A process for preparing light alloy conductors for photovoltaics

Abstract

The application belongs to the technical field of light alloy conductors, and particularly relates to a preparation process of a light alloy conductor for photovoltaics, which comprises the following steps: (1) alloy preparation; (2) alloy smelting; (3) casting and rolling: after refining, the melt is cast into an aluminum alloy ingot; the aluminum alloy ingot is rolled by a rolling mill into an aluminum alloy rod with a diameter of 9.5 mm; (4) solid solution heat treatment: the aluminum alloy rod is subjected to solid solution heat treatment to obtain an aluminum alloy rod after solid solution heat treatment; (5) aging treatment: the aluminum alloy rod after solid solution heat treatment is placed in an aging furnace for aging treatment, and then naturally cooled to room temperature to obtain an aluminum alloy rod material after aging heat treatment; (6) single-wire drawing: the heat-resistant aluminum alloy rod after aging heat treatment is cold-drawn into an aluminum wire with a diameter of 2 mm through a wire drawing equipment to obtain a light alloy conductor for photovoltaics.

Description

Technical Field

[0001] This invention belongs to the field of light alloy conductor technology, and specifically relates to a process for preparing a light alloy conductor for photovoltaic applications. Background Technology

[0002] Lightweight alloy conductors used in photovoltaic systems primarily refer to the wires or cables used to connect solar panels, inverters, and other electrical components. The selection of these conductors is crucial to the overall system efficiency, cost-effectiveness, and long-term reliability. Lightweight alloy conductors typically refer to lightweight alloy materials with good electrical conductivity, which effectively reduce energy loss during power transmission while also easing the burden of installation and transportation.

[0003] To address some of the shortcomings of pure aluminum, such as its low mechanical strength and poor corrosion resistance, aluminum alloys have become increasingly popular lightweight alloy conductors for photovoltaic systems. Aluminum alloy stranded wire is composed of multiple lightweight alloy conductors (aluminum alloy monofilaments) twisted together for photovoltaic systems. Each aluminum alloy monofilament is made of aluminum alloy material, and the properties of the aluminum alloy material directly determine the performance of the aluminum alloy stranded wire.

[0004] Coal mine cables are among the most technologically advanced products in the cable industry. Due to the complex environment and harsh working conditions in coal mines, and the frequent movement of cables, they require excellent abrasion resistance and tensile strength. In areas with high methane accumulation, the safety risks are extremely high, thus demanding very stringent safety requirements for the cables. Ordinary aluminum alloy core cables suffer from poor mechanical properties and corrosion resistance, failing to meet the demanding bending performance required for the frequent movement of coal mine cables; nor can they meet the high conductivity and mechanical strength requirements of the harsh environment in coal mines.

[0005] Therefore, there is an urgent need for a process for preparing lightweight alloy conductors for photovoltaic applications. Summary of the Invention

[0006] The purpose of this invention is to provide a process for preparing lightweight alloy conductors for photovoltaic applications.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A process for fabricating a lightweight alloy conductor for photovoltaic applications includes the following steps:

[0009] (1) Alloy preparation: Weigh the components according to the following weight percentages: 0.31%-0.38% Si, 0.62%-0.76% Mg, 0.22%-0.30% Cu, 0.05%-0.15% Sc, 0.18%-0.25% Er, 0.05%-0.09% Nd, 0.12%-0.23% Cr, 0.11%-0.19% Yb, 0.01%-0.06% Ti, 0.12%-0.18% Ce, 0.03%-0.08% Zr, with the balance being Al;

[0010] (2) Alloy smelting: The components are mixed and smelted to obtain a melt. A refining agent is added to the melt for refining. After refining, the melt is allowed to stand and the surface slag is skimmed off to obtain a refined melt.

[0011] (3) Casting and rolling: The refined melt is heated to 830-840℃ and cast into aluminum alloy ingots; the aluminum alloy ingots are rolled into aluminum alloy rods with a diameter of 8-10.5mm by a rolling mill.

