Aluminum material with super-hydrophobic surface and preparation method and application thereof

Abstract

The present invention discloses an aluminum material with a super-hydrophobic surface, a preparation method thereof, and applications thereof. The aluminum material comprises the following components: 0.52-0.6 wt% Mg, 0.46-0.5 wt% Si, 0.2-0.24 wt% Fe, 0.05-0.1 wt% Cu, 0.05-0.1 wt% Mn, 0.02-0.025 wt% Ti, 0.05-0.1 wt% Zn, and the balance Al; the Mg / Si atomic ratio is 1.25-1.4. The star-shaped tube prepared by the present invention is used in a vaporizer, which can inhibit condensation of water droplets on the star-shaped tube surface, prevent icing during use of the vaporizer, and ensure the heat exchange effect of the vaporizer.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum materials, in particular to an aluminum material with a super-hydrophobic surface and a preparation method and application thereof. Background Art

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

[0003] When aluminum alloy star-shaped tubes prepared by existing methods are used in vaporizers, water vapor in the air is easily adsorbed on the surface of the tubes and condenses into ice under low temperature, covering the surface of the star-shaped tubes, 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 super-hydrophobic surface and a preparation method and application thereof, so as to solve the problems in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an aluminum material with a super-hydrophobic surface, composed of the following components: 0.52-0.6wt% Mg, 0.46-0.5wt% Si, 0.2-0.24wt% Fe, 0.05-0.1wt% Cu, 0.05-0.1wt% Mn, 0.02-0.025wt% Ti, 0.05-0.1wt% Zn, and the balance is Al; the Mg / Si atomic ratio is 1.25-1.4.

[0006] A method for preparing an aluminum material having a super-hydrophobic surface comprises the following steps:

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

[0008] S2: The round bars prepared in S1 are sawn to the specified length and then subjected to a soaking treatment: the temperature is raised to 545°C at a rate of 25°C / h and held for 6 hours, then raised to 560°C at a rate of 10°C / h and held for 3 hours. After the soaking period, the bars are taken out of the furnace and cooled with strong air for 2 hours to below 200°C.

[0009] S3: The round rods after the heat treatment in S2 are peeled and heated to 500℃ before extrusion into star-shaped tubes. The extrusion outlet temperature is 530℃. After the extrusion is completed, strong wind is used to cool the rods to room temperature.

[0010] S4: subjecting the star-shaped tube prepared in S3 to aging treatment: 170°C × 6h;

[0011] S5: The star-shaped tube prepared in S4 is subjected to the first surface treatment: the star-shaped tube is degreased and then polished with a phosphoric acid-sulfuric acid solution, with phosphoric acid / sulfuric acid = 3;

[0012] S6: The star-shaped tube prepared in S5 is subjected to a second surface treatment: the star-shaped tube is phosphated using a Gardobond solution at 50°C for 3-8 minutes; the ratio of 2600TA:H7211:H7101:H7256 in the Gardobond solution is 10:5:2:1;

[0013] S7: The star-shaped tube prepared in S6 is subjected to a third surface treatment: the star-shaped tube is immersed in a 1 wt % stearic acid ethanol solution for surface modification to obtain a surface having a micro-nanoporous composite structure.

[0014] Preferably, before the S6 phosphating treatment, a PL-XG solution with a concentration of 2 g / L is used for surface conditioning treatment, and the pH value is 9.

[0015] Preferably, the free acid content in the S6 solution is controlled to be 1.5-2, the total acid content is 25-30, the accelerator gas point is 2-4, and the free fluorine content is 150-200 ppm.

[0016] Preferably, ultrasonic cleaning is performed using deionized water after the S6 treatment.

[0017] Preferably, the S7 treatment is followed by drying at 100°C.

