Low-thermal-expansion aluminum alloy frame material suitable for photovoltaic module and preparation method of low-thermal-expansion aluminum alloy frame material

Abstract

The invention provides a low-thermal-expansion aluminum alloy frame material suitable for a photovoltaic module and a preparation method of the low-thermal-expansion aluminum alloy frame material, and relates to the technical field of photovoltaic modules, the low-thermal-expansion aluminum alloy frame material comprises aluminum alloy powder and negative thermal-expansion alloy particles, and the aluminum alloy powder is composed of matrix element aluminum and microelements of silicon, magnesium and copper; the negative thermal expansion alloy particles are composed of Hf, Zr, Ta and Fe elements, and specifically, the negative thermal expansion alloy particles are Hf < 0.7 > Zr < 0.2 > Ta < 0.1 > Fe < 2 >; the negative thermal expansion alloy particles with specific components are added into the aluminum alloy powder, the thermal expansion coefficient of the aluminum alloy composite material is remarkably reduced, the aluminum alloy composite material is matched with photovoltaic glass, thermal stress generated in the temperature changing process can be effectively reduced, fatigue failure of a sealing layer is avoided, the risk of glass burst is reduced, and the service life of the aluminum alloy composite material is prolonged. And meanwhile, the photovoltaic module frame has relatively high mechanical strength and corrosion resistance, and meets the use requirements of the photovoltaic module frame.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic modules, in particular to a low thermal expansion aluminum alloy frame material suitable for photovoltaic modules and a preparation method thereof. BACKGROUND

[0002] In photovoltaic modules, the main role of the frame is to protect the edge of the photovoltaic glass, strengthen the sealing of the module, and improve the mechanical strength of the module. At present, the frame of the photovoltaic module mainly uses 6063 / 6061 aluminum alloy material, which has the advantages of light weight, high strength, good corrosion resistance, etc. However, the thermal expansion coefficient of this kind of aluminum alloy is about 23x10 -6 / ℃, which is more than twice the thermal expansion coefficient of photovoltaic glass (about 9.6x10⁻ 6 / ℃). This mismatch in thermal expansion coefficient will lead to fatigue failure of the sealant layer at the aluminum alloy frame-glass interface under the temperature difference between day and night and seasonal temperature fluctuations, and will cause the initiation and propagation of glass edge cracks, increasing the risk of glass burst. Industry statistics show that the failure of the module caused by temperature difference accounts for more than 17%, which seriously affects the reliability and service life of the photovoltaic module. In the prior art, stainless steel frames with a thermal expansion coefficient close to that of photovoltaic glass are used to replace aluminum alloy frames, but they are more expensive and difficult to process. In addition, engineering plastic frames are also considered to replace aluminum alloy frames, but their mechanical strength is insufficient to meet the long-term use requirements of photovoltaic modules. Currently, the thermal stress problem is usually alleviated by adding a buffer layer or optimizing the frame structure, but this will increase the complexity of packaging and lead to an increase in cost. The above methods are difficult to perfectly solve the problem of mismatch between the thermal expansion coefficient of the frame material and the photovoltaic glass, so there is an urgent need for new aluminum alloy materials that can reduce the thermal expansion coefficient to match the thermal expansion coefficient of photovoltaic glass, thereby improving the thermal shock resistance and long-term stability of photovoltaic modules. Therefore, the present application proposes a low thermal expansion aluminum alloy frame material suitable for photovoltaic modules and a preparation method thereof to solve the problems existing in the prior art. SUMMARY

[0003] To solve the above problems, the present application provides a low thermal expansion aluminum alloy frame material suitable for photovoltaic modules and a preparation method thereof. The low thermal expansion aluminum alloy frame material suitable for photovoltaic modules and the preparation method thereof are used for the frame of photovoltaic modules. By adjusting the composition and preparation process of the aluminum alloy, the thermal expansion coefficient is matched with the photovoltaic glass, thereby reducing the generation of thermal stress, avoiding fatigue failure of the sealant and glass burst, and improving the reliability and service life of the photovoltaic module.

[0004] To achieve the purpose of the present application, the present application realizes the following technical solutions: a low-thermal expansion aluminum alloy frame material suitable for a photovoltaic module, comprising aluminum alloy powder and negative thermal expansion alloy particles, wherein the aluminum alloy powder is composed of base element aluminum and trace elements silicon, magnesium and copper; The negative thermal expansion alloy particles are composed of Hf, Zr, Ta and Fe elements, and the negative thermal expansion alloy particles are specifically Hf 0.7 Zr 0.2 Ta 0.1 Fe2.

