Tin-plated aluminum alloy conductor material and preparation method and application thereof

Abstract

The invention discloses a tin-plated aluminum alloy wire rod which is characterized by comprising the following components in percentage by mass: 1-40% of Sn, 1-20% of Al, 1-20% of Al, 1-20% of Al, and the balance of aluminum and inevitable impurities. And the balance of Al and impurities. According to the aluminum alloy conductor material provided by the invention, the hardness, wear resistance, toughness and corrosion resistance of an existing aluminum alloy material are greatly improved, and various performance indexes of the aluminum alloy as the conductor material are effectively optimized. And the tin-plated aluminum alloy has weldability, so that the application field of replacing a copper conductor by an aluminum alloy material is greatly expanded, and the corrosion prevention problem of the aluminum alloy and the problem of connection with a copper terminal are solved on the premise that the original electrical performance and mechanical performance of the aluminum alloy conductor are not influenced. The tin-plated aluminum alloy conductor material can be used in the fields of new energy automobiles, photovoltaic power generation, wind power generation, wires for electrical equipment, electrical switches, power distribution cabinets or household appliances and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation of tin-plated aluminum alloy wire, and relates to a tin-plated aluminum alloy wire and its preparation method and application, in particular to a tin-plated aluminum alloy conductor material and its preparation method and application. Background Art

[0002] Copper, as a commonly used non-ferrous metal material, has been widely used in fields such as power electronics, machinery manufacturing, transportation, construction, and national defense industries. In 2020, China's copper consumption has approached 14.5 million tons, accounting for about 60% of the global total. The global copper ore resources are rich in reserves, and the resource development is mainly concentrated in developing countries such as Chile, Peru, and Mexico. However, the gradual restriction of exports may affect the global supply volume and the safety of China's overseas equity resource assets. Under the background of "dual carbon", the conversion of the energy structure promotes the development of the power system. The development of clean energy industries and new energy vehicle industries represented by photovoltaic and wind power brings new incremental demands for copper. It is expected that China's copper resource consumption will maintain a growth trend before 2035, and the demand will continue to remain at a high level from 2035 to 2050. However, under the circumstances of weak domestic resource bases and limited supply capabilities, the supply of copper resources will still mainly rely on foreign countries. Strengthening the supply guarantee of copper resources is a practical need and a long-term resource strategy issue, which is related to the development of China's national economy and society, whether China's new energy industry chain can build an advantage, and whether the national "dual carbon" goal can be successfully achieved.

[0003] The wire and cable industry is a material-heavy and labor-light, capital-intensive industry. Wire and cable materials account for about 85% - 95% of the total cost of wire and cable. Wire and cable mainly consists of a conductor core, an insulating layer, a sheath, etc. Among them, the conductor core is mainly composed of copper and aluminum materials, and copper raw materials account for the largest proportion among the raw materials required for wire and cable products. Conductor materials are the basic materials in the cable industry. The improvement of their performance will drive the performance improvement of cable products, meet the needs of different scenarios, and bring more added value to cable products.

[0004] Due to the active chemical properties of aluminum and its poor antioxidant performance, an oxide film with a thickness of about 0.005 - 0.015 μm can be formed in the atmosphere. This film is dense and too thin to play a protective role. Especially in coastal areas with relatively high salinity, as well as places where chemical compounds and acid-base corrosion in chemical plants are more serious, the anti-corrosion performance of existing aluminum alloy materials far cannot meet the requirements of industrial use. The substitution of aluminum alloy as a conductor material for copper conductors is limited. Coupled with the fact that the surface of aluminum is very active and easily oxidized in the air, it is very difficult to perform multi-metal plating treatment on the surface of aluminum, making aluminum not weldable. The connection of aluminum alloy conductors is a big problem.

[0005] Due to the soaring price of copper, the demand for aluminum alloy materials has been increasing. The technology of aluminum alloy materials has been developing deeper into the field. Nowadays, with the strong development of new energy in the country, the demand for wire and cable in photovoltaic power generation, wind power generation, and new energy vehicles has increased sharply. Especially in recent years, the explosive growth of new energy power generation and new energy vehicles, aiming at cost reduction and efficiency improvement, has led to an increasing demand for materials. However, the existing technology of aluminum alloy conductor materials can no longer meet the development needs of many fields such as new energy. And the cost of copper materials is too high, resulting in high construction costs and thin profits in the development of new energy. Aluminum has good electrical conductivity, is light in weight and low in price, but due to its poor corrosion resistance and lack of weldability, it greatly restricts the popularization of aluminum alloy application technology.

[0006] Therefore, how to find a more suitable way to solve the above problems existing in aluminum alloy conductor materials and better broaden the depth and breadth of its application has become one of the focuses widely concerned by many front-line researchers in the industry. Summary of the Invention

[0007] 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, especially 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, especially the corrosion resistance of the existing aluminum alloy conductor material. Through surface tin-plating treatment, the aluminum alloy has weldability and can be welded to copper terminals. After the aluminum alloy is tin-plated, it can also be used in photovoltaic solder tapes, bus bars, and electrical hardware, greatly expanding the application field of aluminum alloy conductor materials. Moreover, the process is simple, with strong controllability and high on-site executability, and is suitable for the popularization and application of industrial-scale production.

[0008] The present invention provides a tin-plated aluminum alloy wire, which, by mass percentage, includes:

[0009] Sn: 1% - 40%;

[0010] The balance is Al and impurities.

[0011] Preferably, the tin-plated aluminum alloy wire includes an aluminum alloy wire matrix and a coating compounded on the aluminum alloy wire matrix;

[0012] The coating includes a nickel-plated layer compounded on the wire matrix and a tin-plated layer compounded on the nickel-plated layer;

[0013] The thickness of the tin-plated layer is 0.5 - 100 μm;

[0014] The thickness of the nickel-plated layer is 100 nm - 10 μm;

[0015] The lateral dimension of the aluminum alloy wire matrix is 0.1 - 300 mm;

[0016] The aluminum alloy wire matrix includes one or more of 1xxx series aluminum alloy, 4xxx series aluminum alloy, 5xxx series aluminum alloy, 6xxx series aluminum alloy and 8xxx series aluminum alloy.

[0017] Preferably, the coating further includes D with a mass content of 0.01% to 40%;

[0018] The D is one or more of Ni, Zn, Fe, Mg, Cu, Na, K, Ti, V, As, Sb, O, N and Cl;

[0019] The tin-plated aluminum alloy wire is specifically a tin-plated aluminum alloy wire conductor;

[0020] The wire conductor includes one or more of Class 1 round conductor, Class 2 round conductor, Class 5 round conductor, Class 6 round conductor, bar conductor, strip conductor and tubular conductor.

[0021] Preferably, the coating further includes E with a mass content of 0.01% to 40%;

[0022] The E is one or more of Cr, Ca, Co, Ga, Cd, Bi, C, Mn, Pb, Ag, Si, S, P, B, H and RE.

[0023] The present invention provides a method for preparing a tin-plated aluminum alloy wire, comprising the following steps:

[0024] 1) After subjecting the aluminum alloy wire sample blank to pretreatment, followed by conditioning pretreatment, nickel pre-immersion and nickel plating, an aluminum alloy wire composite with a nickel plating layer is obtained;

[0025] 2) After subjecting the aluminum alloy wire composite with a nickel plating layer obtained in the above step to bright tin plating and then post-treatment, a tin-plated aluminum alloy wire is obtained.

[0026] Preferably, the pretreatment step includes one or more of degreasing with organic solvents, air drying, alkaline etching, water washing and nitric acid brightening and water washing;

[0027] The treatment solution for the conditioning pretreatment includes:

[0028] Ammonia water 320 - 350 ml / L;

[0029] Trisodium citrate 60 - 70 g / L;

[0030] ZnO 50 - 60 g / L;

[0031] The time for the conditioning pretreatment is 2 - 3 min.

[0032] Preferably, the treatment solution for the nickel pre-immersion includes:

[0033] Nickel acetate: 20 - 30 g / L;

[0034] Trisodium citrate: 20 - 25 g / L;

[0035] Ammonia water: 260 - 280 ml / L;

[0036] Triethanolamine: 50 - 60 ml / L;

[0037] Lactic acid: 30 - 59 ml / L;

[0038] The pH value of the treatment solution for nickel pre - immersion is 10 - 11;

[0039] The time for nickel pre - immersion is 3 - 6 min.

