A high-conductivity 6101B aluminum alloy for photovoltaic power generation and a preparation method thereof

Abstract

The present invention provides a high-conductivity 6101B aluminum alloy for photovoltaic power generation and a preparation method thereof. The high-conductivity 6101B aluminum alloy includes the following components by mass percentage: Si: 0.35-0.45%, Mg: 0.4-0.55%, Fe: 0.1-0.15%, B: 0.04-0.06%, La: 0.01-0.04%, Cu≤0.01%, Mn≤0.01%, Zn≤0.01%, Cr≤0.01%, Ti≤0.01%, and the balance is Al and inevitable impurity elements. Advantages of the present invention: The alloy composition of the obtained aluminum alloy profile is still within the scope of the 6101B national standard, that is, the obtained aluminum alloy still belongs to the 6101B alloy, and its conductivity is significantly improved compared with the conventional 6101B aluminum alloy, and the conductivity reaches 58.5% IACS or more; at the same time, it can also ensure that the mechanical properties reach or even exceed the national standards, the tensile strength reaches more than 220Mpa, and the yield strength reaches more than 195Mpa.

Description

[Technical field]

[0001] The present invention relates to the technical field of aluminum alloys, and in particular to a high-conductivity 6101B aluminum alloy for photovoltaic power generation and a preparation method thereof. [Background technology]

[0002] At present, the composition of conventional 6101B alloy (national standard GBT 3190-2008) is: Si: 0.3-0.6%, Mg: 0.35-0.6%, Fe: 0.1-0.3%, Cu≤0.05%, Mn≤0.05%, Zn≤0.1%, and the balance is Al and unavoidable impurity elements. Its conductivity is about 53-54% IACS, the tensile strength is about 215Mpa, and the yield strength is about 190Mpa. Among them, Si, Mg and Fe are the main strengthening elements actively added, and Cu, Mn and Zn are all non-actively added elements.

[0003] 6101B alloy is an aluminum alloy with good electrical conductivity and certain strength, which is widely used in photovoltaic power generation, electrical and electronic, rail transportation and other industries. The 6101B alloy is an Al-Mg-Si alloy that can be strengthened by heat treatment. It can be made into various conductive profiles by extrusion, and the strength and conductivity can be matched by solution quenching and aging treatment.

[0004] With the continuous development of industries such as photovoltaic power generation, higher requirements are placed on the electrical conductivity and mechanical properties of 6101B alloy profiles (requiring both high conductivity and guaranteed mechanical properties). Conventional 6101B alloy materials are obviously unable to meet the comprehensive requirements of electrical conductivity and mechanical properties.

[0005] In order to achieve the purpose of improving the electrical conductivity of 6101B alloy materials, it is currently generally adopted to reduce the content of Si, Mg and Fe alloy elements and other impurity elements, and adopt a high temperature over-aging (heating to 210°C, keeping warm for 10 hours) treatment method. Although the above method can improve the electrical conductivity to a certain extent, usually to 55-56% IACS, the above method will significantly reduce the mechanical properties, so that the obtained 6101B alloy material cannot meet the national standard requirements, and the effect of improving the electrical conductivity is not obvious, which obviously cannot meet the comprehensive requirements of electrical conductivity and mechanical properties. Therefore, it is urgent to provide a 6101B alloy material that can maintain good mechanical properties and further improve electrical conductivity. [Summary of the invention]

[0006] The technical problem to be solved by the present invention is to provide a high-conductivity 6101B aluminum alloy for photovoltaic power generation and a preparation method thereof, which can further improve the conductivity on the basis of maintaining good mechanical properties to meet the industry's comprehensive requirements for conductivity and mechanical properties.

[0007] The present invention is achieved in that:

[0008] In a first aspect, a high-conductivity 6101B aluminum alloy for photovoltaic power generation, the high-conductivity 6101B aluminum alloy comprises the following components in terms of mass percentage:

[0009] Si: 0.35-0.45%, Mg: 0.4-0.55%, Fe: 0.1-0.15%, B: 0.04-0.06%, La: 0.01-0.04%, Cu≤0.01%, Mn≤0.01%, Zn≤0.01%, Cr≤0.01%, Ti≤0.01%, and the balance is Al and unavoidable impurity elements.

[0010] Furthermore, the electrical conductivity of the high-conductivity 6101B aluminum alloy is ≥58.5% IACS, the tensile strength is ≥220 MPa, and the yield strength is ≥195 MPa.

