline etching → water washing → nitric acid brightening and water washing → conditioning pretreatment → nickel pre-dip → electroless nickel plating → water washing → bright tin plating → recycling → water washing → warm water washing → drying → inspection → tinning of aluminum alloy wire billet. Other components are added in the form of chlorides. The composition of the tinned aluminum alloy is listed in Table 1.

[0209] (3) The pretreatment process in step (2) is as follows:

[0210] Ammonia 350ml / L; trisodium citrate 70g / L; ZnO 60g / L; room temperature; time 3min;

[0211] (4) The nickel pre-dip process in step (2) is as follows:

[0212] Nickel acetate 30g / L; trisodium citrate 25g / L; ammonia 280ml / L; triethanolamine 60ml / L; lactic acid 59ml / L; pH 11; room temperature; time 6 minutes;

[0213] (5) Chemical nickel plating process in step (2) is as follows:

[0214] Nickel sulfate 90g / L; sodium hypophosphite 80g / L; trisodium citrate 30g / L; lactic acid 85ml / L; ammonium sulfate 120g / L; dibutyltin dilaurate 50ml / L; silicone oil 50ml / L; pH 5.0; temperature (60±5)℃; time 6min;

[0215] (6) The bright acid tin plating process in step (2) is as follows:

[0216] Stannous sulfate 160g / L; sulfuric acid 260g / L; tartaric acid 35g / L; silicone oil 25ml / L; dibutyltin dimaleate 20ml / L; current density 4A / dm 2 ; Cathode moves; Anode is pure tin plate; Time is 6 minutes.

[0217] The properties of the aluminum alloy prepared according to the above method and the aluminum alloy after tin plating process were tested. The results are shown in Table 2.

[0218] Example 3

[0219] (1) Putting aluminum alloy ingot raw materials into a furnace, manufacturing aluminum alloy rods through smelting, casting, and rolling processes, and then making the aluminum alloy rods into aluminum alloy wires;

[0220] (2) Electroplating a layer of tin with a thickness of 10 μm on the surface of the aluminum alloy wire obtained in step (1). The tin plating process flow of the aluminum alloy wire surface is as follows:

[0221] Aluminum alloy wire billet → degreasing with organic solvent → air drying → alkaline etching → water washing → nitric acid brightening and water washing → conditioning pretreatment → nickel pre-dip → electroless nickel plating → water washing → bright tin plating → recycling → water washing → warm water washing → drying → inspection → tinning of aluminum alloy wire billet. Other components are added in the form of chlorides. The composition of the tinned aluminum alloy is listed in Table 1.

[0222] (3) The pretreatment process in step (2) is as follows:

[0223] Ammonia 324 ml / L; trisodium citrate 61 g / L; ZnO 51 g / L; room temperature; 2 min;

[0224] (4) The nickel pre-dip process in step (2) is as follows:

[0225] Nickel acetate 22g / L; trisodium citrate 21g / L; ammonia 264ml / L; triethanolamine 52ml / L; lactic acid 32ml / L; pH 10.2; room temperature; time 3.5min;

[0226] (5) Chemical nickel plating process in step (2) is as follows:

[0227] Nickel sulfate 82g / L; sodium hypophosphite 72g / L; trisodium citrate 20g / L; lactic acid 77ml / L; ammonium sulfate 104g / L; dibutyltin dilaurate 34ml / L; silicone oil 34ml / L; pH 4.2; temperature (60±5)℃; time 7min;

[0228] (6) The bright acid tin plating process in step (2) is as follows:

[0229] Stannous sulfate 144g / L; sulfuric acid 244g / L; tartaric acid 30g / L; silicone oil 17ml / L; dibutyltin dimaleate 12ml / L; current density 2A / dm 2 ; Cathode moves; Anode is pure tin plate; Time is 7 minutes.

[0230] The properties of the aluminum alloy prepared according to the above method and the aluminum alloy after tin plating process were tested. The results are shown in Table 2.