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

[0019] The invention discloses an application of aluminum material with a super-hydrophobic surface, and the prepared star-shaped tube is used for manufacturing a gasifier.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The prepared aluminum tube is subjected to three surface treatments. The first surface treatment removes the oxide film on the surface of the tube and forms a smooth surface, which is conducive to the subsequent surface treatment to have a clean and smooth surface prerequisite; the second surface treatment forms a micron-sized petal-shaped phosphate film on the surface of the tube through phosphating. The petal-shaped phosphate film has pores of micron and nano mixed sizes, forming a micro-nanopore composite structure on the surface of the star-shaped tube; the third surface treatment modifies the formed phosphate film to reduce the surface energy, make it superhydrophobic, and achieve a surface water droplet contact angle of ≥150°, thereby effectively reducing the condensation and icing of water vapor on the surface during the use of the gasifier.

[0022] 2. By controlling the range of alloying elements in aluminum alloys, controlling the content and ratio of Mg and Si, and combining reasonable heat treatment, the necessary strength and heat transfer effect can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, 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 part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are 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 invention for which protection is sought, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] See also Figure 1 In an embodiment of the present invention, an aluminum material having a super-hydrophobic surface is composed of the following components: 0.52-0.6wt% Mg, 0.46-0.5wt% Si, 0.2-0.24wt% Fe, 0.05-0.1wt% Cu, 0.05-0.1wt% Mn, 0.02-0.025wt% Ti, 0.05-0.1wt% Zn, and the balance is Al; the Mg / Si atomic ratio is 1.25-1.4.

[0027] A method for preparing an aluminum material having a super-hydrophobic surface comprises the following steps:

[0028] S1: melting the aluminum alloy raw materials according to the above ratio and casting them into round bars;

[0029] S2: The round bars prepared in S1 are sawn to the specified length and then subjected to a soaking treatment: the temperature is raised to 545°C at a rate of 25°C / h and held for 6 hours, then raised to 560°C at a rate of 10°C / h and held for 3 hours. After the soaking period, the bars are taken out of the furnace and cooled with strong air for 2 hours to below 200°C.

[0030] S3: The round rods after the heat treatment in S2 are peeled and heated to 500℃ before extrusion into star-shaped tubes. The extrusion outlet temperature is 530℃. After the extrusion is completed, strong wind is used to cool the rods to room temperature.

[0031] S4: subjecting the star-shaped tube prepared in S3 to aging treatment: 170°C × 6h;

[0032] S5: The star-shaped tube prepared in S4 is subjected to the first surface treatment: the star-shaped tube is degreased and then polished with a phosphoric acid-sulfuric acid solution, with phosphoric acid / sulfuric acid = 3;

[0033] S6: The star-shaped tube prepared in S5 is subjected to a second surface treatment: the star-shaped tube is phosphated using a Gardobond solution at 50°C for 3-8 minutes; the ratio of 2600TA:H7211:H7101:H7256 in the Gardobond solution is 10:5:2:1;

[0034] S7: The star-shaped tube prepared in S6 is subjected to a third surface treatment: the star-shaped tube is immersed in a 1 wt % stearic acid ethanol solution for surface modification to obtain a surface having a micro-nanoporous composite structure.

[0035] Preferably, before the S6 phosphating treatment, a PL-XG solution with a concentration of 2 g / L is used for surface conditioning treatment, and the pH value is 9.

[0036] Preferably, the free acid content in the S6 solution is controlled to be 1.5-2, the total acid content is 25-30, the accelerator gas point is 2-4, and the free fluorine content is 150-200 ppm.

[0037] Preferably, ultrasonic cleaning is performed using deionized water after the S6 treatment.

[0038] Preferably, the S7 treatment is followed by drying at 100°C.

[0039] Preferably, the water drop contact angle on the surface of the prepared star-shaped tube is ≥150°.

[0040] The invention discloses an application of aluminum material with a super-hydrophobic surface, and the prepared star-shaped tube is used for manufacturing a gasifier.

[0041] (1) 0.52-0.6 wt% Mg, 0.46-0.5 wt% Si, and Mg / Si atomic ratio of 1.25-1.4

[0042] Mg and Si form the Mg2Si strengthening phase in the alloy, ensuring the required strength during the use of the star tube. A Mg / Si atomic ratio of 1.25-1.4 is conducive to the formation of the β" strengthening phase (β-Mg2Si, a non-equilibrium phase and the main strengthening phase) during aging treatment. Low Mg and Si contents result in fewer strengthening phases, which is detrimental to strength; high Mg and Si contents result in excessive strength and increased processing costs. Improper Mg / Si ratio control is also detrimental to strengthening effects.