[0011] Furthermore, among the inevitable impurity elements, the total content of the impurities is less than 0.1%, and the content of each impurity element is less than 0.03%.

[0012] In a second aspect, a method for preparing a high-conductivity 6101B aluminum alloy for photovoltaic power generation is provided, the preparation method comprising the following steps:

[0013] Ingredients: Provide raw materials according to the composition ratio of high-conductivity 6101B aluminum alloy;

[0014] Melting and casting: Melting and casting the raw materials to form aluminum alloy ingots;

[0015] Homogenization treatment: heating up and cooling down the aluminum alloy ingot in stages;

[0016] Extrusion molding: Extrusion molding of aluminum alloy ingots to obtain aluminum alloy profiles;

[0017] Aging treatment: Double-stage aging treatment is performed on the aluminum alloy profiles.

[0018] Furthermore, the heating and stage-by-stage cooling treatment of the aluminum alloy ingot specifically includes:

[0019] The first stage: heating the aluminum alloy ingot to 560-580℃ and keeping it warm for 8h;

[0020] The second stage: spray rapid cooling, cooling the aluminum alloy ingot to below 300°C at a cooling rate of 280°C / h or more;

[0021] The third stage: slow cooling after being taken out of the furnace. The aluminum alloy ingot is placed outside the furnace to cool naturally to room temperature.

[0022] Furthermore, the double-stage aging treatment of the aluminum alloy profile specifically includes:

[0023] The aluminum alloy profile is heated to 150-160°C and kept warm for 4 hours, then heated to 200-210°C and kept warm for 6 hours, and the aluminum alloy profile is taken out of the furnace and naturally cooled to room temperature.

[0024] Furthermore, in the process of melting and casting the raw materials to form an aluminum alloy ingot, the components B and La are added in the form of a master alloy before the final refining.

[0025] Furthermore, before the aluminum alloy ingot is extruded, the method further includes: heating the aluminum alloy ingot after homogenization to 480-500° C. and keeping the temperature for 2-5 hours.

[0026] Furthermore, the extrusion molding of the aluminum alloy ingot is specifically as follows:

[0027] The heated aluminum alloy ingot is extruded by an extruder to ensure that the discharge temperature of the aluminum alloy profile reaches 510-540°C. The extruded aluminum alloy profile is quenched by online strong air cooling or water cooling.

[0028] By adopting the technical solution of the present invention, at least the following beneficial effects are achieved: by adding B and La elements to the main strengthening elements, B can be used to react with trace transition elements such as Ti, Mn, Cr, and V in the aluminum alloy to generate borides, so that they are transformed from a solid solution state to a precipitation state; La is used to react with other impurities in the alloy to generate precipitates to purify the melt, and at the same time, it can absorb hydrogen in the melt to reduce the hydrogen content of the aluminum alloy, and can effectively refine the grains. By using high-pressure water mist cooling or water spraying to treat the aluminum alloy ingot in the high temperature zone, the precipitation of coarse Mg-Si second phase can be effectively inhibited; in the low temperature zone, natural slow cooling outside the furnace is used to release the residual stress caused by the above-mentioned rapid cooling process, and promote the formation of a large number of fine rod / ribbon Mg-Si precipitation phases, reduce the deformation resistance of the aluminum alloy ingot in the subsequent extrusion process, and make the aluminum alloy ingot easy to dissolve back into the aluminum matrix in the subsequent extrusion online quenching, which is conducive to achieving better precipitation strengthening effect in the final aging treatment. Finally, by adopting a double-stage over-aging treatment, the precipitated phase can be condensed and grown to reduce its dispersion distribution under the premise of ensuring the strength of the aluminum alloy, thereby maximizing the electrical conductivity of the aluminum alloy. Therefore, the aluminum alloy profile obtained by adopting the present invention still has an alloy composition within the range of the 6101B national standard, that is, the obtained aluminum alloy still belongs to the 6101B alloy, and its electrical conductivity is significantly improved compared with the conventional 6101B aluminum alloy, and the electrical conductivity reaches 58.5% IACS or more; at the same time, it can also ensure that the mechanical properties (strength) reach or even exceed the national standard, the tensile strength reaches more than 220Mpa, and the yield strength reaches more than 195Mpa.

