Preparation process of corrosion-resistant coating for aluminum alloy

Abstract

The invention discloses a preparation process of a corrosion-resistant coating for aluminum alloy. The invention relates to a method comprising the following steps; the preparation method comprises the following steps: S1, preparing the following raw materials in parts by weight: 50 parts of methyl phenyl silicone resin, 47-100 parts of a solvent, 1-4 parts of an anti-settling agent, 1-5 parts of a defoaming agent, 10-18 parts of a flatting agent, 5-10 parts of a corrosion-resistant filler and 20-49 parts of a reinforcing agent; s2, grinding methyl phenyl silicone resin, mixing the ground methyl phenyl silicone resin with a solvent, and stirring at a rotating speed of 900-1200r / min for 2-3h to obtain a resin solution; s3, sequentially adding an anti-settling agent, a defoaming agent, a flatting agent, a corrosion-resistant filler and a reinforcing agent into the resin solution, and stirring at the rotating speed of 1000-1200r / min for 3-4 hours to obtain a mixed solution; s4, performing ultrasonic dispersion on the mixed solution, discharging, standing for 2-4 hours, filtering to obtain a corrosion-resistant coating raw material for the aluminum alloy, then drying, and adding a binder; and S5, the corrosion-resistant coating raw material for the aluminum alloy is sprayed on the surface of the aluminum alloy. The coating is uniformly sprayed on the surface of the aluminum alloy through physical or chemical reaction of the coating to form an attractive and flat coating with good corrosion resistance.

Description

Technical Field

[0001] The invention relates to the technical field of metal material processing, and in particular to a preparation process of a corrosion-resistant coating for aluminum alloy. Background Art

[0002] Aluminum alloy is a light metal material made of aluminum as the base material and by adding other alloying elements. It has the characteristics of low density, good mechanical properties, good processing performance, non-toxicity, easy recycling, excellent electrical conductivity, heat transfer and corrosion resistance. The strength of aluminum alloy can be adjusted by adding different alloying elements. Common alloying elements include copper, magnesium, zinc and silicon. Aluminum alloy has a wide range of applications in industry, especially in aviation, aerospace, automobile, machinery manufacturing, shipbuilding and chemical industries. For example, aluminum alloy is the main material for manufacturing aircraft. Because of its low density, high strength and corrosion resistance, it has become an ideal material for aircraft manufacturing. In addition, aluminum alloy is also used to manufacture structural components of automobiles, ships and other means of transportation.

[0003] ‌Aluminum alloys are easily affected by humidity, oxygen, water vapor and other factors in the natural environment, which leads to the formation of oxide films on the surface, thus causing corrosion. This corrosion will lead to the decline of the mechanical properties of aluminum alloys, damage to the appearance quality, and even affect its service life‌.

[0004] It is hoped to provide a process for preparing a corrosion-resistant coating for aluminum alloys that can solve the above-mentioned technical problems.

[0005] SUMMARY OF THE INVENTION The purpose of the present invention is to provide a preparation process of a corrosion-resistant coating for aluminum alloy, wherein the coating is evenly sprayed on the surface of the aluminum alloy through a physical or chemical reaction of the coating to form a beautiful, smooth, and corrosion-resistant coating.

[0006] A process for preparing a corrosion-resistant coating for aluminum alloy comprises the following steps: S1. Raw material ratio: the following raw materials by weight: 50 parts of methyl phenyl silicone resin, 47-100 parts of solvent, 1-4 parts of anti-settling agent, 1-5 parts of defoaming agent, 10-18 parts of leveling agent, 5-10 parts of corrosion-resistant filler and 20-49 parts of reinforcing agent; S2, grinding the methylphenyl silicone resin and mixing it with a solvent, stirring at a speed of 900-1200 r / min for 2-3 hours to obtain a resin solution; S3, adding an anti-settling agent, a defoaming agent, a leveling agent, a corrosion-resistant filler and a reinforcing agent to the resin solution obtained in step S1 in sequence, and stirring at a speed of 1000-1200 r / min for 3-4 hours to obtain a mixed solution; S4, ultrasonically dispersing the mixed solution obtained in step S3, letting the material stand for 2-4 hours, filtering to obtain the raw material for corrosion-resistant coating for aluminum alloy, and then drying and adding a binder; S5, spraying the corrosion-resistant coating raw material for the aluminum alloy prepared in step S4 onto the surface of the aluminum alloy.