[0043] (2) 0.2-0.24wt% Fe

[0044] Aluminum materials inevitably contain Fe. If the Fe content is low, high purity requirements for raw materials are required, which increases costs. If the Fe content is high, coarse compounds are easily formed, which is detrimental to processing performance.

[0045] (3) 0.05-0.1wt% Cu

[0046] An appropriate amount of Cu can promote the density of the phosphate film and facilitate the formation of nanopores. However, a high Cu content is detrimental to corrosion resistance, reduces the service life of the material, and increases cost and processing difficulty.

[0047] (4) 0.05-0.1wt% Mn

[0048] An appropriate amount of Mn is beneficial to combining with Fe, changing the morphology of the Fe-containing phase, and is beneficial to refining the grains and improving the surface smoothness.

[0049] (5) 0.02-0.03wt% Ti

[0050] An appropriate amount of Ti is beneficial to improving the melting and casting of round bars and refining the grains.

[0051] (6) 0.05-0.1wt% Zn

[0052] An appropriate amount of Zn can change the electrochemical potential of the alloy matrix and promote surface treatment.

[0053] The following describes a method for preparing an aluminum material having a super-hydrophobic surface according to the present invention.

[0054] (1) Heat treatment

[0055] The temperature is raised to 545°C at a rate of 25°C / h and held for 6 hours. The temperature is then raised to 560°C at a rate of 10°C / h and held for 3 hours. After the heat is completely held, the cast iron is removed from the furnace and cooled with strong air to below 200°C within 2 hours. Slow heating to 545°C and holding allows the coarse Mg2Si phase formed during casting to fully dissolve back into the matrix, which is beneficial for the aging strengthening effect. The main purpose of controlling the heating rate is to prevent overheating caused by excessive heating. Further slow heating to 560°C and holding allows the Fe-containing phase to fully transform into a granular state, which is beneficial for improving the distribution uniformity and processing performance of the Fe-containing phase and helps to obtain a uniformly distributed microporous structure in subsequent surface treatment.

[0056] (2) Extrusion

[0057] The extrusion process is heated to 500°C and then extruded into a star-shaped tube. The extrusion outlet temperature is set at 530°C, and after extrusion, the tube is cooled to room temperature using strong airflow. The heating temperature is crucial for ensuring proper processing plasticity. The temperature control at the end of extrusion and the cooling method chosen ensure the solid solution of Mg and Si, facilitating aging hardening. Furthermore, air cooling helps prevent deformation of the star-shaped tube fins.

[0058] (3) Aging treatment

[0059] The aging treatment parameters are 170℃×6h, which is conducive to the formation and precipitation of β” strengthening phase, thus achieving the strengthening purpose. If the temperature is too high, the β” phase will grow and transform, reducing the strengthening effect.

[0060] (4) First surface treatment

[0061] By degreasing and polishing, the surface oxide film and micro defects caused by processing are removed, making the surface of the star-shaped tube smoother, which is conducive to subsequent surface treatment and uniform microporous structure.

[0062] (5) Second surface treatment

[0063] Through phosphating treatment, a uniform and dense micron-sized petal-shaped phosphating film is formed on the surface. The petal-shaped phosphating films form a grid structure with pores of mixed micron and nano sizes distributed in between, obtaining the micro-nanopore composite structure necessary for super hydrophobicity.

[0064] (6) Third surface treatment

[0065] The surface of the micro-nano composite structure obtained by phosphating treatment is modified to reduce the surface energy and make the surface have super-hydrophobic properties.