Brief Description of the Drawings

[0029] The present invention will be further described below in conjunction with embodiments with reference to the accompanying drawings.

[0030] Figure 1 This is the secondary electron image of the boron-free sample in Comparative Example 4 of the present invention;

[0031] Figure 2 is the secondary electron image of the boronized sample in Example 1 of the present invention;

[0032] Figure 3 This is the transmission electron image of the boride in Example 1 of the present invention. [Specific implementation method]

[0033] The specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the specific embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0034] It should be noted that certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that technicians may use different nouns to refer to the same component. This specification and claims do not use the difference in nouns as a way to distinguish components, but use the difference in the functions of the components as the criterion for distinction. As mentioned throughout the specification and claims, "including" or "comprising" is an open term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred embodiment of the present invention, but the description is based on the general principles of the specification and is not intended to limit the scope of the present invention. The scope of protection of the present invention shall be determined by the attached claims.

[0035] The present invention discloses a high-conductivity 6101B aluminum alloy for photovoltaic power generation, wherein the aluminum alloy comprises the following components in terms of mass percentage:

[0036] Si: 0.35-0.45%, Mg: 0.4-0.55%, Fe: 0.1-0.15%, B: 0.04-0.06%, La: 0.01-0.04%, Cu≤0.01%, Mn≤0.01%, Zn≤0.01%, Cr≤0.01%, Ti≤0.01%, and the balance is Al and unavoidable impurity elements. Among the unavoidable impurity elements, the total content of impurities is less than 0.1%, and the content of each impurity element is less than 0.03%. Since the present invention adds B and La as main strengthening elements to the alloy, and B and La are used as trace alloying elements, the contents of B and La must be controlled within a reasonable range (i.e., B is controlled within 0.04-0.06%, and La is controlled within 0.01-0.04%). Otherwise, if the contents of B and La are too low, the trace impurities in the melt cannot be completely purified, resulting in an impact on the conductivity of the product; if the contents of B and La are too high, they themselves exist in the melt as an impurity, which also affects the conductivity of the product.

[0037] Because in the actual production process, trace transition elements such as Ti, Mn, Cr, V and trace impurity elements in aluminum alloys have a great influence on the conductivity. The present invention adopts the method of adding B and La elements to the main strengthening elements actively added, wherein B can react with trace transition elements such as Ti, Mn, Cr, V in aluminum alloys to form borides, so that they are transformed from a solid solution state to a precipitation state; La is a very active rare earth element, which can react with other impurities in the alloy to form precipitates to purify the melt, and can also absorb hydrogen in the melt to reduce the hydrogen content of the aluminum alloy, and can effectively refine the grains. Therefore, by actively adding B and La elements to the main strengthening elements, the resistivity of the aluminum alloy can be effectively reduced, that is, the conductivity can be improved.

[0038] In the present invention, the electrical conductivity of the high-conductivity 6101B aluminum alloy is ≥58.5% IACS, the tensile strength is ≥220 MPa, and the yield strength is ≥195 MPa.

[0039] The present invention provides a method for preparing a high-conductivity 6101B aluminum alloy for photovoltaic power generation, the preparation method comprising the following steps:

[0040] Ingredients: The raw materials are provided according to the composition ratio of high-conductivity 6101B aluminum alloy. The elements of the raw materials mainly include actively added Si, Mg, Fe, B and La, and also include inactively added Cu, Mn, Zn, Cr, Ti and other inevitable impurity elements.

[0041] Melting and casting: The raw materials are melted and cast to form aluminum alloy ingots, which specifically includes melting, stirring, refining, degassing, standing, slag cleaning and other operations. The specific process adopted is the conventional process in the industry (unless otherwise specified), so this part of the conventional process will not be described in detail;

[0042] In the melting and casting step, in the process of melting and casting the raw materials to form an aluminum alloy ingot, the components B and La are added in the form of a master alloy before the final refining.