[0007] Specifically, in step S1, the reinforcing agent is any one of a phosphorus-based fire retardant coating reinforcing agent, a nitrogen-based fire retardant coating reinforcing agent, and a silicon-based fire retardant coating reinforcing agent.

[0008] Specifically, in step S1, the solvent is anhydrous ethanol.

[0009] Preferably, in step S5, an electrostatic spraying process is used to spray the corrosion-resistant coating raw material for aluminum alloy onto the surface of the aluminum alloy.

[0010] Specifically, the electrostatic spraying process: the aluminum alloy to be sprayed is first surface cleaned, and then the aluminum alloy that has completed the surface cleaning is heated to 60~80℃ by a high-frequency induction coil and enters the powder spraying workshop. The powder supply pressure is 0.07~0.09MPa, the spraying voltage is 70~80kV, the powder spraying amount is 160~190g / min, and the spraying distance is 100~250mm.

[0011] The preparation process of a corrosion-resistant coating for aluminum alloy of the present invention has the following advantages compared with the prior art: (1) The coating performance, as well as mechanical properties such as hardness, elastic modulus, and bonding strength of the coating are comprehensively improved, significantly increasing the service life of the coating on the surface of aluminum alloy materials; (2) The prepared coating has good corrosion resistance and can maintain good performance under the joint action of various raw materials, so it can effectively protect outdoor materials, with good protective effect and long service life. It does not need to frequently repaint, which is more convenient and effectively reduces costs. DETAILED DESCRIPTION

[0012] The technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only 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 creative work are within the scope of protection of the present invention. Specific embodiment one: A process for preparing a corrosion-resistant coating for aluminum alloy comprises the following steps: S1, raw material ratio, the following raw materials by weight: 50 parts of methyl phenyl silicone resin, 47 parts of solvent, 3 parts of anti-settling agent, 2 parts of defoaming agent, 10 parts of leveling agent, 7 parts of corrosion-resistant filler and 25 parts of reinforcing agent; S2, grinding the methylphenyl silicone resin and mixing it with a solvent, stirring at a speed of 950 r / min for 2.5 h to obtain a resin solution; S3, adding an anti-settling agent, a defoaming agent, a leveling agent, a corrosion-resistant filler and a reinforcing agent to the resin solution obtained in step S1 in sequence, and stirring at a speed of 1100 r / min for 3 hours to obtain a mixed solution; S4, ultrasonically dispersing the mixed solution obtained in step S3, letting the material stand for 2 hours, filtering to obtain the raw material for corrosion-resistant coating for aluminum alloy, and then drying and adding a binder; S5, spraying the corrosion-resistant coating raw material for the aluminum alloy prepared in step S4 onto the surface of the aluminum alloy.

[0014] In this embodiment, in step S1, the reinforcing agent is a phosphorus-based fire retardant coating reinforcing agent.

[0015] In this embodiment, in step S1, the solvent is anhydrous ethanol.

[0016] In this embodiment, in step S5, an electrostatic spraying process is used to spray the corrosion-resistant coating raw material for aluminum alloy on the surface of the aluminum alloy. Electrostatic spraying process: The aluminum alloy to be sprayed is firstly subjected to surface cleaning treatment, and the aluminum alloy after surface cleaning treatment is heated to 60° C. by a frequency induction coil and then enters a powder spraying workshop, with a powder supply pressure of 0.07 MPa, a spraying voltage of 70 kV, a powder spraying amount of 160 g / min, and a spraying distance of 100 mm. Specific embodiment 2: A process for preparing a corrosion-resistant coating for aluminum alloy comprises the following steps: S1, raw material ratio, the following raw materials by weight: 50 parts of methyl phenyl silicone resin, 70 parts of solvent, 3 parts of anti-settling agent, 2 parts of defoaming agent, 18 parts of leveling agent, 7 parts of corrosion-resistant filler and 30 parts of reinforcing agent; S2, grinding the methylphenyl silicone resin and mixing it with a solvent, stirring at a speed of 950 r / min for 3 hours to obtain a resin solution; S3, adding an anti-settling agent, a defoaming agent, a leveling agent, a corrosion-resistant filler and a reinforcing agent to the resin solution obtained in step S1 in sequence, and stirring at a speed of 1000 r / min for 4 hours to obtain a mixed solution; S4, ultrasonically dispersing the mixed solution obtained in step S3, letting the material stand for 4 hours, filtering to obtain the raw material for corrosion-resistant coating for aluminum alloy, and then drying and adding a binder; S5, spraying the corrosion-resistant coating raw material for the aluminum alloy prepared in step S4 onto the surface of the aluminum alloy.