[0066] Example 1

[0067] The aluminum alloy raw materials are melted and cast into round bars according to the proportions in Table 1. The round bars are cut to a fixed length and then subjected to heat treatment: the temperature is raised to 545℃ at a rate of 25℃ / h and kept at this temperature for 6 hours, then raised to 560℃ at a rate of 10℃ / h and kept at this temperature for 3 hours. After the heat preservation is completed, the bars are taken out of the furnace and forced to cool to below 200℃ within 2 hours. After peeling, the round bars are heated to 500℃ for extrusion. The extrusion end temperature is 530℃, and the extruded star-shaped tubes are cooled to room temperature by strong air cooling. The prepared star-shaped tubes are subjected to aging treatment: 170℃×6h, and then air-cooled to room temperature. The star-shaped tubes are cut to a fixed length, degreased, and polished with a phosphoric acid-sulfuric acid solution (phosphoric acid / sulfuric acid volume ratio = 3), and ultrasonically cleaned and dried with deionized water. A second surface treatment was performed: the star-shaped tube was phosphated using a Gardobond solution (2600TA:H7211:H7101:H7256 = 10:5:2:1) at 50°C for 3 minutes. After treatment, the tube was ultrasonically cleaned with deionized water and dried. A third surface treatment was performed: the tube was immersed in a stearic acid-ethanol solution for 4 minutes for surface modification and then dried at 100°C. The treated star-shaped tube was used to manufacture the gasifier.

[0068] Example 2

[0069] The aluminum alloy raw materials are melted and cast into round bars according to the proportions in Table 1. The round bars are cut to a fixed length and then subjected to heat treatment: the temperature is raised to 545℃ at a rate of 25℃ / h and kept at this temperature for 6 hours, then raised to 560℃ at a rate of 10℃ / h and kept at this temperature for 3 hours. After the heat preservation is completed, the bars are taken out of the furnace and forced to cool to below 200℃ within 2 hours. After peeling, the round bars are heated to 500℃ for extrusion. The extrusion end temperature is 530℃, and the extruded star-shaped tubes are cooled to room temperature by strong air cooling. The prepared star-shaped tubes are subjected to aging treatment: 170℃×6h, and then air-cooled to room temperature. The star-shaped tubes are cut to a fixed length, degreased, and polished with a phosphoric acid-sulfuric acid solution (phosphoric acid / sulfuric acid volume ratio = 3), and ultrasonically cleaned and dried with deionized water. A second surface treatment was performed: the star-shaped tube was phosphated using a Gardobond solution (2600TA:H7211:H7101:H7256 = 10:5:2:1) at 50°C for 5 minutes. After treatment, the tube was ultrasonically cleaned with deionized water and dried. A third surface treatment was performed: the tube was immersed in a stearic acid-ethanol solution for 5 minutes to modify its surface, and then dried at 100°C. The treated star-shaped tube was used to manufacture the gasifier.

[0070] Example 3

[0071] The aluminum alloy raw materials are melted and cast into round bars according to the proportions in Table 1. The round bars are cut to a fixed length and then subjected to heat treatment: the temperature is raised to 545℃ at a rate of 25℃ / h and kept at this temperature for 6 hours, then raised to 560℃ at a rate of 10℃ / h and kept at this temperature for 3 hours. After the heat preservation is completed, the bars are taken out of the furnace and forced to cool to below 200℃ within 2 hours. After peeling, the round bars are heated to 500℃ for extrusion. The extrusion end temperature is 530℃, and the extruded star-shaped tubes are cooled to room temperature by strong air cooling. The prepared star-shaped tubes are subjected to aging treatment: 170℃×6h, and then air-cooled to room temperature. The star-shaped tubes are cut to a fixed length, degreased, and polished with a phosphoric acid-sulfuric acid solution (phosphoric acid / sulfuric acid volume ratio = 3), and ultrasonically cleaned and dried with deionized water. A second surface treatment was performed: the star-shaped tube was phosphated using a Gardobond solution (2600TA:H7211:H7101:H7256 = 10:5:2:1) at 50°C for 6 minutes. After treatment, the tube was ultrasonically cleaned with deionized water and dried. A third surface treatment was performed: the tube was immersed in a stearic acid-ethanol solution for 5 minutes to modify its surface, and then dried at 100°C. The treated star-shaped tube was used to manufacture the gasifier.