[0043] Homogenization treatment: heating up and cooling down the aluminum alloy ingot in stages;

[0044] In the homogenization step, the heating and stage-by-stage cooling of the aluminum alloy ingot specifically includes:

[0045] The first stage: heating the aluminum alloy ingot to 560-580°C. In the specific implementation, any value can be taken within the range of 560-580°C, and keeping the temperature for 8 hours;

[0046] The second stage: spray rapid cooling, cooling the aluminum alloy ingot to below 300°C at a cooling rate of 280°C / h or more;

[0047] The third stage: slow cooling after being taken out of the furnace, placing the aluminum alloy ingot outside the furnace to cool naturally to room temperature;

[0048] The present invention can effectively inhibit the precipitation of coarse Mg-Si second phase by treating the aluminum alloy ingot in a high temperature zone (above 300°C) by a rapid cooling method of high-pressure water mist cooling or water spraying; and in a low temperature zone (below 300°C) by natural slow cooling outside the furnace to release the residual stress caused by the above rapid cooling process, and promote the formation of a large number of fine rod / ribbon-shaped Mg-Si precipitation phases, so as to reduce the deformation resistance of the aluminum alloy ingot in the subsequent extrusion process as much as possible, and at the same time make the aluminum alloy ingot easily dissolve back into the aluminum matrix in the subsequent extrusion online quenching, which is conducive to obtaining a better precipitation strengthening effect in the final aging treatment.

[0049] Extrusion molding: Extrusion molding of aluminum alloy ingots, including extrusion, online quenching, straightening and other operations, to obtain aluminum alloy profiles;

[0050] In the present invention, in order to realize extrusion molding of the aluminum alloy ingot, before extrusion molding of the aluminum alloy ingot, it also includes: heating the aluminum alloy ingot after homogenization to 480-500°C and keeping it warm for 2-5h (i.e. 2-5 hours). In specific implementation, any value can be taken within the range of 480-500°C, and the holding time can be taken within 2-5h.

[0051] In the extrusion molding step, the aluminum alloy ingot is extruded and molded specifically as follows: the aluminum alloy ingot after heating is extruded and molded by an extruder, and the discharge temperature of the aluminum alloy profile is ensured to reach 510-540°C, and the extruded aluminum alloy profile is treated by online strong air cooling or water cooling quenching, thereby achieving the superposition effect of extrusion work hardening and solid solution strengthening. In addition, when the present invention is implemented, the extrusion barrel and the extrusion die of the extruder need to be preheated to the required temperature and kept warm. This part of the process belongs to the conventional process in the industry, so it will not be introduced in detail here.

[0052] Aging treatment: Double-stage aging treatment is performed on aluminum alloy profiles;

[0053] In the aging treatment step, the double-stage over-aging treatment of the aluminum alloy profile specifically includes: heating the aluminum alloy profile to 150-160°C and then keeping it warm for 4 hours. In specific implementation, any value can be taken within the range of 150-160°C. At the same time, in the temperature rise of the first stage, if the temperature of the first stage is too high, the product will be over-aged too much, which will cause the product strength to decrease significantly. If the temperature of the first stage is too low, the over-aging effect cannot be achieved, which will cause the product conductivity to fail to increase; heating the aluminum alloy profile to 200-210°C and then keeping it warm for 6 hours. Specifically, any value can be taken within the range of 200-210°C, and the aluminum alloy profile is taken out of the furnace and naturally cooled to room temperature;

[0054] The purpose of the aging treatment in the present invention is to nucleate the strengthening phase in the aluminum alloy, thereby improving the strength; and when the aluminum alloy is peak aged, the elements in the supersaturated solid solution will all be dispersed and uniformly precipitated, and the dense distribution of the dispersed precipitated phase will hinder the movement of electrons, thereby reducing the conductivity of the aluminum alloy; for this reason, the present invention adopts a double-stage over-aging treatment, which can make the precipitated phase condense and grow while ensuring the strength of the aluminum alloy and reduce its dispersed distribution, thereby maximizing the conductivity of the aluminum alloy.