[0018] In this embodiment, in step S1, the reinforcing agent is a nitrogen-based fire retardant coating reinforcing agent.

[0019] In this embodiment, in step S1, the solvent is anhydrous ethanol.

[0020] In this embodiment, in step S5, an electrostatic spraying process is used to spray the corrosion-resistant coating raw material for aluminum alloy onto the surface of the aluminum alloy.

[0021] In this embodiment, the electrostatic spraying process: the aluminum alloy to be sprayed is first surface cleaned, and the aluminum alloy that has completed the surface cleaning is heated to 60~80℃ by a high-frequency induction coil and then enters the powder spraying workshop. The powder supply pressure is 0.08MPa, the spraying voltage is 75kV, the powder spraying amount is 170g / min, and the spraying distance is 150mm. Specific embodiment three: A process for preparing a corrosion-resistant coating for aluminum alloy comprises the following steps: S1, raw material ratio, the following raw materials by weight: 50 parts of methyl phenyl silicone resin, 80 parts of solvent, 2 parts of anti-settling agent, 3 parts of defoaming agent, 17 parts of leveling agent, 6 parts of corrosion-resistant filler and 30 parts of reinforcing agent; S2, grinding the methylphenyl silicone resin and mixing it with a solvent, stirring at a speed of 1200 r / min for 2 h to obtain a resin solution; S3, adding an anti-settling agent, a defoaming agent, a leveling agent, a corrosion-resistant filler and a reinforcing agent to the resin solution obtained in step S1 in sequence, and stirring at a speed of 1200 r / min for 3 hours to obtain a mixed solution; S4, ultrasonically dispersing the mixed solution obtained in step S3, letting the material stand for 4 hours, filtering to obtain the raw material for corrosion-resistant coating for aluminum alloy, and then drying and adding a binder; S5, spraying the corrosion-resistant coating raw material for the aluminum alloy prepared in step S4 onto the surface of the aluminum alloy.

[0023] In this embodiment, in step S1, the reinforcing agent is a silicon-based fire retardant coating reinforcing agent.

[0024] In this embodiment, in step S1, the solvent is anhydrous ethanol.

[0025] In this embodiment, in step S5, an electrostatic spraying process is used to spray the corrosion-resistant coating raw material for aluminum alloy on the surface of the aluminum alloy. Specifically, the electrostatic spraying process: firstly, the surface of the aluminum alloy to be sprayed is cleaned, and the aluminum alloy after the surface cleaning is heated to 80° C. by a frequency induction coil and then enters the powder spraying workshop, the powder supply pressure is 0.09MPa, the spraying voltage is 80kV, the powder spraying amount is 190g / min, and the spraying distance is 250mm. Specific embodiment four: A process for preparing a corrosion-resistant coating for aluminum alloy comprises the following steps: S1. Raw material ratio, the following raw materials in parts by weight: 50 parts of methyl phenyl silicone resin, 100 parts of solvent, 1 part of anti-settling agent, 5 parts of defoaming agent, 10 parts of leveling agent, 10 parts of corrosion-resistant filler and 49 parts of reinforcing agent; S2, grinding the methylphenyl silicone resin and mixing it with a solvent, stirring at a speed of 1150 r / min for 3 hours to obtain a resin solution; S3, adding an anti-settling agent, a defoaming agent, a leveling agent, a corrosion-resistant filler and a reinforcing agent to the resin solution obtained in step S1 in sequence, and stirring at a speed of 1200 r / min for 4 hours to obtain a mixed solution; S4, ultrasonically dispersing the mixed solution obtained in step S3, letting the material stand for 4 hours, filtering to obtain the raw material for corrosion-resistant coating for aluminum alloy, and then drying and adding a binder; S5, spraying the corrosion-resistant coating raw material for the aluminum alloy prepared in step S4 onto the surface of the aluminum alloy.