[0005] Further improvement lies in that the preparation method of the negative thermal expansion alloy particles is as follows: According to the molar mass ratio, Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy ingot is prepared by vacuum arc melting; The Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy ingot is mechanically crushed, and the alloy block after mechanical crushing is placed in a planetary ball mill, and ball milling is performed for 2-3 hours to obtain Hf 0.7 Zr 0.2 Ta 0.1 Fe2 negative thermal expansion alloy particles.

[0006] Further improvement lies in that after the Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy ingot is prepared, in order to ensure the uniformity of the alloy, the alloy ingot is vacuum annealed at 1000 DEG C for 5-7 days: Further improvement lies in that in the planetary ball mill, ball milling is performed according to a ball-to-material ratio of 7-10:1 and a rotation speed of 90-110 r / min.

[0007] Further improvement lies in that the particle size of the aluminum alloy powder is 10-100 mu m, and the total mass percentage of silicon, magnesium and copper is not more than 5%.

[0008] Further improvement lies in that the Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy particles and the aluminum alloy powder have a particle size ratio of 1:5-1:20.

[0009] A preparation method of a low-thermal expansion aluminum alloy frame material suitable for a photovoltaic module, comprising the following steps: S1: Hf 0.7 Zr 0.2 Ta 0.1Fe2 alloy particles are mixed with aluminum alloy powder in a ball mill according to different weight ratios until the alloy components are uniformly mixed; S2: the mixed Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy particles and aluminum alloy powder are loaded into a mold and placed in a vacuum hot pressing furnace, vacuum hot pressing is performed, and then cooled to room temperature to prepare a composite material.

[0010] Further improvement lies in that in S1, the ball-to-material ratio is 7-10:1, the rotation speed is 90-110 r / min, and the ball milling time is 0.5-2 h.

[0011] Further improvement lies in that in S2, the vacuum hot pressing is performed at 560±5℃ and 35±5MPa for 30-40 min, and then cooled to room temperature.

[0012] Further improvement lies in that the hot pressing process is performed under argon protection, the heating rate is 10-15℃ / min, and the cooling rate is ≤5℃ / min after the pressure holding is completed.

[0013] The beneficial effects of the present application are: 1. The present application significantly reduces the thermal expansion coefficient of the aluminum alloy composite material by adding negative thermal expansion alloy particles with specific components in the aluminum alloy powder, which matches the photovoltaic glass, effectively reduces the thermal stress generated during the temperature change, avoids the fatigue failure of the sealing layer, reduces the risk of glass explosion, has high mechanical strength and corrosion resistance, and meets the use requirements of the photovoltaic module frame.

[0014] 2. In the preparation method of the present application, the uniformity and performance stability of the material are ensured by reasonably controlling the process parameters such as vacuum annealing, ball milling, and vacuum hot pressing, the low-thermal-expansion aluminum alloy frame material prepared is suitable for photovoltaic modules, improves the thermal shock resistance and long-term reliability of the photovoltaic modules, effectively improves the service life of the photovoltaic modules, and has simple preparation process, low cost, and is suitable for large-scale production. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy thermal expansion curve of the present application; Figure 2 The Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy particle size distribution graph after ball milling; Figure 3 XRD pattern of the aluminum alloy and the material of the present application; Figure 4 The figure of thermal expansion coefficient of the aluminum alloy, the material of the present application, and the photovoltaic glass; Figure 5 The figure of mechanical properties of the aluminum alloy and the material of the present application. DETAILED DESCRIPTION

[0016] In order to deepen the understanding of the present application, the present application will be further described in combination with the embodiments below, which are only used to explain the present application and do not constitute the limitation to the protection scope of the present application.

[0017] Embodiment one According to Figure 1 , 2 , 3, 4, 5, the present embodiment proposes a low thermal expansion aluminum alloy frame material suitable for photovoltaic modules and a preparation method thereof, which comprises the following components: Aluminum alloy powder (composed of base element aluminum and trace elements silicon, magnesium, copper, etc.); Hf 0.7 Zr 0.2 Ta 0.1 Fe2 negative thermal expansion alloy particles; Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy particles are prepared as follows: According to the molar mass ratio, Hf, Zr, Ta and Fe elements are weighed, and Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy ingot is prepared by vacuum arc melting. In order to ensure the uniformity of the alloy, the alloy ingot is vacuum annealed at 1000℃ for 6 days. The measured negative thermal expansion curve of the alloy composition is shown in the attached Figure 1 ; The alloy block after mechanical crushing of Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy ingot is placed in a planetary ball mill, and ball milling is carried out according to the parameters of ball-to-material ratio of 7~10:1 and rotation speed of 90~110r / min for 2~3 hours, to obtain Hf 0.7 Zr 0.2 Ta 0.1 Fe2 negative thermal expansion alloy particles, the size distribution range of which is shown in the attached Figure 2 ; Hf 0.7 Zr 0.2 Ta 0.1The Fe2 alloy particles are mixed with aluminum alloy powder in different weight ratios in a ball mill, and the ball milling is performed for 0.5 to 2 hours at a ball-to-material ratio of 7 to 10:1 and a rotation speed of 90 to 110 r / min to ensure uniform mixing of the alloy components.