[0231] Example 4

[0232] (1) Putting aluminum alloy ingot raw materials into a furnace, manufacturing aluminum alloy rods through smelting, casting, and rolling processes, and then making the aluminum alloy rods into aluminum alloy wires;

[0233] (2) Electroplating a layer of tin with a thickness of 50 μm on the surface of the aluminum alloy wire obtained in step (1). The tin plating process flow of the aluminum alloy wire surface is as follows:

[0234] Aluminum alloy wire billet → degreasing with organic solvent → air drying → alkaline etching → water washing → nitric acid brightening and water washing → conditioning pretreatment → nickel pre-dip → electroless nickel plating → water washing → bright tin plating → recycling → water washing → warm water washing → drying → inspection → tinning of aluminum alloy wire billet. Other components are added in the form of chlorides. The composition of the tinned aluminum alloy is listed in Table 1.

[0235] (3) The pretreatment process in step (2) is as follows:

[0236] Ammonia 325ml / L; trisodium citrate 62g / L; ZnO 52g / L; room temperature; time 125s;

[0237] (4) The nickel pre-dip process in step (2) is as follows:

[0238] Nickel acetate 28g / L; trisodium citrate 23g / L; ammonia 268ml / L; triethanolamine 56ml / L; lactic acid 38ml / L; pH 10.4; room temperature; time 3.5min;

[0239] (5) Chemical nickel plating process in step (2) is as follows:

[0240] Nickel sulfate 81g / L; sodium hypophosphite 71g / L; trisodium citrate 20g / L; lactic acid 76ml / L; ammonium sulfate 102g / L; dibutyltin dilaurate 32ml / L; silicone oil 32ml / L; pH 4.1; temperature (60±5)℃; time 8min;

[0241] (6) The bright acid tin plating process in step (2) is as follows:

[0242] Stannous sulfate 142g / L; sulfuric acid 242g / L; tartaric acid 28g / L; silicone oil 16ml / L; dibutyltin dimaleate 11ml / L; current density 1A / dm 2 ; Cathode moves; Anode is pure tin plate; Time is 8 minutes.

[0243] The properties of the aluminum alloy prepared according to the above method and the aluminum alloy after tin plating process were tested. The results are shown in Table 2.

[0244] Example 5

[0245] (1) Putting aluminum alloy ingot raw materials into a furnace, manufacturing aluminum alloy rods through smelting, casting, and rolling processes, and then making the aluminum alloy rods into aluminum alloy wires;

[0246] (2) Electroplating a layer of tin with a thickness of 100 μm on the surface of the aluminum alloy wire obtained in step (1). The tin plating process flow of the aluminum alloy wire surface is as follows:

[0247] Aluminum alloy wire billet → degreasing with organic solvent → air drying → alkaline etching → water washing → nitric acid brightening and water washing → conditioning pretreatment → nickel pre-dip → electroless nickel plating → water washing → bright tin plating → recycling → water washing → warm water washing → drying → inspection → tinning of aluminum alloy wire billet. Other components are added in the form of chlorides. The composition of the tinned aluminum alloy is listed in Table 1.

[0248] (3) The pretreatment process in step (2) is as follows:

[0249] Ammonia 328ml / L; trisodium citrate 64g / L; ZnO 54g / L; room temperature; time 135s;

[0250] (4) The nickel pre-dip process in step (2) is as follows:

[0251] Nickel acetate 28g / L; trisodium citrate 24g / L; ammonia 278ml / L; triethanolamine 58ml / L; lactic acid 56ml / L; pH 10.8; room temperature; time 5.5min;

[0252] (5) Chemical nickel plating process in step (2) is as follows:

[0253] Nickel sulfate 84g / L; sodium hypophosphite 74g / L; trisodium citrate 23g / L; lactic acid 79ml / L; ammonium sulfate 108g / L; dibutyltin dilaurate 38ml / L; silicone oil 38ml / L; pH 4.4; temperature (60±5)℃; time 9min;

[0254] (6) The bright acid tin plating process in step (2) is as follows:

[0255] Stannous sulfate 148g / L; sulfuric acid 248g / L; tartaric acid 31g / L; silicone oil 19ml / L; dibutyltin dimaleate 14ml / L; current density 3A / dm 2 ; Cathode moves; Anode is pure tin plate; Time is 9 minutes.