[0040] Preferably, the method of nickel plating includes electroless nickel plating;

[0041] The treatment solution for electroless nickel plating includes:

[0042] Nickel sulfate: 80 - 90 g / L;

[0043] Sodium hypophosphite: 70 - 80 g / L;

[0044] Trisodium citrate: 18 - 30 g / L;

[0045] Lactic acid: 75 - 85 ml / L;

[0046] Ammonium sulfate: 100 - 120 g / L;

[0047] Dibutyltin dilaurate: 30 - 50 ml / L;

[0048] Silicone oil: 30 - 50 ml / L;

[0049] The pH value of the treatment solution for electroless nickel plating is 4.0 - 5.0;

[0050] The temperature for electroless nickel plating is 55 - 65 °C;

[0051] The time for electroless nickel plating is 5 - 10 min.

[0052] Preferably, the method of bright tin plating includes bright acid tin plating process;

[0053] The treatment solution for bright acid tin plating includes:

[0054] Stannous sulfate: 140 - 160 g / L;

[0055] Sulfuric acid: 240 - 260 g / L;

[0056] Tartaric acid: 28 - 35 g / L;

[0057] Silicone oil: 15 - 25 ml / L;

[0058] Dibutyltin dimaleate: 10 - 20 ml / L;

[0059] The current density of the bright acid tin plating is 1 - 4 A / dm 2 ;

[0060] The time of the bright acid tin plating is 5 - 15 min;

[0061] The post-treatment includes one or more steps of water washing, warm water washing, drying and inspection.

[0062] The present invention also provides the application of the tin-plated aluminum alloy wire described in any one of the above technical solutions or the tin-plated aluminum alloy wire prepared by the preparation method described in any one of the above technical solutions in the field of wire conductors.

[0063] The present invention provides a tin-plated aluminum alloy wire. The tin-plated aluminum alloy wire, by mass percentage, includes Sn: 1% - 40%; the balance is Al and impurities. Compared with the prior art, the present invention believes that solving the problem of the surface treatment of aluminum alloy will greatly improve the replaceability of aluminum with copper, which is one of the feasible directions to solve the foregoing problems existing in the 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, especially the corrosion resistance of the existing aluminum alloy conductor material. The alloy cable prepared by the tin-plated aluminum alloy conductor material provided by the present invention can be directly connected to a copper terminal, eliminating the instability brought about by using a copper-aluminum transition terminal connection and the unnecessary installation problems of supporting facilities. The tin-plated aluminum alloy cable of the present invention can be directly crimped to a copper terminal, and according to the national standard GB / T9327 "Test Methods and Requirements for Crimp-Type and Mechanical-Type Connecting Fittings for Conductors of Rated Voltage 35 kV (Um = 40.5 kV) and Below Power Cables", it has passed 1000 thermal cycle tests, and the installation connection is stable and reliable. Moreover, it also avoids the risk of easy corrosion caused by the exposure of the conductor at the joint part, improving the service life of the cable.

[0064] The power fittings prepared by the tin-plated aluminum alloy conductor material provided by the present invention meet the performance indicators of the national standard GB / T14315 "Crimp-Type Copper and Aluminum Terminal Lugs and Connecting Tubes for Conductors of Power Cables". Moreover, the terminal lugs or connecting tubes made of tin-plated aluminum alloy materials can be directly crimped to the aluminum alloy cable. According to the national standard GB / T9327 "Test Methods and Requirements for Crimp-Type and Mechanical-Type Connecting Fittings for Conductors of Rated Voltage 35 kV (Um = 40.5 kV) and Below Power Cables", it has passed 1000 thermal cycle tests, and the installation connection is stable and reliable. It makes the connection of aluminum alloy cables more convenient and safe.

[0065] The surface of the aluminum alloy conductor material provided by the present invention is treated by tin plating, which greatly improves the hardness, wear resistance and toughness of the existing aluminum alloy materials, effectively optimizes the performance indexes of the aluminum alloy as a conductor material, and also endows the aluminum alloy with weldability, enabling it to be welded to copper terminals. After the aluminum alloy is treated by tin plating, it can also be used in photovoltaic solder tapes, busbars, and electrical fittings, greatly expanding the application fields of the aluminum alloy conductor material. Moreover, the present invention also provides a corresponding preparation process. The present invention processes the aluminum alloy wire rod → degreasing with organic solvents → air drying → alkali etching → water washing → brightening with nitric acid and water washing → conditioning pretreatment → nickel pre - immersion → electroless nickel plating → water washing → bright tin plating → recovery → water washing → warm water washing → drying → inspection → tin - plated aluminum alloy wire rod. After a complete set of tin - plating processes, the prepared tin - plated aluminum alloy conductor core has excellent corrosion resistance, far exceeding the anti - corrosion performance of non - tin - plated aluminum alloy. According to GB 10124 "Metallic materials - Laboratory immersion corrosion test for uniform corrosion", the atmosphere corrosion test and electrolyte solution corrosion test are carried out. Under the condition of a test period of 720 hours, the corrosion rate ≤ 0.03 mm / a, and it has good stability in salt spray and salt water, solving the problem that it is not suitable to use ordinary aluminum alloy cables in coastal areas with relatively high salinity and in chemical plants with relatively severe compound and acid - base corrosion. The alloy cable prepared with the tin - plated aluminum alloy conductor material fully meets the requirements of these harsh environments.

[0066] The tin - plating process for aluminum alloy provided by the present invention well solves the technical problem of tin - plating on the surface of aluminum alloy conductors. Through the nickel pre - immersion process, followed by electroless nickel plating on this basis, and finally bright acid tin - plating, the process of tin - plating on the surface of aluminum alloy conductors is successfully realized. Without affecting the original electrical and mechanical properties of the aluminum alloy conductors, the anti - corrosion problem of aluminum alloy and the problem of connection with copper terminals are solved. After the aluminum alloy is successfully tin - plated on the surface, aluminum has weldability. The cable conductors, electrical fittings or photovoltaic solder tapes prepared from the tin - plated aluminum alloy material all have weldability. The weldability of the wire meets GB / T4910 "Tinned round copper wire", and the weldability of the tape meets GB / T31985 "Photovoltaic tinned solder tape", and can be welded to the corresponding electrical equipment, enabling the aluminum alloy to be processed into a conductor material, greatly expanding the application fields of aluminum alloy materials to replace copper conductors, and the application fields are more extensive, and can be used in various fields such as new energy vehicles, photovoltaic power generation, wind power generation, wires for electrical equipment, electrical switches, distribution cabinets or household appliances.

[0067] The experimental results show that the tin - plated aluminum alloy conductor material provided by the present invention has good electrical conductivity, tensile properties and anti - fatigue properties. The conductivity is greater than 62% IACS, the elongation at break is greater than or equal to 10%, and the tensile strength is greater than or equal to 110 MPa. Description of the Drawings

[0068] Figure 1The cross-sectional microscopic image of the tin-plated aluminum alloy conductor wire prepared according to the present invention;

[0069] Figure 2 The microscopic structure image of the coating of the tin-plated aluminum alloy conductor wire prepared according to the present invention. Specific embodiments

[0070] In order to further understand the present invention, the preferred embodiments of the present invention will be 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 limiting the claims of the invention.

[0071] There are no special restrictions on the sources of all raw materials of the present invention, and they can be purchased on the market or prepared by conventional methods well-known to those skilled in the art.

[0072] There are no special restrictions on the purity of all raw materials of the present invention. The present invention preferably adopts the conventional purity requirements in the field of tin-plated aluminum alloy wire preparation.

[0073] All raw materials of the present invention, their grades and abbreviations all belong to the conventional grades and abbreviations in the field. Each grade and abbreviation is clear and definite in the field of its related uses. Those skilled in the art can purchase or prepare them by conventional methods according to the grade, abbreviation and corresponding uses.

[0074] The processes used in the present invention, their abbreviations all belong to the conventional abbreviations in the field. The specific steps and conventional parameters of each abbreviation are clear and definite in the related fields. Those skilled in the art can implement them by conventional methods according to the abbreviations.

[0075] The present invention provides a tin-plated aluminum alloy wire, and the tin-plated aluminum alloy wire, by mass percentage, includes:

[0076] Sn: 1% - 40%;

[0077] The balance is Al and impurities.

[0078] Among them, in the tin-plated aluminum alloy wire, the Sn content can be 5% - 35%, or 10% - 30%, or 15% - 25%.

[0079] In the present invention, the tin-plated aluminum alloy wire preferably comprises an aluminum alloy wire substrate and a coating layer compounded on the aluminum alloy wire substrate. Specifically, the coating layer preferably comprises a nickel-plated layer compounded on the wire substrate and a tin-plated layer compounded on the nickel-plated layer. In the present invention, based on the preparation process, the nickel-plated layer is first deposited on the aluminum alloy wire substrate and then the tin-plated layer is deposited, having the structure of the tin-plated layer and the nickel-plated layer. From the SEM microstructure of the finished tin-plated aluminum alloy wire, there is no obvious layer boundary structure between the tin-plated layer and the nickel-plated layer. Therefore, it can be considered that the aluminum alloy wire substrate in the present invention has an integral coating structure, or there is a mixed layer structure of tin and nickel between the tin-plated layer and the nickel-plated layer.

