An aluminum material with hydrophobic anti-icing function, its preparation method and application

Abstract

The present invention discloses an aluminum material with hydrophobic anti-icing function, its preparation method and application, which consists of the following components: 0.45 - 0.51 wt% Mg, 0.4 - 0.45 wt% Si, 0.25 - 0.3 wt% Fe, 0.11 - 0.15 wt% Cu, 0.08 - 0.16 wt% Mn, 0.02 - 0.03 wt% Ti, 0.25 - 0.3 wt% RE, with the balance being Al, and the mass ratio of Mg / Si being 1 - 1.24. In the present invention, when this star-shaped tube is used for the vaporizer, it can effectively cause the water vapor in the air to condense into water droplets on the surface of the star-shaped tube during the use of the vaporizer and leave the surface under the action of gravity without adsorbing and icing, ensuring the heat exchange effect of the vaporizer.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum materials, and specifically relates to an aluminum material with a hydrophobic and anti-icing function, a preparation method thereof, and an application thereof. Background Art

[0002] Aluminum alloys have a low density, high strength, excellent formability and corrosion resistance, as well as weldability and good heat dissipation performance, and are widely used in the manufacture of heat exchangers and other fields, including vaporizers.

[0003] When the aluminum alloy star-shaped tube prepared by the existing method is used in a vaporizer, water vapor in the air is easily adsorbed on the surface of the pipe and condenses into ice under the action of low temperature, covering the surface of the star-shaped tube, resulting in a serious reduction in the heat exchange efficiency of the vaporizer and requiring frequent manual de-icing. Summary of the Invention

[0004] The purpose of the present invention is to provide an aluminum material with a hydrophobic and anti-icing function, a preparation method thereof, and an application thereof to solve the problems in the prior art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions: An aluminum material with a hydrophobic and anti-icing function is composed of the following components: 0.45-0.51 wt% Mg, 0.4-0.45 wt% Si, 0.25-0.3 wt% Fe, 0.11-0.15 wt% Cu, 0.08-0.16 wt% Mn, 0.02-0.03 wt% Ti, 0.25-0.3 wt% RE, and the balance is Al, and the mass ratio of Mg / Si is 1-1.24.

[0006] A preparation method of an aluminum material with a hydrophobic and anti-icing function includes the following steps:

[0007] S1: Melting and casting the aluminum alloy raw materials according to the above ratio into round bars;

[0008] S2: After sizing and sawing the round bars prepared in S1, perform homogenization heat treatment;

[0009] S3: Extrude the round bars after homogenization heat treatment in S2 into star-shaped tubes;

[0010] S4: Perform aging treatment on the star-shaped tubes prepared in S3;

[0011] S5: Perform the first surface treatment on the star-shaped tubes prepared in S4: Polish the star-shaped tubes;

[0012] S6: Perform the second surface treatment on the star-shaped tubes prepared in S5: Place the star-shaped tubes in an electrolyte for treatment. The electrolyte is a 2-10% NaCl and KCl mixed solution, the mixing ratio NaCl / KCl ≥ 2, and the voltage is 3-10 V; Immediately ultrasonically clean with deionized water after the treatment ends;

[0013] S7: Perform the third surface treatment on the star-shaped tube prepared in S6: Immerse the star-shaped tube in the electrolyte for anodic oxidation treatment. The electrolyte is a 6-10% oxalic acid solution, and the voltage is 40-60V; after anodic oxidation, clean and dry.

[0014] Preferably, the heat treatment parameters in S2 are: heat up to 550°C at a heating rate of 20-50°C / h and hold for 4h, then heat up to 570°C at a rate of 10-20°C / h and hold for 2h. After the heat preservation is completed, take it out of the furnace and air-cool to room temperature.

[0015] Preferably, in S3, before extrusion, the round bar is peeled and then heated to 450-500°C for extrusion. The extrusion outlet temperature is 500-550°C, and after extrusion, it is air-cooled to room temperature.

[0016] Preferably, the aging treatment parameters in S4 are 160-190°C × 4-8h.

[0017] Preferably, the drying parameters in S7 are 100-160°C × 0.5-2h.

[0018] Preferably, the water droplet contact angle on the surface of the prepared star-shaped tube is ≥150°.