[0256] The properties of the aluminum alloy prepared according to the above method and the aluminum alloy after tin plating process were tested. The results are shown in Table 2.

[0257] Example 6

[0258] (1) Putting aluminum alloy ingot raw materials into a furnace, manufacturing aluminum alloy rods through smelting, casting, and rolling processes, and then making the aluminum alloy rods into aluminum alloy wires;

[0259] (2) Electroplating a layer of tin with a thickness of 30 μm on the surface of the aluminum alloy wire obtained in step (1). The tin plating process flow of the aluminum alloy wire surface is as follows:

[0260] Aluminum alloy wire billet → degreasing with organic solvent → air drying → alkaline etching → water washing → nitric acid brightening and water washing → conditioning pretreatment → nickel pre-dip → electroless nickel plating → water washing → bright tin plating → recycling → water washing → warm water washing → drying → inspection → tinning of aluminum alloy wire billet. Other components are added in the form of chlorides. The composition of the tinned aluminum alloy is listed in Table 1.

[0261] (3) The pretreatment process in step (2) is as follows:

[0262] Ammonia 342 ml / L; trisodium citrate 66 g / L; ZnO 56 g / L; room temperature; time 150 s;

[0263] (4) The nickel pre-dip process in step (2) is as follows:

[0264] Nickel acetate 23g / L; trisodium citrate 22g / L; ammonia 266ml / L; triethanolamine 53ml / L; lactic acid 38ml / L; pH 10.3; room temperature; time 3.5min;

[0265] (5) Chemical nickel plating process in step (2) is as follows:

[0266] Nickel sulfate 83g / L; sodium hypophosphite 73g / L; trisodium citrate 22g / L; lactic acid 78ml / L; ammonium sulfate 106g / L; dibutyltin dilaurate 36ml / L; silicone oil 36ml / L; pH 4.3; temperature (60±5)℃; time 10min;

[0267] (6) The bright acid tin plating process in step (2) is as follows:

[0268] Stannous sulfate 146g / L; sulfuric acid 246g / L; tartaric acid 29g / L; silicone oil 18ml / L; dibutyltin dimaleate 13ml / L; current density 2A / dm 2 ; Cathode moves; Anode is pure tin plate; Time is 10 minutes.

[0269] The properties of the aluminum alloy prepared according to the above method and the aluminum alloy after tin plating process were tested. The results are shown in Table 2.

[0270] Example 7

[0271] (1) Putting aluminum alloy ingot raw materials into a furnace, manufacturing aluminum alloy rods through smelting, casting, and rolling processes, and then making the aluminum alloy rods into aluminum alloy wires;

[0272] (2) Electroplating a layer of tin with a thickness of 50 μm on the surface of the aluminum alloy wire obtained in step (1). The tin plating process flow of the aluminum alloy wire surface is as follows:

[0273] Aluminum alloy wire billet → degreasing with organic solvent → air drying → alkaline etching → water washing → nitric acid brightening and water washing → conditioning pretreatment → nickel pre-dip → electroless nickel plating → water washing → bright tin plating → recycling → water washing → warm water washing → drying → inspection → tinning of aluminum alloy wire billet. Other components are added in the form of chlorides. The composition of the tinned aluminum alloy is listed in Table 1.