[0012] (4) Solution heat treatment: The aluminum alloy rod is subjected to solution heat treatment to obtain the aluminum alloy rod after solution heat treatment;

[0013] (5) Aging treatment: The aluminum alloy rod after solution heat treatment is placed in an aging furnace for aging treatment, and then naturally cooled to room temperature to obtain the aluminum alloy rod after aging heat treatment.

[0014] (6) Single-wire drawing: The heat-resistant aluminum alloy rod that has undergone aging heat treatment is cold-drawn into 1-3mm aluminum wire through a wire drawing equipment to obtain a light alloy conductor for photovoltaic use.

[0015] Furthermore, the weight ratio of Si, Mg, and Cu is (0.33-0.36):(0.65-0.70):(0.25-0.29).

[0016] This invention improves the conductivity of lightweight alloy conductors for photovoltaic applications by carefully selecting the alloy's components and proportions. However, the elongation at break of these conductors is not ideal. Extensive testing revealed that a weight ratio of Si, Mg, and Cu of (0.33-0.36):(0.65-0.70):(0.25-0.29) significantly improves the elongation at break, achieving increases of over 15%. This is primarily because under these conditions, the increased brittleness caused by excess Si is effectively prevented, thus maintaining the alloy's ductility. Mg forms fine Mg₂Si phases, which are uniformly distributed in the matrix, further enhancing the alloy's strength and toughness. Simultaneously, it effectively prevents the precipitation of coarse second phases caused by excess Cu, which reduce the alloy's plasticity and toughness. When Si, Mg, and Cu are combined within the aforementioned range, they exhibit a synergistic effect, jointly optimizing the alloy's microstructure. For example, appropriate amounts of Si and Mg can promote the formation of fine Mg₂Si phases, while appropriate amounts of Cu can further enhance the strength and toughness of the alloy by forming fine CuAl₂ and CuMg phases. These fine second phases can effectively hinder dislocation movement, improve the yield strength and tensile strength of the alloy, while maintaining good plasticity and toughness.

[0017] Furthermore, the weight percentage content of Si is greater than the sum of the weight percentage contents of Cu and Sc.

[0018] The average creep rate of a cable refers to the rate at which the cable material gradually undergoes plastic deformation under prolonged constant stress. Creep is the phenomenon of a material gradually elongating or deforming over time under continuous stress, especially under high temperature or long-term load conditions. For cables, creep rate is an important performance indicator because it directly affects the cable's service life and safety. When the weight percentage of Si is greater than the sum of the weight percentages of Cu and Sc, at 150℃, photovoltaic light alloy conductors can have a lower average creep rate, meaning that photovoltaic light alloy conductors undergo less plastic deformation under high temperature and long-term stress, maintaining better mechanical strength and stiffness. This is because Si can dissolve in the aluminum matrix to form a solid solution, improving the alloy's strength and hardness. An appropriate amount of Si can significantly improve the material's creep resistance; Sc can promote grain refinement, improving the uniformity of the alloy's microstructure and the fine-grain strengthening effect. Fine grains can effectively hinder dislocation movement, improving the alloy's strength and creep resistance. An appropriate amount of Si can provide sufficient solid solution strengthening and precipitation strengthening, while the relatively low content of Cu and Sc can avoid the formation of excessive second phases, thus maintaining the alloy's plasticity and toughness. The dominant role of Si can promote the formation of fine, uniformly distributed second phases, which can effectively hinder dislocation movement and improve the alloy's creep resistance.

[0019] Furthermore, Cu weighs (1.0-1.5) times more than Sc and Er.

[0020] When the weight of Cu is (1.0-1.5) times that of Sc and Er, the corrosion resistance of lightweight alloy conductors for photovoltaic applications can be improved. Cu itself has good corrosion resistance, especially in atmospheric environments. Cu can form fine second phases (such as CuAl₂) with aluminum, which can improve the strength and corrosion resistance of the alloy. Er can form fine Al₃Er phases with aluminum, which can improve the strength and heat resistance of the alloy. An appropriate amount of Cu can form fine, uniformly distributed CuAl₂ phases, which can effectively improve the strength and corrosion resistance of the alloy. At the same time, the fine Al₃Sc and Al₃Er phases formed by Sc and Er can further enhance the microstructural stability of the alloy.