[0019] An application of an aluminum material with hydrophobic and anti-icing functions. The prepared star-shaped tube is used to manufacture a vaporizer.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. Perform three surface treatments on the prepared aluminum pipe. The first surface treatment removes the oxide film on the pipe surface and forms a smooth surface, which is beneficial for subsequent surface treatments to have a clean and smooth surface prerequisite; the second surface treatment uses anodic oxidation to form an oxide film with a nano-sized microporous structure on the surface. The Cl- ions react with the oxide film under the action of an electric field, and combined with the electrochemical reaction of the compound and the substrate, micro-etching holes with a micro-nano composite structure are formed on the material surface; the third surface treatment promotes the growth of the number of microporous structures in the surface micro-nano composite structure and is evenly distributed on the pipe surface; through three surface treatments, the star-shaped tube surface has a characteristic of relatively evenly distributed microporous structures, and the water droplet contact angle on the pipe surface is ≥150°, achieving the effect of effectively reducing the surface water vapor condensation and icing phenomena during the use of the vaporizer.

[0022] 2. For the range of each alloying element in the aluminum alloy, control the content and ratio of Mg and Si, and reasonable strength can be obtained after heat treatment to ensure the necessary use strength; adding RE elements to regulate the size and distribution of Fe-containing compounds is beneficial to improving the uniformity of micropore distribution.

[0023] 3. The design of the soaking process can ensure that the Fe-containing phase transforms from thick strip and flake shapes into fine particulate shapes, and promote the re-dissolution of the thick Mg2Si phase formed during casting into the matrix, which is beneficial to ensuring the product performance and the uniformity of the microporous structure during surface treatment; through the optimized design of the drying parameters, while ensuring the drying of the material, it can further promote the precipitation of the strengthening phase, which is beneficial to improving the thermal conductivity of the alloy and contributing to the heat exchange efficiency of the vaporizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings are used to provide a further understanding of the present invention and form a part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation to the present invention. In the drawings:

[0025] Figure 1 is a flowchart of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0027] Please refer to Figure 1 , in an embodiment of the present invention, an aluminum material with hydrophobic and anti-icing functions is composed of the following components: 0.45 - 0.51 wt% Mg, 0.4 - 0.45 wt% Si, 0.25 - 0.3 wt% Fe, 0.11 - 0.15 wt% Cu, 0.08 - 0.16 wt% Mn, 0.02 - 0.03 wt% Ti, 0.25 - 0.3 wt% RE, with the balance being Al, and the Mg / Si mass ratio being 1 - 1.24.

[0028] A preparation method for an aluminum material with hydrophobic and anti-icing functions includes the following steps:

[0029] S1: Melting and casting the aluminum alloy raw materials into round bars according to the above proportions;

[0030] S2: After sizing and sawing the round bars prepared in S1, perform a soaking heat treatment;

[0031] S3: Extrude the round bar after homogenization heat treatment in S2 into a star-shaped tube;

[0032] S4: Perform aging treatment on the star-shaped tube prepared in S3;

[0033] S5: Perform the first surface treatment on the star-shaped tube prepared in S4: Polish the star-shaped tube;

[0034] S6: Perform the second surface treatment on the star-shaped tube prepared in S5: Immerse the star-shaped tube in an electrolyte for treatment. The electrolyte is a mixed solution of 2 - 10% NaCl and KCl, the mixing ratio NaCl / KCl ≥ 2, and the voltage is 3 - 10V; Immediately ultrasonically clean with deionized water after the treatment ends;

[0035] S7: Perform the third surface treatment on the star-shaped tube prepared in S6: Perform anodic oxidation treatment on the star-shaped tube in an electrolyte. The electrolyte is a 6 - 10% oxalic acid solution, and the voltage is 40 - 60V; Clean and dry after anodic oxidation.

[0036] Preferably, the parameters of the homogenization heat treatment in S2 are: Heat up to 550°C at a heating rate of 20 - 50°C / h and hold for 4h, then heat up to 570°C at a heating rate of 10 - 20°C / h and hold for 2h. After the holding ends, take it out of the furnace and air-cool to room temperature.

[0037] Preferably, in S3, before extrusion, the round bar is peeled and then heated to 450 - 500°C for extrusion. The extrusion outlet temperature is 500 - 550°C, and after extrusion, it is air-cooled to room temperature.