[0027] In this embodiment, in step S1, the reinforcing agent is a phosphorus-based fire retardant coating reinforcing agent.

[0028] In this embodiment, in step S1, the solvent is anhydrous ethanol.

[0029] In this embodiment, in step S5, an electrostatic spraying process is used to spray the corrosion-resistant coating raw material for aluminum alloy on the surface of the aluminum alloy. Specifically, the electrostatic spraying process: firstly, the surface of the aluminum alloy to be sprayed is cleaned, and the aluminum alloy after the surface cleaning is heated to 75°C by a frequency induction coil and then enters the powder spraying workshop, the powder supply pressure is 0.09MPa, the spraying voltage is 75kV, the powder spraying amount is 180g / min, and the spraying distance is 240mm.

[0030] Select experiment: Its performance test is shown in Table 1 Test items Example 1 Example 2 Example 3 Example 4 40℃ salt spray 100% relative humidity atmosphere 1200h no blistering, no discoloration, no shedding 1220h no blistering, no discoloration, no shedding 1195h No blistering, no discoloration, no shedding 1220h no blistering, no discoloration, no shedding Elastic modulus 17.53Gpa 19.23Gpa 18.33Gpa 19.56Gpa Mohs hardness 12.5 11.9 12.2 11.8 Bonding strength 6.23Mpa 6.33Mpa 6.73Mpa 6.93Mpa As can be seen from Table 1, the coating prepared by the present invention remains free of blistering, discoloration and shedding after 500 hours and 1000 hours in a 35°C salt spray and 100% relative humidity atmosphere. It has good corrosion resistance and significantly improves the service life of the coating on the surface of steel structure materials (>1000 hours).

[0031] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A process for preparing a corrosion-resistant coating for aluminum alloy, characterized in that: The method comprises the following steps: S1. Raw material ratio: the following raw materials by weight: 50 parts of methyl phenyl silicone resin, 47-100 parts of solvent, 1-4 parts of anti-settling agent, 1-5 parts of defoaming agent, 10-18 parts of leveling agent, 5-10 parts of corrosion-resistant filler and 20-49 parts of reinforcing agent; S2, grinding the methylphenyl silicone resin and mixing it with a solvent, stirring at a speed of 900-1200 r / min for 2-3 hours to obtain a resin solution; S3, adding an anti-settling agent, a defoaming agent, a leveling agent, a corrosion-resistant filler and a reinforcing agent to the resin solution obtained in step S1 in sequence, and stirring at a speed of 1000-1200 r / min for 3-4 hours to obtain a mixed solution; S4, ultrasonically dispersing the mixed solution obtained in step S3, letting the material stand for 2-4 hours, filtering to obtain the raw material for corrosion-resistant coating for aluminum alloy, and then drying and adding a binder; S5, spraying the corrosion-resistant coating raw material for the aluminum alloy prepared in step S4 onto the surface of the aluminum alloy.

2. The process for preparing a corrosion-resistant coating for aluminum alloy according to claim 1, characterized in that: In step S1, the reinforcing agent is any one of a phosphorus-based fire retardant coating reinforcing agent, a nitrogen-based fire retardant coating reinforcing agent, and a silicon-based fire retardant coating reinforcing agent.

3. The process for preparing a corrosion-resistant coating for aluminum alloy according to claim 1, characterized in that: In step S1, the solvent is anhydrous ethanol.

4. The process for preparing a corrosion-resistant coating for aluminum alloy according to claim 1, characterized in that: In step S5, an electrostatic spraying process is used to spray the corrosion-resistant coating raw material for aluminum alloy onto the surface of the aluminum alloy.

5. The process for preparing a corrosion-resistant coating for aluminum alloy according to claim 4, characterized in that: Electrostatic spraying process: First, the surface of the aluminum alloy to be sprayed is cleaned. After the surface cleaning, the aluminum alloy is heated to 60~80℃ by a high-frequency induction coil and then enters the powder spraying workshop. The powder supply pressure is 0.07~0.09MPa, the spraying voltage is 70~80kV, the powder spraying amount is 160~190g / min, and the spraying distance is 100~250mm.