[0274] (3) The pretreatment process in step (2) is as follows:

[0275] Ammonia 326 ml / L; trisodium citrate 66 g / L; ZnO 53 g / L; room temperature; time 130 s;

[0276] (4) The nickel pre-dip process in step (2) is as follows:

[0277] Nickel acetate 21g / L; trisodium citrate 20g / L; ammonia 262ml / L; triethanolamine 51ml / L; lactic acid 33ml / L; pH 10.1; room temperature; time 3 minutes;

[0278] (5) Chemical nickel plating process in step (2) is as follows:

[0279] Nickel sulfate 85g / L; sodium hypophosphite 75g / L; trisodium citrate 24g / L; lactic acid 80ml / L; ammonium sulfate 110g / L; dibutyltin dilaurate 40ml / L; silicone oil 40ml / L; pH 4.5; temperature (60±5)℃; time 9min;

[0280] (6) The bright acid tin plating process in step (2) is as follows:

[0281] Stannous sulfate 152g / L; sulfuric acid 252g / L; tartaric acid 33g / L; silicone oil 22ml / L; dibutyltin dimaleate 16ml / L; current density 3A / dm 2 ; Cathode moves; Anode is pure tin plate; Time is 11 minutes.

[0282] The properties of the aluminum alloy prepared according to the above method and the aluminum alloy after tin plating process were tested. The results are shown in Table 2.

[0283] Example 8

[0284] (1) Putting aluminum alloy ingot raw materials into a furnace, manufacturing aluminum alloy rods through smelting, casting, and rolling processes, and then making the aluminum alloy rods into aluminum alloy wires;

[0285] (2) Electroplating a layer of tin with a thickness of 8 μm on the surface of the aluminum alloy wire obtained in step (1). The tin plating process flow of the aluminum alloy wire surface is as follows:

[0286] Aluminum alloy wire billet → degreasing with organic solvent → air drying → alkaline etching → water washing → nitric acid brightening and water washing → conditioning pretreatment → nickel pre-dip → electroless nickel plating → water washing → bright tin plating → recycling → water washing → warm water washing → drying → inspection → tinning of aluminum alloy wire billet. Other components are added in the form of chlorides. The composition of the tinned aluminum alloy is listed in Table 1.

[0287] (3) The pretreatment process in step (2) is as follows:

[0288] Ammonia 348 ml / L; trisodium citrate 68 g / L; ZnO 58 g / L; room temperature; time 170 s;

[0289] (4) The nickel pre-dip process in step (2) is as follows:

[0290] Nickel acetate 25g / L; trisodium citrate 23g / L; ammonia 270ml / L; triethanolamine 55ml / L; lactic acid 40ml / L; pH 10.5; room temperature; time 4 minutes;

[0291] (5) Chemical nickel plating process in step (2) is as follows:

[0292] Nickel sulfate 86g / L; sodium hypophosphite 76g / L; trisodium citrate 24g / L; lactic acid 72ml / L; ammonium sulfate 112g / L; dibutyltin dilaurate 42ml / L; silicone oil 42ml / L; pH 4.6; temperature (60±5)℃; time 8min;

[0293] (6) The bright acid tin plating process in step (2) is as follows:

[0294] Stannous sulfate 150g / L; sulfuric acid 250g / L; tartaric acid 32g / L; silicone oil 20ml / L; dibutyltin dimaleate 15ml / L; current density 3A / dm 2 ; Cathode moves; Anode is pure tin plate; Time is 12 minutes.

[0295] The properties of the aluminum alloy prepared according to the above method and the aluminum alloy after tin plating process were tested. The results are shown in Table 2.

[0296] Example 9

[0297] (1) Putting aluminum alloy ingot raw materials into a furnace, manufacturing aluminum alloy rods through smelting, casting, and rolling processes, and then making the aluminum alloy rods into aluminum alloy wires;

[0298] (2) Electroplating a layer of tin with a thickness of 40 μm on the surface of the aluminum alloy wire obtained in step (1). The tin plating process flow of the aluminum alloy wire surface is as follows:

[0299] Aluminum alloy wire billet → degreasing with organic solvent → air drying → alkaline etching → water washing → nitric acid brightening and water washing → conditioning pretreatment → nickel pre-dip → electroless nickel plating → water washing → bright tin plating → recycling → water washing → warm water washing → drying → inspection → tinning of aluminum alloy wire billet. Other components are added in the form of chlorides. The composition of the tinned aluminum alloy is listed in Table 1.