[0072] Example 4

[0073] The aluminum alloy raw materials are melted and cast into round bars according to the proportions in Table 1. The round bars are cut to a fixed length and then subjected to heat treatment: the temperature is raised to 545℃ at a rate of 25℃ / h and kept at this temperature for 6 hours, then raised to 560℃ at a rate of 10℃ / h and kept at this temperature for 3 hours. After the heat preservation is completed, the bars are taken out of the furnace and forced to cool to below 200℃ within 2 hours. After peeling, the round bars are heated to 500℃ for extrusion. The extrusion end temperature is 530℃, and the extruded star-shaped tubes are cooled to room temperature by strong air cooling. The prepared star-shaped tubes are subjected to aging treatment: 170℃×6h, and then air-cooled to room temperature. The star-shaped tubes are cut to a fixed length, degreased, and polished with a phosphoric acid-sulfuric acid solution (phosphoric acid / sulfuric acid volume ratio = 3), and ultrasonically cleaned and dried with deionized water. A second surface treatment was performed: the star-shaped tube was phosphated using a Gardobond solution (2600TA:H7211:H7101:H7256 = 10:5:2:1) at 50°C for 8 minutes. After treatment, the tube was ultrasonically cleaned with deionized water and dried. A third surface treatment was performed: the tube was immersed in a stearic acid-ethanol solution for 6 minutes for surface modification and then dried at 100°C. The treated star-shaped tube was used to manufacture the gasifier.

[0074] Table 1

[0075]

[0076] The above preparation method can be used to prepare a star-shaped tube with a micro-nanopore composite structure distributed on the surface. The water droplet contact angle on the tube surface is ≥150°. When used to manufacture a vaporizer, it can inhibit the condensation of water vapor on the star-shaped tube surface, prevent icing during the use of the vaporizer, and ensure the heat exchange effect of the vaporizer.

[0077] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An aluminum material having a super-hydrophobic surface, characterized in that: It is composed of the following components: 0.52-0.6wt% Mg, 0.46-0.5wt% Si, 0.2-0.24wt% Fe, 0.05-0.1wt% Cu, 0.05-0.1wt% Mn, 0.02-0.025wt% Ti, 0.05-0.1wt% Zn, and the balance is Al; the Mg / Si atomic ratio is 1.25-1.4; The method for preparing the aluminum material having a super-hydrophobic surface comprises the following steps: S1: melting the aluminum alloy raw materials according to the above ratio and casting them into round bars; S2: The round bars prepared in S1 are sawn to the specified length and then subjected to a soaking treatment: the temperature is raised to 545°C at a rate of 25°C / h and held for 6 hours, then raised to 560°C at a rate of 10°C / h and held for 3 hours. After the soaking period, the bars are taken out of the furnace and cooled with strong air to below 200°C within 2 hours. S3: After the round rods have been soaked in S2, they are peeled and heated to 500°C for extrusion into star-shaped tubes. The extrusion outlet temperature is 530°C. After extrusion, they are cooled to room temperature using strong air. S4: subjecting the star-shaped tube prepared in S3 to aging treatment: 170°C × 6h; S5: The star-shaped tube prepared in S4 is subjected to the first surface treatment: the star-shaped tube is degreased and then polished with a phosphoric acid-sulfuric acid solution, with phosphoric acid / sulfuric acid = 3; S6: The star-shaped tube prepared in S5 is subjected to a second surface treatment: the star-shaped tube is phosphated using a Gardobond solution at 50°C for 3-8 minutes; the ratio of 2600TA:H7211:H7101:H7256 in the Gardobond solution is 10:5:2:1; S7: The star-shaped tube prepared in S6 is subjected to a third surface treatment: the star-shaped tube is immersed in a 1 wt% stearic acid ethanol solution for surface modification to obtain a surface with a micro-nanoporous composite structure; Before phosphating treatment, S6 was treated with PL-XG solution at a concentration of 2 g / L and a pH value of 9; In S6 solution, free acid is controlled at 1.5-2, total acid at 25-30, accelerator gas point at 2-4, and free fluorine at 150-200 ppm; After S6 treatment, ultrasonic cleaning was performed using deionized water; After S7 treatment, it was dried at 100°C; The water drop contact angle on the surface of the prepared star-shaped tube is ≥150°.

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