[0021] Further, the components are weighed according to the following weight percentages: 0.35% Si, 0.68% Mg, 0.27% Cu, 0.06% Sc, 0.20% Er, 0.05%-0.09% Nd, 0.12-0.23% Cr, 0.11-0.19% Yb, 0.01-0.06% Ti, 0.12%-0.18% Ce, 0.03%-0.08% Zr, with the balance being Al;

[0022] Furthermore, in step (2), the refining agent is hexachloroethane gas, the amount added is 0.3-0.4% of the melt weight, and the refining temperature is 710-720℃.

[0023] Furthermore, the melting temperature in step (2) is 780-800℃.

[0024] Furthermore, in step (2), the refined product is left to stand for 15-20 minutes.

[0025] Furthermore, the conditions for aging treatment in step (5) are as follows: the temperature of the first stage is 180-190℃ and the time is 5-6h; the temperature of the second stage is 220-230℃ and the time is 8-9h.

[0026] Furthermore, the conditions for solution heat treatment in step (4) are as follows: the temperature of the first stage is 260-280℃ and the time is 6-7h; the temperature of the second stage is 410-420℃ and the time is 4-5h; the temperature of the third stage is 500-510℃ and the time is 8-9h.

[0027] This invention improves the fatigue bending performance of light alloy conductors for photovoltaic applications at 100°C through specific solution heat treatment and aging treatment, thereby enhancing the fatigue resistance of aluminum alloy materials at high temperatures.

[0028] Furthermore, the melting temperature in step (2) is 790°C.

[0029] Furthermore, the conditions for aging treatment in step (5) are as follows: the temperature of the first stage is 185℃ and the time is 5.5h; the temperature of the second stage is 225℃ and the time is 8.5h.

[0030] Furthermore, the conditions for solution heat treatment in step (4) are as follows: the temperature of the first stage is 270℃ and the time is 6.5h; the temperature of the second stage is 415℃ and the time is 4.5h; and the temperature of the third stage is 505℃ and the time is 8.5h.

[0031] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0032] 1. This invention improves the conductivity of light alloy conductors for photovoltaic applications by carefully selecting the components and proportions of the alloy.

[0033] 2. In the system of the present invention, when the weight ratio of Si, Mg and Cu is (0.33-0.36):(0.65-0.70):(0.25-0.29), the elongation at break of the photovoltaic light alloy conductor can be improved, and the elongation at break of the prepared photovoltaic light alloy conductor can be as high as 15% or more.

[0034] 3. In the preparation system of the present invention, when the weight percentage of Si is greater than the sum of the weight percentages of Cu and Sc, the photovoltaic light alloy conductor can have a lower average creep rate at 150°C. This means that the photovoltaic light alloy conductor undergoes less plastic deformation under high temperature and long-term stress, thus maintaining better mechanical strength and stiffness.

[0035] 4. In the preparation system of the present invention, when the weight of Cu is (1.0-1.5) times that of Sc and Er, the corrosion resistance of the light alloy conductor for photovoltaic applications can be improved.

[0036] 5. This invention improves the fatigue bending performance of light alloy conductors for photovoltaic applications at 100°C through specific solution heat treatment and aging treatment, thereby enhancing the fatigue resistance of aluminum alloy materials at high temperatures. Detailed Implementation

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Example 1

[0039] This embodiment provides a process for preparing a light alloy conductor for photovoltaic applications, including the following steps:

[0040] (1) Alloy preparation: Weigh the components according to the following weight percentages: 0.35% Si, 0.68% Mg, 0.27% Cu, 0.06% Sc, 0.20% Er, 0.06% Nd, 0.17% Cr, 0.13% Yb, 0.04% Ti, 0.15% Ce, 0.08% Zr, with the balance being Al;

[0041] (2) Alloy smelting: The components are mixed and smelted at a temperature of 790℃ for 20 minutes to obtain a melt. A refining agent is added to the melt for refining. After refining, the melt is allowed to stand for 18 minutes and the surface slag is skimmed off to obtain a refined melt. The refining agent is hexachloroethane gas, and the amount added is 0.35% of the melt weight. The refining temperature is 715℃ and the gas venting time is 20 minutes.