[0300] (3) The pretreatment process in step (2) is as follows:

[0301] Ammonia 340ml / L; trisodium citrate 65g / L; ZnO 55g / L; room temperature; time 140s;

[0302] (4) The nickel pre-dip process in step (2) is as follows:

[0303] Nickel acetate 27g / L; trisodium citrate 24g / L; ammonia 275ml / L; triethanolamine 57ml / L; lactic acid 50ml / L; pH 10.7; room temperature; time 5 minutes;

[0304] (5) Chemical nickel plating process in step (2) is as follows:

[0305] Nickel sulfate 87g / L; sodium hypophosphite 77g / L; trisodium citrate 26g / L; lactic acid 82ml / L; ammonium sulfate 115g / L; dibutyltin dilaurate 45ml / L; silicone oil 45ml / L; pH 4.7; temperature (60±5)℃; time 6min;

[0306] (6) The bright acid tin plating process in step (2) is as follows:

[0307] Stannous sulfate 155g / L; sulfuric acid 255g / L; tartaric acid 33g / L; silicone oil 23ml / L; dibutyltin dimaleate 16ml / L; current density 4A / dm 2 ; Cathode moves; Anode is pure tin plate; Time is 14 minutes.

[0308] The properties of the aluminum alloy prepared according to the above method and the aluminum alloy after tin plating process were tested. The results are shown in Table 2.

[0309] Example 10

[0310] (1) Putting aluminum alloy ingot raw materials into a furnace, manufacturing aluminum alloy rods through smelting, casting, and rolling processes, and then making the aluminum alloy rods into aluminum alloy wires;

[0311] (2) Electroplating a layer of tin with a thickness of 15 μm on the surface of the aluminum alloy wire obtained in step (1). The tin plating process flow of the aluminum alloy wire surface is as follows:

[0312] Aluminum alloy wire billet → degreasing with organic solvent → air drying → alkaline etching → water washing → nitric acid brightening and water washing → conditioning pretreatment → nickel pre-dip → electroless nickel plating → water washing → bright tin plating → recycling → water washing → warm water washing → drying → inspection → tinning of aluminum alloy wire billet. Other components are added in the form of chlorides. The composition of the tinned aluminum alloy is listed in Table 1.

[0313] (3) The pretreatment process in step (2) is as follows:

[0314] Ammonia 345 ml / L; trisodium citrate 67 g / L; ZnO 57 g / L; room temperature; time 160 s;

[0315] (4) The nickel pre-dip process in step (2) is as follows:

[0316] Nickel acetate 26g / L; trisodium citrate 24g / L; ammonia 272ml / L; triethanolamine 56ml / L; lactic acid 44ml / L; pH 10.6; room temperature; time 5 minutes;

[0317] (5) Chemical nickel plating process in step (2) is as follows:

[0318] Nickel sulfate 88g / L; sodium hypophosphite 78g / L; trisodium citrate 28g / L; lactic acid 84ml / L; ammonium sulfate 118g / L; dibutyltin dilaurate 48ml / L; silicone oil 48ml / L; pH 4.8; temperature (60±5)℃; time 5min;

[0319] (6) The bright acid tin plating process in step (2) is as follows:

[0320] Stannous sulfate 158g / L; sulfuric acid 258g / L; tartaric acid 34g / L; silicone oil 24ml / L; dibutyltin dimaleate 18ml / L; current density 4A / dm 2 ; Cathode moves; Anode is pure tin plate; Time is 15 minutes.

[0321] The properties of the aluminum alloy prepared according to the above method and the aluminum alloy after tin plating process were tested. The results are shown in Table 2.

[0322] Table 1

[0323] Table 2

[0324] See Table 3, which is a performance test data table of an aluminum alloy conductor material prepared in a comparative example without any surface treatment.

[0325] The aluminum alloy conductor wires in Comparative Examples 1 to 10 are the same as the aluminum alloy conductor wires in Examples 1 to 10, respectively.