[0018] Hf mixed in different proportions 0.7 Zr 0.2 Ta 0.1 Fe2 alloy particles and aluminum alloy powder are loaded into the mold and placed in a vacuum hot pressing furnace and vacuumed. The hot pressing temperature and pressure are too high, Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy particles react with aluminum at the interface. If the temperature and pressure are too low, the density of the composite material will be reduced and the mechanical properties will be reduced. Therefore, the present invention selects vacuum hot pressing at 560±5℃ and 35±5MPa for 30~40 minutes and then cools to room temperature to prepare Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy particles / aluminum alloy composite materials.

[0019] X-ray diffraction (XRD) was performed on each alloy and composite material, as shown in the attached Figure 3 As shown, it can be observed that with the increase of Hf 0.7 Zr 0.2 Ta 0.1 The increase of Fe2 negative thermal expansion alloy ratio, Hf 0.7 Zr 0.2 Ta 0.1 The characteristic diffraction peaks of Fe2 alloy gradually increase and strengthen.

[0020] Adding different proportions of Hf 0.7 Zr 0.2 Ta 0.1 The thermal expansion performance of the Fe2 alloy particles and aluminum alloy composites was characterized. Figure 4 As shown, with Hf 0.7 Zr 0.2 Ta 0.1 With the increase of the proportion of Fe2 alloy particles, the thermal expansion coefficient of the aluminum alloy composite material gradually decreases from the initial 23.7×10-6 / ℃ to 15.3×10-6 / ℃, a decrease of about 35.4%.

[0021] Aluminum alloy composites with Hf 0.7 Zr 0.2 Ta 0.1 As the addition ratio of Fe2 alloy particles increases, the tensile strength and yield strength also increase, and the ductility decreases to a certain extent, indicating that Hf 0.7 Zr 0.2 Ta0.1 The addition of Fe2 alloy has a strengthening effect on aluminum alloy. Figure 5 shown.

[0022] Example 2 according to Figure 1 、 2 As shown in , 3, 4, and 5, this embodiment proposes a low thermal expansion aluminum alloy frame material suitable for photovoltaic modules and a preparation method thereof, including: Hf 0.7 Zr 0.2 Ta 0.1 Preparation of Fe2 alloy particles: Hf, Zr, Ta and Fe elements were weighed according to the molar mass ratio (the purity of the elements was greater than 99.9%), and Hf was prepared by vacuum arc melting. 0.7 Zr 0.2 Ta 0.1 Fe2 alloy ingots were vacuum annealed at 1000℃ for 6 days to ensure uniform composition of the alloy sample. The negative thermal expansion curve of the alloy composition was measured as shown in the attached figure. Figure 1 As shown; Hf 0.7 Zr 0.2 Ta 0.1 The alloy blocks after mechanical crushing of Fe2 alloy ingot were put into planetary ball mill and milled for 2 hours at a ball-to-material ratio of 9:1 and a rotation speed of 95 r / min to obtain Hf 0.7 Zr 0.2 Ta 0.1 The size distribution range of Fe2 alloy particles is as shown in the attached Figure 2 shown.

[0023] Hf 0.7 Zr 0.2 Ta 0.1 Preparation of Fe2 alloy / aluminum alloy composite materials: Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy particles are mixed with pure aluminum or aluminum alloy powder in a ball mill at a weight ratio of 4 wt.%, and ball milled for 1.5 hours at a ball-to-powder ratio of 10:1 and a rotation speed of 110 r / min to ensure uniform mixing of the alloy components. The mixed Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy particles / aluminum alloy powder were loaded into a mold and placed in a vacuum hot pressing furnace. Vacuum was applied and hot pressed at 560℃ and 35MPa for 35 minutes. Then the mold was cooled to room temperature to obtain Hf 0.7 Zr 0.2 Ta0.1 Fe2 alloy particles / aluminum alloy composite materials, such as the attached Figure 4 As shown, the thermal expansion coefficient of the composite material is 20.9×10⁻ 6 / ℃.