[0042] (3) Casting and rolling: The refined melt is heated to 835°C and cast into shape, and cooled to room temperature at a rate of 60°C / s to form an aluminum alloy ingot; the aluminum alloy ingot is rolled into an aluminum alloy rod with a diameter of 9.5 mm by a rolling mill.

[0043] (4) Solution heat treatment: The aluminum alloy rod is subjected to solution heat treatment. The conditions for solution heat treatment are: the temperature of the first stage is 270℃ and the time is 6.5h; the temperature of the second stage is 415℃ and the time is 4.5h; the temperature of the third stage is 505℃ and the time is 8.5h, and the aluminum alloy rod after solution heat treatment is obtained.

[0044] (5) Aging treatment: The aluminum alloy rod after solution heat treatment is placed in an aging furnace for aging treatment. The aging treatment conditions are: the temperature of the first stage is 185℃ and the time is 5.5h; the temperature of the second stage is 225℃ and the time is 8.5h; then it is naturally cooled to room temperature to obtain the aluminum alloy rod after aging heat treatment.

[0045] (6) Single wire drawing: The heat-resistant aluminum alloy rod that has undergone aging heat treatment is cold drawn into 2mm aluminum wire through a wire drawing equipment to obtain a light alloy conductor for photovoltaic use.

[0046] Example 2

[0047] This embodiment provides a process for preparing a light alloy conductor for photovoltaic applications, including the following steps:

[0048] (1) Alloy preparation: Weigh the components according to the following weight percentages: 0.33% Si, 0.70% Mg, 0.25% Cu, 0.05% Sc, 0.20% Er, 0.05% Nd, 0.23% Cr, 0.19% Yb, 0.01% Ti, 0.18% Ce, 0.03% Zr, with the balance being Al;

[0049] (2) Alloy smelting: The components are mixed and smelted at a temperature of 800℃ for 25 minutes to obtain a melt. A refining agent is added to the melt for refining. After refining, the melt is allowed to stand for 15 minutes and the surface slag is skimmed off to obtain a refined melt. The refining agent is hexachloroethane gas, and the amount added is 0.3% of the melt weight. The refining temperature is 720℃ and the gas venting time is 15 minutes.

[0050] (3) Casting and rolling: The refined melt is heated to 840°C and cast into shape, and cooled to room temperature at a rate of 80°C / s to form an aluminum alloy ingot; the aluminum alloy ingot is rolled into an aluminum alloy rod with a diameter of 9.5 mm by a rolling mill.

[0051] (4) Solution heat treatment: The aluminum alloy rod is subjected to solution heat treatment. The conditions for solution heat treatment are: the temperature of the first stage is 260℃ and the time is 7h; the temperature of the second stage is 410℃ and the time is 5h; the temperature of the third stage is 500℃ and the time is 9h, so as to obtain the aluminum alloy rod after solution heat treatment.

[0052] (5) Aging treatment: The aluminum alloy rod after solution heat treatment is placed in an aging furnace for aging treatment. The aging treatment conditions are: the temperature of the first stage is 180℃ and the time is 6h; the temperature of the second stage is 220℃ and the time is 9h; then it is naturally cooled to room temperature to obtain the aluminum alloy rod after aging heat treatment.

[0053] (6) Single wire drawing: The heat-resistant aluminum alloy rod that has undergone aging heat treatment is cold drawn into 2mm aluminum wire through a wire drawing equipment to obtain a light alloy conductor for photovoltaic use.

[0054] Comparative Example 1

[0055] The difference between this comparative example and Example 1 is that the component ratios are different.

[0056] Alloy preparation: Weigh the following components according to the following weight percentages: 0.45% Si, 0.58% Mg, 0.17% Cu, 0.16% Sc, 0.10% Er, 0.16% Nd, 0.07% Cr, 0.23% Yb, 0.14% Ti, 0.05% Ce, 0.18% Zr, with the balance being Al.