[0326] Table 3

[0327] See Table 4, which is a performance test data table of an aluminum alloy conductor material with only nickel plating on its surface, prepared in a comparative example.

[0328] The aluminum alloy conductor wires in Comparative Examples 11 to 20 are respectively the same as the aluminum alloy conductor wires in Examples 1 to 10, and the nickel plating process and corresponding parameters are also respectively the same as those of the aluminum alloy conductor wires in Examples 1 to 10.

[0329] Table 4

[0330] By comparing the examples, it was found that the aluminum alloy conductor material in the examples was tin-plated, while the aluminum alloy in the comparative example without any surface treatment and the aluminum alloy wire with only nickel plating on the surface had little difference in tensile strength and elongation at break, but there were obvious differences in electrical properties. The electrical conductivity of the aluminum alloy wire only plated with nickel was significantly worse than that of the aluminum alloy wire without any treatment. The nickel plating treatment caused the electrical properties to deteriorate. The electrical conductivity of the tin-plated aluminum alloy conductor wire was significantly improved compared with the aluminum alloy conductor wire without any treatment. This shows that the electrical properties of the aluminum alloy conductor material are significantly improved after the surface is tinned. Aluminum alloys without any surface treatment are obviously inferior to aluminum alloy materials with only nickel plating and aluminum alloy materials with tin plating in terms of corrosion resistance and connection performance with copper terminals. The corrosion rate of tin-plated aluminum alloy is ≤0.03mm / a, which is obviously much better than the corrosion resistance of ordinary aluminum alloy without surface treatment, and much better than the corrosion resistance of aluminum alloy with only nickel plating. After connecting with copper terminals, it can pass 1000 thermal cycle tests. Tin-plated aluminum alloy conductors are much more convenient to connect and are safer and more reliable. Ordinary aluminum alloys without any surface treatment cannot pass 1000 thermal cycle tests when directly connected to copper terminals.

[0331] In terms of welding performance, aluminum alloy without any surface treatment has no welding performance, and aluminum alloy wire with only nickel plating has extremely poor weldability. Although the solder resist can achieve a certain welding effect, the solderability test of the nickel-plated aluminum alloy wire alone cannot pass the welding performance test requirements of the GB / T 4910 standard. In this embodiment, the tin-plated aluminum alloy wire can easily pass the welding performance test requirements of the GB / T 4910 standard, and does not require any solder resist. It has excellent welding performance and can be directly welded to the tin-plated copper terminal.

[0332] Terminal blocks or terminal barrels made of tin-plated aluminum alloy comply with performance testing in accordance with GB / T14315. In addition to cold-pressing, they can also be welded to tin-plated aluminum alloy conductors. This makes connections more convenient and efficient, especially for wiring harnesses using plug-in components or small connectors. Busbars or welding strips made of tin-plated aluminum alloy are also weldable. The weldability of photovoltaic welding strips made of tin-plated aluminum alloy conductors complies with GB / T31985, "Photovoltaic Tin-Coated Soldering Strips," and all other performance indicators meet the requirements of GB / T5585 or GB / T31985. This provides a new solution for replacing copper with aluminum alloy as a conductor in multiple applications.

[0333] The above is a detailed introduction to a tin-plated aluminum alloy conductor material provided by the present invention, its preparation method, and application. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enables any technician in the field to practice the present invention, including the manufacture and use of any device or system, and the implementation of any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the literal description of the claims, or if they include equivalent structural elements that are not substantially different from the literal description of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A tinned aluminum alloy wire, characterized in that: The tinned aluminum alloy wire comprises, by mass percentage: Sn: 1%~40%; The balance is Al and impurities.

2. The tinned aluminum alloy wire according to claim 1, characterized in that: The tinned aluminum alloy wire comprises an aluminum alloy wire substrate and a coating composited on the aluminum alloy wire substrate; The coating comprises a nickel coating composited on the wire substrate and a tin coating composited on the nickel coating; The thickness of the tin-plated layer is 0.5 to 100 μm; The thickness of the nickel plating layer is 100nm to 10μm; The lateral dimension of the aluminum alloy wire substrate is 0.1 to 300 mm; The aluminum alloy wire matrix includes one or more of 1 series aluminum alloy, 4 series aluminum alloy, 5 series aluminum alloy, 6 series aluminum alloy and 8 series aluminum alloy.