[0024] Example 3 according to Figure 1 、 2 As shown in , 3, 4, and 5, this embodiment proposes a low thermal expansion aluminum alloy frame material suitable for photovoltaic modules and a preparation method thereof, including: Hf 0.7 Zr 0.2 Ta 0.1 Preparation of Fe2 alloy particles: Hf, Zr, Ta and Fe elements were weighed according to the molar mass ratio (the purity of the elements was greater than 99.9%), and Hf was prepared by vacuum arc melting. 0.7 Zr 0.2 Ta 0.1 Fe2 alloy ingots were vacuum annealed at 1000℃ for 6 days to ensure uniform composition of the alloy sample. The negative thermal expansion curve of the alloy composition was measured as shown in the attached figure. Figure 1 As shown; Hf 0.7 Zr 0.2 Ta 0.1 The alloy blocks after mechanical crushing of Fe2 alloy ingot were put into planetary ball mill and milled for 2 hours at a ball-to-material ratio of 9:1 and a rotation speed of 95 r / min to obtain Hf 0.7 Zr 0.2 Ta 0.1 The size distribution range of Fe2 alloy particles is as shown in the attached Figure 2 shown.

[0025] Hf 0.7 Zr 0.2 Ta 0.1 Preparation of Fe2 alloy / aluminum alloy composite materials: Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy particles are mixed with pure aluminum or aluminum alloy powder in a ball mill at a weight ratio of 8 wt.%, and ball milled for 1.5 hours at a ball-to-powder ratio of 10:1 and a rotation speed of 110 r / min to ensure uniform mixing of the alloy components. The mixed Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy particles / aluminum alloy powder were loaded into a mold and placed in a vacuum hot pressing furnace. Vacuum was applied and hot pressed at 560℃ and 35MPa for 35 minutes. Then the mold was cooled to room temperature to obtain Hf0.7 Zr 0.2 Ta 0.1 Fe2 alloy particles / aluminum alloy composite materials, such as the attached Figure 4 As shown, the thermal expansion coefficient of the composite material is 18.1×10⁻ 6 / ℃.

[0026] Example 4 according to Figure 1 、 2 As shown in , 3, 4, and 5, this embodiment proposes a low thermal expansion aluminum alloy frame material suitable for photovoltaic modules and a preparation method thereof, including: Hf 0.7 Zr 0.2 Ta 0.1 Preparation of Fe2 alloy particles: Hf, Zr, Ta and Fe elements were weighed according to the molar mass ratio (the purity of the elements was greater than 99.9%), and Hf was prepared by vacuum arc melting. 0.7 Zr 0.2 Ta 0.1 Fe2 alloy ingots were vacuum annealed at 1000℃ for 6 days to ensure uniform composition of the alloy sample. The negative thermal expansion curve of the alloy composition was measured as shown in the attached figure. Figure 1 As shown; Hf 0.7 Zr 0.2 Ta 0.1 The alloy blocks after mechanical crushing of Fe2 alloy ingot were put into planetary ball mill and milled for 2 hours at a ball-to-material ratio of 9:1 and a rotation speed of 95 r / min to obtain Hf 0.7 Zr 0.2 Ta 0.1 The size distribution range of Fe2 alloy particles is as shown in the attached Figure 2 shown.

[0027] Hf 0.7 Zr 0.2 Ta 0.1 Preparation of Fe2 alloy / aluminum alloy composite materials: Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy particles are mixed with pure aluminum or aluminum alloy powder at a weight ratio of 12 wt.% in a ball mill, and ball milled for 1.5 hours at a ball-to-powder ratio of 10:1 and a rotation speed of 110 r / min to ensure uniform mixing of the alloy components. The mixed Hf 0.7 Zr 0.2 Ta 0.1The Fe2 alloy particles / aluminum alloy powder is loaded into a mold and placed into a vacuum hot pressing furnace, vacuumized, vacuum hot pressed at 560 DEG C and 35 MPa for 35 minutes, and then cooled to room temperature to prepare a Hf0.7Zr0.2Ta0.1Fe2 alloy particle / aluminum alloy composite material, as shown in the accompanying Figure 4 The thermal expansion coefficient of the composite material is 15.3x10⁻ 6 / ℃ The present application significantly reduces the thermal expansion coefficient of the aluminum alloy composite material by adding negative thermal expansion alloy particles of a specific composition to the aluminum alloy powder, matches the photovoltaic glass, effectively reduces the thermal stress generated during the temperature change, avoids fatigue failure of the sealing layer, reduces the risk of glass explosion, has high mechanical strength and corrosion resistance, and meets the use requirements of the photovoltaic module frame. In addition, by reasonably controlling the process parameters such as vacuum annealing, ball milling, and vacuum hot pressing in the preparation method, the uniformity and performance stability of the material are ensured, the low-thermal-expansion aluminum alloy frame material prepared has good performance, is suitable for photovoltaic modules, improves the thermal shock resistance and long-term reliability of the photovoltaic module, effectively improves the service life of the photovoltaic module, and has simple preparation process and low cost, which is suitable for large-scale production.