[0057] Comparative Example 2

[0058] The difference between this comparative example and Example 1 is that the percentage contents of Si, Mg, and Cu are different.

[0059] Alloy preparation: Weigh the following components according to the following weight percentages: 0.45% Si, 0.48% Mg, 0.37% Cu, 0.06% Sc, 0.20% Er, 0.06% Nd, 0.17% Cr, 0.13% Yb, 0.04% Ti, 0.15% Ce, 0.08% Zr, with the balance being Al.

[0060] Comparative Example 3

[0061] The difference between this comparative example and Example 1 is that the weight percentages of Si, Cu, and Sc are different.

[0062] Alloy preparation: Weigh the following components according to the following weight percentages: 0.20% Si, 0.68% Mg, 0.32% Cu, 0.16% Sc, 0.20% Er, 0.06% Nd, 0.17% Cr, 0.13% Yb, 0.04% Ti, 0.15% Ce, 0.08% Zr, with the balance being Al.

[0063] Comparative Example 4

[0064] The difference between this comparative example and Example 1 is that the weight percentages of Cu, Sc, and Er are different.

[0065] Alloy preparation: Weigh the following components according to the following weight percentages: 0.35% Si, 0.68% Mg, 0.17% Cu, 0.11% Sc, 0.25% Er, 0.06% Nd, 0.17% Cr, 0.13% Yb, 0.04% Ti, 0.15% Ce, 0.08% Zr, with the balance being Al.

[0066] Comparative Example 5

[0067] The difference between this comparative example and Example 1 is that the conditions for aging treatment in step (5) are: the temperature of the first stage is 150°C and the time is 8h; the temperature of the second stage is 250°C and the time is 6h.

[0068] Comparative Example 6

[0069] The difference between this comparative example and Example 1 is that the conditions for solution heat treatment in step (4) are: the temperature of the first stage is 300℃ and the time is 8h; the temperature of the second stage is 400℃ and the time is 6h; and the temperature of the third stage is 530℃ and the time is 4h.

[0070] Performance testing

[0071] The photovoltaic light alloy conductors prepared in Examples 1-2 and Comparative Examples 1-6 were subjected to performance tests.

[0072] 1. Conduct conductivity tests according to GB / T3956-2008;

[0073] 2. Conduct the fracture elongation test according to GB / T228-2002, the creep test (1-100 hours) under the temperature of 150℃ and the compressive stress of 120MPa, the fatigue bending test at 100℃, and the corrosion resistance test for 600 hours.

[0074] 3. Conduct 9,000 cycles of bending resistance test according to the test method specified in MT818.1.

[0075] The results are shown in Table 1.

[0076] Table 1 Performance Test Results

[0077]

[0078] The performance test results above show that the photovoltaic light alloy conductors of Examples 1-2 have high conductivity and good mechanical properties, especially the comprehensive performance of Example 1, which is mainly due to the synergistic effect of component ratio and processing conditions.

[0079] The comparative examples, lacking the necessary technical solutions, showed significantly inferior performance compared to the exemplary examples in relevant performance tests. In Comparative Example 1, altering the alloy composition ratio resulted in a decrease in the overall performance of the photovoltaic light alloy conductor. In Comparative Example 2, changing the weight ratio of Si, Mg, and Cu decreased the elongation at break of the photovoltaic light alloy conductor, potentially dropping below 15%. In Comparative Example 3, changing the weight percentages of Si, Cu, and Sc resulted in poor average creep performance of the photovoltaic light alloy conductor at 150°C. In Comparative Example 4, changing the weight percentages of Cu, Sc, and Er decreased the corrosion resistance of the photovoltaic light alloy conductor. In Comparative Examples 5 and 6, different solution heat treatments and aging treatments resulted in decreased fatigue bending performance of the photovoltaic light alloy conductor at 100°C. These experimental results further demonstrate the importance of the technical solutions defined in this invention for its technical effectiveness.