[0055] In summary, the present invention can utilize B and La elements to react with trace transition elements such as Ti, Mn, Cr, and V in aluminum alloys to generate borides by adding additional B and La elements to the main strengthening elements, so that they are transformed from a solid solution state to a precipitation state; utilize La to react with other impurities in the alloy to generate precipitates to purify the melt, and at the same time absorb hydrogen in the melt to reduce the hydrogen content of the aluminum alloy, and effectively refine the grains. By using high-pressure water mist cooling or water spraying to treat the aluminum alloy ingot in the high temperature zone, the precipitation of coarse Mg-Si second phase can be effectively inhibited; in the low temperature zone, natural slow cooling outside the furnace is used to release the residual stress caused by the above-mentioned rapid cooling process, and promote the formation of a large number of fine rods / band-shaped Mg-Si precipitation phases, reduce the deformation resistance of the aluminum alloy ingot in the subsequent extrusion process, and make the aluminum alloy ingot easy to dissolve back into the aluminum matrix in the subsequent extrusion online quenching, which is conducive to achieving better precipitation strengthening effect in the final aging treatment. Finally, by adopting a double-stage over-aging treatment, the precipitated phase can be condensed and grown to reduce its dispersion distribution under the premise of ensuring the strength of the aluminum alloy, thereby maximizing the electrical conductivity of the aluminum alloy. Therefore, the aluminum alloy profile obtained by adopting the present invention still has an alloy composition within the range of the 6101B national standard, that is, the obtained aluminum alloy still belongs to the 6101B alloy, and its electrical conductivity is significantly improved compared with the conventional 6101B aluminum alloy, and the electrical conductivity reaches 58.5% IACS or more; at the same time, it can also ensure that the mechanical properties (strength) reach or even exceed the national standard, the tensile strength reaches more than 220Mpa, and the yield strength reaches more than 195Mpa.

[0056] The technical solution of the present invention is further described in detail below in conjunction with some specific embodiments and comparative examples:

[0057] Example 1

[0058] Ingredients: The composition ratio of high conductive 6101B aluminum alloy is Si: 0.42%, Mg: 0.53%, Fe: 0.13%, B: 0.055%, La: 0.03%, Cu: 0.002%, Mn: 0.003%, Zn: 0.001%, Cr: 0.001%, Ti: 0.005%, and the balance is Al and unavoidable impurity elements;

[0059] Melting and casting: The raw materials are melted and cast to form aluminum alloy ingots, and components B and La are added in the form of master alloys before the final refining;

[0060] Homogenization treatment: firstly heat the aluminum alloy ingot to 570℃ and keep it at this temperature for 8h; then spray and rapidly cool it to 280℃ at a cooling rate of 300℃ / h; finally, take it out of the furnace and slowly cool it, and place the aluminum alloy ingot outside the furnace to cool naturally to room temperature;

[0061] Extrusion molding: The aluminum alloy ingot after homogenization is heated to 490°C and kept warm for 3 hours; the heated aluminum alloy ingot is extruded by an extruder, and the discharge temperature of the aluminum alloy profile is ensured to reach 520°C;

[0062] Aging treatment: Heat the aluminum alloy profile to 155℃ and keep it for 4 hours, then heat it to 205℃ and keep it for 6 hours, and let the aluminum alloy profile cool down naturally to room temperature after being taken out of the furnace.

[0063] Example 2

[0064] Ingredients: The composition ratio of high conductive 6101B aluminum alloy is Si: 0.45%, Mg: 0.55%, Fe: 0.15%, B: 0.06%, La: 0.04%, Cu: 0.01%, Mn: 0.01%, Zn: 0.01%, Cr: 0.01%, Ti: 0.01%, and the balance is Al and unavoidable impurity elements;

[0065] Melting and casting: The raw materials are melted and cast to form aluminum alloy ingots, and components B and La are added in the form of master alloys before the final refining;

[0066] Homogenization treatment: firstly heat the aluminum alloy ingot to 580℃ and keep it at this temperature for 8h; then spray and rapidly cool the aluminum alloy ingot to 295℃ at a cooling rate of 320℃ / h; finally, take it out of the furnace and slowly cool it, and place the aluminum alloy ingot outside the furnace to cool naturally to room temperature;

[0067] Extrusion molding: The aluminum alloy ingot after homogenization is heated to 500°C and kept warm for 5 hours; the heated aluminum alloy ingot is extruded by an extruder, and the discharge temperature of the aluminum alloy profile is ensured to reach 540°C;

[0068] Aging treatment: heat the aluminum alloy profile to 160℃ and keep it for 4h, then heat it to 210℃ and keep it for 6h, and let the aluminum alloy profile cool down naturally to room temperature after being taken out of the furnace.