[0038] Preferably, the parameters of the aging treatment in S4 are 160 - 190°C × 4 - 8h.

[0039] Preferably, the drying parameters in S7 are 100 - 160°C × 0.5 - 2h.

[0040] Preferably, the water droplet contact angle on the surface of the prepared star-shaped tube is ≥ 150°.

[0041] An application of an aluminum material with hydrophobic and anti-icing functions. The prepared star-shaped tube is used to manufacture a vaporizer.

[0042] Specifically:

[0043] The prepared aluminum alloy is composed of elements such as Mg, Si, Fe, Cu, Mn, Ti, RE, etc. within a specific content range, and the balance is composed of Al and unavoidable impurities. By optimizing the combination of each element, the strength of the material can be achieved to meet the surface treatment requirements and usage requirements.

[0044] (1) 0.45 - 0.51wt% Mg, 0.4 - 0.45wt% Si, and the mass ratio of Mg / Si is 1 - 1.24;

[0045] Mg and Si can form the strengthening phase Mg2Si in the alloy to ensure the strength requirement during the use of the star tube. A Mg / Si mass ratio of 1 - 1.24 is more conducive to the formation of the β” strengthening phase (the non-equilibrium phase of β-Mg2Si, which is the main strengthening phase morphology) during aging treatment. If the contents of Mg and Si are low, fewer strengthening phases are formed, which is not conducive to strength; if the contents are high, the strength is excessive, and the processing cost increases; an unreasonable control of the Mg / Si ratio is not conducive to the strengthening effect.

[0046] (2) 0.25 - 0.3 wt% Fe

[0047] Fe element is inevitably contained in the aluminum material. If the content control is low, the requirement for the purity of raw materials is high, resulting in an increase in cost; if the content is high, it is easy to form coarse compounds, which is not conducive to the processing performance.

[0048] (3) 0.11 - 0.15 wt% Cu

[0049] An appropriate amount of Cu can promote the uniformity of corrosion and improve the strength to a certain extent. If the Cu content is high, it is not conducive to the corrosion resistance, reducing the service life of the material; and it also increases the cost and the difficulty of processing.

[0050] (4) 0.08 - 0.16 wt% Mn

[0051] An appropriate amount of Mn is beneficial to combine with Fe, change the morphology of the Fe-containing phase, and is conducive to refining the grains.

[0052] (5) 0.02 - 0.03 wt% Ti

[0053] An appropriate amount of Ti is beneficial to improving the melting and casting of the round bar and refining the grains.

[0054] (6) 0.25 - 0.3 wt% RE

[0055] An appropriate amount of RE can change the morphology and distribution uniformity of the Fe-containing phase, which is beneficial to improving the uniformity of micropores in the subsequent surface treatment. If the content is low, the effect is limited; if the content is high, it is easy to form coarse RE-containing phases, which is instead not conducive to the processing performance.

[0056] The preparation method of the aluminum material for the vaporizer with hydrophobic and anti-icing functions described in the present invention will be described below.

[0057] (1) Homogenization heat treatment

[0058] Heat at a rate of 20 - 50 °C / h to 550 °C and hold for 4 h, then heat at a rate of 10 - 20 °C / h to 570 °C and hold for 2 h. After the holding is completed, take it out of the furnace and air-cool to room temperature. Heating to 550 °C and holding can make the coarsened Mg2Si phase formed during casting dissolve back into the matrix, which is beneficial to the age hardening effect. Controlling the heating rate mainly prevents overburning due to too fast heating. Further heating to 570 °C and holding is beneficial to transform the Fe-containing phase from thick flakes and laths into granular shape, which is beneficial to improving the distribution uniformity and workability of the Fe-containing phase, and helps to obtain a uniformly distributed microporous structure in subsequent surface treatment.

[0059] (2) Extrusion

[0060] The heating temperature is 450 - 500 °C, the extrusion end temperature is 500 - 550 °C, and air cooling is used after extrusion. The heating temperature mainly ensures appropriate processing plasticity. Controlling the extrusion end temperature and selecting the cooling method can ensure the solid solution of Mg and Si, which is beneficial to age hardening; at the same time, using air cooling is beneficial to preventing the deformation of the star-shaped tube fins.