[0080] See Figure 1 , Figure 1 is the cross-sectional microscopic image of the tin-plated aluminum alloy conductor wire prepared according to the present invention.

[0081] See Figure 2 , Figure 2 is the microscopic structure image of the coating layer of the tin-plated aluminum alloy conductor wire prepared according to the present invention.

[0082] In the present invention, the thickness of the tin-plated layer is preferably 0.5 - 100 μm, more preferably 5 - 80 μm, more preferably 10 - 60 μm, and more preferably 30 - 40 μm.

[0083] In the present invention, the thickness of the nickel-plated layer is preferably 100 nm - 10 μm, more preferably 500 nm - 8 μm, and more preferably 2 μm - 6 μm.

[0084] In the present invention, the lateral dimension of the aluminum alloy wire substrate is preferably 0.1 - 300 mm, more preferably 0.5 - 200 mm, more preferably 1 - 100 mm, and more preferably 10 - 50 mm. Specifically, the lateral 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 strip conductor or a bar conductor, etc.

[0085] In the present invention, the tin-plated aluminum alloy wire is specifically preferably a tin-plated aluminum alloy wire conductor.

[0086] In the present invention, the wire conductor preferably comprises one or more of a Class 1 round conductor, a Class 2 round conductor, a Class 5 round conductor, a Class 6 round conductor, a bar conductor, a strip conductor, and a tubular conductor, and more preferably a Class 1 round conductor, a Class 2 round conductor, a Class 5 round conductor, a Class 6 round conductor, a bar conductor, a strip conductor, or a tubular conductor.

[0087] In the present invention, in the tin-plated aluminum alloy wire, the mass content of the tin-plated layer (or the coating layer) is preferably 1% - 40%, more preferably 5% - 30%, and more preferably 10% - 20%.

[0088] In the present invention, the aluminum alloy wire substrate preferably comprises one or more of 1xxx series aluminum alloy, 4xxx series aluminum alloy, 5xxx series aluminum alloy, 6xxx series aluminum alloy and 8xxx series aluminum alloy, and more preferably is 1xxx series aluminum alloy, 4xxx series aluminum alloy, 5xxx series aluminum alloy, 6xxx series aluminum alloy or 8xxx series aluminum alloy.

[0089] In the present invention, the coating further comprises D with a preferably mass content of 0.01% to 40%, more preferably 0.1% to 20%, and even more preferably 1% to 10%.

[0090] 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, and more preferably Ni, Zn, Fe, Mg, Cu, Na, K, Ti, V, As, Sb, O, N or Cl.

[0091] In the present invention, the coating further comprises E with a preferably mass content of 0.01% to 40%, more preferably 0.1% to 20%, and even more preferably 1% to 10%.

[0092] In the present invention, 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%, and preferably 0.2% to 0.4%. Among them, the RE includes one or more of Ce, La, Pr, Nd, Pm, Sm, Eu, Y and Sc.

[0093] In the present invention, the tin plating method is adopted to form the tin plating layer. However, due to the inevitable presence of other elements in the raw materials or the process, or due to the inspection method, other elements exist in the results. Therefore, after the detection of the tin plating layer provided by the present invention, there will be a certain amount of the above elements.

[0094] The present invention provides a preparation method of a tin-plated aluminum alloy wire, comprising the following steps:

[0095] 1) After the aluminum alloy wire sample blank is pretreated, it is then subjected to conditioning pretreatment, nickel pre-immersion and nickel plating to obtain an aluminum alloy wire composite with a nickel plating layer;

[0096] 2) The aluminum alloy wire composite with a nickel plating layer obtained in the above step is subjected to bright tin plating and then post-treatment to obtain a tin-plated aluminum alloy wire.

[0097] In the present invention, first, a sample blank of aluminum alloy wire is pretreated and then subjected to conditioning pretreatment, nickel pre - immersion, and nickel plating to obtain an aluminum alloy wire composite with a nickel - plated layer.

[0098] In the present invention, the pretreatment step preferably includes one or more of degreasing with organic solvents, air drying, alkaline etching, water washing, and nitric acid brightening and water washing, and more preferably includes multiple of degreasing with organic solvents, air drying, alkaline etching, water washing, and nitric acid brightening and water washing.

[0099] In the present invention, the treatment solution for the conditioning pretreatment preferably includes:

[0100] Ammonia water 320 - 350 ml / L;

[0101] Trisodium citrate 60 - 70 g / L;

[0102] ZnO 50 - 60 g / L;

[0103] In the present invention, the addition amount of the ammonia water is preferably 320 - 350 ml / L, more preferably 325 - 345 ml / L, and even more preferably 330 - 340 ml / L.

[0104] In the present invention, the addition amount of the trisodium citrate is preferably 60 - 70 g / L, more preferably 62 - 68 g / L, and even more preferably 64 - 66 g / L.

[0105] In the present invention, the addition amount of the ZnO is preferably 50 - 60 g / L, more preferably 52 - 58 g / L, and even more preferably 54 - 56 g / L.

[0106] In the present invention, the time for the conditioning pretreatment is preferably 2 - 3 min, more preferably 2.2 - 2.8 min, and even more preferably 2.4 - 2.6 min.

[0107] In the present invention, the treatment solution for the nickel pre - immersion preferably includes:

[0108] Nickel acetate 20 - 30 g / L;

[0109] Trisodium citrate 20 - 25 g / L;

[0110] Ammonia water 260 - 280 ml / L;

[0111] Triethanolamine 50 - 60 ml / L;

[0112] Lactic acid 30 - 59 ml / L;

[0113] In the present invention, the addition amount of the nickel acetate is preferably 20 - 30 g / L, more preferably 22 - 28 g / L, and even more preferably 24 - 26 g / L.

[0114] 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.

[0115] In the present invention, the addition amount of ammonia water is preferably 260 - 280 ml / L, more preferably 264 - 276 ml / L, and even more preferably 268 - 272 ml / L.

[0116] 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.

[0117] In the present invention, the addition amount of lactic acid is preferably 30 - 59 ml / L, more preferably 35 - 54 ml / L, and even more preferably 40 - 49 ml / L.

[0118] In the present invention, the pH value of the pretreatment solution for nickel pre - immersion is preferably 10 - 11, more preferably 10.2 - 10.8, and even more preferably 10.4 - 10.6.

[0119] In the present invention, the time for nickel pre - immersion is preferably 3 - 6 min, more preferably 3.5 - 5.5 min, and even more preferably 4 - 5 min.

[0120] In the present invention, the nickel plating method preferably includes electroless nickel plating.

[0121] In the present invention, the treatment solution for electroless nickel plating preferably includes:

[0122] Nickel sulfate 80 - 90 g / L;

[0123] Sodium hypophosphite 70 - 80 g / L;

[0124] Trisodium citrate 18 - 30 g / L;

[0125] Lactic acid 75 - 85 ml / L;

[0126] Ammonium sulfate 100 - 120 g / L;

[0127] Dibutyltin dilaurate 30 - 50 ml / L;

[0128] Silicone oil 30 - 50 ml / L.

[0129] In the present invention, the addition amount of nickel sulfate is preferably 80 - 90 g / L, more preferably 82 - 88 g / L, and even more preferably 84 - 86 g / L.

[0130] In the present invention, the addition amount of sodium hypophosphite is preferably 70 - 80 g / L, more preferably 72 - 78 g / L, and even more preferably 74 - 76 g / L.

[0131] In the present invention, the addition amount of trisodium citrate is preferably 18 - 30 g / L, more preferably 20 - 28 g / L, and even more preferably 22 - 26 g / L.

[0132] In the present invention, the addition amount of lactic acid is preferably 75 - 85 ml / L, more preferably 77 - 83 ml / L, and even more preferably 79 - 81 g / L.

[0133] In the present invention, the addition amount of ammonium sulfate is preferably 100 - 120 g / L, more preferably 104 - 116 g / L, and even more preferably 108 - 112 g / L.

[0134] Specifically, the addition amount of dibutyltin dilaurate is preferably 30 - 50 ml / L, more preferably 34 - 46 ml / L, and even more preferably 38 - 42 ml / L.

[0135] In the present invention, the addition amount of silicone oil is preferably 30 - 50 ml / L, more preferably 34 - 46 ml / L, and even more preferably 38 - 42 ml / L.

[0136] In the present invention, the pH value of the electroless nickel plating treatment solution is preferably 4.0 - 5.0, more preferably 4.2 - 4.8, and even more preferably 4.4 - 4.6.

[0137] In the present invention, the temperature of the electroless nickel plating is preferably 55 - 65 °C, more preferably 57 - 63 °C, and even more preferably 59 - 61 °C.