[0069] Example 3

[0070] Ingredients: The composition ratio of high conductive 6101B aluminum alloy is Si: 0.35%, Mg: 0.4%, Fe: 0.1%, B: 0.04%, La: 0.01%, Cu: 0.005%, Mn: 0.002%, Zn: 0.001%, Cr: 0.001%, Ti: 0.001%, and the balance is Al and unavoidable impurity elements;

[0071] Melting and casting: The raw materials are melted and cast to form aluminum alloy ingots, and components B and La are added in the form of master alloys before the final refining;

[0072] Homogenization treatment: firstly heat the aluminum alloy ingot to 560℃ and keep it at this temperature for 8h; then spray and rapidly cool the aluminum alloy ingot to 270℃ at a cooling rate of 280℃ / h; finally, take it out of the furnace and slowly cool it, and place the aluminum alloy ingot outside the furnace to cool naturally to room temperature;

[0073] Extrusion molding: The aluminum alloy ingot after homogenization is heated to 480°C and kept warm for 2 hours; the heated aluminum alloy ingot is extruded by an extruder, and the discharge temperature of the aluminum alloy profile is ensured to reach 510°C;

[0074] Aging treatment: heat the aluminum alloy profile to 150℃ and keep it for 4 hours, then heat it to 200℃ and keep it for 6 hours, and let the aluminum alloy profile cool naturally to room temperature after being taken out of the furnace.

[0075] Example 4

[0076] Ingredients: The composition ratio of high conductive 6101B aluminum alloy is Si: 0.39%, Mg: 0.49%, Fe: 0.14%, B: 0.049%, La: 0.03%, Cu: 0.001%, Mn: 0.002%, Zn: 0.001, Cr: 0.001%, Ti: 0.004%, and the balance is Al and unavoidable impurity elements;

[0077] Melting and casting: The raw materials are melted and cast to form aluminum alloy ingots, and components B and La are added in the form of master alloys before the final refining;

[0078] Homogenization treatment: firstly heat the aluminum alloy ingot to 560℃ and keep it at this temperature for 8h; then spray and rapidly cool it to 290℃ at a cooling rate of 300℃ / h; finally, take it out of the furnace and slowly cool it, and place the aluminum alloy ingot outside the furnace to cool naturally to room temperature;

[0079] Extrusion molding: The aluminum alloy ingot after homogenization is heated to 500°C and kept warm for 4 hours; the heated aluminum alloy ingot is extruded by an extruder, and the discharge temperature of the aluminum alloy profile is ensured to reach 525°C;

[0080] Aging treatment: heat the aluminum alloy profile to 156℃ and keep it for 4h, then heat it to 208℃ and keep it for 6h, and let the aluminum alloy profile cool down naturally to room temperature after being taken out of the furnace.

[0081] Example 5

[0082] Ingredients: The composition ratio of high conductive 6101B aluminum alloy is Si: 0.37%, Mg: 0.46%, Fe: 0.12%, B: 0.043%, La: 0.02%, Cu: 0.001%, Mn: 0.004%, Zn: 0.002%, Cr: 0.001%, Ti: 0.003%, and the balance is Al and unavoidable impurity elements;

[0083] Melting and casting: The raw materials are melted and cast to form aluminum alloy ingots, and components B and La are added in the form of master alloys before the final refining;

[0084] Homogenization treatment: firstly heat the aluminum alloy ingot to 575℃ and keep it at this temperature for 8h; then spray and rapidly cool the aluminum alloy ingot to 285℃ at a cooling rate of 285℃ / h; finally, take it out of the furnace and slowly cool it, and place the aluminum alloy ingot outside the furnace to cool naturally to room temperature;

[0085] Extrusion molding: The aluminum alloy ingot after homogenization is heated to 485°C and kept warm for 2.5 hours; the heated aluminum alloy ingot is extruded by an extruder, and the discharge temperature of the aluminum alloy profile is ensured to reach 530°C;

[0086] Aging treatment: Heat the aluminum alloy profile to 160℃ and keep it warm for 4h, then heat it to 205℃ and keep it warm for 6h, and let the aluminum alloy profile cool down naturally to room temperature after being taken out of the furnace.

[0087] Comparative Example 1

[0088] The difference from Example 1 is that: in the homogenization step, a conventional homogenization process is adopted (the aluminum alloy ingot is heated to 580°C and then kept warm for 8 hours, then taken out of the furnace and naturally cooled to room temperature); at the same time, a conventional aging process is adopted in the aging treatment step (the aluminum alloy profile is heated to 175°C and then kept warm for 8 hours, then naturally cooled to room temperature); the rest of the contents are exactly the same as in Example 1.