[0080] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A process for preparing a lightweight alloy conductor for photovoltaic applications, characterized in that, Includes the following steps: (1) Alloy preparation: Weigh the components according to the following weight percentages: 0.31%-0.38% Si, 0.62%-0.76% Mg, 0.22%-0.30% Cu, 0.05%-0.15% Sc, 0.18%-0.25% Er, 0.05%-0.09% Nd, 0.12%-0.23% Cr, 0.11%-0.19% Yb, 0.01%-0.06% Ti, 0.12%-0.18% Ce, 0.03%-0.08% Zr, with the balance being Al; The weight ratio of Si, Mg, and Cu is (0.33-0.36):(0.65-0.70):(0.25-0.29). The weight percentage content of Si is greater than the sum of the weight percentage contents of Cu and Sc; The weight of Cu is (1.0-1.5) times that of Sc and Er; (2) Alloy smelting: The components are mixed and smelted to obtain a melt. A refining agent is added to the melt for refining. After refining, the melt is allowed to stand and the surface slag is skimmed off to obtain a refined melt. (3) Casting and rolling: The refined melt is heated to 830-840℃ and cast into aluminum alloy ingots; the aluminum alloy ingots are rolled into aluminum alloy rods with a diameter of 8-10.5mm by a rolling mill. (4) Solution heat treatment: The aluminum alloy rod is subjected to solution heat treatment to obtain the aluminum alloy rod after solution heat treatment; (5) Aging treatment: The aluminum alloy rod after solution heat treatment is placed in an aging furnace for aging treatment, and then naturally cooled to room temperature to obtain the aluminum alloy rod after aging heat treatment. (6) Single-wire drawing: The heat-resistant aluminum alloy rod that has undergone aging heat treatment is cold-drawn into 1-3mm aluminum wire through a wire drawing equipment to obtain a light alloy conductor for photovoltaic use; The conditions for aging treatment in step (5) are as follows: the temperature of the first stage is 180-190℃ and the time is 5-6h; the temperature of the second stage is 220-230℃ and the time is 8-9h. The conditions for solution heat treatment in step (4) are as follows: the temperature of the first stage is 260-280℃ and the time is 6-7h; the temperature of the second stage is 410-420℃ and the time is 4-5h; the temperature of the third stage is 500-510℃ and the time is 8-9h.

2. The photovoltaic light alloy conductor preparation process according to claim 1, characterized in that, Weigh the components according to the following weight percentages: 0.35% Si, 0.68% Mg, 0.27% Cu, 0.06% Sc, 0.20% Er, 0.05%-0.09% Nd, 0.12-0.23% Cr, 0.11-0.19% Yb, 0.01-0.06% Ti, 0.12%-0.18% Ce, 0.03%-0.08% Zr, with the balance being Al.

3. The process for preparing a light alloy conductor for photovoltaic applications according to claim 1, characterized in that, In step (2), the refining agent is hexachloroethane gas, and the amount added is 0.3-0.4% of the melt weight. The refining temperature is 710-720℃.

4. The process for preparing a photovoltaic light alloy conductor according to claim 1, characterized in that, The melting temperature in step (2) is 780-800℃.

5. The process for preparing a photovoltaic light alloy conductor according to claim 1, characterized in that, In step (2), the refined product is left to stand for 15-20 minutes.

6. The photovoltaic light alloy conductor preparation process according to claim 4, characterized in that, The melting temperature in step (2) is 790℃.

7. The process for preparing a light alloy conductor for photovoltaic applications according to claim 1, characterized in that, The conditions for aging treatment in step (5) are as follows: the temperature in the first stage is 185℃ and the time is 5.5h; the temperature in the second stage is 225℃ and the time is 8.5h.

8. The process for preparing a light alloy conductor for photovoltaic applications according to claim 1, characterized in that, The conditions for solution heat treatment in step (4) are as follows: the temperature of the first stage is 270℃ and the time is 6.5h; the temperature of the second stage is 415℃ and the time is 4.5h; and the temperature of the third stage is 505℃ and the time is 8.5h.

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