[0061] (3) Ageing treatment

[0062] The ageing treatment parameters are 160 - 190 °C × 4 - 8 h, which is beneficial to the formation and precipitation of β” strengthening phase to achieve the strengthening purpose. If the temperature is too high, the β” phase will grow and transform, reducing the strengthening effect.

[0063] (4) First surface treatment

[0064] By polishing, remove the surface oxide film and micro-defects brought by processing, make the surface of the star-shaped tube smoother, which is beneficial to subsequent surface treatment and the uniformity of the microporous structure.

[0065] (5) Second surface treatment

[0066] Use anodic oxidation to form an oxide film with a nano-sized microporous structure on the surface. Cl- ions react with the oxide film under the action of an electric field, and combined with the electrochemical reaction of the compound and the matrix, micro-etching holes with a micro-nano composite structure are formed on the material surface.

[0067] (6) Third surface treatment

[0068] Through anodic oxidation, the number of micropores in the surface micro-nano composite structure is further increased, and a microporous structure feature with a uniformly distributed microporous structure is finally formed on the surface of the pipe.

[0069] (7) Drying

[0070] After surface treatment, dry at 100 - 160 °C × 0.5 - 2 h. In addition to removing the moisture in the micropores, it can also further promote the precipitation of β”, which is beneficial to the alloy strength and thermal conductivity.

[0071] Example 1

[0072] The aluminum alloy raw materials are melted and cast into round bars according to the ratio in Table 1. After the round bars are cut to a fixed length, homogenization heat treatment is carried out: heating up to 550 °C at a heating rate of 20 °C / h and holding for 4 h, then heating up to 570 °C at a heating rate of 20 °C / h and holding for 2 h. After the heat preservation is completed, the furnace is taken out and air-cooled to room temperature. The round bars are peeled and then heated to 450 °C for extrusion. The extrusion end temperature is 500 °C, and the extruded star-shaped pipes are cooled to room temperature by air cooling. The prepared star-shaped pipes are subjected to aging treatment: 160 °C × 8 h, and after treatment, they are air-cooled to room temperature. The star-shaped pipes are cut to a fixed length and then subjected to chemical polishing treatment; after cleaning and drying, a second surface treatment is carried out: the star-shaped pipes are put into an electrolytic cell, and the electrolyte is a 2% NaCl and KCl mixed solution (mixing ratio NaCl / KCl = 2), the voltage is 10 V, and after the treatment is completed, ultrasonic cleaning is carried out with deionized water. A third surface treatment is carried out: the star-shaped pipes are put into the electrolytic cell for anodic oxidation treatment, the electrolyte is a 10% oxalic acid solution, and the voltage is 40 V; after anodic oxidation, they are cleaned and dried at 100 °C for 2 h. The treated star-shaped pipes are used to manufacture gasifiers.

[0073] Example 2

[0074] The aluminum alloy raw materials are melted and cast into round bars according to the ratio in Table 1. After the round bars are cut to a fixed length, homogenization heat treatment is carried out: heating up to 550 °C at a heating rate of 50 °C / h and holding for 4 h, then heating up to 570 °C at a heating rate of 10 °C / h and holding for 2 h. After the heat preservation is completed, the furnace is taken out and air-cooled to room temperature. The round bars are peeled and then heated to 500 °C for extrusion. The extrusion end temperature is 550 °C, and the extruded star-shaped pipes are cooled to room temperature by air cooling. The prepared star-shaped pipes are subjected to aging treatment: 190 °C × 4 h, and after treatment, they are air-cooled to room temperature. The star-shaped pipes are cut to a fixed length and then subjected to chemical polishing treatment; after cleaning and drying, a second surface treatment is carried out: the star-shaped pipes are put into an electrolytic cell, and the electrolyte is a 10% NaCl and KCl mixed solution (mixing ratio NaCl / KCl = 4), the voltage is 3 V, and after the treatment is completed, ultrasonic cleaning is carried out with deionized water. A third surface treatment is carried out: the star-shaped pipes are put into the electrolytic cell for anodic oxidation treatment, the electrolyte is a 6% oxalic acid solution, and the voltage is 60 V; after anodic oxidation, they are cleaned and dried at 160 °C for 0.5 h. The treated star-shaped pipes are used to manufacture gasifiers.