[0138] In the present invention, the time of the electroless nickel plating is preferably 5 - 10 min, more preferably 6 - 9 min, and even more preferably 7 - 8 min.

[0139] Finally, in the present invention, the aluminum alloy wire composite with a nickel plating layer obtained by the above steps is subjected to bright tin plating and then post - treatment to obtain a tin - plated aluminum alloy wire.

[0140] In the present invention, the method of bright tin plating preferably includes a bright acidic tin plating process.

[0141] In the present invention, the treatment solution for bright acidic tin plating preferably includes:

[0142] Stannous sulfate 140 - 160 g / L;

[0143] Sulfuric acid 240 - 260 g / L;

[0144] Tartaric acid 28 - 35 g / L;

[0145] Silicone oil 15 - 25 ml / L;

[0146] Dibutyltin dimaleate: 10 - 20 ml / L.

[0147] In the present invention, the addition amount of stannous sulfate is preferably 140 - 160 g / L, more preferably 144 - 156 g / L, and even more preferably 148 - 152 g / L.

[0148] In the present invention, the addition amount of sulfuric acid is preferably 240 - 260 g / L, more preferably 244 - 256 g / L, and even more preferably 248 - 252 g / L.

[0149] In the present invention, the addition amount of tartaric acid is preferably 28 - 35 g / L, more preferably 29 - 34 g / L, even more preferably 30 - 33 g / L, and even more preferably 31 - 32 g / L.

[0150] In the present invention, the addition amount of silicone oil is preferably 15 - 25 ml / L, more preferably 17 - 23 ml / L, and even more preferably 19 - 21 ml / L.

[0151] In the present invention, the addition amount of dibutyltin dimaleate is preferably 10 - 20 ml / L, more preferably 12 - 18 ml / L, and even more preferably 14 - 16 ml / L.

[0152] In the present invention, the current density of bright acid tin plating is preferably 1 - 4 A / dm 2 , more preferably 1.5 - 3.5 A / dm 2 , even more preferably 2 - 3 A / dm 2 .

[0153] In the present invention, the time of bright acid tin plating is preferably 5 - 15 min, more preferably 7 - 13 min, and even more preferably 9 - 11 min.

[0154] In the present invention, the post-treatment preferably includes one or more steps of water washing, warm water washing, drying, and inspection, and more preferably multiple steps of water washing, warm water washing, drying, and inspection.

[0155] In order to complete and refine the overall technical solution of the present invention, better ensure the structure and composition of the tin-plated aluminum alloy wire, and further improve the performance of the tin-plated aluminum alloy wire, the above-mentioned tin-plated aluminum alloy wire and its preparation method may specifically include the following content:

[0156] A tin-plated aluminum alloy, the components included in the tin-plated aluminum alloy and the weight percentages of each component are as follows:

[0157] Sn: 1 - 40%;

[0158] The balance is Al and impurities.

[0159] For the matrix aluminum in the aluminum alloy, industrial pure aluminum Al99.70 can be used, enabling the aluminum alloy prepared by the present invention to have advantages such as sufficient raw material supply, low cost, and convenient procurement. At the same time, refined aluminum or high-purity aluminum can also be used as the matrix alloy for the aluminum base, which has higher quality than ordinary aluminum base materials, and the processed products are more advantageous in terms of electrical and mechanical properties.

[0160] In the specific embodiment of the present invention, aluminum is used as the matrix, and various trace alloying elements are added to improve the properties of the aluminum alloy, and to improve the mechanical strength, tensile properties, tensile strength, yield properties, heat resistance and creep resistance of the aluminum alloy.

[0161] Specifically, the tin-plated aluminum alloy further contains 0.01 to 40% by weight of D, and D is at least one element selected from Ni, Zn, Fe, Mg, Cu, Na, K, Ti, V, As, Sb, O, N, Cl.

[0162] Specifically, the tin-plated aluminum alloy further contains 0.01 to 40% by weight of E, and E is at least one element selected from Cr, Ca, Co, Ga, Cd, Bi, C, Mn, Pb, Ag, Si, S, P, B, H, RE.

[0163] Specifically, the tin-plated aluminum alloy further contains 0.01 to 1% by weight of RE.

[0164] The aluminum alloy material is processed through melting, casting, and rolling processes to obtain aluminum alloy rods, strips or bands, and then processed into aluminum alloy wires, strips or tubes.

[0165] In the specific embodiment of the present invention, a tin layer with a thickness of ≧100 nm is electroplated on the surface of the aluminum alloy material. The thickness of the tin plating layer on the surface of the aluminum alloy material can be made as thick as possible, but from the perspective of economic cost, without affecting the performance, the thickness is preferably controlled within the most reasonable range.

[0166] Specifically, the aluminum alloy material is processed through melting, casting, and rolling processes to obtain aluminum alloy rods, strips or bands, and then processed into aluminum alloy wires, strips or tubes, that is, aluminum alloy sample blanks.

[0167] Specifically, the aluminum alloy sample blank → degreasing with organic solvent → air drying → alkaline etching → water washing → nitric acid brightening and water washing → conditioning pretreatment → nickel pre-immersion → electroless nickel plating → water washing → bright tin plating → recovery → water washing → warm water washing → drying → inspection → tin-plated aluminum alloy sample blank.

[0168] Specifically, in order to elaborate on the tin plating process in more detail, the present invention further elaborates on the conditioning pretreatment process, and the conditioning pretreatment process is as follows:

[0169] Ammonia water: 320 - 350 ml / L; Sodium citrate: 60 - 70 g / L; ZnO: 50 - 60 g / L; Temperature: room temperature; Time: 2 - 3 min.

[0170] After the aluminum parts are pretreated under the conditioning conditions, their surfaces are in an activated state and are directly immersed in the nickel pre - dipping solution without water washing.

[0171] Since the prior art cannot solve the problem of tin plating on the surface of aluminum wire, in order to enhance the bonding force between the tin plating layer and the aluminum substrate, the present invention selects to pre - plate a layer of nickel on the aluminum alloy surface and then plate tin on the basis of nickel, which is very easy to achieve.

[0172] According to the present invention, the nickel pre - dipping process is further elaborated in detail. The nickel pre - dipping process is as follows:

[0173] Nickel acetate: 20 - 30 g / L; Sodium citrate: 20 - 25 g / L; Ammonia water: 260 - 280 ml / L; Triethanolamine: 50 - 60 ml / L; Lactic acid: 30 - 59 ml / L; pH value: 10 - 11; Temperature: room temperature; Time: 3 - 6 min.

[0174] Since the nickel pre - dipping layer is very thin, directly plating acidic bright tin on it is easily penetrated, resulting in a poor bonding force between the tin plating layer and the aluminum substrate. Therefore, it is necessary to thicken the intermediate plating layer. Through experiments, an electroless nickel plating process is adopted. After the aluminum parts are pre - dipped in nickel, they are directly subjected to the electroless nickel plating process without water washing.

[0175] According to the present invention, the electroless nickel plating process is further elaborated in detail. The electroless nickel plating process is as follows:

[0176] Nickel sulfate: 80 - 90 g / L; Sodium hypophosphite: 70 - 80 g / L; Sodium citrate: 18 - 30 g / L; Lactic acid: 75 - 85 ml / L; Ammonium sulfate: 100 - 120 g / L; Dibutyltin dilaurate: 30 - 50 ml / L; Silicon oil: 30 - 50 ml / L; pH value: 4.0 - 5.0; Temperature: (60 ± 5) °C; Time: 5 - 10 min.

[0177] The electroless nickel plating time is generally controlled within 5 - 10 min. If the time is too short, the electroless nickel plating layer is relatively thin and is easily penetrated in the bright acidic tin plating solution, affecting the bonding force of the plating layer.

[0178] According to the present invention, the bright acidic tin plating process is further elaborated in detail. The bright acidic tin plating process is as follows:

[0179] Stannous sulfate: 140 - 160 g / L; Sulfuric acid: 240 - 260 g / L; Tartaric acid: 28 - 35 g / L; Silicon oil: 15 - 25 ml / L; Dibutyltin dimaleate: 10 - 20 ml / L; Current density: 1 - 4 A / dm 2; Cathode movement; Anode pure tin plate; Time: 5 - 15 min.

[0180] During the operation, it is required to enter the tank with electricity. The cathode needs to move. After plating, the workpiece should be cleaned thoroughly. The tin plating time depends on the required thickness.