3. The tinned aluminum alloy wire according to claim 2, characterized in that: The coating also includes D with a mass content of 0.01% to 40%; The D is one or more of Ni, Zn, Fe, Mg, Cu, Na, K, Ti, V, As, Sb, O, N and Cl; The tinned aluminum alloy wire is specifically a tinned aluminum alloy wire conductor; The wire conductor includes one or more of a Class 1 circular conductor, a Class 2 circular conductor, a Class 5 circular conductor, a Class 6 circular conductor, a strip conductor, a ribbon conductor and a tubular conductor.

4. The tinned aluminum alloy wire according to claim 1, characterized in that: The coating also includes E with a mass content of 0.01% to 40%; The E is one or more of Cr, Ca, Co, Ga, Cd, Bi, C, Mn, Pb, Ag, Si, S, P, B, H and RE.

5. A method for preparing a tinned aluminum alloy wire, characterized in that: The following steps are involved: 1) After the aluminum alloy wire sample is pre-treated, it is subjected to conditioning pretreatment, nickel pre-dipping and nickel plating to obtain an aluminum alloy wire with a composite nickel-plated layer; 2) The aluminum alloy wire with nickel coating obtained in the above step is plated with bright tin and then After post-processing, tinned aluminum alloy wire is obtained.

6. The tinned aluminum alloy wire according to claim 5, characterized in that: The pre-treatment step comprises one or more of organic solvent degreasing, air drying, alkali etching, water washing and nitric acid polishing water washing; The treatment solution of the conditioned pretreatment comprises: Ammonia water 320~350ml / L; Trisodium citrate 60-70 g / L; ZnO 50~60g / L; The conditioning pretreatment time is 2 to 3 minutes.

7. The tinned aluminum alloy wire according to claim 5, characterized in that: The treatment solution for pre-dipping nickel comprises: Nickel acetate 20-30 g / L; Trisodium citrate 20-25 g / L; Ammonia 260-280 ml / L; Triethanolamine 50-60ml / L; Lactic acid 30-59 ml / L; The pH value of the nickel pre-immersion treatment solution is 10 to 11; The nickel pre-immersion time is 3 to 6 minutes.

8. The tinned aluminum alloy wire according to claim 5, characterized in that: The nickel plating method includes chemical nickel plating; The treatment solution of the chemical nickel plating comprises: Nickel sulfate 80-90 g / L; Sodium hypophosphite 70-80g / L; Trisodium citrate 18-30 g / L; Lactic acid 75-85 ml / L; Ammonium sulfate 100-120 g / L; Dibutyltin dilaurate 30-50ml / L; Silicone oil 30-50ml / L; The pH value of the chemical nickel plating treatment solution is 4.0 to 5.0; The temperature of the chemical nickel plating is 55-65° C. The time for the chemical nickel plating is 5 to 10 minutes.

9. The tinned aluminum alloy wire according to claim 5, characterized in that: The bright tin plating method includes a bright acid tin plating process; The treatment solution of the bright acid tin plating comprises: Stannous sulfate 140-160 g / L; Sulfuric acid 240~260g / L; Tartaric acid 28-35 g / L; Silicone oil 15-25 ml / L; Dibutyltin dimaleate 10-20ml / L; The current density of the bright acid tin plating is 1 to 4 A / dm 2 ; The bright acid tin plating time is 5 to 15 minutes; The post-treatment comprises one or more steps of water washing, warm water washing, drying and inspection.

10. Use of the tinned aluminum alloy wire according to any one of claims 1 to 4 or the tinned aluminum alloy wire prepared by the preparation method according to any one of claims 5 to 9 in the field of wire conductors.

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