[0075] Example 3

[0076] The aluminum alloy raw materials are melted and cast into round bars according to the ratio in Table 1. After the round bars are cut to a fixed length, they are subjected to homogenization heat treatment: heated to 550°C at a heating rate of 30°C / h and held for 4 h, then heated to 570°C at a heating rate of 15°C / h and held for 2 h. After the heat preservation is completed, they are taken out of the furnace and air-cooled to room temperature. After the round bars are peeled, they are heated to 480°C for extrusion, and the extrusion end temperature is 530°C. The extruded star-shaped pipe is cooled to room temperature by air cooling. The prepared star-shaped pipe is subjected to aging treatment: 175°C × 6 h, and then air-cooled to room temperature after treatment. After the star-shaped pipe is cut to a fixed length, it is subjected to chemical polishing treatment; after cleaning and drying, it is subjected to a second surface treatment: the star-shaped pipe is placed in an electrolytic cell, and the electrolyte is an 8% NaCl and KCl mixed solution (mixing ratio NaCl / KCl = 2), with a voltage of 6 V. After the treatment is completed, it is ultrasonically cleaned with deionized water. Then, a third surface treatment is carried out: the star-shaped pipe is put into the electrolytic cell for anodic oxidation treatment, and the electrolyte is an 8% oxalic acid solution, with a voltage of 50 V; after anodic oxidation, it is cleaned and dried at 130°C for 1 h. The treated star-shaped pipe is used to manufacture a vaporizer.

[0077] Table 1

[0078]

[0079] Through the above preparation method, a star-shaped pipe with a micro-nano composite structure distributed on the surface can be prepared. The water droplet contact angle on the surface of the pipe is ≥150°. When used to manufacture a vaporizer, it can effectively cause the water vapor in the air to condense into water droplets on the surface of the star-shaped pipe under the action of gravity and leave the surface without adsorption and icing during the use of the vaporizer, ensuring the heat exchange effect of the vaporizer.

[0080] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An aluminum material with hydrophobic anti-icing function, characterized in that: It consists of the following components: 0.46 wt% Mg, 0.4 wt% Si, 0.3 wt% Fe, 0.12 wt% Cu, 0.16 wt% Mn, 0.03 wt% Ti, 0.3 wt% RE, with the balance being Al, and the mass ratio of Mg / Si being 1.15; The preparation method of the aluminum material with hydrophobic anti-icing function includes the following steps: S1: Melting and casting the aluminum alloy raw materials into round bars according to the above ratio; S2: After sizing and sawing the round bars prepared in S1, perform homogenization heat treatment; S3: Extrude the round bars after homogenization heat treatment in S2 into star-shaped tubes; S4: Perform aging treatment on the star-shaped tubes prepared in S3; S5: Perform the first surface treatment on the star-shaped tubes prepared in S4: Polish the star-shaped tubes; S6: Perform the second surface treatment on the star-shaped tubes prepared in S5: Immerse the star-shaped tubes in the electrolyte for treatment. The electrolyte is an 8% NaCl and KCl mixed solution, with the mixing ratio of NaCl / KCl = 2 and the voltage of 6V; Immediately perform ultrasonic cleaning with deionized water after the treatment ends; S7: Perform the third surface treatment on the star-shaped tubes prepared in S6: Perform anodic oxidation treatment on the star-shaped tubes in the electrolyte. The electrolyte is an 8% oxalic acid solution and the voltage is 50V; Clean and dry after anodic oxidation; The homogenization heat treatment parameters in S2 are: Raise the temperature to 550 °C at a heating rate of 30 °C / h and hold for 4 h, then raise the temperature to 570 °C at a heating rate of 15 °C / h and hold for 2 h. After the holding ends, take it out of the furnace and air-cool to room temperature; In S3, before extrusion, the round bars are peeled and heated to 480 °C for extrusion. The extrusion outlet temperature is 530 °C, and after extrusion, it is air-cooled to room temperature; The aging treatment parameters in S4 are 160 - 190 °C × 4 - 8 h; The drying parameters in S7 are 100 - 160 °C × 0.5 - 2 h; The water droplet contact angle on the surface of the prepared star-shaped tube = 151°.

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