[0181] Specifically, the tin - plated aluminum alloy material prepared through the above - mentioned process can be made into circular conductors of Class 1, Class 2, Class 5, or Class 6, or strip - shaped conductors, or ribbon - shaped conductors, or tubular conductors. The tin - plated aluminum alloy material prepared by the present invention through the above - mentioned process can be further processed into circular conductors of Class 1, Class 2, Class 5, or Class 6, which can be used for the conductor cores of wires and cables. It can also be processed into strip - shaped conductors, ribbon - shaped conductors, tubular conductors or special - shaped conductors, and used for photovoltaic solder tapes, bus bars or electrical fittings, etc.

[0182] The present invention provides the application of the tin - plated aluminum alloy wire described in any one of the above - mentioned technical solutions or the tin - plated aluminum alloy wire prepared by the preparation method described in any one of the above - mentioned technical solutions in the field of wire conductors.

[0183] The above content of the present invention provides a tin - plated aluminum alloy conductor material, its preparation method and application. The tin - plated aluminum alloy wire provided by the present invention, the alloy cable prepared from this tin - plated aluminum alloy conductor material can be directly connected to copper terminals, eliminating the instability brought by using copper - aluminum transition terminals for connection and unnecessary installation problems with supporting facilities. The tin - plated aluminum alloy cable of the present invention can be directly crimped to copper terminals, and according to the national standard GB / T9327 "Test Methods and Requirements for Press - type and Mechanical Connection Fittings for Conductors of Rated Voltage 35 kV (Um = 40.5 kV) and Below Power Cables", it has passed 1000 - cycle thermal cycle experiments, with stable and reliable installation connections. Moreover, it also avoids the risk of easy corrosion due to the exposure of the conductor at the joint part, improving the service life of the cable.

[0184] The electrical fittings prepared from the tin - plated aluminum alloy conductor material provided by the present invention meet all performance indicators of the national standard GB / T14315 "Press - type Copper and Aluminum Terminal Lugs and Connection Tubes for Conductors of Power Cables". And the terminal lugs or connection tubes made of tin - plated aluminum alloy material can be directly crimped to aluminum alloy cables. According to the national standard GB / T9327 "Test Methods and Requirements for Press - type and Mechanical Connection Fittings for Conductors of Rated Voltage 35 kV (Um = 40.5 kV) and Below Power Cables", it has passed 1000 - cycle thermal cycle experiments, with stable and reliable installation connections. This makes the connection of aluminum alloy cables more convenient and safe.

[0185] The surface of the aluminum alloy conductor material provided by the present invention is treated by tin plating, which greatly improves the hardness, wear resistance and toughness of the existing aluminum alloy materials, and effectively optimizes the performance indexes of the aluminum alloy as a conductor material. Moreover, the present invention also provides a corresponding preparation process. The present invention processes the aluminum alloy wire rod blank → degreasing with organic solvent → air drying → alkaline etching → water washing → brightening with nitric acid and water washing → conditioning pretreatment → nickel pre-immersion → electroless nickel plating → water washing → bright tin plating → recovery → water washing → warm water washing → drying → inspection → tin-plated aluminum alloy wire rod blank. After a complete set of tin plating processes, the prepared tin-plated aluminum alloy conductor core has excellent corrosion resistance, far exceeding the anti-corrosion performance of the non-tin-plated aluminum alloy. According to GB 10124 "Metallic Materials - Laboratory Immersion Corrosion Test for Uniform Corrosion", the atmospheric corrosion test and electrolyte solution corrosion test are carried out. Under the condition of a test cycle of 720 hours, the corrosion rate ≤ 0.03 mm / a, and it has good stability in salt spray and salt water, solving the problem that it is not suitable to use ordinary aluminum alloy cables in coastal areas with relatively high salinity, as well as in chemical plants where compound and acid-base corrosion are relatively serious. The alloy cable prepared with the tin-plated aluminum alloy conductor material fully meets the requirements of these harsh environments.

[0186] The tin plating process for aluminum alloy provided by the present invention well solves the technical problem of tin plating on the surface of the aluminum alloy conductor. Through the nickel pre-immersion process, and then electroless nickel plating on this basis, and finally bright acid tin plating, the process of tin plating on the surface of the aluminum alloy conductor is successfully realized. Without affecting the original electrical and mechanical properties of the aluminum alloy conductor, the anti-corrosion problem of the aluminum alloy and the problem of connection with copper terminals are solved. After the aluminum alloy is successfully tin-plated on the surface, the aluminum has weldability. The cable conductors, electrical hardware or photovoltaic soldering tapes prepared from the tin-plated aluminum alloy materials all have weldability. The weldability of the wire meets GB / T4910 "Tinned Round Copper Wire", and the weldability of the strip meets GB / T31985 "Photovoltaic Tinned Solder Tape", and can be welded and connected with the supporting power implementation, making the aluminum alloy processed into a conductor material with a wider application field.

[0187] The experimental results show that the tin-plated aluminum alloy conductor material provided by the present invention has good electrical conductivity, tensile properties and anti-fatigue properties. The conductivity is greater than 62% IACS, the elongation at break is greater than or equal to 10%, and the tensile strength is greater than or equal to 110 MPa.

[0188] In order to further illustrate the present invention, the following takes examples to describe in detail a tin-plated aluminum alloy wire and its preparation method and application provided by the present invention. However, it should be understood that these examples are implemented on the premise of the technical solution of the present invention, and the detailed implementation methods and specific operation processes are given, only to further illustrate the features and advantages of the present invention, rather than a limitation on the claims of the present invention. The protection scope of the present invention is not limited to the following examples.

[0189] Example 1

[0190] (1) Put the aluminum alloy ingot raw material into the furnace, and make it into aluminum alloy rods through smelting, casting, and rolling processes, and then make the aluminum alloy rods into aluminum alloy wires;

[0191] (2) Electroplate a layer of tin with a thickness of 100 nm on the surface of the aluminum alloy wire obtained in step (1). The process flow of tin plating on the surface of the aluminum alloy wire is as follows:

[0192] Aluminum alloy wire blank → Degreasing with organic solvent → Drying → Alkali etching → Water washing → Pickling and water washing with nitric acid → Conditioning pretreatment → Pre - immersion nickel → Electroless nickel plating → Water washing → Bright tin plating → Recovery → Water washing → Warm water washing → Drying → Inspection → Tin - plated aluminum alloy wire blank. Other components are added in the form of chlorides. The composition of the tin - plated aluminum alloy is listed in Table 1;

[0193] See Table 1. Table 1 is the composition table (wt%) of the tin - plated aluminum alloy prepared in the embodiment of the present invention.

[0194] (3) The pretreatment process in step (2) is as follows:

[0195] Ammonia water 320 ml / L; Sodium citrate 60 g / L; ZnO 50 g / L; Temperature room temperature; Time 2 min;

[0196] (4) The pre - immersion nickel process in step (2) is as follows:

[0197] Nickel acetate 20 g / L; Sodium citrate 20 g / L; Ammonia water 260 ml / L; Triethanolamine 50 ml / L; Lactic acid 30 ml / L; pH value 10; Temperature room temperature; Time 3 min;

[0198] (5) The electroless nickel plating process in step (2) is as follows:

[0199] Nickel sulfate 80 g / L; Sodium hypophosphite 70 g / L; Sodium citrate 18 g / L; Lactic acid 75 ml / L; Ammonium sulfate 100 g / L; Dibutyltin dilaurate 30 ml / L; Silicon oil 30 ml / L; pH value 4.0; Temperature (60 ± 5) °C; Time 5 min;

[0200] (6) The bright acid tin plating process in step (2) is as follows:

[0201] Stannous sulfate 140 g / L; Sulfuric acid 240 g / L; Tartaric acid 28 g / L; Silicon oil 15 ml / L; Dibutyltin dimaleate 10 ml / L; Current density 1 A / dm 2 ; Cathode movement; Anode pure tin plate; Time 5 min.

[0202] The properties of the aluminum alloy prepared by the above method and the aluminum alloy after the tin plating process were tested, and the results are shown in Table 2. Table 2 is the performance test data table of the tin-plated aluminum alloy conductor material prepared in the examples of the present invention.