[0089] Comparative Example 2

[0090] The difference from Example 1 is that in the homogenization step, a conventional homogenization process is adopted (the aluminum alloy ingot is heated to 580°C and then kept warm for 8 hours, then taken out of the furnace and naturally cooled to room temperature); the rest of the contents are exactly the same as in Example 1.

[0091] Comparative Example 3

[0092] The difference from Example 1 is that a conventional aging process is used in the aging treatment step (the aluminum alloy profile is heated to 175° C., kept warm for 8 hours, and then naturally cooled to room temperature); the rest of the contents are exactly the same as Example 1.

[0093] Comparative Example 4

[0094] The difference from Example 1 is that in the batching step, conventional 6101B alloy composition is used, specifically Si: 0.45%, Mg: 0.56%, Fe: 0.13%, Cu: 0.002%, Mn: 0.003%, Zn: 0.001%, and the balance is Al and unavoidable impurity elements, that is, B and La are not added; the rest of the content is exactly the same as in Example 1.

[0095] Comparative Example 5

[0096] The difference from Example 1 is that in the batching step, B: 0.1%, La: 0.09%; the rest of the contents are exactly the same as in Example 1.

[0097] Comparative Example 6

[0098] The difference from Example 1 is that B: 0.005%, La: 0.005%; the rest of the contents are exactly the same as Example 1.

[0099] Specific parameter performance is detailed in Table 1 below:

[0100] Table 1 Performance table of embodiments and comparative examples

[0101] performance Electrical conductivity (%IACS) Tensile strength(Mpa) Yield Strength(Mpa) Example 1 58.6 236 211 Example 2 58.6 241 215 Example 3 58.7 225 198 Example 4 58.7 231 205 Example 5 59.1 224 198 Comparative Example 1 55.8 244 221 Comparative Example 2 56.3 231 206 Comparative Example 3 55.9 246 219 Comparative Example 4 56.2 235 208 Comparative Example 5 56 237 213 Comparative Example 6 56.5 231 206

[0102] As can be seen from Table 1 above, the electrical conductivity of the aluminum alloy profiles obtained in Examples 1 to 5 is above 58.5% IACS, and at the same time, the tensile strength and yield strength reach or even exceed the national standard of 6101B alloy. It can be seen that by adopting the above technical solution of the present invention, the electrical conductivity of 6101B alloy can be further improved on the basis of maintaining good mechanical properties, thereby meeting the comprehensive requirements of the photovoltaic power generation industry for electrical conductivity and mechanical properties. While the aluminum alloy profiles obtained in Comparative Examples 1 to 6, although their tensile strength and yield strength reach the national standard of 6101B alloy, their electrical conductivity is below 57% IACS. It can be seen that the technical solution of the present invention improves the electrical conductivity of 6101B alloy by at least 1.5% IACS, and the alloy composition is still within the national standard range of 6101B, and the mechanical properties still meet the national standard of 6101B alloy, which is a major breakthrough for the photovoltaic power generation industry. It can also be seen from Comparative Examples 5 and 6 that too low or too high content of B and La will affect the conductivity of the product, so that the conductivity of the product cannot reach 58.5% IACS or above. In addition, it can also be clearly known from the above embodiments and comparative examples that the technical effect of the present invention is obtained under the joint action of alloy composition design, high temperature rapid cooling and low temperature slow cooling of the homogenization process, and two-stage over-aging treatment. The lack of any one of these links cannot achieve the technical effect.

[0103] Finally, the samples without boron and those treated with boron were analyzed by transmission electron microscopy, and the results were as follows: Figure 1-3 As shown, Figure 1 This is the secondary electron image of the boron-free sample in Comparative Example 4. Figure 2 This is the secondary electron image of the boronized sample in Example 1. Figure 3 This is the transmission electron image of the boride in Example 1.

[0104] like Figure 1 As shown, for the sample without boron addition, the number of particle phases in the grains is large, and they are irregularly distributed in the matrix in the shape of irregular short rods or spheres.

[0105] like Figure 2 As shown in the figure, for the borided sample, the content of particle phase in the sample grains is very small, and larger-sized particle phases are gathered near the grain boundaries, which are spherical or elliptical, and the phase edges on the grain boundaries are smoother. It can be seen that the addition of B improves the distribution morphology of the phases in the organization, the intracrystalline organization is cleaner, the phases at the grain boundaries are gathered and regularly distributed, and at the same time improves the morphology of the impurity phases, making the Fe and Mn phases at the grain boundaries discontinuously distributed. It can be inferred that B can combine with Fe and Mn, thereby changing the distribution and morphology of the impurity phases at the grain boundaries.