[0028] The basic principles, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A low thermal expansion aluminum alloy frame material suitable for photovoltaic modules, comprising aluminum alloy powder and negative thermal expansion alloy particles, characterized in that: The aluminum alloy powder is composed of the matrix element aluminum and trace elements silicon, magnesium and copper; The negative thermal expansion alloy particles are composed of Hf, Zr, Ta and Fe elements, and the negative thermal expansion alloy particles are specifically: Hf 0.7 Zr 0.2 Ta 0.1 Fe2.

2. The low thermal expansion aluminum alloy frame material suitable for photovoltaic modules according to claim 1, characterized in that: The preparation method of the negative thermal expansion alloy particles is as follows: Hf, Zr, Ta and Fe elements were weighed according to the molar mass ratio and Hf was prepared by vacuum arc melting. 0.7 Zr 0.2 Ta 0.1 Fe2 alloy ingot; Hf 0.7 Zr 0.2 Ta 0.1 The alloy blocks after mechanical crushing of Fe2 alloy ingots were placed in a planetary ball mill and milled for 2-3 hours to obtain Hf 0.7 Zr 0.2 Ta 0.1 Fe2 negative thermal expansion alloy particles.

3. The low thermal expansion aluminum alloy frame material suitable for photovoltaic modules according to claim 2, characterized in that: Preparation of Hf 0.7 Zr 0.2 Ta 0.1 After the Fe2 alloy ingot is cast, in order to ensure the uniformity of the alloy, the alloy ingot is vacuum annealed at 1000°C for 5-7 days.

4. The low thermal expansion aluminum alloy frame material suitable for photovoltaic modules according to claim 2, characterized in that: In a planetary ball mill, ball milling is carried out according to the ball-to-material ratio of 7-10:1 and the rotation speed of 90-110r / min.

5. The low thermal expansion aluminum alloy frame material suitable for photovoltaic modules according to claim 1, characterized in that: The particle size of the aluminum alloy powder is 10 μm-100 μm, and the total mass percentage of silicon, magnesium and copper does not exceed 5%.

6. The low thermal expansion aluminum alloy frame material suitable for photovoltaic modules according to claim 5, characterized in that: The Hf 0.7 Zr 0.2 Ta 0.1 The particle size ratio of Fe2 alloy particles to aluminum alloy powder is 1:5-1:

20.

7. A method for preparing a low thermal expansion aluminum alloy frame material suitable for photovoltaic modules, applied to the low thermal expansion aluminum alloy frame material suitable for photovoltaic modules as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: S1: Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy particles are mixed with aluminum alloy powder in a ball mill according to different weight ratios until the alloy components are evenly mixed; S2: Mix Hf 0.7 Zr 0.2 Ta 0.1 Fe2 alloy particles and aluminum alloy powder are loaded into a mold and placed in a vacuum hot pressing furnace. Vacuuming is performed for hot pressing, and then cooling is performed to room temperature to prepare a composite material.

8. The method for preparing a low thermal expansion aluminum alloy frame material suitable for photovoltaic modules according to claim 7, characterized in that: In the above S1, during mixing, the mixture is ball-milled for 0.5-2 hours at a ball-to-material ratio of 7-10:1 and a rotation speed of 90-110 r / min.

9. The method for preparing a low thermal expansion aluminum alloy frame material suitable for photovoltaic modules according to claim 7, characterized in that: In the S2, vacuum hot pressing is performed at 560±5° C. and 35±5 MPa for 30-40 minutes, and then cooled to room temperature.

10. The method for preparing a low thermal expansion aluminum alloy frame material suitable for photovoltaic modules according to claim 9, characterized in that: The hot pressing process is carried out under argon protection, with a heating rate of 10-15°C / min, and after the pressure is maintained, it is cooled to below 200°C at a rate of ≤5°C / min.

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