[0203] Example 2

[0204] (1) The aluminum alloy ingot raw materials were put into a furnace, and aluminum alloy rods were manufactured through smelting, casting, and rolling processes, and then the aluminum alloy rods were made into aluminum alloy wires;

[0205] (2) A layer of tin with a thickness of 1 μm was electroplated on the surface of the aluminum alloy wire obtained in step (1). The process flow of the tin plating process on the surface of the aluminum alloy wire is as follows:

[0206] Aluminum alloy wire blank → degreasing with organic solvent → air drying → alkaline etching → water washing → nitric acid brightening and water washing → conditioning pretreatment → nickel pre - immersion → electroless nickel plating → water washing → bright tin plating → recovery → water washing → warm water washing → drying → inspection → tin - plated aluminum alloy wire blank. Other components were added in the form of chlorides, and the composition of the tin - plated aluminum alloy is listed in Table 1;

[0207] (3) The pretreatment process in step (2) is as follows:

[0208] Ammonia water 350 ml / L; trisodium citrate 70 g / L; ZnO 60 g / L; temperature room temperature; time 3 min;

[0209] (4) The nickel pre - immersion process in step (2) is as follows:

[0210] Nickel acetate 30 g / L; trisodium citrate 25 g / L; ammonia water 280 ml / L; triethanolamine 60 ml / L; lactic acid 59 ml / L; pH value 11; temperature room temperature; time 6 min;

[0211] (5) The electroless nickel plating process in step (2) is as follows:

[0212] Nickel sulfate 90 g / L; sodium hypophosphite 80 g / L; trisodium citrate 30 g / L; lactic acid 85 ml / L; ammonium sulfate 120 g / L; dibutyltin dilaurate 50 ml / L; silicone oil 50 ml / L; pH value 5.0; temperature (60 ± 5) °C; time 6 min;

[0213] (6) The bright acid tin plating process in step (2) is as follows:

[0214] Stannous sulfate 160 g / L; sulfuric acid 260 g / L; tartaric acid 35 g / L; silicone oil 25 ml / L; dibutyltin dimaleate 20 ml / L; current density 4 A / dm 2 ; cathode movement; anode pure tin plate; time 6 min.

[0215] The properties of the aluminum alloy prepared by the above method and the aluminum alloy after the tin plating process were tested, and the results are shown in Table 2.

[0216] Example 3

[0217] (1) The aluminum alloy ingot raw material was put into a furnace, and an aluminum alloy rod was manufactured through the processes of melting, casting, and rolling. Then, the aluminum alloy rod was made into an aluminum alloy wire.

[0218] (2) A layer of tin with a thickness of 10 μm was electroplated on the surface of the aluminum alloy wire obtained in step (1). The process flow of the tin plating on the surface of the aluminum alloy wire is as follows:

[0219] Aluminum alloy wire blank → Degreasing with organic solvent → Drying → Alkali etching → Water washing → Pickling and water washing with nitric acid → Conditioning pretreatment → Nickel pre - immersion → Electroless nickel plating → Water washing → Bright tin plating → Recovery → Water washing → Warm water washing → Drying → Inspection → Tin - plated aluminum alloy wire blank. Other components were added in the form of chlorides, and the composition of the tin - plated aluminum alloy is listed in Table 1;

[0220] (3) The pretreatment process in step (2) is as follows:

[0221] Ammonia water 324 ml / L; Sodium citrate 61 g / L; ZnO 51 g / L; Temperature room temperature; Time 2 min;

[0222] (4) The nickel pre - immersion process in step (2) is as follows:

[0223] Nickel acetate 22 g / L; Sodium citrate 21 g / L; Ammonia water 264 ml / L; Triethanolamine 52 ml / L; Lactic acid 32 ml / L; pH value 10.2; Temperature room temperature; Time 3.5 min;

[0224] (5) The electroless nickel plating process in step (2) is as follows:

[0225] Nickel sulfate 82 g / L; Sodium hypophosphite 72 g / L; Sodium citrate 20 g / L; Lactic acid 77 ml / L; Ammonium sulfate 104 g / L; Dibutyltin dilaurate 34 ml / L; Silicon oil 34 ml / L; pH value 4.2; Temperature (60 ± 5) °C; Time 7 min;

[0226] (6) The bright acid tin plating process in step (2) is as follows:

[0227] Stannous sulfate 144 g / L; Sulfuric acid 244 g / L; Tartaric acid 30 g / L; Silicon oil 17 ml / L; Dibutyltin dimaleate 12 ml / L; Current density 2 A / dm 2 ; Cathode movement; Anode pure tin plate; Time 7 min.

[0228] The properties of the aluminum alloy prepared by the above method and the aluminum alloy after the tin plating process were tested, and the results are shown in Table 2.

[0229] Example 4

[0230] (1) The aluminum alloy ingot raw material was put into a furnace, and an aluminum alloy rod was manufactured through the processes of melting, casting, and rolling, and then the aluminum alloy rod was made into an aluminum alloy wire;

[0231] (2) A layer of tin with a thickness of 50 μm was electroplated on the surface of the aluminum alloy wire obtained in step (1). The process flow of the tin plating process on the surface of the aluminum alloy wire is as follows:

[0232] Aluminum alloy wire blank → Degreasing with organic solvent → Drying → Alkali etching → Water washing → Pickling and water washing with nitric acid → Conditioning pretreatment → Nickel pre - immersion → Electroless nickel plating → Water washing → Bright tin plating → Recovery → Water washing → Warm water washing → Drying → Inspection → Tin - plated aluminum alloy wire blank. Other components were added in the form of chlorides, and the composition of the tin - plated aluminum alloy is listed in Table 1;

[0233] (3) The pretreatment process in step (2) is as follows:

[0234] Ammonia water 325 ml / L; Sodium citrate 62 g / L; ZnO 52 g / L; Temperature room temperature; Time 125 s;

[0235] (4) The nickel pre - immersion process in step (2) is as follows:

[0236] Nickel acetate 28 g / L; Sodium citrate 23 g / L; Ammonia water 268 ml / L; Triethanolamine 56 ml / L; Lactic acid 38 ml / L; pH value 10.4; Temperature room temperature; Time 3.5 min;

[0237] (5) The electroless nickel plating process in step (2) is as follows:

[0238] Nickel sulfate 81 g / L; Sodium hypophosphite 71 g / L; Sodium citrate 20 g / L; Lactic acid 76 ml / L; Ammonium sulfate 102 g / L; Dibutyltin dilaurate 32 ml / L; Silicone oil 32 ml / L; pH value 4.1; Temperature (60 ± 5)°C; Time 8 min;

[0239] (6) The bright acid tin plating process in step (2) is as follows:

[0240] Stannous sulfate 142 g / L; Sulfuric acid 242 g / L; Tartaric acid 28 g / L; Silicone oil 16 ml / L; Dibutyltin dimaleate 11 ml / L; Current density 1 A / dm 2 ; Cathode movement; Anode pure tin plate; Time 8 min.

[0241] The properties of the aluminum alloy prepared by the above method and the aluminum alloy after the tin plating process were tested, and the results are shown in Table 2.

[0242] Example 5

[0243] (1) The aluminum alloy ingot raw material was put into a furnace, and an aluminum alloy rod was manufactured through the processes of melting, casting, and rolling. Then, the aluminum alloy rod was made into an aluminum alloy wire.

[0244] (2) A layer of tin with a thickness of 100 μm was electroplated on the surface of the aluminum alloy wire obtained in step (1). The process flow of the tin plating on the surface of the aluminum alloy wire is as follows:

[0245] Aluminum alloy wire blank → Degreasing with organic solvent → Drying → Alkali etching → Water washing → Pickling and water washing with nitric acid → Conditioning pretreatment → Nickel pre - immersion → Electroless nickel plating → Water washing → Bright tin plating → Recovery → Water washing → Warm water washing → Drying → Inspection → Tin - plated aluminum alloy wire blank. Other components were added in the form of chlorides, and the composition of the tin - plated aluminum alloy is listed in Table 1.

[0246] (3) The pretreatment process in step (2) is as follows:

[0247] Ammonia water 328 ml / L; Trisodium citrate 64 g / L; ZnO 54 g / L; Temperature room temperature; Time 135 s;

[0248] (4) The nickel pre - immersion process in step (2) is as follows:

[0249] Nickel acetate 28 g / L; Trisodium citrate 24 g / L; Ammonia water 278 ml / L; Triethanolamine 58 ml / L; Lactic acid 56 ml / L; pH value 10.8; Temperature room temperature; Time 5.5 min;

[0250] (5) The electroless nickel plating process in step (2) is as follows:

[0251] Nickel sulfate 84 g / L; Sodium hypophosphite 74 g / L; Trisodium citrate 23 g / L; Lactic acid 79 ml / L; Ammonium sulfate 108 g / L; Dibutyltin dilaurate 38 ml / L; Silicon oil 38 ml / L; pH value 4.4; Temperature (60 ± 5)°C; Time 9 min;

[0252] (6) The bright acid tin plating process in step (2) is as follows:

[0253] Stannous sulfate 148 g / L; Sulfuric acid 248 g / L; Tartaric acid 31 g / L; Silicon oil 19 ml / L; Dibutyltin dimaleate 14 ml / L; Current density 3 A / dm 2 ; Cathode movement; Anode pure tin plate; Time 9 min.

[0254] The properties of the aluminum alloy prepared by the above method and the aluminum alloy after the tin plating process were tested, and the results are shown in Table 2.

[0255] Example 6

[0256] (1) The aluminum alloy ingot raw material was put into a furnace, and an aluminum alloy rod was manufactured through the processes of melting, casting, and rolling, and then the aluminum alloy rod was made into an aluminum alloy wire.