[0106] from Figure 3 It can be seen that the boride particles combined with B and impurity elements are distributed in regular spherical shapes, the boride particle size is about 100 nm, the interface is clear, there are no other derived impurity particles around the boride particles, the matrix is ​​clean, and the regularly agglomerated compound phase is more conducive to electron propagation, reducing the hindering effect of diffuse reflection on electron movement, and has a positive effect on improving conductive properties.

[0107] Although the specific implementation modes of the present invention are described above, those skilled in the art should understand that the specific implementation modes described are only illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A high-conductivity 6101B aluminum alloy for photovoltaic power generation, characterized in that: The high-conductivity 6101B aluminum alloy includes the following components by mass percentage: Si: 0.35-0.45%, Mg: 0.4-0.55%, Fe: 0.1-0.15%, B: 0.04-0.06%, La: 0.01-0.04%, Cu≤0.01%, Mn≤0.01%, Zn≤0.01%, Cr≤0.01%, Ti≤0.01%, and the balance is Al and unavoidable impurity elements.

2. A high-conductivity 6101B aluminum alloy for photovoltaic power generation as claimed in claim 1, characterized in that: The electrical conductivity of the high-conductivity 6101B aluminum alloy is ≥58.5% IACS, the tensile strength is ≥220 MPa, and the yield strength is ≥195 MPa.

3. The high-conductivity 6101B aluminum alloy for photovoltaic power generation according to claim 1, characterized in that: Among the inevitable impurity elements, the total content of the impurities is less than 0.1%, and the content of each impurity element is less than 0.03%.

4. A method for preparing a high-conductivity 6101B aluminum alloy for photovoltaic power generation according to any one of claims 1 to 3, characterized in that: The preparation method comprises the following steps: Ingredients: Provide raw materials according to the composition ratio of high-conductivity 6101B aluminum alloy; Melting and casting: Melting and casting the raw materials to form aluminum alloy ingots; Homogenization treatment: heating up and cooling down the aluminum alloy ingot in stages; Extrusion molding: Extrusion molding of aluminum alloy ingots to obtain aluminum alloy profiles; Aging treatment: Double-stage aging treatment is performed on the aluminum alloy profiles.

5. The method for preparing a high-conductivity 6101B aluminum alloy for photovoltaic power generation according to claim 4, characterized in that: The heating and stage-by-stage cooling treatment of the aluminum alloy ingot specifically includes: The first stage: heating the aluminum alloy ingot to 560-580℃ and keeping it warm for 8h; The second stage: spray rapid cooling, cooling the aluminum alloy ingot to below 300°C at a cooling rate of 280°C / h or more; The third stage: slow cooling after being taken out of the furnace. The aluminum alloy ingot is placed outside the furnace to cool naturally to room temperature.

6. The method for preparing a high-conductivity 6101B aluminum alloy for photovoltaic power generation according to claim 4, characterized in that: The double-stage aging treatment of the aluminum alloy profile specifically includes: The aluminum alloy profile is heated to 150-160°C and kept warm for 4 hours, then heated to 200-210°C and kept warm for 6 hours, and the aluminum alloy profile is taken out of the furnace and naturally cooled to room temperature.

7. The method for preparing a high-conductivity 6101B aluminum alloy for photovoltaic power generation according to claim 4, characterized in that: In the process of melting and casting the raw materials to form an aluminum alloy ingot, the components B and La are added in the form of a master alloy before the final refining.

8. The method for preparing a high-conductivity 6101B aluminum alloy for photovoltaic power generation according to claim 4, characterized in that: Before the aluminum alloy ingot is extruded, the method also includes: heating the aluminum alloy ingot after homogenization to 480-500° C. and keeping the temperature for 2-5 hours.

9. The method for preparing a high-conductivity 6101B aluminum alloy for photovoltaic power generation according to claim 4, characterized in that: The extrusion molding of the aluminum alloy ingot is specifically as follows: The heated aluminum alloy ingot is extruded by an extruder to ensure that the discharge temperature of the aluminum alloy profile reaches 510-540°C. The extruded aluminum alloy profile is quenched by online strong air cooling or water cooling.

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