[0257] (2) A layer of tin with a thickness of 30 μm was electroplated on the surface of the aluminum alloy wire obtained in step (1). The process flow of the tin plating on the surface of the aluminum alloy wire is as follows:

[0258] Aluminum alloy wire blank → Degreasing with organic solvent → Drying → Alkali etching → Water washing → Pickling and water washing with nitric acid → Conditioning pretreatment → Nickel pre - immersion → Electroless nickel plating → Water washing → Bright tin plating → Recovery → Water washing → Warm water washing → Drying → Inspection → Tin - plated aluminum alloy wire blank. Other components were added in the form of chlorides, and the composition of the tin - plated aluminum alloy is listed in Table 1.

[0259] (3) The pretreatment process in step (2) is as follows:

[0260] Ammonia water 342 ml / L; Sodium citrate 66 g / L; ZnO 56 g / L; Temperature room temperature; Time 150 s.

[0261] (4) The nickel pre - immersion process in step (2) is as follows:

[0262] Nickel acetate 23 g / L; Sodium citrate 22 g / L; Ammonia water 266 ml / L; Triethanolamine 53 ml / L; Lactic acid 38 ml / L; pH value 10.3; Temperature room temperature; Time 3.5 min.

[0263] (5) The electroless nickel plating process in step (2) is as follows:

[0264] Nickel sulfate 83 g / L; Sodium hypophosphite 73 g / L; Sodium citrate 22 g / L; Lactic acid 78 ml / L; Ammonium sulfate 106 g / L; Dibutyltin dilaurate 36 ml / L; Silicon oil 36 ml / L; pH value 4.3; Temperature (60 ± 5)°C; Time 10 min.

[0265] (6) The bright acid tin plating process in step (2) is as follows:

[0266] Stannous sulfate 146 g / L; Sulfuric acid 246 g / L; Tartaric acid 29 g / L; Silicon oil 18 ml / L; Dibutyltin dimaleate 13 ml / L; Current density 2 A / dm 2 ; Cathode movement; Anode pure tin plate; Time 10 min.

[0267] The properties of the aluminum alloy prepared by the above method and the aluminum alloy after the tin plating process were tested, and the results are shown in Table 2.

[0268] Example 7

[0269] (1) The aluminum alloy ingot raw material was put into a furnace, and an aluminum alloy rod was manufactured through the processes of melting, casting, and rolling, and then the aluminum alloy rod was made into an aluminum alloy wire.

[0270] (2) A layer of tin with a thickness of 50 μm was electroplated on the surface of the aluminum alloy wire obtained in step (1). The process flow of the tin plating on the surface of the aluminum alloy wire is as follows:

[0271] Aluminum alloy wire blank → Degreasing with organic solvent → Drying → Alkali etching → Water washing → Pickling and water washing with nitric acid → Conditioning pretreatment → Nickel pre - immersion → Electroless nickel plating → Water washing → Bright tin plating → Recovery → Water washing → Warm water washing → Drying → Inspection → Tin - plated aluminum alloy wire blank. Other components were added in the form of chlorides, and the composition of the tin - plated aluminum alloy is listed in Table 1.

[0272] (3) The pretreatment process in step (2) is as follows:

[0273] Ammonia water 326 ml / L; Sodium citrate 66 g / L; ZnO 53 g / L; Temperature room temperature; Time 130 s;

[0274] (4) The nickel pre - immersion process in step (2) is as follows:

[0275] Nickel acetate 21 g / L; Sodium citrate 20 g / L; Ammonia water 262 ml / L; Triethanolamine 51 ml / L; Lactic acid 33 ml / L; pH value 10.1; Temperature room temperature; Time 3 min;

[0276] (5) The electroless nickel plating process in step (2) is as follows:

[0277] Nickel sulfate 85 g / L; Sodium hypophosphite 75 g / L; Sodium citrate 24 g / L; Lactic acid 80 ml / L; Ammonium sulfate 110 g / L; Dibutyltin dilaurate 40 ml / L; Silicon oil 40 ml / L; pH value 4.5; Temperature (60 ± 5) °C; Time 9 min;

[0278] (6) The bright acid tin plating process in step (2) is as follows:

[0279] Stannous sulfate 152 g / L; Sulfuric acid 252 g / L; Tartaric acid 33 g / L; Silicon oil 22 ml / L; Dibutyltin dimaleate 16 ml / L; Current density 3 A / dm 2 ; Cathode movement; Anode pure tin plate; Time 11 min.

[0280] The properties of the aluminum alloy prepared by the above method and the aluminum alloy after the tin plating process were tested, and the results are shown in Table 2.

[0281] Example 8

[0282] (1) Put the aluminum alloy ingot raw material into the furnace, and manufacture it into an aluminum alloy rod through the processes of melting, casting, and rolling, and then make the aluminum alloy rod into an aluminum alloy wire;

[0283] (2) Electroplate a layer of tin with a thickness of 8 μm on the surface of the aluminum alloy wire obtained in step (1). The process flow of the tin plating process on the surface of the aluminum alloy wire is as follows:

[0284] Aluminum alloy wire blank → Degreasing with organic solvent → Drying → Alkali etching → Water washing → Pickling and brightening with nitric acid and water washing → Conditioning pretreatment → Nickel pre - immersion → Electroless nickel plating → Water washing → Bright tin plating → Recovery → Water washing → Warm water washing → Drying → Inspection → Tin - plated aluminum alloy wire blank. Other components are added in the form of chlorides. The composition of the tin - plated aluminum alloy is listed in Table 1;

[0285] (3) The pretreatment process in step (2) is as follows:

[0286] Ammonia water 348 ml / L; Sodium citrate 68 g / L; ZnO 58 g / L; Temperature room temperature; Time 170 s;

[0287] (4) The nickel pre - immersion process in step (2) is as follows:

[0288] Nickel acetate 25 g / L; Sodium citrate 23 g / L; Ammonia water 270 ml / L; Triethanolamine 55 ml / L; Lactic acid 40 ml / L; pH value 10.5; Temperature room temperature; Time 4 min;

[0289] (5) The electroless nickel plating process in step (2) is as follows:

[0290] Nickel sulfate 86 g / L; Sodium hypophosphite 76 g / L; Sodium citrate 24 g / L; Lactic acid 72 ml / L; Ammonium sulfate 112 g / L; Dibutyltin dilaurate 42 ml / L; Silicon oil 42 ml / L; pH value 4.6; Temperature (60 ± 5) °C; Time 8 min;

[0291] (6) The bright acid tin plating process in step (2) is as follows:

[0292] Stannous sulfate 150 g / L; Sulfuric acid 250 g / L; Tartaric acid 32 g / L; Silicon oil 20 ml / L; Dibutyltin dimaleate 15 ml / L; Current density 3 A / dm 2 ; Cathode movement; Anode pure tin plate; Time 12 min.

[0293] Test the performance of the aluminum alloy prepared according to the above method and the aluminum alloy after the tin plating process. The results are shown in Table 2.

[0294] Example 9

[0295] (1) Feed the aluminum alloy ingot raw material into a melting furnace, and manufacture it into aluminum alloy rods through the processes of melting, casting, and rolling, and then make the aluminum alloy rods into aluminum alloy wires;

[0296] (2) Electroplate a layer of tin with a thickness of 40 μm on the surface of the aluminum alloy wire obtained in step (1). The process flow of the tin plating on the surface of the aluminum alloy wire is as follows:

[0297] Aluminum alloy wire blank → Degreasing with organic solvent → Air drying → Alkali etching → Water washing → Pickling and water washing with nitric acid → Conditioning pretreatment → Nickel pre - immersion → Electroless nickel plating → Water washing → Bright tin plating → Recovery → Water washing → Warm water washing → Drying → Inspection → Tinned aluminum alloy wire blank. Other components are added in the form of chlorides. The composition of the tinned aluminum alloy is listed in Table 1;

[0298] (3) The pretreatment process in step (2) is as follows:

[0299] Ammonia water 340 ml / L; Sodium citrate 65 g / L; ZnO 55 g / L; Temperature room temperature; Time 140 s;

[0300] (4) The nickel pre - immersion process in step (2) is as follows:

[0301] Nickel acetate 27 g / L; Sodium citrate 24 g / L; Ammonia water 275 ml / L; Triethanolamine 57 ml / L; Lactic acid 50 ml / L; pH value 10.7; Temperature room temperature; Time 5 min;

[0302] (5) The electroless nickel plating process in step (2) is as follows:

[0303] Nickel sulfate 87 g / L; Sodium hypophosphite 77 g / L; Sodium citrate 26 g / L; Lactic acid 82 ml / L; Ammonium sulfate 115 g / L; Dibutyltin dilaurate 45 ml / L; Silicon oil 45 ml / L; pH value 4.7; Temperature (60 ± 5) °C; Time 6 min;

[0304] (6) The bright acid tin plating process in step (2) is as follows:

[0305] Stannous sulfate 155 g / L; Sulfuric acid 255 g / L; Tartaric acid 33 g / L; Silicon oil 23 ml / L; Dibutyltin dimaleate 16 ml / L; Current density 4 A / dm 2 ; Cathode movement; Anode pure tin plate; Time 14 min.

[0306] Test the performance of the aluminum alloy prepared according to the above method and the aluminum alloy after the tin plating process. The results are shown in Table 2.

[0307] Example 10

[0308] (1) Put the aluminum alloy ingot raw materials into the furnace, and manufacture aluminum alloy rods through smelting, casting, and rolling processes, and then make the aluminum alloy rods into aluminum alloy wires;

[0309] (2) Electroplate a layer of tin with a thickness of 15 μm on the surface of the aluminum alloy wire obtained in step (1). The process flow of tin plating on the surface of the aluminum alloy wire is as follows:

[0310] Aluminum alloy wire blank → Degreasing with organic solvent → Air drying → Alkali etching → Water washing → Pickling and water washing with nitric acid → Conditioning pretreatment → Nickel pre - immersion → Electroless nickel plating → Water washing → Bright tin plating → Recovery → Water washing → Warm water washing → Drying → Inspection → Tin - plated aluminum alloy wire blank. Other components are added in the form of chlorides. The composition of the tin - plated aluminum alloy is listed in Table 1;

[0311] (3) The pretreatment process in step (2) is as follows:

[0312] Ammonia water 345 ml / L; Sodium citrate 67 g / L; ZnO 57 g / L; Temperature: room temperature; Time: 160 s;

[0313] (4) The nickel pre - immersion process in step (2) is as follows:

[0314] Nickel acetate 26 g / L; Sodium citrate 24 g / L; Ammonia water 272 ml / L; Triethanolamine 56 ml / L; Lactic acid 44 ml / L; pH value 10.6; Temperature: room temperature; Time: 5 min;

[0315] (5) The electroless nickel plating process in step (2) is as follows:

[0316] Nickel sulfate 88 g / L; Sodium hypophosphite 78 g / L; Sodium citrate 28 g / L; Lactic acid 84 ml / L; Ammonium sulfate 118 g / L; Dibutyltin dilaurate 48 ml / L; Silicone oil 48 ml / L; pH value 4.8; Temperature: (60 ± 5) °C; Time: 5 min;

[0317] (6) The bright acid tin plating process in step (2) is as follows:

[0318] Stannous sulfate 158 g / L; Sulfuric acid 258 g / L; Tartaric acid 34 g / L; Silicone oil 24 ml / L; Dibutyltin dimaleate 18 ml / L; Current density 4 A / dm 2 ; Cathode movement; Anode pure tin plate; Time: 15 min.

[0319] Test the properties of the aluminum alloy prepared by the above method and the aluminum alloy after the tin - plating process. The results are shown in Table 2.

[0320] Table 1

[0321]

[0322] Table 2

[0323]

[0324] Refer to Table 3, which is a data sheet for performance tests of aluminum alloy conductor materials without any surface treatment prepared in the comparative examples.

[0325] Among them, the aluminum alloy conductor wires in Comparative Examples 1-10 are the same as those in Examples 1-10 respectively.

[0326] Table 3

[0327]

[0328]

[0329] Refer to Table 4, which is a data sheet for performance tests of aluminum alloy conductor materials with only nickel plating treatment on the surface prepared in the comparative examples.

[0330] Among them, the aluminum alloy conductor wires in Comparative Examples 11-20 are the same as those in Examples 1-10 respectively, and the nickel plating process and corresponding parameters are also the same as those in the aluminum alloy conductor wires in Examples 1-10 respectively.

[0331] Table 4

[0332]

[0333] Through comparison of the examples, it is found that in the examples, the aluminum alloy conductor materials are subjected to tin plating treatment, while in the comparative examples, there is little difference in the tensile strength and elongation at break between the aluminum alloy without any surface treatment and the aluminum alloy wire with only nickel plating treatment on the surface, but there are obvious differences in electrical properties. The electrical conductivity of the aluminum alloy wire with only nickel plating treatment is significantly worse than that of the aluminum alloy wire without any treatment. Nickel plating treatment leads to a decrease in electrical properties. The electrical conductivity of the tin-plated aluminum alloy conductor wire is significantly higher than that of the aluminum alloy conductor wire without any treatment, indicating that the electrical properties are significantly improved after the surface of the aluminum alloy conductor material is subjected to tin plating treatment. The aluminum alloy without any surface treatment is significantly inferior to the aluminum alloy material with only nickel plating treatment and the aluminum alloy material after tin plating treatment in terms of corrosion resistance and connection performance with copper terminals. The corrosion rate of the tin-plated aluminum alloy is ≤0.03 mm / a, which is significantly superior to that of the ordinary aluminum alloy without surface treatment and is also superior to that of the aluminum alloy with only nickel plating treatment on the surface. After connection with copper terminals, it can pass 1000 thermal cycle tests, and the connection of the tin-plated aluminum alloy conductor is much more convenient and the safety is more reliable. For the ordinary aluminum alloy without any surface treatment, when directly connected to copper terminals, it cannot pass 1000 thermal cycle tests.

[0334] In terms of welding performance, aluminum alloy without any surface treatment has no welding performance, and aluminum alloy wire with only nickel plating on the surface has extremely poor weldability. Although a certain welding effect can be achieved with the help of solder resist, the solderability test of only nickel-plated aluminum alloy wire cannot pass the welding performance test requirements in the GB / T 4910 standard. In this embodiment, the tin-plated aluminum alloy wire can easily pass the welding performance test requirements in the GB / T 4910 standard, and does not require any solder resist. It has excellent welding performance and can be directly welded with tin-plated copper terminals.

[0335] The performance test of the terminal block or terminal tube made of tin-plated aluminum alloy material complies with GB / T14315. In addition to the cold-pressed connection method, it can also be connected to the tin-plated aluminum alloy conductor by welding, which is more convenient and efficient, especially for the connection of plug-in parts or small connectors. The busbar or welding strip made of tin-plated aluminum alloy is also weldable. The weldability of photovoltaic welding strip made of tin-plated aluminum alloy conductor material complies with GB / T31985 "Photovoltaic Tin-coated Solder Strip", and other performance indicators comply with the requirements of GB / T5585 or GB / T31985. This provides a new solution for aluminum alloy as a conductor material to replace copper in many fields.

[0336] 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 in this article 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 principle of the present invention, the present invention can also be improved and modified in several ways, 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 text of the claims, or if they include equivalent structural elements that are not substantially different from the text 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 described tin-plated aluminum alloy wire, by mass percentage, includes: Sn: 1% - 40%; The balance is Al and impurities.

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

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

4. The tinned aluminum alloy wire according to claim 1, wherein, The coating also includes E with a mass content of 0.01% - 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 preparation method of a tin-plated aluminum alloy wire, characterized in that It includes the following steps: 1) After the aluminum alloy wire sample blank is pretreated, then subjected to conditioning pretreatment, pre-dipping in nickel, and nickel plating, an aluminum alloy wire compounded with a nickel-plated layer is obtained; 2) After the aluminum alloy wire compounded with a nickel-plated layer obtained in the above step is subjected to bright tin plating and then post-treatment, a tin-plated aluminum alloy wire is obtained.

6. The tinned aluminum alloy wire according to claim 5, characterized in that, The pretreatment steps include one or more of degreasing with organic solvents, air drying, alkaline etching, water washing, and nitric acid brightening and water washing; The treatment solution for the conditioning pretreatment includes: Ammonia water 320 - 350 ml / L; Trisodium citrate 60 - 70 g / L; ZnO 50 - 60 g / L; The time for the conditioning pretreatment is 2 - 3 min.

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

8. The tinned aluminum alloy wire according to claim 5, wherein, The method of nickel plating includes electroless nickel plating; The treatment solution for the electroless nickel plating includes: 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; The pH value of the treatment solution for the electroless nickel plating is 4.0 - 5.0; The temperature for the electroless nickel plating is 55 - 65 °C; The time for the electroless nickel plating is 5 - 10 min.

9. The tinned aluminum alloy wire according to claim 5, wherein The method of bright tin plating includes a bright acidic tin plating process; The treatment solution for the bright acidic tin plating includes: 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; The current density of the bright acid tin plating is 1-4 A / dm 2 ; The time for bright acid tin plating is 5 - 15 min; The post-treatment includes one or more steps of water washing, warm water washing, drying and inspection.

10. Application 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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